Introduction and First Lecture

ECE 633 MODELING AND SIMULATION OF POWER SYSTEM COMPONENTS

August 23, 2005

Oleg Wasynczuk

Contact Information

Oleg Wasynczuk1285 Electrical Engineering

Purdue University

West Lafayette, IN 47907-1285 Office/Lab: 765 494-3475 Lab EE58 wasynczu@ecn.purdue.edu

Include ECE633 in subject line http://shay.ecn.purdue.edu/~wasynczu

Computer Requirements

Ready access to computer with Simulink Version 6 (R14)* – preferred Simulink Version 5 (R13) - acceptable

Ability to email compressed folders containing reports and Simulink models (.doc, .pdf, and .mdl files)

* We will not use any of the many optional toolboxes

Questionnaire – email before Session 2

Name, major, degree objective, expected date of graduation

Degree of familiarity with (a) Matlab, (b) Simulink 1 - no clue, 2- ketbd, 3-basics, 4-adept, 5-expert

Other simulation languages you use and degree of familiarity

Thesis topic (if known), current research and/or job related projects, description of technical interests,…

Course expectations

Grading

70% Approximately 10 Simulink-based projects Late work will be penalized at 20% per day unless

prior arrangements are made 15% Midterm 15% Final

Cheating Policy

You may discuss projects, including results, with fellow students; however, Sharing of models is not permitted

No two people should have the same models Report must be your own thoughts and

words First occurrence results in stern warning Second occurrence results in non-passing

grade for course

Office/Lab Hours (EE58)

Tuesday/Thursday 1:30-3:30 pm (tentative)

Pre- or Co-requisites by Subject

Pre-requisite Junior or senior course in electric machinery

and/or power systems such as ECE 321, 425, or 432

Co-requisite Graduate course in energy conversion such

as ECE 610 Please let me know if you have

questions/concerns

Course Outline

Will follow spirit of published course outline (see web site)

Major topics to be covered include: Distributed- and lumped-parameter models

of transmission lines Single- and three-phase transformers

Magnetic saturation Induction machines (and drives) Synchronous machines (and drives)

Required Text

Chee-Mun Ong, Dynamic Simulation of Electric Machinery Using Matlab Simulink, Prentice Hall, 1998, ISBN 0-13-723785-5.

First Reading Assignment

Read Chapters 1 and 2 before Session 2

Modeling Philosophy for Dynamic Simulation of Power System Components

Modeling Versus Simulation

Modeling Expression of relevant physical principles in

mathematical form (PDE’s, ODE’s, AE’s, circuit/block diagrams) along with pertinent initial/boundary conditions

Simulation Application of suitable numerical algorithms to

generate numerical solution to set of models Always an approximation (round-off, truncation

errors)

Synchronous Machine Models

Distributed Parameter Coupled Circuit Steady State

)( uxfx

,dtd

IZEeV j ~~

jEe

jXRZ

I~

V~

Power Electronic ModelsAverage ValueDetailed

)( uxfx

,dtd

)()(

)()( );(

iiiif

if

iiiiii

sgst

ttsdtd

,,

,

1

110

x

Txxxfx

Simulation Approaches

Finite-Element-Based Approaches (Ansys, Maxwell, …)

Circuit-Based Approaches (Spice, EMTP, Saber, PSIM, Simplorer)

System-Based Approaches (Simulink, ACSL, Dymola) Block-diagram and/or differential equation oriented Extensive set of tool boxes including

ASMG (Simulink, ACSL) Power System Blockset (Simulink) …

Finite-Element Based Approaches

4000-10000 Nodes

uSaa

M dtd

FEA

Simulation Approaches

Finite-Element-Based Approaches (Ansys, Maxwell, …)

Circuit-Based Approaches (Spice, EMTP, Saber, PSIM, Simplorer)

System-Based Approaches (Simulink, ACSL, Dymola) Block-diagram and/or differential equation oriented Extensive set of tool boxes including

ASMG (Simulink, ACSL) Power System Blockset (Simulink) …

Circuit-Based Approaches

Circuit-Based Approaches

Example Subsystem (Motor Controller)

Circuit-Based Approaches

Circuit-Based Approaches

Resistor-Companion Circuit

15

2

1

654

321321

9

8

7

k

SS

S

S

v

v

v

ggg

gggggggg

i

i

i

i

i

Update Formula

O(n3) computational complexity where n = number of non-datum nodes

Circuit-Based Approaches

Simulation Approaches

Finite-Element-Based Approaches (Ansys, Maxwell, …)

Circuit-Based Approaches (Spice, Saber, PSIM, Simplorer)

System-Based Approaches (Simulink, ACSL, Dymola) Block-diagram and/or differential equation oriented Extensive set of tool boxes including

ASMG (Simlink, ACSL) Power System Blockset (Simulink) PLEX (Simulink) …

System-Based Approaches

Hierarchical system definition

System-Based Approaches

Common Simulink Component Models

System-Based Approaches

System-Based Approaches

1

1

1

0

1p

i

ikiki

p

i

iki

k th ,xfxx

When user starts model, Simulink applies selected integration algorithm to approximate solution at discrete but not necessarily uniform instants of time

General Multi-step Update Formula:

Implicit algorithms require solution of nonlinear equation (dimension = number of states) at each time step. Newton-Raphson iteration generally used.

Explicit if 01

System-Based Approaches

Choice of coefficients determines name of algorithm

Many different algorithms out there See Appendix A for brief introduction

System-Based Approaches

Stiff System: A system with both fast and slow dynamics

Stiffly Stable Integration Algorithm: the ability to increase the time step after fast transients subside

Stiffly Stable Algorithms are implicit!

System-Based Approaches

Computational Complexity

System-Based Approaches

Simulink Fixed-Step Algorithms

Shampine and Reichelt, The MATLAB ODE Suite, SIAM J. Sci. Comput.,Vol. 18, No. 1, pp. 1-22, January 1997.

System-Based Approaches

Simulink Variable-Step Algorithms

Shampine and Reichelt, The MATLAB ODE Suite, SIAM J. Sci. Comput.,Vol. 18, No. 1, pp. 1-22, January 1997.

System-Based Approaches

Simulation Approaches (Conclusion)

Co-simulation Finite Element/Circuit Circuit/System

Distributed Heterogeneous Simulation Any combination of the above mentioned

approaches