PF Detailed Product Information En

I N T E G R AT E D P O W E R S Y S T E M A N A LY S I S S O F T W A R E

DIgSILENT

PowerFactory 15.1

DIG

SILENT

PowerFactory

T R A N S M I S S I O N | D I S T R I B U T I O N | I N D U S T R I A L | D I S T R I B U T E D G E N E R AT I O N | W I N D P O W E R

Detailed Product Information

DIgSILENT PowerFactoryVersion 15.1

Detailed Product Information

DIgSILENT GmbH

Gomaringen, Germany

August 2014

Publisher:DIgSILENT GmbH

Heinrich-Hertz-Straße 972810 Gomaringen / Germany

Tel.: +49 (0) 7072-9168-0Fax: +49 (0) 7072-9168-88

Please visit our homepage at:http://www.digsilent.de

Copyright DIgSILENT GmbHAll rights reserved. No part of thispublication may be reproduced or

distributed in any form without permissionof the publisher.

August 2014r1424

http://www.digsilent.de

CONTENTS

Contents

1 Introduction 1

2 PowerFactory Overview 3

2.1 Functional Integration and Applications . . . . . . . . . . . . . . . . . . . . . . . 3

2.2 PowerFactory Software Concept . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

3 Network Models 6

3.1 Grid Representations and Power Equipment . . . . . . . . . . . . . . . . . . . . . 6

3.2 Built-in Calculation and Integrated Modelling Functions . . . . . . . . . . . . . . . 9

3.3 Load and Generation Profiles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

4 Data Management 11

4.1 Standard Data Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

4.1.1 Arrangement of Data in Project Folders . . . . . . . . . . . . . . . . . . . 11

4.1.2 Study Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4.2 Data Organisation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

5 Network Diagrams and Graphic Capabilities 13

6 Results and Reporting 16

6.1 Text Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

6.2 Spreadsheet Reports (Tabular Views) . . . . . . . . . . . . . . . . . . . . . . . . 16

6.3 Reporting in Network Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

6.4 Result File Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

6.5 Plots and Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

6.6 Additional Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

7 External Data Format Support 19

7.1 Standard Data Formats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

7.2 DIgSILENT Data Base Level Exchange (DGS) . . . . . . . . . . . . . . . . . . . 19

8 Scripting Languages- DIgSILENT Programming Language 20

8.1 DPL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

DIgSILENT PowerFactory 15.1, Detailed Product Information i

CONTENTS

8.2 Python Integration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

9 PowerFactory Modes of Operation 23

9.1 Standard Windowing Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

9.2 Engine and Hybrid Execution Mode . . . . . . . . . . . . . . . . . . . . . . . . . 23

10 Power Flow Analysis 24

11 Fault Analysis 26

11.1 Supported Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

11.2 Complete Method/Multiple Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

11.3 DC Short Circuit Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

11.4 Fault Analysis Results (all Methods) . . . . . . . . . . . . . . . . . . . . . . . . . 28

12 Network Reduction 29

12.1 General Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

13 Voltage Stability Analysis 30

13.1 PV Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

13.2 Q-V Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

13.3 Eigenvalue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

14 Load Flow Sensitivities 31

15 Contingency Analysis 32

16 Overhead Line and Cable Parameter Calculation 34

16.1 Overhead Line Parameter Calculation . . . . . . . . . . . . . . . . . . . . . . . . 34

16.2 Cable Parameter Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

16.3 Automatic Cable Sizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

17 Distribution Network Functions 36

17.1 Feeder Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

17.2 Low-Voltage Network Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

17.3 Stochastic Load Modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

17.4 Cable Reinforcement optimisation . . . . . . . . . . . . . . . . . . . . . . . . . . 37

ii DIgSILENT PowerFactory 15.1, Detailed Product Information

CONTENTS

17.5 Feeder Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

18 Protection Functions 39

18.1 Protection Model Library and Functionality . . . . . . . . . . . . . . . . . . . . . . 39

18.2 Output and Graphical Representation . . . . . . . . . . . . . . . . . . . . . . . . 41

18.3 Overcurrent-Time Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

18.4 Distance Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

18.5 Coordination Assistant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

19 Arc-Flash Hazard Analysis 44

19.1 Supported Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

19.2 Results visualisation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

20 Distribution Network optimisation 45

20.1 Optimal Capacitor Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

20.2 Open Tie optimisation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

21 Harmonic and Power Quality Analysis 46

21.1 Harmonic Load Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

21.2 Frequency Sweep . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

21.3 Ripple Control Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

21.4 Filter Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

21.5 Power Quality Assessment according to D-A-CH-CZ Guideline . . . . . . . . . . 48

22 Optimal Power Flow (OPF) 49

22.1 AC optimisation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

22.2 DC optimisation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

23 Techno-Economical Calculation 52

24 Reliability Analysis Functions 53

24.1 Failure Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

24.2 State Enumeration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

24.3 Failure Effect Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

24.4 System Indices and Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

DIgSILENT PowerFactory 15.1, Detailed Product Information iii

CONTENTS

24.5 Special Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

24.5.1 High Flexibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

24.5.2 Tracing of Individual Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 56

24.5.3 Powerful Output Tools for Result Representation . . . . . . . . . . . . . . 57

24.5.4 Contribution to Reliability Indices . . . . . . . . . . . . . . . . . . . . . . . 57

24.5.5 Development of Indices over Years . . . . . . . . . . . . . . . . . . . . . . 57

24.6 Optimal Power Restoration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

24.6.1 Optimal Power Restoration . . . . . . . . . . . . . . . . . . . . . . . . . . 57

25 State Estimation 59

26 Quasi Dynamic Simulation 60

27 Dynamic Modelling Flexibility (DSL) 61

28 Power System Dynamics 63

28.1 General Capabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

28.2 Stability Analysis Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

28.2.1 RMS Simulation with a-b-c Phase Representation . . . . . . . . . . . . . 66

28.2.2 Long-term Stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

28.3 Electromagnetic Transients (EMT) . . . . . . . . . . . . . . . . . . . . . . . . . . 66

28.4 System Parameter Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

28.5 PowerFactory Real-Time Simulators . . . . . . . . . . . . . . . . . . . . . . . . . 68

29 Small Signal Stability 69

30 Motor Starting 71

30.1 Static Motor Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

30.2 Transient Motor Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

31 PowerFactory Interfaces 73

31.1 DGS Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

31.2 OPC Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

31.3 API (Application Programming Interface) . . . . . . . . . . . . . . . . . . . . . . . 74

iv DIgSILENT PowerFactory 15.1, Detailed Product Information

CONTENTS

32 Interfacing PowerFactory 76

32.1 PowerFactory - GIS integration . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

32.2 PowerFactory - SCADA integration . . . . . . . . . . . . . . . . . . . . . . . . . . 77

32.3 PowerFactory - Simulation Interface (SIMULINK, etc.) . . . . . . . . . . . . . . . 78

32.4 PowerFactory - A/D Signal Interfacing Capability . . . . . . . . . . . . . . . . . . 78

32.5 PowerFactory Monitoring System (PFM) . . . . . . . . . . . . . . . . . . . . . . . 79

33 PowerFactory Installation Options 80

33.1 PowerFactory Workstation License . . . . . . . . . . . . . . . . . . . . . . . . . . 80

33.2 PowerFactory Server License . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

33.3 License Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

33.4 Installation Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

34 PowerFactory Function Definitions and Prices 88

34.1 PowerFactory Function Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . 88

34.2 PowerFactory Prices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

35 The DIgSILENT Company 90

36 History of the DIgSILENT Software 91

DIgSILENT PowerFactory 15.1, Detailed Product Information v

CONTENTS

vi DIgSILENT PowerFactory 15.1, Detailed Product Information

1 INTRODUCTION

1 Introduction

DIgSILENT has set standards and trends in power system modeling, analysis and simulationfor more than 25 years. The proven advantages of the PowerFactory software are its overallfunctional integration, its applicability to the modeling of generation-, transmission-, distribution-and industrial grids, the analysis of these grids’ interactions and power restoration. Electricalgrids, planning processes and operation processes are becoming increasingly complex due tomarket unbundling, expansion of interconnections and distributed generation. This increasesthe demands on software tools in terms of data quality, flexibility and manageability. With Pow-erFactory Version 15, DIgSILENT presents a further step towards seamless integration of func-tionality and data management within a team working environment. The building and organisingof schemes, scenarios, versions and running arrangements is available for improved handling.

New Version 15 Key Features

• Installation directory and workspace export/import functions

• Automatic log on for single user work station and switch user function

• Project archiving for decreasing the used database storage space and increase perfor-mance of large multi-user databases

• Import of Integral files

• Geographic Diagram concept

• Improvements in colouring modes and annotation layers

• Graphical representation of Protection Devices and neutral connections

• DC short-circuit calculation

• Quasi dynamic simulation

• Time-Overcurrent plots and coordination assistant

• Arithmetic post-processing in Virtual Instruments (VI)

• Optimal manual restoration for distribution networks

• New models for PV systems, impulse source, DC machine, DC battery and series RLCfilter

• Python scripting language integration

DIgSILENT PowerFactory is the most economical solution, as data handling, modelling capa-bilities and overall functionality replace a set of other software systems, thereby minimisingproject execution costs and training requirements. The all-in-one PowerFactory solution pro-motes highly-optimised workflow.

DIgSILENT PowerFactory is easy to use and caters for all standard power system analysisneeds, including high-end applications in new technologies such as wind power and distributedgeneration and the handling of very large power systems. In addition to the stand-alone solution,the PowerFactory engine can be smoothly integrated into GIS, DMS and EMS supporting opensystem standards.

DIgSILENT PowerFactory 15.1, Detailed Product Information 1

1 INTRODUCTION

Figure 1.1: DIgSILENT PowerFactory v15 integrated features overview

2 DIgSILENT PowerFactory 15.1, Detailed Product Information

2 POWERFACTORY OVERVIEW

2 PowerFactory Overview

2.1 Functional Integration and Applications

• Implemented as a single software solution allowing for fast ’walk around’ through thedatabase and execution environment

• No need to reload modules and update, transfer and convert data and results betweendifferent program applications

• Vertically integrated power equipment model concept allowing models to be shared by allanalysis functions

• Support of transmission-, distribution- and industrial system design and simulation

• Modelling and simulation of railway systems

• Simulation of any kind of wind turbines and wind parks

• Smart Grid modelling including virtual power plants and distributed generation such asPV-panels, micro turbines, battery storage, CHP, etc.

2.2 PowerFactory Software Concept

Single Database Concept

• Optimal data organisation and project definitions for performing any type of calculation,storage of settings, diagrams and visualisation options or software operation sequences.

• No need for tedious organisation of several files for defining the various analysis aspectsand project execution workflows.

• Database environment fully integrates all necessary data, such as that required for defin-ing cases, scenarios, variants, single-line graphics, outputs, run conditions, calculationoptions, graphics or user-defined models. Saving a project includes everything requiredto rerun all defined cases at a later stage.

• Access to all data via a comfortable and powerful data manager, object browser, plusvarious types of diagrams and wizards.

• Comprehensive, non-redundant data model supporting all calculation functions

User Roles

• Access to user information through a user accounting system

• Protection of data through different types of access rights

• Folder sharing between users with ”read-only” access. This is especially useful for librariesand network base cases which should be administrated only by authorised personnel.

Multi-User Operation and Team working

• Multi-user data administration supporting MS-SQL or ORACLE databases



• Support of user accounting, access rights and data sharing, featuring the powerful op-tion of allowing several users to work on the same project in a coordinated way. Thisdemonstrates the concept of non-redundant data management in PowerFactory ..

• Management of multi-user data editing via the definition of a base project, project versionsand derived projects (virtual projects).

• Support of version control including rollback functions and merge/compare tools.

Network Variations, Expansion Stages Management and Operational Scenarios

• Support of time-stamped network variations.

• Variation scheduler for easy handling of sub-projects

• Activation of network stages according to study time. This automatically addresses thehandling of power system components according to their commissioning and de-commissioningdates

Multi-Level Models

• Data describing network models such as cables, machines, loads, transformers, etc., aresubdivided into element data and type data which point to libraries.

• All data to be entered are grouped into basic data (data required for all calculations) andfunction level data (data required only for executing specific calculations).

• Data are simply entered in physical quantities rather than in per unit values, minimisingthe need for manual recalculation and conversion of data.

• Verification of input data, with detailed warning and error messages

• Verification of input data, with detailed warning and error messages

Batch Mode, Engine Mode and Interfaces

• Fully interactive windowing mode according to the latest, proven standards

• Engine mode for background operation and parallel processing

• Various communication features to exchange data with other applications such as GIS,SCADA and real-time control systems via OPC, shared memory, DGS (CSV, ODBC), etc.

• Hybrid operation switching between background and windowing mode according to users’needs

• Data exchange via CIM, PSS/E, ENTSO-E and many other file formats

• The Engine Manager component provides access to multiple PowerFactory Engines viaweb services.

• The built-in queuing and scheduling simplifies the Engine integration into other applica-tions.

Business Process Automation

• Support of ENTSO-E operation planning processes such as D2CF, DACF and IDCF (In-traday). The Intraday process runs as a fully-automated, parallelised process.



• The ESB interface adapter features message-based data exchange such as load fore-cast, planned generator dispatch, day-ahead cross-border exchange programs, UCTE-DEF/ENTSO-E files, EMS snapshots, dynamic line rating and market coupling data.

• The combined MV/LV calculation for the distribution grid of a whole country (¿2000 MVsubstations) has been automated using PowerFactory and bulk data GIS exports.


3 NETWORK MODELS

3 Network Models

3.1 Grid Representations and Power Equipment

Grid Models

• Meshed and radial AC systems with 1-, 2-, 3-, and 4-phases

• Meshed and radial DC systems

• Combined AC and DC system modelling

• Model validity from LV up to ultra-high voltage

Phase Technologies

• Single phase with/without neutral

• Two-phase with/without neutral

• Bi-phase with/without neutral

• Three-phase with/without neutral

Substations

• Simple terminal models to be used for ”node and branch” representation, marshallingpanels, terminal blocks, terminal strips, clamping bars, joints and junctions.

• Complex substation models with the provision of various standard busbar configurationssuch as single- and double busbars with/without tie-breakers, bypass busbars, 1 busbarsystems and flexible busbar configurations according to user-specific needs.

• Secondary Substation object which provides templates with a broad variety of predefinedsecondary substation configurations.

• Templates for holding any type of user-specific busbar configuration, including pre-configuredprotection schemes.

Generators and Sources

• Synchronous and asynchronous generator

• Doubly-fed induction generator

• Static generator (for PV, fuel cell, wind generator, battery storage, etc.)

• External grid

• AC voltage source

• AC current source

• 2-terminal AC voltage source

• PV system


3 NETWORK MODELS

• Impulse source

Loads and Motors

• General load model (for HV and MV-feeders)

• Complex load model (for feeders with a large number of induction motors)

• Low voltage load (can be assigned across line and cable sections)

• Medium voltage load, representing a distribution transformer together with a reducedload/generation model.

• Synchronous and asynchronous motor load

Reactive Power Compensation

• Static Var Compensator (SVC)

• Shunt/Filter (RLC, RL, C, RLCRp, RLCCRp)

• Series RLC filter

Branch models

• Overhead line and cable models (PI-models and distributed parameter models)

• Circuits and line sub-sections

• Mutual data, line couplings, tower geometries

• 2-, 2-N-winding transformer and auto transformer

• 3-winding transformer, booster transformer

• Series reactor, series capacitor and common impedance

DC Models

• 1-terminal and 2-terminal DC voltage source and DC current source

• DC/DC converter

• Inductive DC-coupling

• DC machine

• DC battery

Power Electronics Devices

• Thyristor/Diode converter models

• Self-commutated converter models (VSC-converter)

• DC valve (for building individual converter topologies)

• Softstarter


3 NETWORK MODELS

Switches and Substation Equipment

• Circuit Breaker and Disconnector

• Load-Break-Disconnector

• Load-Switch

• Grounding Switch

• Fuse

• NEC/NER, grounding devices

• Surge arrester

Composite Models

• Composite node models, e.g. representing complex substations

• Composite branch models

• Template library for handling composite models

Parameter characteristics

• Time characteristics and discrete characteristics

• Scalar, vector and matrix characteristics

• File references and polygons

• Continuous and discrete triggers

• Frequency and time scales

Controllers

• Station controller, secondary controller (SCO), virtual power plant

• Tap controller, shunt controller

• User-definable capability diagrams and controllers

Organisation and Grouping

• Site, station, substation, area, zone

• Feeder, branch, bay

• Operator, owner

• Boundaries

Operational Library

• Substation running arrangements


3 NETWORK MODELS

• CB ratings

• Thermal ratings

• Library of faults/contingencies

• Library of (planned) outages

Others

• Protection relays with over 30 basic protection function blocks

• Manufacturer-specific relay library with relay models from all major manufacturers

• CT, VT and various measurement transducers (P, Q, f, etc.)

• Fourier source, harmonic source, FFT

• Clock, sample and hold, sample and hold noise generator

PowerFactory supports several different objects for defining, organising and storing users’ griddefinitions and project settings. The above-listed objects are a summary of those most fre-quently used.

3.2 Built-in Calculation and Integrated Modelling Functions

PowerFactory provides a number of functions which assist users in entering data which mayhave come from datasheets or product catalogues. Not only do these functions greatly simplifydata entry, but they also provide valuable output and results.

Identification of asynchronous machine parameters

• Support of two different parameter input modes: (a) electrical parameters and (b) slip-torque/current characteristic

• When entering electrical parameters, such as the rated mechanical power, stator resis-tance and reactance, magnetisation reactance, etc., all electrical parameters which pre-cisely define and describe the asynchronous machine are then calculated. This includesthe determination of the torque-/speed characteristic.

• The alternative definition via the slip-torque/current characteristic requires entering datasuch as characteristics at nominal operation point, torque at stalling point, locked rotortorque and other parameters typically available from manufacturer handbooks or test re-ports. This alternative data entering method will then determine the electrical machineparameters.

Calculation of Overhead Line Parameters and Cable Parameters

Please refer to Section 16 (Overhead Line and Cable Parameter Calculation)

3.3 Load and Generation Profiles

• Load and generator parameter characteristics can be defined on a per-element basis forparametric studies. Parameter characteristics can be imposed on each input parameter.They may be time-dependent, refer to predefined discrete cases, or result from externalsources.


3 NETWORK MODELS

• The input data can be either manually inserted in a predefined table or by using externaldata files (.csv or even customised formats). The recurrence base (daily, weekly, monthly,yearly, none) and the time step (minutes or hours) can be easily changed.

• All operational data (generation and demand patterns, switch positions, etc) can be savedand maintained in distinct Operation Scenarios.


4 DATA MANAGEMENT

4 Data Management

4.1 Standard Data Model

4.1.1 Arrangement of Data in Project Folders

All data required for grid modelling, project organisation and project execution are arrangedin project folders. Project data are structured into Libraries, Network Models, OperationScenarios and Study Cases.

Libraries

• Libraries contain equipment types, special operation information, DPL scripts, templatesand user-defined models.

• The Equipment Type Library can store manufacturer and standard data for cables, con-ductors, circuit breakers, transformers, motors, generators, protection devices, PV panels,converters, wind turbines, etc.

• Operational Libraries help organise standard settings and operational structures of grids.Typical entries include specific device Mvar limits and capability curves, outages, faultconditions and sequences, specific thermal ratings, running arrangements, etc.

Network Models

• All network data are organised and stored in various folders such as grid- and area fold-ers, folders for boundaries, circuits, feeders, routes, zones, etc.

• Comprehensive network topology handling defining: Nodes, Substations, Sites, Bound-aries, Circuits, Routes, Operators and Owners.

• Graphical information such as overview diagrams, simplified single line diagrams and de-tailed single line diagrams are automatically organised in a separate diagram folder

• Grid Variations are linked to the original grid data, allowing non-redundant grid variationmanagement.

• Easy and non-redundant handling of grid expansion alternatives.

• Planned grid expansions are organised by time-stamped Expansion Stages which areconsidered depending on the selected Study Time.Expansion Stages are stored in Vari-ations and handled via the Variation Scheduler.In other words, variations can be seenas expansion plans composed of different stages which are activated chronologically.

Operation Scenarios

• Definition of operation and dispatch conditions, grid loading, ambient temperature, dailyload variation pattern, etc

• Organisation of characteristics to generate ranges of values such as daily load curves,temperature dependencies, wind conditions, solar radiation pattern, etc

• Definition of triggers for easy selection of certain conditions to be analysed

• Comparison of Operation Scenarios


4 DATA MANAGEMENT

Study Cases

• Grid configurations, operation conditions, trigger settings, calculation options, fault se-quences, results and DPL scripts to be executed are all stored in Study Cases

• Study Cases can be activated to reproduce any grid condition and its associated calcula-tion results

4.1.2 Study Time

PowerFactory extends grid modelling into the dimension of time. The model may span a periodof months or years considering network expansions, planned outages and other system events.The period of validity of a project therefore specifies the time span that the of the model’s validity.

• The Study Time automatically determines which expansion stages of a variation will beconsidered.

• Selection of Study Time along with the operational conditions will automatically creategrid expansion scenarios

4.2 Data Organisation

Simultaneous use of grid data takes place when two different parties work with the same project.This kind of situation occurs most frequently in larger companies where software-based team-working capabilities are a basic requirement. Versioning

• Project Versions constitute a snapshot of a project at a specific point in time

• Project versions are under full control of owner rights

• Rollback functions allow a controlled ”Undo” of a project’s execution steps, thereby ”rollingback” to a specific stage of the project

• Reporting facilities for Derived Projects which depend on a certain version

Derived Projects

• Master Projects can be published in a public area of the database

• Derived Projects are ”virtual” copies of a Version of a Master Project that can be developedby any number of users simultaneously. Only the differences to the original version arestored

• Derived Projects are always linked to their original Master Project

• The users will be automatically notified if a new version of their Master Project is available

• Comprehensive tools for merging several derived projects and/or their versions into a newproject via the Merge Tool. This allows the consolidation of independent and parallelmodel modifications introduced by different users.


5 NETWORK DIAGRAMS AND GRAPHIC CAPABILITIES

5 Network Diagrams and Graphic Capabilities

Categories of Network Diagrams

• Simplified Single Line Diagrams with various options for a schematic view of substationtopology and switching status

• Detailed Single Line Diagrams showing all switches (circuit breakers and disconnectors)

• Intelligent Overview Diagrams providing a node and branch representation of the net-work. Can be schematically, geographically or semi-geographically arranged

• Visual representation of the network by using GPS coordinates to generate geographicdiagrams.

General Features

• Handle mixed representations of Detailed Single Line Diagrams, Simplified Single LineDiagrams and Overview Diagrams

• Access equipment editing menus in the single line diagram via cursor selection of theappropriate element, region or composite model

• Zoom-in or zoom-out of area networks or composite model graphics

• Initiate calculation events directly within the graphical environment, including circuit breakerswitching, fault implementation and other data changes

• Option to immediately reflect any editing activity on the graphical level

• Display any calculation results immediately in result boxes in single line diagrams. All pro-gram variables and signals can be displayed according to a highly flexible user definitionfor various object categories and analysis functions

• Display any calculation result to be defined on various functional levels and categories forany object

• Insert freely-configured result displays

• Provision of auxiliary graphics editing for enhanced documentation

• Perform copy/paste operation on single objects and groups

• View and operate several graphic windows with different layers and grid sections simulta-neously. utilise several graphical representations of the same system simultaneously.

• Spread large diagrams over several pages

• Support of pre-defined and user-defined graphical layers

• Support the use of multiple layers, which can be reorder, hide and move offering a highdegree of flexibility. Import/export annotation layers is possible.

• Graphical representation of protection devices and neutral conecctions.

• Placement of user-definable icons as buttons for executing DPL scripts. This way userscan create custom panels of frequently-executed DPL-initiated commands.

Colouring of Network Diagrams



• Provision of various colouring modes according to topology criteria such as areas, zones,owners, operators, routes, station connectivity, energising status, boundaries/interior re-gions, isolated grids, etc.

• Colouring options to display voltage levels, equipment loading and operation ranges

• Define colouring based on AC/DC equipment category and phase technology

• Display of grid modifications and variants, recording of expansion stage modifications,missing grid connections

• Provision of feeder colouring and path definitions

• User-defined filters based on complex equations or DPL scripts

User-definable Symbols

• Support of user-definable symbols based on standard graphical formats (.wmf,.bmp). E.g.use your own symbols for wind turbines, PV panels, hydro units, etc.

• Define specific graphical representations for transformers, shunts, circuit breakers, isola-tors to fit individual needs.

Composite Graphics

• Elements can be grouped together and stored as Composite Graphics. Typical appli-cations are standard busbar arrangements, switchboard configurations, HVDC structures,PV panels, typical wind turbine configurations or complete wind parks.

• Composite Graphics can be easily handled via the Template Manager. Templates canbe populated with type and element data. For drawing Composite Graphics, the TemplateManager is operated as Drawing Tool Box.

Virtual Instruments

• DIgSILENT PowerFactory applies the concept of Virtual Instruments (VI) as a tool for dis-playing any calculated result or variable.

• Results may be displayed in the form of bar graphs, plotted curves, or even tables ofvalues, with all of these representations being completely user-definable.

• VIs are used to display protection curves, harmonics analysis results or to view electricalvariables from any location in the network single line diagram, and any model variableduring RMS and EMT simulations.

• Many VIs provide additional built-in functionality such as curve labelling and measuring,scaling, curve fitting, filtering and digitizer functions.

Typical Virtual Instruments Available

• x-t, x-y and 2y axis plots

• Bar diagrams, harmonic distortion diagram

• Overcurrent-time-diagrams, distance-time diagrams

• Vector and path diagram



• Relay plots

• Voltage sag diagram, waveform diagram

• Eigenvalue, phasor diagram and FFT plot

• Scales and measurement diagram

• Bitmaps, buttons, DPL-command buttons, digital display

• Curve-digitising diagram

• Text label


6 RESULTS AND REPORTING

6 Results and Reporting

6.1 Text Reports

Automatic reports for calculation results, such as load flow, short-circuit, harmonic calculations,contingency calculation, reliability analysis, etc.

• Numerous predefined reports for all key calculation functions

• Flexible selection of elements for reporting

• Reports can be user-configured allowing user-definable formatting

Automatic reports for documentation of network components, such as transformers, lines, gen-erators, relay settings, etc.

• Flexible selection of network components for documentation

• Flexible selection of calculation module, e.g. report only input data required for load flowand short-circuit

6.2 Spreadsheet Reports (Tabular Views)

• Numerous predefined spreadsheet reports for all key calculation functions via ”FlexibleData Pages”

• User-definable setup of ”Flexible Data Pages”. Tabular view of any combination of inputparameters/ calculation results

• Several ”Flexible Data Page” definitions (variable selections) may exist concurrently

• Independent variable selections for every calculation

• Sorting facilities for tabular views

• Automatic statistical summaries for values in tables

• Flexible filters for selecting elements for output

• Output facilities to: Output window, clipboard and clipboard with column headers for usein spreadsheet programs such as MS Excel

6.3 Reporting in Network Diagrams

• Concept of ”result boxes” in network diagrams to flexibly display any element/type param-eter, as well as any calculation result

• Easy-to-configure ”result box” format on both component and calculation levels



6.4 Result File Management

More complex calculation results can be stored in ”Result Files”, e.g. for calculations such astransient stability results, harmonic analysis results, contingency results, etc.

• Allows easy configuration of outputs (plots, reports, etc)

• Accessible by post-processing through DPL

• Export functionality to export result data to:

– Output window

– Clipboard (compatible with spreadsheet programs such as MS EXCEL)

– Text file (compatible with spreadsheet programs such as MS EXCEL)

– COMTRADE (for transient data)

– PowerFactory measurement file (ASCII)

6.5 Plots and Diagrams

• DIgSILENT PowerFactory applies the concept of Virtual Instruments (VI) as a tool forvisualising calculation results as plots and diagrams.

• VIs are used to display (for example):

– Results of RMS and EMT simulations (any pre-selected monitoring variable/signal)

– Protection configurations and results (R-X diagrams, automatic time-distance dia-grams, relay characteristics, etc)

– Harmonic analysis results

• Many VIs provide additional built-in functionality such as curve labelling and measuring,scaling, curve fitting, filtering and digitizer functions.

• Arithmetic Post-processing of the signals in VIs

Selected List of Most Common Virtual Instruments:

• Plots for simulation results

– Monitored variables/signals over time

– Trajectories

• Harmonics

– Harmonic distortion diagram

– FFT diagrams

– Waveform plots

• Protection

– Time-overcurrent diagrams

– Time-distance diagrams

– Relay characteristic diagram

• Additional diagrams for results of load flow, short circuit, harmonics, etc.:



– Bar diagrams

– Vector diagrams

– Path diagram

– x-y diagrams

• Voltage sag diagram

• Eigenvalue calculation

– Eigenvalue diagram

– Phasor diagrams and bar diagrams (controllability, observability, participation)

• Measurement VIs

– Digital display

– Metering device (vertical/horizontal scales)

– Combination of both

• Picture box for displaying graphic files. Supported file formats are:

– Windows metafiles (*.wmf)

– AutoCAD graphic file (*.dxf)

– Bitmaps (*.bmp)

• Curve-digitising diagram

6.6 Additional Features

The PowerFactory graphic windows such as the single line graphic, plots, and block diagrams,offer the following functionality:

• Printing or plotting to any device supported by the Windows Print Manager to producehigh quality graphical documents from within the program.

• Export to standard file formats such as:

– Windows Metafile (*.wmf) with high precision coordinates

– Bitmap (*.bmp)

• Conversion of graphic files between several file formats such as *.png, *.dxf, *.gif, *.tiff,*.eps, etc. This is achieved via an external tool which is shipped with PowerFactory


7 EXTERNAL DATA FORMAT SUPPORT

7 External Data Format Support

7.1 Standard Data Formats

In many cases, migration of data from other power system software is required. PowerFactorytherefore supports foreign file Import of several versions from the following software packages:

• PSS/E, PSS/U and PSS/Adept (Siemens)

• DVG and UCTE/ENTSO-E (entsoe.eu)

• NEPLAN (BCP) version 4 (*.mcb, *.ldb) and 5 (*.ndt, *.edt, *.cde)

• ISU (SAP, billing data)

• NETCAL (STZ Konstanz) and ReticMaster (Inspired Interfaces)

• ELEKTRA

• Integral 7

Foreign file Export is supported for PSS/E and UCTE/ENTSO-E. CIM object and format defi-nitions are increasingly used for standardised data exchange. Although the CIM standards arestill under development, PowerFactory already supports CIM import and export:

• CIM 61970 (CIM for Transmission) only ENTSO-E 2009 profile

7.2 DIgSILENT Data Base Level Exchange (DGS)

DGS is PowerFactory standard bi-directional interface specifically designed for bulk data ex-change with other applications such as GIS and SCADA, and for example, for exporting calcu-lation results to produce Crystal Reports, or to interchange data with any other power systemsoftware. DGS (”DGS”=DIgSILENT-GIS-SCADA) does not feature the exchange of PowerFac-tory execution commands.

• User-specific definition of objects and object parameters

• Supported objects: elements, types and libraries, graphics and results

• Import and export of complete network models as well as incremental data for updatingexisting models

• Database support for: Oracle, MS-SQL and ODBC System DSN

• File formats supported: ASCII Text (CSV), XML, MS-Excel and MS Access

• Available for PowerFactory Interactive Window Mode and PowerFactory Engine Mode


8 SCRIPTING LANGUAGES- DIGSILENT PROGRAMMING LANGUAGE

8 Scripting Languages- DIgSILENT Programming Language

8.1 DPL

The DPL-Programming Language offers a flexible interface for automating PowerFactory ex-ecution tasks. The DPL scripting language adds a new dimension to PowerFactory softwareby allowing the implementation of new calculation functions. Typical examples of user-specificDPL-scripts are:

• Parametric sweep calculations (e.g. sliding fault location, wind profile load flows)

• Implementation of user-specific commands (e.g. transfer capability analysis, penalty factorcalculation)

• Automatic protection coordination and device response checks

• Specific voltage stability analysis via PV-/QV-curve analysis, etc.

• Contingency screening according to user-specific needs

• Verification of connection conditions

• Data pre-processing including input/output handling

• Equipment sizing and dimensioning

• Report generation

The DPL object-oriented scripting language is intuitive and easy to learn. The basic set ofcommands includes:

• C++- like, object-oriented syntax

• Flow commands such as ”if-then-else”, ”do-while”

• Input/import, output/export and reporting routines

• Mathematical expressions, support of vectors and matrices

• Access to any PowerFactory object and parameter including graphical objects

• Definition and execution of any PowerFactory command

• Object filtering and batch execution

• PowerFactory object procedure calls and DPL subroutine calls

• New: Calling of external libraries (DLLs) for linking and executing other applications

Easy Development

DPL’s basic syntax allows for the quick creation of simple high-level commands to automatetasks. Such tasks may include renaming objects, search and replace, post-processing calcula-tion results and creating specific reports.

Transparency

All parameters of all objects in the network models are accessible. DPL can be used to querythe entire database and to process all user-input and result parameters without restrictions.



standardising Commands

The DPL language can be used to create new ’standardised’ DPL commands that can be usedover and over again. DPL commands allow input parameters to be defined, and can be executedfor specific selections of objects. Proven DPL commands can be safely stored in DPL commandlibraries and be used from there without the risk of damaging the scripts.

Control

DPL commands can configure and execute all PowerFactory commands. This includes not onlythe load flow and short-circuits calculation commands, but also the commands for transientsimulation, harmonic analysis, reliability assessment, etc. New objects can be created by DPLin the database, and existing objects can be copied, deleted and edited. New reports can bedefined and written to the output window; new graphs can be created and existing graphs canbe adjusted to reflect a user-defined selection or the current calculation results.

Modularity

A DPL command may contain other DPL commands as subroutines. This modular approachallows the execution of subroutines as independent commands. Existing commands can becombined to quickly create more complex commands.

8.2 Python Integration

PowerFactory offers support for the Python scripting language. Python can now be used forvarious kinds of automation tasks within PowerFactory and integration tasks from external ap-plications. Although the proprietary built-in scripting language will still be supported, there areseveral good reasons to start using Python:

• Non-proprietary, widely spread and very popular scripting language

• Open source licensed

• Extensive standard libraries and third party modules

– Interfaces to external databases and MS-Office like applications

– Web-services, etc.

• Support for debugging

• Can be compiled

PowerFactory Module in Python

The functionality of PowerFactory is offered in Python through a dynamic module with the name”powerfactory.pyd”. Some facts about this module:

• Dynamic module implemented in Boost.Python using the PowerFactory API

• Offers access to

– all objects

– all attributes (element data, type data, results)

– all commands (load flow calculation, etc.)

– lots of special built-in functions (DPL functions)



• Usable from

– within PowerFactory through the new command ComPython

– external (PowerFactory is started by the module as an engine)

Integration of a Python Script into PowerFactory

Every Python script file (*.py) is represented in PowerFactory by a ComPython object. AComPython object holds only the path, not the file itself. With the ”Open in external Editor”button it is possible to edit the file directly. The ”Execute” button executes the script.

Python scripts (ComPython) objects can be executed like DPL scripts (ComDpl objects) andinterrupted with the ”Break” button in the main toolbar.


9 POWERFACTORY MODES OF OPERATION

9 PowerFactory Modes of Operation

9.1 Standard Windowing Mode

The standard execution of DIgSILENT PowerFactory is via the classical windowing mode oper-ated via mouse and keyboard.

9.2 Engine and Hybrid Execution Mode

When operated in ”Engine Mode” PowerFactory is executed as a background process featuringa number of additional application options:

• Bi-directional, high-speed exchange of data via ”DIgSILENT Shared Memory Interface” orvia ”OPC” (OLE for Process Control). When using OPC, PowerFactory is executed as anOPC-Client.

• Remote-execution of any PowerFactory command including activation of projects, modifi-cation of data, execution of analysis functions and DPL scripts, generation of output andreports, etc.

• Temporary activation/popup of the ”Windowing Mode” featuring interactive windowing op-eration until the windowing mode is closed and the engine mode resumes (”Hybrid Oper-ation Mode”).

In principle, a number of additional application features may be operated as background pro-cesses in situations where it is integrated into GIS/NIS or SCADA systems or linked with othersimulation tools such as Matlab/SIMULINK, ASPENTECH’s process simulation tool or othersoftware systems requiring interaction with network analysis procedures. The engine modealso features parallel processing with other PowerFactory processes. The ”Engine Mode” per-mits the remote control of all PowerFactory functions with fast data and execution commandexchange. Hybrid operation mode is supported by activating the Windowing Operation modefor combined operation.


10 POWER FLOW ANALYSIS

10 Power Flow Analysis

Within the Load Flow analysis environment, the accurate representation of a variety of networkconfigurations and power system components is possible.

• DIgSILENT PowerFactory offers a selection of calculation methods, including a full ACNewton-Raphson technique (balanced and unbalanced) and a linear DC method. Theenhanced non-decoupled Newton-Raphson solution technique with current or power mis-match iterations, typically yields round-off errors below 1 kVA for all buses. The imple-mented algorithms exhibit excellent stability and convergence. Several iteration levelsguarantee convergence under all conditions, with optional automatic relaxation and modi-fication of constraints. The DC load flow, solving for active power flows and voltage angles,is extremely fast and robust (linear system; no iterations required).

• Any combination of meshed 1-, 2-, and 3-phase AC and/or DC systems can be repre-sented and solved simultaneously, from HV transmission systems, down to residentialand industrial loads at LV voltage levels. Neutral conductors can be modelled explicitly.

• The Load Flow tool accurately represents unbalanced loads, generation, grids with vari-able neutral potentials, HVDC systems, DC loads, adjustable speed drives, SVSs andFACTS devices, etc., for all AC and DC voltage levels.

• DIgSILENT PowerFactory offers a new, intuitive and easy-to-use modelling technique whichavoids the definition of bus types such as SL, PV, PQ, PI, AS, etc. PowerFactory simplyprovides the control mechanisms and device characteristics which are found in reality.

More Load Flow Analysis Features

• Consideration of reactive power limits: detailed model for generator Mvar capability curves(including voltage-dependency).

• Practical station control features with various local and remote control modes for voltageregulation and reactive power generation. Reactive power is automatically adjusted toensure that generator output remains within its capability limits.

• Various active power control modes, e.g. as dispatched, according to secondary or pri-mary control, or inertial response.

• Supports device characteristics, such as voltage-dependent loads and asynchronous ma-chines with saturation and slip dependency, etc.

• Comprehensive area/network power exchange control features using Secondary Con-trollers (SCO) with flexible participation factors.

• Transformer OLTC able to control local or remote bus voltages, reactive power flows andvoltage-drop compensation (LDC) within distribution systems. Special transformer con-troller model for parallel transformers. Transformer tap adjustment supports discrete andcontinuous methods.

• Device controllers for shunts, doubly-fed asynchronous machines and other power elec-tronics elements such as self-commutated converters (VSC), thyristor/diode converters orintegrated FACTS devices.

• Local and remote control mechanisms for SVCs. Automatic and continuous control ofTCR and TSC switching is performed within component ratings to hold the voltage at agiven value.

• Correct representation of transformer vector groups and phase displacement.


10 POWER FLOW ANALYSIS

• Shunts can be modelled to consist of a combination of series and/or parallel connectedcapacitors, reactors and resistors. Shunts can be connected to busbars and feeders or tothe remote ends of cables and lines. Filters may consist of any number of shunt combina-tions, and automatic shunt switching can be included in the automatic voltage regulation.

• Support of the Virtual Power Plant model for generator dispatch based on merit orderalgorithm.

• Feeder load scaling to control power flows at feeder entry point - including nested andparallel feeders.

• Full support of any parameter characteristic and scale to allow parametric studies or easydefinition of loading scenarios or load profiles.

• All operational data (generation and demand patterns, switch positions, etc) can be savedand maintained in distinct Operational Scenarios.

Further Special Functions

• Analysis of system control conditions

• Consideration of protection devices

• Determination of ’Power at Risk’

• Calculation of Load Flow Sensitivities. Evaluation of expected active/reactive power flowand voltage changes in the network based on the effect of demand/generation or trans-former tap change.

• Support of DPL scripts; e.g. to perform load balancing, determination of penalty factors orany other parameter required.

Load Flow Results

• Implicit calculation of a large number of individual result variables and summary figures

• Display of any variable within the single line graphic, station diagram, and a tabular FlexibleData Page

• Various colouring modes for the single line graphic to visualise quantities such as calcu-lated loading and/or voltage levels

• Detailed analysis reporting, which can list overloaded system elements, unacceptable busvoltages, system islands, out-of-service components, voltage levels, area summaries, andmore

• Detailed textual output with pre-defined or user-defined filters and levels

• DPL interactivity with all results

• Result export to other software applications such as MS-EXCEL


11 FAULT ANALYSIS

11 Fault Analysis

DIgSILENT PowerFactory features fault calculation functionality based on international stan-dards as well as the most accurate DIgSILENT General Fault Analysis (GFA) method.

The following features and options are supported by all implemented fault analysis methods:

• Calculation of fault levels at all busbars.

• Calculation of short-circuit quantities at a selected busbar or along a defined section ofline/cable, including all branch contributions and busbar voltages

• Calculation of all symmetrical components as well as phase quantities.

• User-definable fault impedance

• Provision of specially designed graphs and diagrams including all quantities typically re-quired by the protection engineer

• Thermal overloads highlighted on the single line graphic for busbars and cables, with allequipment overloads available in a summary text report

• Calculation of Thevenin impedances as seen from the faulty node

• Calculation of apparent phase impedances (magnitude and angle) at any location along atransmission line/cable or busbar, for all branches, selected subsets thereof, or 1, 2 or 3nodes from the faulted node

11.1 Supported Standards

IEC 60909 and VDE 0102/0103

PowerFactory provides a strict and complete implementation of the most frequently used stan-dard for component design world-wide; the IEC 60909 and VDE 0102/0103 fault calculationstandard, according to the most recently published versions.

• Calculation of the initial symmetrical peak current Ik” and short-circuit power Sk”, peakshort-circuit current ip, symmetrical short-circuit breaking current Ib, and thermal equiva-lent current Ith (IEC 60909-0 2001). Both minimum and maximum short-circuit currentscan also be calculated based on network voltage c-factors

• Support of all fault types (three-phase, two-phase, two-phase to ground, single-phase toground)

• Calculation of Ik with selectable ”Decaying Aperiodic Component”

• Selectable method for calculating the peak short-circuit current in meshed networks

• User-definable fault impedance, conductor temperature and c-voltage factor.

• Fault calculation can optionally include or exclude motor contribution to the fault current

• Provision of specially designed graphs and diagrams required by the protection engineerfor protection coordination and design


11 FAULT ANALYSIS

IEEE 141 / ANSI e 37.5

PowerFactory provides a thorough implementation of the IEEE 141/ANSI e37.5 fault calculationstandard according to the latest published version. Special features are:

• Transformer tap positions can be included in the fault current calculation

• User-defined fault impedance and pre-fault voltage can be included in the fault currentcalculation

Other Standards

G 74 and IEC 61363

11.2 Complete Method/Multiple Faults

DIgSILENT PowerFactory Complete Method is especially designed for protection coordinationpurposes or for analysing observed system contingencies. It provides the required algorithmsand precision for determining the ”true” or ”operational” short-circuit currents without consider-ing the simplifications or assumptions typically made in standard fault analysis. In addition tothe high precision network model, multiple faults which occur simultaneously in the system orunusual fault conditions such as inter-circuit faults or single-phase interruptions can be anal-ysed.

• The Multiple Fault Analysis executes a complete network analysis based on subtransientand transient representations of electrical machines taking into account all specified net-work devices with their full representation and pre-faulted load conditions.

• Combination with IEC60909 principles for the calculation of aperiodic components andpeak short-circuit currents

• Calculation of peak-break and break-RMS currents

• Consideration of a complete multi-wire system representation. Applicable to single-phaseor two-phase networks.

• Analysis of multiple fault conditions

• Calculation of any asymmetrical, single or multiple fault condition with or without faultimpedance, including single- and double-phase line interruptions.

11.3 DC Short Circuit Calculation

PowerFactory offers the following DC Short Circuit Calculation options:

• DC Short Circuit according to IEC 61660

• DC Short Circuit according to ANSI/IEEE 946

The maximum and minimum short-circuit currents can be analysed from various DC basedmodels such as:

• AC/DC converters (rectifier/inverter) in bridge connection (ElmRec and ElmRecMono)


11 FAULT ANALYSIS

• Smoothing capacitors (only for IEC 61660) (ElmShnt)

• Batteries (ElmBattery)

• DC motor/generator (ElmDcm)

The DC Short Circuit Calculation can be initialised using the results of a Load Flow Calculation(optional). With this option selected, instead of taking a constant pre-fault voltage factor intoaccount, the Load Flow Calculation is used to determine the pre-fault voltages in the DC system.Upon completion of the calculation, the user may access a complete set of result variables asdefined in the standards, among them:

• Peak short-circuit current

• Quasi-steady-state short circuit current

• Time to peak

• Rise & decay times, rate of rise

• Equivalent system resistance and inductance, network time constant, etc.

11.4 Fault Analysis Results (all Methods)

PowerFactory offers many reporting options, including detailed reporting on all short-circuit lev-els for all faults, or alternatively, a specific report for a particular fault type. Special protectionreports can also be generated to include impedance, current and voltage information.

• Display of any variable within the single line graphic, station diagram and Flexible DataPage

• Fully flexible filter mechanisms to display objects in colour mode

• Detailed analysis reporting, which can list overloaded system elements, unacceptable busvoltages, system islands, out-of-service components, voltage levels, area summaries andmore

• Detailed text output with pre-defined or user-defined filters and levels

• DPL interactivity with all results

• Result export to other software applications such as MS-EXCEL or MS-ACCESS


12 NETWORK REDUCTION

12 Network Reduction

The typical application of the network reduction tool is a project where a specific network has tobe analysed but cannot be studied independently of a neighbouring network of the same or of ahigher or lower voltage level. In this case, one option is to model both networks in detail for thecalculation. However, there may be situations in which it is not desirable to perform studies withthe complete model; for example when the calculation time would increase significantly, or whenthe data of the neighbouring network is confidential. In such cases it is good practise to providea representation of the neighbouring network which contains the interface nodes (connectionpoints) which may be connected by equivalent impedances and voltage sources.

The objective of Network Reduction is to calculate the parameters of a reduced AC equiva-lent of part of a network, as defined by a boundary. This boundary must completely split thenetwork into two parts. The equivalent network is valid for both load flow and short-circuitcalculations. ,Following this, a model variation can be optionally created in the PowerFactorydatabase, whereby the full representation of the portion of network that has been reduced isreplaced by the equivalent.

12.1 General Features

• Flexible definition and maintenance of network boundaries. Various features such ascolouring of boundaries and topological checks

• Network Reduction can be calculated at any appropriate boundary

• Support of Standard Ward (PQ-equivalent), Extended Ward (PV-equivalent) and equiva-lent loads

• Support of short-circuit equivalents for transient, subtransient, peak-make and peak-breakcurrents

• The reduced network can be created in a network variation. This allows for simple com-parison and swapping between reduced and non-reduced cases.

• Robust reduction algorithms based on the sensitivity approach, i.e. reduced networkmatches for the current operating point as well as for network sensitivities

• Implicit result verification feature


13 VOLTAGE STABILITY ANALYSIS

13 Voltage Stability Analysis

13.1 PV Curves

PowerFactory supports the calculation of PV curves by applying specifically implemented scripts.These scripts perform the calculation of voltage variations against:

• Load variation in a selected area

• Load shift across boundaries (keeping the total load constant)

• Generator shift across boundaries (keeping the total generation constant)

PV curves can be calculated for a selected set of contingencies. Diagrams are automaticallycreated.

13.2 Q-V Analysis

For analysing the required reactive power reserve at individual busbars, PowerFactory providesscripts for the calculation of Q-V curves.

13.3 Eigenvalue

PowerFactory includes eigenvalue calculation and analysis tools. A specify eigenvalue, forwhich the stability behaviour (i.e. the eigenvectors and participation factors) is to be analysed,can be selected.


14 LOAD FLOW SENSITIVITIES

14 Load Flow Sensitivities

Supplementing PowerFactory voltage stability analysis suite is the Sensitivity Analysis tool. Itis often required to not only know the critical point of a system, but also how this critical pointis affected by changes in system conditions. PowerFactory Sensitivity Analysis tool performs astatic voltage stability calculation according to the following options:

• Sensitivity to a single busbar (calculation of the voltage sensitivities of all busbars andbranch flow sensitivities according to variations in power (∆P and ∆Q) at the selectedbusbar).

• Option to calculate sensitivities with respect to all busbars simultaneously.

• Sensitivity to a transformer tap position change (calculation of the voltage sensitivitiesof all busbars and branch flow sensitivities according to changes of a transformer/quadbooster tap).

• Modal analysis

– Identification of ”weak” and ”strong” parts of the network based on modal transfor-mation of the ∂v/∂Q sensitivity matrix.

– Eigenvalue calculation on the ∂v/∂Q sensitivity matrix, with a user-defined number ofeigenvalues to be calculated.

– Results of eigenvalues are displayed (in descending order according to magnitude),and branch/bus sensitivities can be displayed for each mode.


15 CONTINGENCY ANALYSIS

15 Contingency Analysis

The new Contingency Analysis tool in DIgSILENT PowerFactory has been designed to offer ahigh degree of flexibility in configuration, calculation methods and reporting options. Single-and multipletime-phase contingency analyses are available, both of which offer automatic oruser-defined contingency creation based on events, and the consideration of controller timeconstants and thermal (short-term) ratings.

Calculation Options for Contingency Analysis:

• Support of three calculation methods:

– AC load flow calculation

– DC load flow calculation

– Combined DC/AC calculation; i.e. full DC load flow calculation and automatic recal-culation of critical contingencies by AC load flow

• Single- and Multiple- Time-Phase calculations. Multiple time-phase contingency analysisfacilitates user-defined post-fault actions within discrete time periods.

• Generator Effectiveness and Quad Booster Effectiveness calculation: This calculation fea-ture assists the planner in defining appropriate measures for overstressed components incritical contingency cases: During contingency analysis, the possible impact of individualgenerator re-dispatch or transformer tap changes on overstressed lines is evaluated. Cor-responding reports are available that list the generator and quad booster effectiveness ona per-case basis.

• Ultimate Performance via Grid Computing: Possibility to perform the contingency analysiscalculation in parallel (on multi-core machines and/or clustered PCs)

Management of Contingencies/Fault Cases:

• User-friendly definition of contingencies (n-1, n-2, n-k, busbar) as ’Fault Cases’ supportinguser-defined events to model post-fault actions (re-switching, re-dispatching, tap adjust-ment, load shedding)

• Clustering of ’Fault Cases’ into ’Fault Groups’ for efficient data management

• Special Operational Libraries to manage ’Fault Cases’ and ’Fault Groups’ for future re-use

• Automatic creation of contingency cases based on Fault Cases, considering current net-work topology

Result File Management:

• Recording of results in (sparse) result file; accessible for any kind of export and/or customer-specific post-processing

• Predefined and user-definable monitoring lists for recording of results; selection of indi-vidual components, component classes and their associated variables to be recorded.Any available calculation result for a standard load flow calculation is accessible duringcontingency analysis.

• User-defined limits for recording of results (thermal loadings, voltage limits, voltage stepchange)


15 CONTINGENCY ANALYSIS

Reports:

A wide range of standard reports is available, facilitating summary views or the presentation ofresults on a per-contingency basis:

• Maximum Loadings Report

• Loading Violations (per case) Report

• Voltage Ranges Report

• Voltage Violations (per case) Report

• Generator and Quad Booster Effectiveness Report

Other key features:

• Tracing Facilities: Use of the new ’Trace’ function to step through events in a multipletime-phase contingency, while viewing updated results in the single-line graphic

• Support of component-wise Short-Term Ratings based on pre-fault loading and post-faulttime

• Special ”Contingency Analysis” toolbar for user-friendly configuration, calculation and re-porting

Parallel Computing Option: Calculation of contingencies in parallel represents an importantrequired computation time reduction depending on the number of cores being used.

• Management of the parallel computation function

• Dedicated settings for the execution of the contingency analysis


16 OVERHEAD LINE AND CABLE PARAMETER CALCULATION

16 Overhead Line and Cable Parameter Calculation

DIgSILENT PowerFactory incorporates the automatic calculation of the electrical parameters ofany cable/overhead line configuration starting from layout and geometric characteristics whichare typically available in manufacture’s datasheets. The calculation is applicable over a widerange of frequencies and supports the step-up process of highly accurate line and cable modelsfor harmonic analysis, frequency sweep and EMT-simulation among others. The supportedoptions are described below.

16.1 Overhead Line Parameter Calculation

• Any combination of line circuits (1-, 2- and 3-ph), neutral conductors and earth wires,with/without automatic reduction of earth wires

• A flexible definition of tower types and tower geometries, including conductor sags, allow-ing a multiple combination of tower geometries and conductor types that avoids entry ofredundant data

• A flexible definition of tower types and tower geometries, including conductor sags, allow-ing a multiple combination of tower geometries and conductor types that avoids entry ofredundant data

• Solid and tubular conductor types, including sub-conductors for phase circuits and earthwires

• Skin effect

• Equivalent impedance and admittance matrices in natural, reduced and symmetrical com-ponents

16.2 Cable Parameter Calculation

• Multi-phase single core and pipe type cable systems

• Flexible definition of cable layouts, including conducting, semi-conducting and insulatinglayers

• Compact and hollow core shapes, filling factor for stranded conductors

• Consideration of skin effect

Calculation of layer impedances and admittances in natural, reduced and symmetrical compo-nents, including sheath and armour reduction, cross-bonding.

16.3 Automatic Cable Sizing

Automatic Cable Sizing optimisation in accordance with various international standards.

The Cable Sizing command can be executed on a network model, balanced or unbalanced,with or without any cable types previously defined. PowerFactory will assign types and calculatecable ratings according to the selected international standard, such as:


16 OVERHEAD LINE AND CABLE PARAMETER CALCULATION

• IEC 60364-5-52

• BS 7671

• NF C15-100

• NF C13-200


17 DISTRIBUTION NETWORK FUNCTIONS

17 Distribution Network Functions

17.1 Feeder Analysis

• Feeder Plots: Graphical display feature (Virtual Instrument, VI) to increase transparencyin grid loading and voltage profile analysis along the feeder. Displayed result variables arefreely configurable. Full interactivity is given via the VI to access all relevant data of thecomponents belonging to the feeder.

• Schematic visualisation of Feeder: Automatic generation of single line diagram to visualisecomponents of the feeder with distance/index view.

• Feeder Load Scaling: A load flow calculation feature that allows the automatic adjustmentof individual bus loads to match a specified total feeder load. The selection of loads whichare to participate in the feeder scaling procedure is user-defined. This method allows forcomplex scaling scenarios with nested and parallel feeders.

• Backbone Calculation: A calculation that allows the determination and visualisation of themain connections between meshed feeders. Various methods are available to determinebackbones, ranging from purely topological criteria, and cross-section analysis, to moresophisticated methods that score quality of power restoration.

17.2 Low-Voltage Network Analysis

• Define loads in terms of numbers of customers connected to a line

• Consider load diversity

• Perform a load flow analysis that considers load diversity for calculating maximum voltagedrops and maximum branch current

• Perform cable reinforcement optimisation to either automatically reinforce selected cables,or to provide a report of recommendations

• Perform voltage drop and cable loading analysis

• Perform statistical calculations of neutral currents caused by unbalanced single-phaseloading and load diversity, to represent a realistic network

17.3 Stochastic Load Modelling

On the basis of defined ’customer units’ the user may specify a number of customers connectedto a line. Load flow options are provided to define the load per unit customer according to:

• Power per customer unit

• Power factor

• Coincidence factor for an infinite number of loads (i.e. ’simultaneity factor’)

In addition, the user may select one of two methods for considering the stochastic nature ofloads:

• Stochastic evaluation (theoretical approach, also applicable to meshed networks)



• Maximum current estimation (application of stochastic rules for estimating maximum branchflow and maximum voltage drops)

The Load Flow with stochastic load modelling then provides maximum currents for each branchcomponent, maximum voltage drops, and minimum voltages at every bus bar.. The usual vari-ables for currents and voltages in this case represent average values of voltages and currents.Losses are calculated based on average values; the maximum circuit loading is calculated usingmaximum currents.

17.4 Cable Reinforcement optimisation

PowerFactory Cable Reinforcement optimisation determines the most cost-effective option forupgrading overloaded cables in balanced and unbalanced networks. The objective function isto minimise annual costs for reinforcing lines (i.e. investment, operational costs and insurancefees). Constraints for the optimisation are the admissible voltage band and cable loading limitsfor the planned network.

• optimisation along pre-definable feeder

• User-definable library of available cable/OHL types with costs that can be used for rein-forcement

• The analysis can be performed on a network model without any cable types previouslydefined. Types are assigned from the selected library, with consideration to the specifiedloading and voltage drop constraints

• Consideration of:

– Admissible voltage band limits

– Maximum voltage drop limit at the end of the feeder

– Maximum admissible Cable/OHL overloading

• Various plausibility checks for final solution

• Calculated results: report of the recommended new cable/overhead types for lines andcost evaluation for the recommended upgrading

• Report mode to propose cable/OHL type changes or automatic type replacement

• Report on the short-circuit loading of lines and cables

17.5 Feeder Tools

The PowerFactory Feeder Tools comprise a set of tools for radial systems to change voltagelevels, phase technology or to optimise phasing from a particular point downwards.

Voltage and Phase Technology Change Tool

• Automatic change of the voltage level and/or phase technology inside a pre-defined feeder

• Automatic replacement of type data (for transformers, lines, loads and motors) accordingto pre-configurable type mapping tables - including automatic creation of new compatibletypes if necessary



Auto-Balancing Tool

• Automatic balancing of feeders such that voltage unbalance at terminals is minimised

• Reconfiguration of phasing of loads, lines, or transformers and combinations thereof

• Supports fixed phasing elements

• Colouring modes to visualise phase technology before and after change


18 PROTECTION FUNCTIONS

18 Protection Functions

The basic functional model library of DIgSILENT PowerFactory protection analysis tool has beenextended to include additional devices such as CTs, VTs, relays, fuses and more complex pro-tection schemes including user-defined modelling capabilities. Additionally, there are speciallydesigned interactive VIs (Virtual Instruments) for displaying system quantities and, more impor-tantly, for modifying protection settings in the graphical environment. This last feature is espe-cially useful, as coordinated settings between different protection schemes can be modified viathe cursor in the graphical environment, following which the settings in both the database andthe simulation environment are also updated.

All protective devices are fully-functional under steady-state and transient conditions, allowingdevice response assessment under all possible simulation modes, including load flow calcula-tion, fault analysis, RMS and Instantaneous Values (EMT) simulation.

PowerFactory main protection features are:

• Accurate steady-state relay checking via short-circuit and load flow (balanced and unbal-anced)

• Precise dynamic relay checking with RMS and EMT simulations

• Consideration of current transformer saturation

• Diagrams for overcurrent and distance coordination:

– Time-overcurrent diagrams

– R-X characteristic diagrams

– Time distance diagrams

• Automatic Protection Coordination Wizard for time-overcurrent protection schemes

• Short Circuit Trace to examine the performance of a protection scheme in response to afault or combination of faults

18.1 Protection Model Library and Functionality

The DIgSILENT PowerFactory protection analysis tool contains a comprehensive protection de-vice model library. All relays are modelled for steady-state calculations (short-circuit, load flow),RMS and EMT simulation modes. The definition of relay types is highly flexible via block dia-grams. For RMS and EMT simulation purposes, relays may be extended and adopted to copewith user specific requirements via the PowerFactory DSL language The features of the protec-tion model library are listed below.

Fuses are represented by their melting curves. It is possible to take minimum and maximummelting curves into account.

Time-Overcurrent Relays for 1-phase, 3-phase, ground and negative sequence time over-currents. Additionally, the relay characteristics can incorporate the following standards andsolution methods:

• IEC 255-3, ANSI/IEEE and ANSI/IEEE squared

• ABB/Westinghouse CO (Mdar)



• Linear approximation, Hermite-spline approximation

• Analytical expressions via built-in formula editor and analyser (DSL)

Instantaneous Overcurrent Relays for 1- phase, 3-phase, ground and negative sequence timeover-currents.

Directional Relays for overcurrent, power, ground current, and any combination of time andinstantaneous overcurrent relays. Additionally, voltage and current polarisation is used for thedetection of negative and zero sequence components considering also dual polarisation. Op-tional: with voltage memory.

Distance Relays for phase, ground and zone distance protection. Provision is available forincorporating overcurrent and under-impedance starting units (U-I or Z) as well as angle under-impedance. Different characteristics are available for distance relay zones including:

• MHO, offset MHO

• Polygonal, offset polygonal

• Tomatoes, lens and circle

• R/X Blinders and quadrilateral

Support of various polarisations such as:

• Self-polarised

• Cross polarised (90 connection)

• Positive, negative sequence polarised

• Optional: voltage memory

Zero sequence and parallel line compensation

Voltage Relays for under-voltage, instantaneous voltage, voltage balance and unbalance. Ad-ditional devices such as: Breaker Fail, Motor Protection, Generator Protection, DifferentialProtection, Reclosing Relays, Low Voltage Circuit Breakers, and Out-of-Step Relays.

In addition to these protection functions and relays, DIgSILENT PowerFactory provides furtherdevices and characteristics for more detailed protection system modelling, such as:

• Current and voltage transformers that include saturation effects

• Conductor, cable damage curves, cable overload curves and inrush peak current mod-elling

• Transformer damage curves (ANSI/IEEE Standard C57.109-1985) and inrush peak cur-rent modelling

• Motor starting curves, cold and hot stall, in-rush peak current modelling, and any user-defined curves

All protection device models are implemented within the composite model frame environment.This allows users to easily design and implement their own models, by utilising the graphicaluser interface for constructing block diagrams.



18.2 Output and Graphical Representation

Time-Overcurrent Diagrams

• Overcurrent curve adjustment using drag and drop

• Display of tripping curve tolerances during drag and drop

• User-defined labels

• Tripping times are automatically displayed for calculated currents in time-overcurrent dia-grams

• Display of an unlimited number of overcurrent curves in diagrams

• Simple creation and addition of diagrams via single line graphics

• Display of motor starting curves, conductor/cable and transformer damage curves

• Balloon help showing name of relay, etc.

• Double-click on curves to change relay settings

• Additional axis for voltage levels

• Display of single-line diagram paths in time-overcurrent diagrams

R-X Characteristic Diagrams

• Display branch impedances with several options

• Automatic display of calculated impedances

• Adding relays with offset

• Flexible display of zones (starting zones, etc.)

Time Distance Diagrams

• Different methods for calculating curves: kilometrical or short-circuit sweep method

• Forward and/or reverse diagram

• Selectivity check of distance and overcurrent relays/fuses in same diagram

• Separate overreach zone representation

• Additional axis showing relay locations and busbars/terminals

• Selectable x-axis scaling (length, impedance, reactance, 1/conductance)

Single Line Diagram

• Colouring of switches according to relay locations, relay tripping times

• Display of relay tripping times in result boxes

• Additional text boxes for relay settings



Relay Setting Report

• Simplified ASCII reports generated in the output window

• Tabular report command can be customised to deal with the structure of complex relaymodels and for a protective device class

Relay Tripping Report

18.3 Overcurrent-Time Protection

The coordination of overcurrent-time protection is performed graphically using the current-timediagram as the basis. Relay settings are modified using drag and drop to move characteristics.Short-circuit currents calculated by the short-circuit command, are shown in the diagram as avertical line. In addition, the corresponding tripping times of the relays are displayed. Coordina-tion between relays at different voltage levels is available. Therefore, currents are automaticallybased on the leading voltage level, which can be selected by the user.

18.4 Distance Protection

For distance protection coordination, two powerful graphical features are integrated. The firstof these features is the R-X diagram for displaying the tripping zone of distance relays andthe line impedances. Several relays can be visualised in the same R-X diagram. This canbe useful for the comparison of two relays that are located at different ends of the same line.The relay characteristics and the impedance characteristic of the connecting line will be shownin the same R-X diagram. Following short-circuit calculations, the measured impedances arevisualised with a marker in the shape of a small arrow or cross. From the location of the markerthe user can see the tripped zone and its associated tripping time. For dynamic simulation,measured impedances of the relays can be displayed, thereby visualising the functioning ofpower swing blocking or out-of-step tripping relays.

The second powerful graphical feature is the time-distance diagram, which is used for checkingthe selectivity between relays along a coordination path. The relays on a coordination path canbe displayed in diagrams for forward, reverse or for both directions. Consequently, it is veryeasy to check the selectivity of the relays along a coordination path. Two different methods forcalculation of the tripping curves are provided. These are the kilometric and the short-circuitmethod.

• Kilometric method: The reach of the zones is calculated from the intersection of the givenpositive sequence impedance of the lines, and the impedance characteristic of the relays.

• Short-circuit method: This is the main method for checking the selectivity. Short-circuits(user-defined fault type) are calculated along the coordination path. The tripping times forthe time-distance curve are determined using the calculated impedances. The startingsignal of a relay is also considered.

A special feature of the distance protection is the consideration of blocking signals or POTT (per-missive over-reach transfer tripping), PUTT (permissive under-reach transfer tripping), whichare also taken into account. In addition to tripping curves of distance relays, the curves of over-current relays can be displayed and coordinated in the same diagram using the short-circuitmethod. Both the kilometric and the short-circuit method consider breaker opening times in thecalculation of tripping times. The breaker opening time can be optionally ignored.



18.5 Coordination Assistant

The coordination assistant helps the protection engineer to quickly find well structured and con-sistent network protection solutions and afterwards easily analyse, tune and implement the cho-sen settings in the protection devices. The algorithm is flexible, automated and comprehensivefeaturing the following options:

• User-definable coordination area (paths)

• Automatic coordination of distance protection relays

• Determination of relay protection zones

• Reactive reach via zone-factors (independent, cumulative, ref. to line 1)

• Resistive reach based on prospective fault/load resistance

• Output options:

– Tabular report

– Time-distance diagram

– Automatic update of protection devices

• Time distance plots are automatically obtained after executing the algorithm


19 ARC-FLASH HAZARD ANALYSIS

19 Arc-Flash Hazard Analysis

PowerFactory offers the possibility to perform calculations to determine Personal ProtectiveEquipment (PPE) requirements by means of the Arc-Flash Hazard Analysis tool:

• Arc-Flash calculations can be performed using globally or individually specified circuit-breaker tripping times, or protection clearing times based on actual protection settings.The calculation takes into account the arc resistance when determining protection clearingtimes.

• Incident Energy and PPE requirements can be displayed on the Single Line Graphic.

• Easy preparation and use of Arc-Flash labels based on the calculation results.

19.1 Supported Standards

• IEEE-1584 2002

• NFPA 70E 2008

• German Standard BGI/GUV-I 5188

With the first method, IEEE-1584 2002, the arcing current is calculated based on the equationspresented in the standard. Internally, PowerFactory calculates the arc resistance required tolimit the fault current to the calculated value. When the NFPA method is selected, the boltedfault current is used for the calculation. For either method, when the user selects to use relaytripping times, a second calculation is performed at a reduced fault current and the associatedclearing time. PowerFactory compares the results of these two cases and reports on the worstcase result.

19.2 Results visualisation

The Arc-Flash Hazard Analysis tool in PowerFactory offers different option to visualise results:

• Result boxes and colouring mode in the Single Line Graphic

• Arc-Flash reports dialogue to configure tabular result output

• Arc-Flash labels to export a selected set of variables to Microsoft Excel


20 DISTRIBUTION NETWORK OPTIMISATION

20 Distribution Network optimisation

In order to reduce network unbalance and improve quality of supply, DIgSILENT PowerFactoryncorporates features to assist the user in distribution network optimisation:

• Optimal capacitor placement

• Open tie optimisation

• Cable reinforcement optimisation

• Feeder tools for voltage/technology change

• Auto-balancing to minimise voltage unbalance

20.1 Optimal Capacitor Placement

PowerFactory ’s Optimal Capacitor Placement determines the optimal locations, types and sizesof capacitors to be installed in radial distribution networks. The economic benefits due to energyloss reduction are weighted against the installation costs of the capacitors while keeping thevoltage profile within defined limits. This feature includes:

• User-definable library of proposed capacitor candidates together with annual installationcosts

• Consideration of:

– Benefits due to loss reduction

– Voltage limits

– Maximum total investment costs

• Support of load profiles

• Calculated results: set of locations where capacitors should be installed, which type ofcapacitor(s) should be installed at each site, and whether or not a switched capacitor isproposed.

• User-friendly presentation of results with fully-integrated post-processing features

20.2 Open Tie optimisation

PowerFactory s Open Tie optimisation finds a loss-minimal switch configuration of the network,which results in a radial topology while maintaining all thermal limits. This feature includes:

• Heuristic algorithm which explores all potential meshes in the grid to evaluate the optimaltie-points to open

• Consideration of loading limits

• User-definable section of the network where optimal open tie-points should be determined

• Report mode to propose switch status changes or automatic switch reconfiguration


21 HARMONIC AND POWER QUALITY ANALYSIS

21 Harmonic and Power Quality Analysis

The harmonic analysis functionality is ideal for applications in transmission, distribution andindustrial networks for filter design, ripple control signal simulation or for the determination ofnetwork resonance frequencies.

For analysing the impact of harmonics in power systems, DIgSILENT PowerFactory providestwo harmonic analysis functions.

21.1 Harmonic Load Flow

The DIgSILENT PowerFactory harmonic load flow features the calculation of harmonic voltageand current distributions based on defined harmonic sources and grid characteristics. It allowsthe modelling of any user-defined harmonic voltage or current source, both in magnitude andphase including inter-harmonics. The harmonic sources can be located at any busbar in thepower system and may be implemented within any network topology.

Harmonic current sources can be associated with any load, SVC (TCR injection), rectifier orinverter. Harmonic voltage sources can be modelled using the AC voltage source model or thePWM AC/DC converter model. The built-in rectifier models inject the spectrum of ideal 6-pulserectifiers if no other injection has been defined.

DIgSILENT PowerFactory supports any type of characteristic harmonic, un-characteristic har-monic (even harmonics etc.) and non-integer (inter-) harmonics. Unbalanced harmonic sources(e.g. single-phase rectifiers) are also fully-supported. The analysis of inter-harmonics or unbal-anced harmonic sources is based on a complete abc-phase network model.

Because of the phase correct representation of harmonic sources and network elements, thesuperposition of harmonic currents injected by 6-pulse rectifiers (via Y-Y and Y-D transformersleading to a reduction in 5th, 7th, 17th, 19th etc. harmonic currents) is modelled correctly.

DIgSILENT PowerFactory calculates all symmetrical and asymmetrical harmonic indices for cur-rents and voltages, as defined by relevant IEEE standards, including harmonic current indicesand harmonic losses, such as:

• THD and HD ((Total) Harmonic Distortion)

• TAD (Total Arithmetic Distortion)

• IT product

• Harmonic losses

• Active and reactive power at any frequency

• Total active and reactive power, displacement and power factor

• Network impedances at selected buses

• RMS values

• Unbalance factors

• Integer and non-integer harmonic order values

• Flicker Assessment:



– Pst, Plt (Short-, and long-term Flicker Disturbance Factors; continuous and switchingoperation)

– Relative voltage change value

Results can be represented:

• In the single line diagram (total harmonic indices)

• As histograms (frequency domain)

• As waveform (transformation into the time domain)

• As profile (e.g. THD versus busbars)

The frequency dependent representation of network elements such as lines, cables, two- andthree-winding transformers, machines, loads, filter banks etc. for considering skin effects isfully-supported.

21.2 Frequency Sweep

The frequency sweep performs a continuous analysis in the frequency domain. The most com-mon application is the calculation of self- and mutual network impedances for identifying theresonance points of the network and for supporting filter design.

• All impedances are calculated simultaneously in the same run. Since DIgSILENT Pow-erFactory uses a variable step-size algorithm, the calculation time of frequency sweepsis very low while the resolution around resonance points remains very high (typically 0.1Hz).

• Frequency sweeps can either be performed with the positive-sequence network model(very fast) or the complete three-phase abc-network model.

• Calculation of self- and mutual network impedances

• Calculation of voltage amplification factors

• Calculation of voltage amplification factors

In addition to common applications relating to harmonic distortion, PowerFactory ’s FrequencySweep function can also be used for subsynchronous resonance studies. The calculation ofdamping and undamping torques is supported by special scripts.

Network Modelling

The skin effect is considered by associating frequency characteristics with line or transformerresistances and inductances. These characteristics can be specified by either setting the pa-rameters of a polynomial expression or by entering the characteristic point by point using tables.DIgSILENT PowerFactory uses cubic splines or hermite polynoms for appropriate interpolation.

• Lines are modelled either by approximate PI sections or by the highly-accurate dis-tributed parameter line model that should always be used for long lines or high frequencyapplications. The skin effect can be included in both line models.



• Filters can be specified by either ’layout’ parameters or ’design’ parameters. ’Layout’parameters are typically the rated reactive power, the resonance frequency and the qualityfactor. ’Design’ parameters are the actual R, L, and C values.

In addition to the explicit specification of frequency dependent resistance or inductance viaparameter characteristics, overhead lines can be modelled by defining the tower geometry andcables can be modelled by specifying the cable layout. In such cases, frequency dependenteffects, such as the skin effect or frequency dependent earth return, are automatically calculatedand considered by the model.

21.3 Ripple Control Signals

DIgSILENT PowerFactory provides full support for analysing and dimensioning ripple controlsystems. Series and parallel coupling of ripple control systems can be modelled including allnecessary filter elements.

• The level of the ripple control signal in the entire network is calculated and reported in thesingle line diagram, the output window or the browser.

21.4 Filter Rating

DIgSILENT PowerFactory features a special, easy-to-use function for calculating the rating ofall components of a filter. All relevant voltages across all components are calculated and madeavailable in the ’Filter Sizing’ report.

21.5 Power Quality Assessment according to D-A-CH-CZ Guideline

The Connection Request Assessment Tool is a very useful feature for power quality calcula-tions according to D-A-CH-CZ guideline ’Technical Rules for the Assessment of Network Dis-turbances’ as used in Germany, Austria, Switzerland and Czech Republic. A new ”ConnectionRequest Assessment” command is available as well as the Connection Request element. Thiselement represents a new load installation which is to be connected to the grid.

Full assessment of the D-A-CH-CZ guideline is performed based on the following criteria:

• Voltage Changes and Flicker

• Voltage Unbalance

• Harmonics

• Commutation Notches

• Interharmonic Voltages

Following the calculation, a detailed report and summary are made available for further analysis.


22 OPTIMAL POWER FLOW (OPF)

22 Optimal Power Flow (OPF)

The PowerFactory Optimal Power Flow (OPF) serves as the ideal complement to the existingload flow functions. Where the standard load flow calculates branch flows and busbar voltagesbased on specified ”set points” (active/reactive power generation, generator voltage, transformertap positions, etc.), the OPF also calculates the ”best possible” values for optimising a user-specified objective function and a number of user-defined constraints. In this way, the OPFadds intelligence and consequently improves efficiency and throughput of power system studiessignificantly.

Building on the load flow calculation, PowerFactory offers two calculation methods:

• AC optimisation based on a state-of-the-art interior-point algorithm

• DC optimisation based on linear programming using simplex methods, also supportingcontingency constrained optimisation.

OPF in PowerFactory allows easy configuration of the optimisation task via the simple selec-tion of an objective function, controls (i.e. system variables to be optimised), and constraints.The optimal solution for the selected objective function is calculated under the considerationof a number of possible constraints with which the final solution must comply. All controls andconstraints can be flexibly-defined on a component level.

22.1 AC optimisation

Supported Objective Functions:

• minimisation of system losses

• minimisation of costs (based on arbitrary (non-linear) cost curves for generators and loadtariffs for external grids)

• minimisation of load shedding

Control Variables:

• Generator active power dispatch

• Generator reactive power dispatch

• Transformer tap positions

• Switchable shunts

• Load consumption (for optimal load shedding)

Supported Constraints:

• Branch flow limits (loading)

• Voltage limits (min/max) for busbars/terminals

• Active power limits of generators



• Reactive power limits of generators

• Transformer tap changer limits

• Adjustable shunt limits

• Boundary flow limits (min/max limits for active and reactive power flow along any user-definable boundary)

Since the OPF can dispatch the active power of generators considering reserve limits and con-sidering fuel cost minimisation (which is based on non-linear fuel cost functions), the PowerFac-tory OPF is also a highly advanced economic dispatch function.

22.2 DC optimisation

The DC optimisation builds on a sensitivity-based linear programming approach. Most notably, itallows a contingency constrained optimisation to be carried out for any predefined list of contin-gency cases. The optimisation simultaneously considers all contingency cases, and the solutionis globally optimal and guaranteed to be feasible over all contingency cases (i.e. not violatingany constraints in any of the contingencies).

Supported Objective Functions:

• Feasibility check

• minimisation of costs (based on arbitrary (non-linear) cost curves for generators and loadtariffs for external grids)

• minimisation of generator dispatch change, i.e. finding a feasible solution with minimalre-dispatching

• minimisation of pre- to post-fault generator dispatch change (available for contingencyconstrained optimisation only), i.e. finding optimal dispatch for the base case and eachcontingency case such that the change between the base case and each contingencycase is minimal

• minimisation of pre- to post-fault transformer tap change (available for contingency con-strained optimisation only), i.e. finding optimal transformer tap settings for the base caseand each contingency case such that the change between the base case and each con-tingency case is minimal

Control Variables:

• Generator active power dispatch - for base case and all contingency cases

• Transformer tap positions - for base case and all contingency cases

• Load consumption

Supported Constraints:

• Branch flow limits (loading) - for base case and all contingency cases

• Active power limits of generators - for base case and all contingency cases

• Transformer tap changer limits - for base case and all contingency cases



• Boundary flow limits (min/max limits for active and reactive power flow along any user-definable boundary) - for base case and all contingency cases

• Maximum number of tap changes per contingency


23 TECHNO-ECONOMICAL CALCULATION

23 Techno-Economical Calculation

Techno-economical calculations are used to perform an economic assessment and comparisonof network expansions (projects) through an analysis of:

• The cost of electrical losses.

• The economic impact of failure rates (reliability).

• Investment costs (including initial costs, initial value, scrap value, and expected life span).

• Project timing.

The output of the Techno-Economical Calculation is the Net Present Value (NPV) of the projectover the selected period. The command can optionally reconfigure the network at each step ofthe calculation to minimise losses (using the Tie Open Point optimisation command).

Output results are:

• Reference to the result object

• Summary report of selected calculation options, and annual costs, total costs, and NetPresent Value (NPV) in the output window


24 RELIABILITY ANALYSIS FUNCTIONS

24 Reliability Analysis Functions

Reliability calculations are essential for the evaluation and comparison of electrical power sys-tems in terms of both design and operation. Although non-stochastic contingency analyses(i.e. n-1) are able to highlight obviously unacceptable operational events, they cannot rankthese events in terms of either frequency or duration. The DIgSILENT PowerFactory ReliabilityAnalysis tool incorporates standard reliability assessment features together with sophisticatedmodelling techniques that enable all forms of reliability assessment to be carried out.

Failure models are defined using mean yearly failure frequency and repair duration data. Forlines and cables, this data is entered in per-length terms. Detailed models are available forgenerators that enable de-rated states to be represented, with maintenance and common modemodels also available.

Load forecast and growth curves can be imposed via time-varying load characteristics. Loadmodels are additionally available for hard-to-predict industrial situations, and each can be as-signed its own interruption cost using one of the following cost functions: cost/customer/interruption,cost/kW/interruption or cost/interruption.

All failure and load models can be represented either by the Markov method, where simplemean repair durations are modelled, or by the sophisticated Weibull-Markov method, whererepair duration variance is additionally modelled. The Weibull-Markov model also has the uniqueproperty that annual interruption cost indices such as load and process (industrial) interruptioncosts can be calculated both analytically and quickly. Consequently, PowerFactory s ReliabilityAnalysis tool enables the comparison and justification of alternative investment proposals on afinancial basis.

The basic calculation method used is analytical state enumeration. This method is very efficient,produces exact results and is flexible for addressing a wide range of reliability calculation prob-lems. The network reliability analysis can be carried out on the basis of a simple connectivitycheck (primarily intended for distribution networks) or on the basis of AC load flow calculationswhich consider load curtailments due to overloading or voltage constraints (for bulk power sys-tem analysis).

The approach combines fast topological analysis for fault clearance, fault isolation and powerrestoration, with AC load flow and optimisation techniques for addressing energy at risk, loadtransfer and load shedding.

Finally, the results of all reliability assessments can be presented in text format, as user-definedgraphs, or within the single-line graphics environment.

24.1 Failure Models

The failure models for network reliability assessment include:

• Failures of lines, cables, transformers, generators/external grids and busbars

• Independent second failures (”n-2”)

• Common mode failures

• Double earth faults

• Protection/circuit breaker malfunction

• Transient fault model (for momentary interruption indices)



In addition to the above-listed failure models, planned outages such as scheduled maintenancecan also be considered.

Special failure models can be used by various network components to share failure data. Thefailure models hold stochastic failure information (mean yearly failure frequency for sustained,transient and earth faults on a per km basis, as well as mean repair durations). PowerFactory suser-interface allows for both an easy setup, as well as for simple modification of input data forvarious studies.

The Maintenance feature simulates the effects of network reliability under predefined plannedoutage scenarios. Maintenance of individual network components can be modelled on an hourlybasis.

24.2 State Enumeration

Based on the network model and the given failure data, the reliability analysis generates andanalyses the resulting contingency cases.

In addition, the user can model load forecast and growth curves by imposing time-varying loadcharacteristics. PowerFactory has a very efficient handling of the reliability assessment overtime with varying load data, through the use of the following techniques:

• Clustering of load states in the state enumeration algorithm

• Analysing load variation correlations, thereby reducing the overall number of load states

• Using linear approximation techniques to improve performance in the case of large num-bers of load states

24.3 Failure Effect Analysis

The Failure Effect Analysis (FEA) simulates both the automatic and manual reactions to faultsof installed protection and of the system operators during each reliability assessment. TheFEA can be checked and fine-tuned in an interactive way to exactly match the real system andoperator reactions.

The Failure Effect Analysis comprises:

• Automatic fault clearance by protection devices

• Automatic or manual fault isolation

• Automatic or manual power restoration by network reconfiguration. This includes sophisti-cated sectionalising and strategic power restoration methods that operate in three distinctphases:

– Phase 1: sectionalising by remote controlled switch devices

– Phase 2: Sub-sectionalising of strategic areas

– Phase 3: Full system restoration

• Overload alleviation by optimised generator re-dispatch, load transfer and load shedding,under consideration of load priorities and the amount of load that is available for shedding.

• Under-voltage load-shedding



For classical bulk power system analysis, it is assumed that post-fault overloads may occur. Afull AC load flow, incorporating basic generator re-dispatch and automatic tap changing, is usedto analyse post-fault system conditions. Additional load transfer and/or load shedding will thenbe simulated.

In cases where it can be assumed that system restoration will not lead to any overloading, theoverload alleviation can be omitted and a fast network connectivity analysis is sufficient.

24.4 System Indices and Results

PowerFactorys Network Reliability Assessment calculates all common reliability indices. Amongothers, the following indices are available:

System indices (also available for user-defined feeders, zones, and areas):

• SAIFI, System Average Interruption Frequency Index

• CAIFI, Customer Average Interruption Frequency Index

• SAIDI, System Average Interruption Duration Index

• CAIDI, Customer Average Interruption Duration Index

• ASIFI, Average System Interruption Frequency Index

• ASIDI, Average System Interruption Duration Index

• ASAI, Average Service Availability Index

• ASUI, Average Service Unavailability Index

• ENS, Energy Not Supplied

• AENS, Average Energy Not Supplied

• ACCI, Average Customer Curtailment Index

• EIC, Expected Interruption Cost

• IEAR, Interrupted Energy Assessment Rate

• SES, System Energy Shed

• LOLE, Loss of Load Expectancy

• LOEE, Loss of Energy Expectation

• LOLF, Loss of Load Frequency

• LOLD, Loss of Load Duration

• MAIFI, Momentary Average Interruption Frequency Index

Load Indices:

• AID, Average Interruption Duration

• ACIF, Average Customer Interruption Frequency

• ACIT, Average Customer Interruption Time



• LPIT, Load Point Interruption Time

• LPIF, Load Point Interruption Frequency

• LPENS, Load Point Energy Not Supplied

• LPEIC, Load Point Expected Interruption Costs

• LPCNS, Load Point Customers Not Supplied

• LPPNS, Load Point Power Not Supplied

• LPPS, Load Point Power Shed

• LPES, Load Point Energy Shed

• LPIC, Load Point Interruption Costs

• TCIF, Total Customer Interruption Frequency

• TCIT, Total Customer Interruption Time

Busbar Indices:

• AID, Average Interruption Duration

• LPIF, Yearly Interruption Frequency

• LPIT, Yearly Interruption Time

24.5 Special Features

The Network Reliability Assessment is fully-integrated into PowerFactory , thus profiting fromthe extremely flexible data management and data handling for setting up individual studies.

24.5.1 High Flexibility

Each contingency case is created and analysed based on events (i.e. switch events, loadshedding events, generator re-dispatch events). By default, the events are created automaticallyby the reliability calculation algorithm. This allows the user to analyse, adjust and fine-tune theindividual cases in a very flexible manner. The reliability calculation will then consider the user-defined events for the FEA instead of creating them automatically.

24.5.2 Tracing of Individual Cases

The user can examine the results of a single fault by running the fault case of interest in the tracemode, a step-by-step analysis that sweeps over the individual actions of the FEA. The switchingactions and load shedding/generator dispatch events created by the reliability calculation willthen be applied to the network and the results can be viewed and analysed after each timestep.



24.5.3 Powerful Output Tools for Result Representation

Results can be viewed in a variety of ways:

• Formatted reports

• Tabular result views (integrated into the PowerFactory Data Manager)

• Graphical result representations

• Various colouring modes

24.5.4 Contribution to Reliability Indices

Post-processing tools allow the calculation of individual components’ contributions to systemindices. In this way the user can study the impact of certain network components (such aslines/cables, transformers, etc) on the overall system indices. Likewise, loads can be groupedinto load classes (industrial, agricultural, domestic, etc) and their contribution to, for example,energy indices can be evaluated.

24.5.5 Development of Indices over Years

Taking into account the evolution of the network model and the failure data over time, Power-Factory supports the calculation and visualisation of the reliability indices over years.

24.6 Optimal Power Restoration

PowerFactory offers Power Restoration tools for distribution networks incorporating Tie OpenPoint optimisation methods to achieve an utmost level of resupply. I.e., PowerFactory is auto-matically evaluating — as part of the Power Restoration strategy — the benefits of any move oftie open points in any neighboring feeder.

Additional Features

• Unbalanced calculations

• Handle of feeder constraints

• Calculation of reliability indices

• Use of load distribution states

• Use of Time Tariffs and Energy Tariffs

24.6.1 Optimal Power Restoration

Optimal Power Restoration studies can be conducted for single case to obtain a ”RecoveryScheme Report” — even in the case where no failure data is available for the network com-ponents. This function includes the feature to trace the stages of the restoration and view theimpacts of the restoration on the single line graphic.

Features



• Animated tracing of individual cases

• Optimal Remote Control Switch (RCS) Placement

• Optimal Manual Restoration


25 STATE ESTIMATION

25 State Estimation

The PowerFactory State Estimator provides an accurate real-time analysis of the full operatingsystem based on the information provided by selectively monitored data, e.g. that of an in-stalled SCADA system. The objective of the state estimator is to assess the generator and loadinjections in a way such that the resulting load flow solution matches as closely as possible themeasured branch flows and busbar voltages. The features of PowerFactory s State Estimationtool include:

• Flexible definition of external measurement devices in the network model supporting thefollowing measurement types:

– Active and reactive power branch flows– Branch current (magnitude)– Busbar voltage (magnitude)– Breaker status– Transformer tap position

• User-definable selection of system states to be estimated/optimised:

– Loads: Active and reactive power demand, or alternatively the scaling factor– Generators and static generators: Active and reactive power generation– Asynchronous machines: Active power generation– Static Var Systems: Reactive power injection– Transformers: Tap positions

• High-precision estimation of full system state that minimises deviations from measure-ments

• Fast-converging non-linear optimisation algorithms

• Observability check based on a novel sensitivity analysis approach

– Detection of unobservable system states– Grouping of unobservable states in equivalence classes– Detection of redundant measurement locations

• Innovative patch strategies for unobservable areas; usage of automatically created pseudo-measurements

• Bad data detection in the loop

• Measurement plausibility checks as pre-processing, such as:

– Node sum checks for active and reactive power– Check for consistent active power flow directions at each side of branch elements– Check for unrealistic branch losses and unrealistic branch loadings– Check for negative losses on passive branch elements– Check for large branch flows on open-ended branch elements

• Statistical report and colouring modes to visualise measurement qualities

• Fully featured, large scale AC/DC system representation

The PowerFactory State Estimator is supporting a variety of communication options such asOPC (OLE for Process Control) or Shared Memory Interface for implementing data interchangewith any kind of SCADA system.


26 QUASI DYNAMIC SIMULATION

26 Quasi Dynamic Simulation

PowerFactory offers the execution of medium to long term simulations thanks to the new QuasiDynamic Simulation engine. If simulation periods ranging from hours up to years are underinvestigation, the Quasi Dynamic Simulation automates the entire simulation process. MultipleLoad Flow Calculations are carried out with user defined time step sizes between each simu-lation. The results from each calculation are stored and are available for post processing. Thetool is particularly suitable for planning studies in which long term load and generation profilesare defined in parallel with multiple contingency scenarios, variations and expansion stages. Interms of user handling, the tool is easy to use.

Additional Features

• All Load Flow Calculation variables are available for storing and plotting

• Statistical data for the variables

• Results such as the maximum, minimum, average, variance, etc. are provided

• Energy estimation for the studied time interval

• Tabular reports for the most relevant results as loading/voltage ranges and non conver-gency cases

• Export to HTML or Excel options


27 DYNAMIC MODELLING FLEXIBILITY (DSL)

27 Dynamic Modelling Flexibility (DSL)

DIgSILENT PowerFactory features unmet flexibility in implementing user-specific modeling needsfor stability analysis (RMS and EMT) purposes. The fundamental level of flexibility level is pro-vided by graphical object wiring diagrams called Composite Model Frames. They provide auser-friendly means to configure functional block relations (Slots) using object signal connec-tions.

• Any existing PowerFactory object can be plugged into a Composite Model Frame Slot.

• Frames can be lumped and nested to any degree of complexity.

• Hundreds of objects such as power system components (e.g. busbars, generators, lines,transformers, motors, voltage controllers, prime movers, power system stabilisers, motordriver machines, relays, relay components, CTs, VTs, measurement files, FFT devices,real time clock, RMS signal transducer, parameter identifiers, controllers, power plant con-trol components, A/D converter, RPC links), result files or display objects are at the user’sdisposal.

• In cases where additional functions are required which are not included in the built-inmodel- and macros-library, these can be created using the DSL language.

DIgSILENT Simulation Language (DSL) main features:

• Flexible definition of macros, functions and models, which is not limited to the use ofpredefined blocks of a block-oriented simulation language (BOSL).

• DSL is a Continuous System Simulation Language (CSSL) featuring a complete syntac-tical description of continuous linear and nonlinear as well as digital systems. DSL isdedicated to common control and logic diagrams; it is a non-procedural language as thesequence of elements can be chosen arbitrarily.

• DSL syntax elements are algebraic and differential equations as well as intrinsic functionssuch as signal limiting blocks, tables and curve approximation, delay, interrupt procedures,logical blocks, etc.

• Basic control elements such as PID, PTn or even complete physical subsystems such asHVDC valve groups or excitation systems can be defined as macros or high-level func-tions.

• Automatic calculation of initial conditions utilising various iterative procedures for initialis-ing complex, nonlinear equations of coupled systems.

• Provision of various formal procedures for error detection and testing purposes, e.g. al-gebraic loop detection, reporting of unused and undefined variables and missing initialconditions.

• DSL models are considered by the PowerFactory EMT/RMS simulation. Multi-level mod-elling is provided for the different steady-state descriptions and transient time domains(short/mid-term, long-term and electromagnetic).

• DSL models can be created by drawing a ”block diagram”. Any ”block” may contain an-other DSL model, a macro or any sequence of DSL syntax. The DSL-editor will thengenerate the DSL description automatically and will also provide direct model testing func-tions such as eigenvalue analysis or step-response tests of the complete DSL model or ofsub-models only.


27 DYNAMIC MODELLING FLEXIBILITY (DSL)

DSL Implementation

The DIgSILENT Simulation Language (DSL) is fully-integrated into the PowerFactory programkernel via the graphical interface.

• Signals: Specific input- and output signals defined for all PowerFactory objects as wellas any variable defined in a DSL model can be accessed in their corresponding read- orwrite- mode.

• Interrupts: Conditions derived by DSL models can cause interrupts to be sent to the sim-ulation kernel where they are scheduled within the event queue.

• Output and Monitoring: Conditions may trigger an output to be displayed in the outputwindow and stored in the simulation log file.

Advanced Features

• DSL models feature the direct interaction with external processes such as DAQ inter-faces, SIMULINK modules or other software systems via time-synchronised communica-tion channels

• Support of OPC Client and shared memory communication

• Procedures ritten in C++ code can be directly linked via appropriate interface mechanisms

• Encryption of DSL models to conceal confidential data

User-specific C++ Code

1. 1. User-defined intrinsic functions can be linked via external DLL for extending the alreadybroad range of DSL standard intrinsic functions such as: ”abs”, ”sin”, ”cos”, ”exp”, etc. andDSL special functions such as ”lapprox”, ”lim”, ”limstate”, ”delay”, ”picdro”, ”time”, ”file”,”flipflop”, etc. User defined intrinsic functions are to be linked to PoerFactory via the DLL”digexfun”.

2. 2. Complete user-defined models of any modelling level, linked via the DLL ”digexdyn” issupported for any discrete system. Typical applications are digital control systems whichare executed via clock-synchronised calls, simulation models being implemented via dif-ference equations, or models which incl. their state variables and integration algorithmsinternally.


28 POWER SYSTEM DYNAMICS

28 Power System Dynamics

28.1 General Capabilities

PowerFactory ’s high precision time-domain RMS- and EMT -simulation kernel, complementedby a comprehensive model library and a user-definable, graphical modelling function (DIgSI-LENT Simulation Language (DSL)), provides a flexible and powerful platform for solving both,system stability and electromagnetic simulation tasks.

Grid Modelling Capabilities

• Simulation of radial and meshed 1-, 2-, 3- and 4-phase AC and/or DC systems

• Modelling validity ranging from low-voltage (LV) up to ultra high-voltage (UHV)

• Distributed generation modelling and simulation capabilities

• High precision wind power models of various technologies

• Balanced and unbalanced grid loading conditions

• Simulation of railway systems

Advanced Simulation Models

• High precision models for both solid and salient pole synchronous machines, asynchronousmachine model including a doubly-fed induction machine model with integrated or exter-nally connected PWM converter.

• VSD (Variable Speed Drives) systems, PWM converter and other power electronic ele-ments such as the softstarter, inverter and rectifier. In general, all available power systemelements are also supported for stability simulations.

• General load models where load inertia, bus voltage and frequency dependence is rep-resented; a special lumped load model to accurately represent feeders containing a highpercentage of motor load (RMS only). The capability of modelling motor stall effects isincluded, and was developed on the basis of comprehensive system tests.

• Generic wind turbine models with doubly-fed induction generator, direct driven synchronousgenerator and asynchronous generator with static compensation (STATCOM).

• Manufacturer-specific high-precision wind turbine models are available upon request.

• Large library of IEEE controller models covering prime movers, automatic voltage regula-tors (AVR) and power system stabilisers (PSS).

• Support of the comprehensive DIgSILENT Protection Library in stability mode.

Based on a converged load flow, the calculation of initial conditions is carried out prior to thestart of a dynamic RMS- or EMT-simulation offering the following grid representation options:RMS simulation only

• Positive sequence only - the classical RMS representation for stability studies

RMS and EMT simulation



• a-b-c phase RMS representation supporting unbalanced grid loading initialised by a bal-anced or unbalanced load flow, featuring precise definition of any unbalanced grid faultcondition including single- and double-phase line interruptions. This system represen-tation mode avoids tedious hand-calculations of equivalent fault impedance and allowsaccess to any a-b-c phase quantity for plotting or precise modelling purposes (e.g. pro-tection devices).

RMS Simulation Algorithms

• Highly accurate, fixed or variable step-size integration technique for solving AC and DCnetwork load flow and dynamic model equations. This is combined with a non-linearelectromechanical model representation to enable a high degree of solution accuracy,algorithmic stability and time range validity.

• A-stable simulation algorithm for the efficient handling of stiff systems. This is applicable toall or any individually selected model featuring error-controlled automatic step-size adap-tation, ranging from milliseconds up to minutes or even hours, including precise handlingof interrupts and discontinuities.

EMT Simulation Algorithms

• The calculation of initial conditions is carried out prior to the EMT simulation, and is basedon a solved load flow (symmetrical or asymmetrical). Consequently, there is no need forsaving steady state conditions being reached after transients are damped out aiming insimulation re-starting under steady state conditions.

• Special numerical integration methods have been implemented in DIgSILENT PowerFac-tory in order to avoid numerical oscillations caused by switching devices and other non-linear characteristics.

• Highly accurate, fixed or variable step-size integration technique for solving AC and DCnetwork transients and dynamic model equations. This is combined with a non-linearelectromechanical model representation to enable a high degree of solution accuracy,algorithmic stability and time range validity.

Simulation Scan

• Allow to monitor network results and parameters during time-domain simulations.

• Possibility to define multiple modules to monitor the same or different quantities.

• If a defined limit is exceeded, an action to display an output message or a ”Stop Simula-tion” event can be triggered.

• Limits that can be monitored are as follows:

– Frequency maximum and minimum limits.

– Synchronous machine loss of synchronism.

– User-selected parameter maximum and minimum limits.

– Voltage maximum limit and maximum voltage violation time, and minimum limit andminimum voltage violation time.

– Voltage recovery and voltage recovery time.

Faults and Interrupt Handling



• The user can interrupt the simulation at any time, either manually, by a scheduled inter-rupt time or automatically via interrupt conditions. When the simulation is interrupted,most PowerFactory commands such as displaying or printing power flow results, checkingthe bus voltages, calculating eigenvalues or analysing the controller status, etc., can beexecuted.

• By activating predefined fault types, or by accessing and modifying PowerFactory vari-ables, any type of fault can be implemented. Typical faults are:

– Tripping of any power system element such lines, transformers, feeder loads or gen-erators;

– Application and clearing of faults at substations or along lines;

– Opening and closing of circuit breakers - e.g. simulating load shedding, shunt switch-ing,starting/tripping of synchronous and asynchronous machines, or when simulatingthe synchronisation of isolated areas via synchro-check relays;

– Opening and closing of circuit breakers - e.g. simulating load shedding, shunt switch-ing,starting/tripping of synchronous and asynchronous machines, or when simulatingthe synchronisation of isolated areas via synchro-check relays;

– Definition and introduction of inter-circuit events;

– Generation of message- and outage-events;

– Modification of integration step sizes;

– Event-driven modification of variables and signals either manually, via DSL modelsor by reference to external measurement files.

Simulation Output Processing

• Any PowerFactory variable, or any quantity identified in the transmission network, built-indynamic models or DSL models, may be selected for simulation observation or for laterplotting within x/t or x/y diagrams or any other VI (Virtual Instrument) provided. In addi-tion to these variables, the DSL algebraic expression interpreter and logical expressionevaluator can be applied to generate further signals or any user-defined quantity.

• Plotting files may be retained for re-plotting in comparison with subsequent runs.

• Output window log of all simulation events, providing a detailed analysis of manually en-tered or automatically initiated events.

• Simulation results are stored in a proprietary binary PowerFactory file format which can bedirectly converted into COMTRADE files.

Special PowerFactory Stability Simulation Features

• 1-click simulation utilising PowerFactory project and study case definition

• Real-time simulation mode with user-defined real-time synchronisation periods (RMS only)

• Parallel and sequential synchronisation for integrated simulation, e.g. for simulation cer-tain grid sections in RMS mode whilst others are simulated in EMT mode.

• Real-time inter-process signal communication via OPC link

• A/D and D/A interfacing capabilities (e.g. hardware-in-the-loop simulation)



28.2 Stability Analysis Functions

28.2.1 RMS Simulation with a-b-c Phase Representation

The a-b-c phase, steady-state component representation of the power system, features thefundamental frequency analysis of any asymmetrical grid operation condition.

• initialisation via balanced or unbalanced power flow

• Simulation of unbalanced loading conditions in 1-, 2- and 3-phase AC and DC systems

• Simulation of any number and combination of unbalanced faults including single- anddouble-phase line interruptions

• The a-b-c phase system representation mode avoids tedious hand-calculations of equiv-alent fault impedance

• The a-b-c phase system representation mode avoids tedious hand-calculations of equiv-alent fault impedance

28.2.2 Long-term Stability

In many cases stability calculations must be run for long periods thus taking into account effectsof slower control systems such as boiler control, network exchange control or transformer tap-changer control. Other applications are varying loads or applications of wind power where theimpact of wind speed fluctuations must be analysed. In such cases, short-term and mid-termdynamics have already reached steady-state but slower transients are still being observed.

• Long-term stability simulations based on adaptive step-size algorithms with accuracy-controlled step-size adaptation ranging from milliseconds to several minutes without anydecrease in precision or even manipulation of transient behaviour.

• A-stable simulation algorithm which fully covers fast transients as well as slow, semisteady-state dynamics with high-precision event handling (stiff systems).

Typical Applications

• Voltage stability analysis considering effects of load variations, tap-changer control andreactive power limits

• Long-term flicker analysis in cases such as fluctuating renewable generation or varyingloads

• Secondary control analysis and optimisation

28.3 Electromagnetic Transients (EMT)

DIgSILENT PowerFactory PowerFactory provides an EMT simulation kernel for solving powersystem transient problems such as lightning, switching and temporary over-voltages, ferro-resonance effects or sub-synchronous resonance problems. Together with a comprehensivemodel library and a graphical, user-definable modelling system (DIgSILENT Simulation Lan-guage (DSL)), it provides an extremely flexible and powerful platform for solving power systemelectromagnetic transient problems.



Any combination of meshed 1-, 2-, and 3-phase AC and/or DC systems can be represented andsolved simultaneously, from HV transmission systems, down to residential and industrial loadsat LV distribution levels. Standard built-in models include:

• Lumped and distributed parameter line/cable models; constant and frequency-dependent.

• 2- and 3-winding transformers and autotransformers for 1-, 2- or 3-phase systems, in-cluding stray capacitances, tap dependent impedance and saturation effects. Flexibledefinition of non-linear magnetising reactance: two-slope, polynomial, flux-current values

• Passive RLC branches, capacitor banks and filters of multiple layouts

• Surge arresters, including calculation of energy absorption

• Voltage and current, AC-, DC- sources

• Impulse sources (to be modelled via DSL)

• VT, CT and PT models, including saturation effects

• Series capacitor, including MOV and bypass switches

• Series capacitor, including MOV and bypass switches

• HVDC valve groups (6- and 12-pulse Graetz bridge configurations) and other FACTS de-vices such as SVCs, UPFCs, TCSCs and STATCOMs

• Synchronous and asynchronous machine, doubly-fed induction generator

• Circuit breaker models (to be modelled via DSL)

• Stochastic switching (procedures to be implemented via DPL scripts).

The package provides a powerful user-friendly graphical environment for the evaluation of sim-ulation results characterised by:

• User-customisable plots for waveform visualisation, including filtering options, scaling, etc.

• Calculation of Fast Fourier Transform (FFT)

• Export capability to COMTRADE-Files, spreadsheet-format, CSV-files, WMF-files, etc.

28.4 System Parameter Identification

Built-in system identification and general optimisation procedures provide an easy and accuratemethod to perform model parameter identification on the basis of system tests and field mea-surements. The PowerFactory Parameter Identification tool is suitable for parameter estimationof multi-input multi-output (MIMO) systems, which are described by any type of nonlinear DSLmodel. The identification procedure is fully integrated into the graphical frame definition andblock diagram, and also features parameter estimation for integrated models (such as loads orgenerators) which form part of a power system model.

The optimisation procedures provided are highly generic and can also be used for optimallytuning parameters such as PSS settings according to defined model response functions.



28.5 PowerFactory Real-Time Simulators

The PowerFactory stability simulation (RMS mode) can be optionally executed in real-time of-fering a number of additional applications.

The Real-Time Training Simulator is integrated into existing SCADA systems to:

• train operator personnel to precisely and efficiently respond to abnormal system condi-tions, thereby preventing further system deterioration;

• locate and investigate insecure operating conditions and calculate required security mar-gins;

• facilitate the operator in understanding phenomena such as basic system dynamics, sys-tem control and stability and protection, which are typically too fast for the operator toobserve

Hardware-in-the-Loop Testing is often required to develop, analyse and tune control systemsfor any kind of turbine, generator or superimposed control systems such as a ”Smart Grid Con-troller”. Applications include:

• Real-time simulation of typical grids, test systems or substations including generators,their control systems and associated protection.

• Communication with existing hardware such as controllers or relays via OPC, sharedmemory or A/D systems.

Simulation of grid disturbance scenarios, sensitivity analysis on grid operating conditions, tuningoptimisation of controllers, investigation of control structures, etc.


29 SMALL SIGNAL STABILITY

29 Small Signal Stability

The DIgSILENT PowerFactory modal analysis tool features small signal analysis of a dynamicmulti-machine system. System representation is identical to the time domain model. It covers allnetwork components such as generators, motors, loads, SVS, FACTS, or any other componentused in the system representation, including controllers and power plant models.

Analysis of eigenvalues and eigenvectors is appropriate for applications such as low-frequencyoscillatory stability studies, PSS tuning, determination of interconnection options and its basiccharacteritics, and is a natural complement to the time domain simulation environment. It alsoallows for the computation of modal sensitivities with respect to generator or power plant con-trollers, load characteristics, reactive compensation or any other dynamically-modelled equip-ment.

PowerFactory ’s Eigenvalue Analysis is very user-friendly, requiring minimal configuration of thecommand. Its calculation steps are as follows:

• Based on a converged and adjusted power flow, the modal analysis starts with the calcu-lation of the system initial conditions. Alternatively, any interrupted status of a time domainsimulation could be used as the initial condition.

• The system A-matrix is constructed automatically for the complete system (including gen-erators, general loads, predefined system plant and controller models as well as DSLdevices).

• System and model linearisation - including user-defined models - is performed by iterativeprocedures. Limiting devices are disabled automatically. The representation of the net-work model is equivalent to the simulation model, allowing a direct comparison/validationbetween time domain simulations and modal analysis results.

• Support of QR- and QZ-algorithm as well as the Arnoldi-Lanczos method.

– Calculation of all eigenvalues based on QR algorithm

– Selective eigenvalue calculation:

* computation of a certain part of the eigenvalue spectrum: calculation of a user-definable number of (closest) eigenvalues around a complex reference point

* based on the Arnoldi-Lanczos method

* recommended as a fast approach for higher order systems for which calculationof all eigenvalues by QR algorithm is too time-consuming

* additional models such a ElmAsm, ElmVscmono, ElmVsc, StaSua, TypLodind,ElmDcm, TypLne, ElmShnt, ElmValve are supported using the QZ method

• Calculation results include eigenvalues (together with oscillation information such as dampedfrequency, damping, damping ratio, damping time constant, etc) and left and right eigen-vectors. From eigenvectors, the individual machines’ controllability, observability, and par-ticipation factors are derived with respect to each mode.

• Powerful post-processing tools for result visualisation

– Tabular result representation of:

* Eigenvalues (including all oscillation information such as damped frequency,damping, damping ratio, damping time constant, etc)

* Eigenvectors (individual controllability, observability, participation of individualmachines for any selected mode)

– Eigenvalue Plot


29 SMALL SIGNAL STABILITY

* visualisation of calculated eigenvalues in the Gaussian plane

* Various filter and scaling options

* Automatic determination of stability border, highlighting of stable/unstable eigen-values

* Plot has interactive features that facilitate detailed analysis of individual modes;convenient creation of phasor plots/bar diagrams for each mode

– Mode Bar Plot

* Bar diagram visualisation of controllability, observability and participation factorsof individual machines for a given mode

* Various filter options (e.g. restriction to minimum participation, and/or individualgenerators)

– Mode Phasor Plot

* Phasor diagram visualisation of controllability, observability and participation fac-tors of individual machines for a given mode

* Various filter options

* Automatic detection and highlighting of clusters for convenient identification ofinter-area modes

• Possibility to obtain MATLAB compatible output results and system matrices


30 MOTOR STARTING

30 Motor Starting

PowerFactory s Transient Motor Starting functionality analyses motor starting scenarios wherethe effect of a motor starting on the grid frequency is negligible. In such situations, the typicalquestions to be answered are:

• What is the maximum voltage sag? (This is typically not the initial voltage sag at t=0)

• Will the motor be able to be started against the load torque?

• What is the time required to reach nominal speed?

• How will the supply grid be loaded and which starting options should be considered?

30.1 Static Motor Starting

The Static Motor Starting Simulation makes use of the load flow and static short-circuit cal-culation by executing a series of calculations to analyse the scenario.

• Executes a load flow calculation when the motors are disconnected from the system

• Then, it will execute a short-circuit calculation, using the complete method, simultaneouslywith the occurrence of the motors being connected to the network

• Finally, a load flow calculation will be executed after the motors have been connected tothe system.

30.2 Transient Motor Starting

The Transient Motor Starting function makes use of the PowerFactory stability module by pro-viding a pre-configured shortcut for easy-to-use motor starting analysis. The motor starting isinitiated by selecting the respective motors within the single line diagram and initiating the motorstarting calculation.

• A complete symmetrical or asymmetrical AC/DC load flow will be computed prior to themotor starting event; pre-selected and pre-configured VIs are automatically created andscaled with full flexibility for user-configuration.

• Consideration of high-precision, complex motor models with built-in parameter estimation.A comprehensive library of low voltage, medium voltage and high voltage motors is pro-vided.

• Typical motors supported are: single- and double cage asynchronous machines, squirreland slip-ring motors, double-fed induction machine, synchronous motors.

• Typical motors supported are: single- and double cage asynchronous machines, squirreland slip-ring motors, double-fed induction machine, synchronous motors.

• Support of various starting methods such as direct start, star-delta starting, variable rotorresistor, thyristor softstarter, transformer softstarter, variable speed drives, etc.; start fromany rotational speed.

• Full flexibility in considering starting sequences.


30 MOTOR STARTING

• Completion of motor voltages before, during, and after starting. As well as successfullymotor staring assessment.

Full representation of generators with exciter/AVR model support on the basis of built-in models(e.g. IEEE models) as well as user-defined models utilising the DSL approach; consideration ofprotection devices such as under-voltage protection, over-current protection, automatic restart-ing relays (EMR) or transformer OLTC.


31 POWERFACTORY INTERFACES

31 PowerFactory Interfaces

PowerFactory offers a number of mechanisms and options for interfacing with external appli-cations such as GIS and SCADA, or for a complete integration and background execution in”Engine Mode”. Depending on the application, the user may choose from the options describedbelow.

31.1 DGS Interface

DGS (DIgSILENT-GIS-SCADA) is PowerFactory ’s standard bi-directional interface specificallydesigned for bulk data exchange with other applications such as GIS and SCADA, and, forexample, for exporting calculation results to produce Crystal Reports, or to interchange datawith any other power system software. DGS does not support the exchange of PowerFactoryexecution commands.

• Available for PowerFactory Interactive Window Mode and PowerFactory Engine Mode

• User-specific definition of objects and object parameters

• Supported objects: elements, types and libraries, graphics and results

• Import and export of complete network models

• Import and export of incremental data for updating existing models

• Databases supported: Oracle, MS-SQL and ODBC System DSN

• File formats supported: ASCII Text (CSV), XML, MS-Excel and MS Access

31.2 OPC Interface

OPC (OLE for Process Control) is an asynchronous communication and data exchange mecha-nism used in process interaction and is widely applied in SCADA and control systems.PowerFactoryOPC-implementation assumes that the PowerFactory software is executed as an OPC-Clientwhile the OPC Server is controlled via the external source. OPC server libraries are availablefrom various manufacturers. An example of a freeware OPC-Server is that available from Ma-trikon (”MatrikonOPC Simulation Server”).

• Supported of the PowerFactory Engine Mode

• OPC-Client/Server exchange of any PowerFactory object parameter as well as any signal

• PowerFactory listening mode to receive any data or signal from a registered OPC Server

• PowerFactory sending mode to write back any data or signal to a registered OPC Server



31.3 API (Application Programming Interface)

The DIgSILENT PowerFactory Application Programming interface (API) offers third party appli-cations the possibility to embed PowerFactory s functionality into their own program. It offersdirect access to the PowerFactory data model and gives access to the varied calculations andits results.

Based on one single dll, the idea is to keep the interface as small as possible while providingall the necessary functions to manipulate objects and execute commands. Technically, theinterface is realised in C++ and provided as a DLL that can dynamically be linked to any externalapplication.



�

2.2 Physical Structure

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6�"��

��E� �� %��

digapi.dll

void Function1();

void Function2();

void Function3();

...

digcal.dl

l

digapl.dl

l

digadm.dl

l

dig*.dl

Figure 31.1: API Physical Structure


32 INTERFACING POWERFACTORY

32 Interfacing PowerFactory

Interfacing and integrating power system software with other applications such as GIS (Graph-ical Information Systems) and SCADA (Supervisory Control And Data Acquisition) systems isan important requirement. utilising the implemented DGS, OLE and Shared Memory interfacingtechniques, DIgSILENT PowerFactory features great flexibility in supporting any level of inter-facing and integration needs. The following sections summarise some typical examples.

32.1 PowerFactory - GIS integration

PowerFactory - GIS integration is preferably implemented via the DGS-interface. As object andparameter definitions at the GIS side usually reflect user-specific needs, standarised interfacingis only provided when a standard application module/standard process model provided by therespective GIS manufacturer is in use. As soon as user-specific object and parameter definitionsare applied, individual object mapping will be required.

Implementation Options

• Unidirectional GIS to PowerFactory data transfer via DGS format definitions (CSV or ODBC)

• Bidirectional data transfer (e.g. via the PowerFactory shared memory interface) when run-ning PowerFactory in ”Engine Mode” or ”Hybrid Mode”, which features full integration ofPowerFactory analysis functions and additional graphic display options in the GIS system

Characteristics

• Incremental data exchange utilising PowerFactory ’s user accounting, project manage-ment and merge tools featuring GIS -to -PowerFactory team working

• Combines and merges several data sources via PowerFactory ’s data handling capabili-ties, thereby avoiding any middleware requirement

Application Aspects



• Sharing of data sources, thereby avoiding duplication of data entry and maintenance

• utilising key capabilities of PowerFactory and GIS while sharing data

• Amalgamating data from various sources at the PowerFactory level

As most applications require the merging of additional data such as customer load consump-tion, dispersed generation infeeds and SCADA readings, PowerFactory - GIS integration is oftenhandled as a project implemented via clearly defined specification of data sources and overallworkflow.

32.2 PowerFactory - SCADA integration

Interfacing with SCADA gives direct access to dynamic and/or static SCADA data, allowingboth real-time system analysis and incident analysis from previous snapshots. As DIgSILENTPowerFactory already integrates topology processing, interfacing can be done on a point-to-point basis using foreign database keys. In addition to the option of exchanging data betweenSCADA applications and PowerFactory , a full SCADA integration of the PowerFactory engine issupported when using PowerFactory OPC link features. Typical applications are operators’ ac-cess to calculations such as load flow, contingency analysis, etc., including real-time simulationfor operator training.

• Support of PowerFactory Engine Mode and Hybrid Mode

• SCADA - PowerFactory communication via OPC, executing PowerFactory as a client

• Direct 1-to-1 relation between SCADA network objects due to full substation topologysupport of PowerFactory



• utilisation of SCADA manufacturer’s state estimation functions, or, if not present, Power-Factory ’s advanced state estimation features

• Operator’s access to all PowerFactory functions such as load flow, contingency analysis,optimal power flow, spinning reserve allocation

32.3 PowerFactory - Simulation Interface (SIMULINK, etc.)

Although PowerFactory offers great flexibility in controller modelling, some applications may re-quire special control toolboxes from the Matlab/SIMULINK software package. The PowerFactory- Matlab/SIMULINK interface is a flexible and fully synchronised link for distributed simulation oflinked models. The bi-directional communication link is easily implemented via the PowerFac-tory Frame and Slot technique with a built-in RPC interface block for Matlab/SIMULINK. A typicalapplication example might be the simulation of a large network with a number of conventionallycontrolled generation units together with a fuzzy-controller implemented at a specific plant.

32.4 PowerFactory - A/D Signal Interfacing Capability

PowerFactory ’s Frame and Slot technique utilising the real-time capabilities of built-in blocksfor data acquisition has become the basis for the PowerFactory Monitoring system (PFM). Theportable or cabinet-mounted Control and Monitoring Units (CMU) along with different types ofhigh precision Signal Units (SU), is featuring the configuration of highly-flexible plant measure-ment and grid performance analysis systems. Typical application aspects of the PowerFactoryMonitor are system tests for simulation model validation, supervision of grid connection condi-tions, load parameter identification, fault recording, power quality observation analysis or systemstability supervision.

Due to the superior flexibility in software setup, there is almost no limit in defining measurementand test applications including closed-loop operation with A/D-interfaced controllers, relays orother simulators.



32.5 PowerFactory Monitoring System (PFM)

The DIgSILENT PowerFactory Monitor provides an excellent overview on grid operation as-pects. As an integrated Multifunctional data acquisition system, covers recording, monitoringand analysis of signals in all relevant time frames. It is especially designed to cover all needs ofTransmission, Distribution and Generation on all voltage levels.

PFM fully integrates with DIgSILENT PowerFactory software featuring easy access of recordeddata, analysis of trends, verification of system upset responses and test results.

Applications

• Dynamic System network Performance monitor (DSM)

• Subsynchronous Oscillation Monitor (SOM)

• Power Quality Monitor (PQM)

• Power Plant Monitor (PPM)

• Multifunctional Disturbance and Event Recorder

• Grid Code Monitor (GCM)

• Phasor Measurement Unit (PMU)

Configuration Options

• Distributed Smart Signal Units (SSU)

• Centrally Connected Signals Units (SU)

• Portable PFM System


33 POWERFACTORY INSTALLATION OPTIONS

33 PowerFactory Installation Options

33.1 PowerFactory Workstation License

PowerFactory Workstation License is a standalone solution which is shipped with a freesingle-user database and is preferably installed locally, on the user’s hardware. This is theoption with the fastest performance as database access is directly managed via fast local harddisk I/O, thereby avoiding any LAN traffic.

Figure 33.1: Typical Single-User Workstation Installation with local single-user database

Although it is technically possible to store the PowerFactory database on any network drive, thisis not recommended as it requires high-speed LAN capabilities and might exhibit less reliabilityregarding database integrity when the LAN connection is unexpectedly interrupted.

Figure 33.2: Typical Single-User Workstation Installation with remote single-user database

Multiple Single-User Licenses

DIgSILENT PowerFactory software offers a number of licensing mechanisms. The Workstation



License is a Single-User License and is operated via a local USB port hardlock. The hardlockis programmed to include those functions licensed to the user. The locally attached hardlock isonly accessible by the locally installed Workstation License.

Figure 33.3: Typical multiple Single-User Workstation Installation

If you have purchased several Workstation Licenses, the USB hardlock installation is requiredon all computers where the Workstation License is to be used. Of course, if PowerFactory isinstalled on more computers than there are USB hardlocks available, only those installationscan be used simultaneously where the USB hardlock is plugged-in at that point in time.

33.2 PowerFactory Server License

PowerFactory Server License comes with additional features which are not available with thePowerFactory Workstation license:

1. Provision of a License Server which can be installed centrally managing any indepen-dent number of licensed functions. The License Server comes with only one single USBhardlock holding all licensed functions. The License Server must be accessible for allPowerFactory installations via a network IP-address.

2. Support of multi-user database operation, featuring the simultaneous access of all con-nected users to a single database. The Server License comes with database driversfor both databases; MS-SQL and ORACLE (the database servers themselves are notincluded).

3. Ability to work in Offline Mode when a network connection to the multiuser database serverand license server is unavailable.

4. The Server License can be executed in a Client-Server (Application Server) environmentsuch as MS Sever 2003/2005 or CITRIX, which has the advantage of centralised softwareinstallation and maintenance - a typical requirement of modern IT infrastructures.

Multi-User License via License Server

The Multi-User License Server gives more flexibility than the single USB hardlock (holding alllicenses). This solution provides a license server which is to be installed as an MS WindowsService on any computer in a network that is accessible from the users’ computers via an IPaddress. This computer could be one of the users’ computers but is recommended to be a sep-arate computer located in a secured room. Upon login, the PowerFactory software on the user’s



computer connects to the license server via a LAN to access the license. The license serveradministrator assigns certain PowerFactory functions to each user when the login procedure isexecuted. This facilitates the purchase of the optimal number of licenses depending on users’needs.

Figure 33.4: Typical Multi-User installation with License Server

An optional feature of the Multi-User License Server is the Floating License which allows thetemporary transfer of a user license from the license server to a local PC. This option is typicallyrequired when a user is traveling with his/her laptop, thereby preventing him/her from accessingthe license server. When downloading the floating license to a local machine, the license willdisappear from the license server and will move to the local PC until the user reconnects to thelicense server. The floating license is time-limited and, if not reconnected to the license server,will automatically ”fly back” to the license server after a defined time.



Figure 33.5: Typical Multi-User installation with License Server and Floating License Option

Note: A clear advantage of the License Server is its ability to host a different number oflicenses for certain functions. This allows a more economical solution which considers thesimultaneity of users. The allocation of functions is made upon user login and not upon theexecution of a certain PowerFactory command. This philosophy is based on the notion thatupon successful login and allocation of functions, those functions should be available to the

user throughout the entire PowerFactory session.

Multi-User Database

centralised data handling is supported by a multi-user database featuring the simultaneousaccess of all connected users to a single data source. Currently, database drivers for MS-SQLand ORACLE are available. This execution option is designed for PowerFactory installations witha large number of users requiring access to the same project data and, who would benefit fromthe PowerFactory team-working tools such as Master Project management, Project Versioning,Project Deriving along with Project Compare- and Merge tools, which make concurrent modelbuilding and data entry very easy.



Figure 33.6: Typical Multi-User installation with License Server and Multi-User Database

In the configuration shown above, the execution of the PowerFactory software will still take placeon the user’s local PC while the multi-user database resides on a special high-speed databaseserver.

For multi-user databases, project administration may be executed via a scheduled overnighthousekeeping task. In this way project purging, emptying of user recycle bins and deletion ofold projects can be automatised. This can let users activate projects more quickly and alsospeed up quitting PowerFactory . Moreover, housekeeping moves heavy data processing tooff-peak periods, offering better performance for normal daytime users.

Application Server

A further step often required in large companies with tens or hundreds of users is the cen-tralised installation and execution of the PowerFactory software, the database and the LicenseServer. This Application Server installation is currently supported for MS Server 2003/8 andother server add-ons such as CITRIX. The figure below shows a typical example of such acentralised installation environment.



Figure 33.7: Typical Application Server Installation with a multi-user database

Offline Mode

When a network connection to the database server is unavailable PowerFactory offers the optionto work in Offline Mode. This option requires project data to be cached to the users localmachine, which can then later be synchronised to the server database. Floating licenses aregenerated which allow to work without a permanent connection to a License Server. OfflineMode requires Multi-user database and Floating Licenses module.



Note: Offline Mode requires Multi-user database and Floating Licenses module.

This section describes the installation and configuration of the Offline Proxy Service , a software com-ponent of PowerFactory to be used with the Offline Mode database driver on Microsoft Server 2008R2. Figure 3.3.1 gives an overview over all components.

Figure 3.3.1: Offline Mode Components Overview

The installation procedure consists of the following steps:

1. First a PowerFactory environment in normal (i.e. not-offline) mode has to be set up. It contains atleast a PowerFactory installation, a License Server , and a multi-user database server (Oracleor SQL Server) (see section 3.3.1).

2. Installation of the Offline Proxy Serviceon an application server (see section 3.3.2).

Figure 33.8: Offline Mode Components Overview

33.3 License Overview

Figure 33.9: pf License and Installation Options

33.4 Installation Requirements

PowerFactory requires no special hardware or additional software to guarantee good perfor-mance. However, taking into account that solving power system analysis tasks is far beyondstandard office applications, the following hardware is recommended:

Workstation Licenses:

• 17-23” monitor with min. 1280x1024 pixel resolution

• Intel/AMD CPU with 2.0 GHz or higher

• 1 GB available hard disk space (*)

• 0.5 -3 GB main memory available for the PowerFactory process (**)

• (*) Required hard disk space will heavily depend on the number of projects handled, num-ber of objects (e.g. size of the network modelled), number of scenarios, etc. Total diskspace requirements are therefore determined individually.

• (**) The required main memory capacity will heavily depend on the network size and thetype of calculations being performed. A typical memory requirement would be between0.5-1.0 GB exclusively for executing PowerFactory unbalanced load flow, fault analysisand stability for a 5000-bus system.



• Supported operating systems are Windows 7 and Windows 8.

Application Server:

• Application Server hardware requirements are similar to those defined for workstation in-stallations, taking into account that main memory requirements will be duplicated accord-ing to the number of simultaneous users. In addition, the number of CPUs is correlatedwith the number of simultaneous users.

• Supported operating systems are MS Windows Server 2003/8 and CITRIX. Multi-Userdatabase support is available for MS SQL 2005/2008 and Oracle Server 10.x and 11.xwith Client 11.1.


34 POWERFACTORY FUNCTION DEFINITIONS AND PRICES

34 PowerFactory Function Definitions and Prices

34.1 PowerFactory Function Definitions

PowerFactory function definitions refer to the latest issue of PowerFactory V15.1 Product Infor-mation to specify the content of the PowerFactory software delivery.

Item PowerFactory Functions Product Information Section Refer-ence

1 PowerFactory Base Package Included: Section 3Section 31.1Not Included: Section 7.1PSS/E export, CIM Import/Export

2 Overcurrent-Time Protection (only) Included: Section 18.1-18.3

3 Protection Functions (Overcurrent-time &Distance) Included: Section 18

Not Included: Section 18.44 Arc-Flash Analysis Included: Section 195 Cable Sizing Included: Section 16.36 Distribution Network Functions Included: Section 207 Harmonic and Power Quality Analysis Included: Section 21

8 Optimal Power Flow I (Reactive Power op-timisation) Included: Section 22.1

Active Power Controls disabled

9 Optimal Power Flow II (OPF I + EconomicDispatch) Included: Section 22

10 Reliability Analysis Functions Included: Section 2411 State Estimation (SE) Included: Section 25

12 Stability Analysis Functions (RMS) Included: Section 27, DSL Crypt ex-cludedSection 28.1, EMT excludedSection 28.2-30.2,28.5 and 32.3

13 Electromagnetic Transients (EMT) Included: Section 27, DSL Crypt ex-cludedSection 28.1, RMS excludedSection 28.3

14 Motor Starting Functions Included: Section 27, DSL Crypt ex-cludedSection 30.2

15 Small Signal Stability (Eigenvalue Analy-sis)

Included: Section 27, DSL Crypt ex-cludedSection 29

16 System Parameter Identification Included: Section 27, DSL Crypt ex-cludedSection 28.4Stability Analysis Functions required

17 DSL Crypting Function Included: DSL Crypt Section 2718 PSS/E Export (*.raw, *.seq, *.dyn) Reference: Section 7.119 CIM Import and Export Reference: Section 7.120 OPC Interface (Ole for Process Control) Included: Section 31.221 Floating License Reference: Section 33.222 Connection Request Assessment Reference: Section 21.5


34 POWERFACTORY FUNCTION DEFINITIONS AND PRICES

34.2 PowerFactory Prices

The integrated PowerFactory v15.1 software is offered as Base Package with optional functionalextensions allowing the user to configure the PowerFactory installation according to his specificneeds. The Base Package itself is covering a comprehensive collection of core functions for in-tegrated analysis of transmission, distribution, and industrial systems, most modern generationtechnologies (wind power, photovoltaic, microturbines, etc.) and Smart Grids.

Base Package 100 nodes 250 nodes 500 nodes unlimited no.Edition max. max. max. of nodesWorkstation Edition e3.900,- e6.100,- e9.800,- e10.900,-Server Edition∗ e5.070,- e7.930,- e12.740,- e14.170,-∗ Includes Multi-User Database Driver. Server Edition with local Database is also available

Indicated prices do not include any tax and shipping.

PowerFactory is a perpetual license with initial maintenance period of one year. Prices of func-tional extensions can be requested from DIgSILENT and respective International Representa-tives.


35 THE DIGSILENT COMPANY

35 The DIgSILENT Company

DIgSILENT GmbH is a consulting and software company providing specialised services in thefield of electrical power systems for transmission, distribution, generation and industrial plants.DIgSILENT develops the leading integrated power system analysis software PowerFactory cov-ering the full range from standard to highly sophisticated and advanced applications includingreal-time simulation and performance monitoring systems for system testing and supervision.

DIgSILENT GmbH is staffed with experts of various disciplines relevant for performing researchactivities, consulting services, user training and educational programs and software develop-ments. Special expertise is available in many actual fields of electrical engineering for theliberalised power markets and latest developments in power generation technologies such aswind power and dispersed generation.

DIgSILENT GmbH founded in 1985 is a fully independent, privately owned company located inGomaringen, Germany where the new offices are in operation since early 2002. DIgSILENTcontinued expansion by establishing offices in Australia, South Africa, Italy, Spain, Chile andFrance allowing to better serve the world-wide increase in its software products and services.

DIgSILENT has established a strong partner network in many countries such as Mexico, Malaysia,UK, Switzerland, Colombia, Brazil, Peru, Argentina, Iran, Saudi Arabia, Oman, India, China,Norway, Russia, Finland and Venezuela. DIgSILENT has software installations and conductedservices in more than 120 countries.

DIgSILENT GmbHHeinrich-Hertz-Strasse 972810 Gomaringen / GermanyPhone: +49-7072-9168-0Fax: +49-7072-9168-88E-mail: [email protected]


36 HISTORY OF THE DIGSILENT SOFTWARE

36 History of the DIgSILENT Software

1986 First commercial product for UNIX operation systems (Version 1.0 - 6.0)

1989 First version for Personal Computer (Version 7.0, SAA standard)

1992 First version for Windows 3.1 and Windows NT (Version 9.0)

1993 Start of DIgSILENT re-design project using latest software technologies (C++, object-oriented data base, composite models, etc.)

1994 First fully integrated power system analysis software for Windows (Version 10.2) integrat-ing: load flow, fault analysis, RMS stability, eigenvalue analysis, protection coordination,harmonic analysis and optimal unit commitment

1995 Version 10.31 - for Windows 95 and Windows NT with high degree of compatibility to theWindows standard (last release of the original DIgSILENT software).

1997 Release of the universal model kernel for mixed, arbitrarily meshed 1-,2- and 3-phase ACsystems and DC systems.

1998 First release of the new generation software Version 11: DIgSILENT PowerFactory inte-grating load flow, fault analysis, RMS/EMT stability, eigenvalue analysis, harmonic analy-sis, protection coordination, reliability.

1999 Presentation of the DIgSILENT PowerFactory Monitor (PFM/DSM) featuring: system mon-itoring and fault recording, load measurement and identification, supervision of connectionconditions, etc.

2000 Completion of re-implementation of the version 10.31 features (load flow, fault analysis,RMS stability, electromagnetic transients, eigenvalue analysis, harmonic load flow, protec-tion coordination, network reduction, optimisation, reliability, cable ampacity, distributionfeatures, etc.)

2001 Release of PowerFactory Version 12.0


2003 Release of PowerFactory Version 13








36 HISTORY OF THE DIGSILENT SOFTWARE


DIgSILENT GmbH

Heinrich-Hertz-Straße 9

72810 Gomaringen

Germany

T +49 7072 9168-0

F +49 7072 9168-88

[email protected]

www.digsilent.de

DIgSILENT

Company Profile

DIgSILENT is a consulting and software company

providing engineering services in the field

of electrical power systems for transmission,

distribution, generation and industrial plants.

DIgSILENT was founded in 1985 and is a fully

independent, privately owned company located

in Gomaringen/Tübingen, Germany. DIgSILENT

continued expansion by establishing offices in

Australia, South Africa, Italy, Chile, Spain and

France, thereby facilitating improved service

following the world-wide increase in usage of

its software products and services. DIgSILENT

has established a strong partner network in

many countries such as Mexico, Malaysia, UK,

Switzerland, Colombia, Brazil, Peru, China

and India. DIgSILENT services and software

installations have been conducted in more than

120 countries.

DIgSILENT PowerFactory

DIgSILENT develops the leading integrated

power system analysis software PowerFactory,

which covers the full range of functionality from

standard features to highly sophisticated and

advanced applications including wind power,

distributed generation, real-time simulation

and performance monitoring for system testing

and supervision. For wind power applications,

PowerFactory has become the power industry’s

de-facto standard tool, due to PowerFactory

models and algorithms providing unrivalled

accuracy and performance.

DIgSILENT StationWare is a reliable central

protection settings database and management

system, based on latest .NET technology.

StationWare stores and records all settings in a

central database, allows modelling of relevant

workflow sequences, provides quick

access to relay manuals, interfaces with

manufacturer specific relay settings and

integrates with PowerFactory software, allowing

powerful and easy-to-use settings coordination

studies.

PowerFactory Monitor is a flexible performance

recording and monitoring system that

copes easily and efficiently with the special

requirements for system test implementation,

system performance supervision and the

determination and supervision of connection

characteristics. Numerous monitoring systems

installed at various grid locations can be

integrated to a Wide-Area-Measurement-System

(WAMS). PowerFactory Monitor can be fully

integrated with PowerFactory software.

DIgSILENT Consulting

DIgSILENT GmbH is staffed with experts of

various disciplines relevant for performing

consulting services, research activities, user

training, educational programs and software

development. Highly specialised expertise is

available in many fields of electrical engineering

applicable to liberalised power markets and to

the latest developments in power generation

technologies such as wind power and distributed

generation. DIgSILENT has provided expert

consulting services to several prominent wind-

grid integration studies.

Documents

PF Detailed Product Information En