Finalized Project Plan

8/2/2019 Finalized Project Plan

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Finalized Project Plan

Influence of the modelling depth of the generator/converter system on

the calculated loads of a wind turbine drive train

Cand.Deeban Chakravarthi Mathivanan

Supervisor :Stefan Hauptmann

Febrauary,2012

1 Program Description ........................................................................ .........2

1.1 Background . .................................................................................22 Goals and objectives

2.1Main objectives .................................................................................33 Planned procedure and expected results

3.1Solution Strategy3.1.1 Introductory work .....................................................................33.2.1 Modelling of a asynchronous generator using SIMULINK......43.3.1 Simulation and analysis of generator and Grid Interactions.....43.4.1 Comparison of the models using MATLAB-SIMPACK .........5

3.2Literature and contacts....................................................................................64 Draft of the table of contents .................................................................................7

5 Formalities ................................................................................9


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1.Problem Description :

In the recent years ,Wind energy has emerged

as one of the most efficient alternative source

of electricity.Various types of wind turbines

such as fixed speed and variable speed

windturbines have been developed. Somemulti MW wind turbines are running with

variable speed, so that their efficiency can be

optimised and the dynamic loads, noise and

interactions with the electrical grid cane be

reduced.The steadystate static and dynamic

behaviour(windfield,aerodynamics,structural

dynamics and control) and the resulting loads

of the wind turbines are currently being

computed by softwares spec ifically developed

for that purpose (e.g.,Flex5 or

Bladed).However,these programs have

intereaction with other parts of the wind

turbines e.g., bedplate,the supporting

structure of the rotor .In this project a

combination of different simulation packages

namely MATLAB and SIMPACK are used to

model the mechanical and electrical aspects

of the wind turbine in detail.

3.1BACKGROUND

Wind Energy has established itself as a major source of non-polluting, inexhaustible renewable

energy source. In the wind energy research ,dynamic modelling of the whole system has been

already done extensively .This project mainly focuses on the improvement of the modelling of wind

turbines ,the standard multibody software SIMPACK is being used .

The advantages of SIMPACK, as far as the investigations of the drive train dynamics are concerned

are numerous for the investigation of the drive train dynamics.As a part of this work,

MATLAB/SIMULINK will be used to build generator models in a multiple levels of detail and


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implement them under an existing SIMPACK wind turbine model with different load conditions.

This tool will then be used to identify the interactions of the electrical system with the wind turbine

and especially the drive train.

Goals and Objectives

3.2Main Objectives

Programming of a flex5-alike basic asynchronous generator in SIMULINK andcomparing it with an existing SIMPACK User routine.

Development of SIMULINK model with different level of complexity of a doubly fedasynchronous generator with power converter.

Implementation of SIMPACK multibody model of the wind turbine. Using the MATLAB-SIMPACK interface and evaluate the influence of different loads.

3 Planned procedure and expected results

3.1 Solution Strategy

3.1.1 Introductory work

This phase at the beginning of the work will focus primarily on the study of previous literature and

familiarizing with the Simulation softwares like MATLAB and SIMPACK. Referring to

Developing pre and post-processors for SIMPACK using Suzlon S82 Data done by Malte holdeis also of great use to the planned project. Nevertheless, additional literature research ,especially in

the generators and about various interactions with other parts of the turbine will be carried out.The

first familiarization is done using the User manual and in collaboration with theresearchers at the

SWE.The primary work has already been done and the effective main work will be started

officially from February 7 ,2012.


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3.1.2 Modelling of Asynchronous Generator using SIMULINK

The next ideal step would be to develop a basic induction generator.The input data provided is of

Suzlon S82 turbine. The basic model is compared with the already existing SIMPACK user routine

developed already. Parameters such as loads (at different wind conditions),generating torque are

compared.This helps to get an overview of the detailed project.

The next step in the process is the development of doubly fed induction generator with different

levels of complexity and detail. Various research has been done on the simulation and control of

wind turbines .However most of it uses only simple mechanical structural and aerodynamic models

which neglects the important characterestics of the turbine. Wind turbines use a doubly-fed

induction generator (DFIG) and an IGBT-based PWM converter. The rotor winding is fed at

variable frequency to AC/DC/AC converter.

The DFIG technology allows utilizing the turns ratio of the machine, now the converter can

function at a speed less than the rated speed.The rotor s ide converter (RSC) usually provides active

and reactive power control of the machine is provided by the rotor side converter (RSC) while the

grid-side converter (GSC) keeps the voltage of the DC-link constant.

3.1.1 Comparision of the models using MATLAB-SIMPACK Interface

Wind turbines are subject to various mechanical loads. The tower effect, shear effect, gyroscopic

effect and the impact of sudden wind speed variations put high fatigue loads on the turbine and the

drive train. The turbine needs to be well designed for these loads. Most research on turbine design

focuses on the estimation of the loads on the turbine side of the drive train.

But also at the generator side of the drive train, possible sources for fluctuating torques are present.These are due to the fact that the generator electromagnetic torque is, function of the generator type,

more or less dependent on the grid voltage and frequency. Deteriorated power quality, for instance

voltage fluctuations or voltage dips, may lead to fluctuating electromagnetic torques, causing high

loads on the drive train.The doubly fed generator is simulated using MATLAB and the the

interaction with Turbine with various loads are done in SIMPACK .


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Simulation and analysis of generator and Grid Intereactions

The grid model includes the electric components in the wind farm power collection system and thesubstation, and uses equivalents for the remaining grid.The individual wind turbine model includes

electrical, mechanical and aerodynamic sub-models such as the electrical sub-model which includes

an induction generator ,a capacitor bank for reactive power compensation ,a soft starter and a step

up transformer .The dynamics of the drive train are elaborated by the mechanical sub-model. The

aerodynamic sub model is a standard Cp based model with stall effects. The interactions between

these models are taken into account. The changes in the various interactions with various load are

observed and compared with MATLAB-SIMULINK.


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LITERATURE AND CONTACTS

DYNAMICMODELLING OF WIND FARMGRID INTERACTION

Anca D. Hansen , Poul Srensen , Frede Blaabjerg and John Becho

(DIGSILENT GMBH)

Dynamic Modeling and Control of Doubly Fed Induction Generators Driven by WindTurbines

-Wei Qia

Dynamic modelingof doubly fed induction generator wind turbines

Ekanayake, J.B.; Holdsworth, L.; XueGuang Wu; Jenkins, N.

Induction generator in Dynamic Simulation Tools

Hans Knudsen and Vladislav Akhmatov

Grid Integration ofWind Energy Conversion Systems

Siegfried Heier

ISBN:-0-471-97143-X

WIND TURBINE TECHNOLOGYDAVID.A.SPERA

ISBN: 0-7918-1205-7


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TABLE OF CONTENTS

ABSTRACT

ACKNOWLEDEMENTS

CHAPTER 1

1.1 WIND TURBINE TECHNOLOGY1.2 MOTIVATION AND OBJECTIVE OF THE PROJECT1.3 THESIS OUTLINE

CHAPTER 2

2. SIMULATION OF BASIC ASYNCHRONOUS GENERATOR

2.1 ASYNCHRONOUS GENERATOR DEFINTION2.2 MODELING OF BASIC ASYNCHRONOUS GENERATOR2.3 COMPARISION OF EXISTING SIMPACK USER-ROUTINE

CHAPTER 3

2 INDUCTION MACHINE MODELS AND CONTROL3.1GENERAL EQUATIONS OF ABC/abc REFERENCE FRAME

3.1.1 Complex space Vector representation3.1.2 Using space vector for the general machine equations

3.2 THE PRINCIPLE OF DFIG CONTROL3.3 THE DFIG ROTOR CONVERTER CONTROL3.4 THE DFIG GRID CONVERTER CONTROL3.5 SIMULATIONS OF THE ROTOR AND GRID CONTROLLER

5.1.1 SIMULATION OF POWER STEP DIFFERENT LOADS5.1.2 SIMULATION OF SPEED STEP5.1.3 DISCUSSION AND SIMULATION OF RESULTS


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CHAPTER 4

4. WIND TURBINE MODELLING

4.1AERODYNAMIC MODELLING4.2PITCH MODEL4.3MECHANICAL MODEL

CHAPTER 5

5. POWER SYSTEM MODELLING IN MATLAB AND SIMPACK

5.1DYNAMIC NODE TECHNIQUE5.2POWER SYSTEM ELEMENTS

5.2.1 General modelling5.2.2 Transmission line modelling5.2.3 Model implementation in Matlab/Simulink

5.3Modelling in SIMPACK5.3.1 Modelling of different loads using Simpack5.3.2 MATLAB and SIMPACK Interface5.3.3 Influence of the machine coupling5.3.4 Comparision of models using existing user-routines5.3.5 Discussion of the simulated results

CHAPTER 6

6. CONCLUSION

6.1 SUMMARY OF THE WORK6.2 RESULTS OBTAINED IN THE THESIS6.3FUTURE WORK

CHAPTER 7

7. APPENDIX

7.1REFERENCES7.2

GLOSSARY OF SYMBOLS


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Formalities

The thesis is carried out under Stiftungslehrstuhl Windenergie am Institut fur Flugzeugbau

(SWE).The supervisor at the Otto Von Guericke University(OVGU) will be

Dr.Zbigniew Styczynski and the tutor at the Endowed Chair of Wind Energy (SWE) at the

University of Stuttgart will be Mr.Stefan Hauptmann .

The scheduled timeframe for the thesis is 7.02.2012 until 07.08.2012. A complete written

report and conference/journal paper of the thesis will be provided at the end of the timeframe

and the work will be presented orally at the University of Magdeburg and the SWE.

Confidentiality and contract issues will be dealt with at the begin of the work directly at SWE.

The oral presentation and the written report will be evaluated and marked by a committee of

the supervisors at OVGU and the SWE.

_____________________________

DEEBAN MATHIVANAN


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Finalized Project Plan