Abstract I
Acknowledgements II
Table of contents III
List of figures VI
List of tables VIII
List of symbols XI
Chapter 1 Introduction 1
1.1. Motivation 1
1.2. Literature survey 2
1.3. Contribution of the thesis 3
1.4. Layout of the thesis 4
Chapter 2 Mathematical modeling of the studied system 5
2.1. Configuration of the studied system 5
2.2. Modeling of SG and its subsystems 6
2.2.1. Synchronous generator model 6
2.2.2. Excitation system model 11
2.2.3. Steam-turbine and speed-governor models 12
2.3. Modeling of DFIG-based wind turbine system 14
2.3.1. Configuration of DFIG-based wind turbine system 14
2.3.2. Wind speed model 15
2.3.3. Wind turbine model 17
2.3.4. Drive train model 17
2.3.5. Doubly-fed induction generator model 18
2.3.6. DC-link model 21
2.3.7. Model of controllers 21
2.4. SSSC model 26
2.4.1. Configuration of a SSSC 26
2.4.2. SSSC power flow controller 29
2.5. Network equations 30
Chapter 3 Design of an oscillation damping controller for SSSC 33
3.1. Configuration of the SSSC oscillation damping controller 33
3.2. Design of the ODC for SSSC using pole assignment method 34
3.3. Analysis of closed-loop system eigenvalue sensitivities 40
Chapter 4 Steady-state analysis of the studied system under various operating conditions 42
4.1. Different operating active power conditions of SG 42
4.2. Various terminal voltages of SG 57
4.3. Distinct operating power factors of SG 68
4.4. Different wind-speed conditions 82
4.5. Various operating voltage conditions of DFIG 96
4.6. Distinct compensating levels of SSSC 106
Chapter 5 Time-domain simulations 113
5.1. Disturbance on input mechanical torque of SG 114
5.2. Disturbance on grid voltage 121
5.3. Wind-speed variations 127
5.4. Wind farm certainly tripped 133
5.5. Step changes on local load 136
5.6. Three-phase short-circuit fault at utility grid 143
Chapter 6 Conclusion and future work 149
6.1. Conclusion 149
6.2. Future work 149
References 151
Appendix 157
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