Title Page
Abstract
Contents
List of Acronyms 16
CHAPTER Ⅰ. Introduction 18
1.1. Literature Review and Related Works 21
1.2. Dissertation Objectives and Contributions 21
1.3. Dissertation Outline 22
CHAPTER Ⅱ. Theoretical Background 23
2.1. Wind Power System 23
2.1.1. Wind Power Integration and Intermittency 23
2.1.2. Wind Turbine Generator (WTG) Model 23
2.1.3. Wind Turbines Model Classification 24
2.1.4. DFIG Model Structure 27
2.2. Wind Power Penetration 28
2.3. Wind Power Fluctuation 30
2.4. Conventional Power System 30
2.4.1. Frequency Regulation 31
2.4.2. Active Power Control 31
2.4.3. Frequency Stability 34
2.5. Conventional Generation System 34
2.6. Power System Contingency 34
2.7. Energy Storage Systems 35
CHAPTER Ⅲ. System Modeling 37
3.1. Test System Attributes 37
3.1.1. Wind Power Modeling 37
3.1.2. Wind Turbine Controls 41
3.1.3. Pitch Control System Model 41
3.1.4. Electrical Model 45
3.1.5. Aerodynamic System Model 45
3.2. Energy Storage System Modeling 47
3.2.1. Voltage Source Inverter (VSI) Model 47
3.2.2. ESS Power Conversion System 48
3.2.3. Active and Reactive Power (P/Q) Control Scheme 49
3.3. Generator Model 51
3.3.1. Synchronous Generator 52
3.3.2. The Governing System 54
3.3.3. Droop Control Concept 56
3.3.4. Inertia Control Concept 59
3.3.5. Excitation System 60
3.3.6. Power System Stabilizer 62
3.4. Proposed ESS-Droop Control for Frequency Regulation 64
3.4.1. ESS State of Charge 66
3.4.2. ESS Control Algorithm 67
3.4.3. Pitch Limit with ESS Control Scheme 70
3.5. Test System Configuration 70
CHAPTER Ⅳ. Case Studies and Simulation Results 74
4.1. Case Studies Scenarios 74
4.2. Scenario 1: The power system without wind power integration 74
4.2.1. Case Study Event I: Generator Trip 76
4.2.2. Simulation Results and Discussion 76
4.2.3. Case Study Event II: Load Change 81
4.2.4. Simulation Results and Discussion 81
4.3. Scenario 2: The power system with wind power integration 86
4.3.1. Case Study Event I: Generator Trip 87
4.3.2. Simulation Results and Discussion 87
4.3.3. Case Study Event II: Load Change 96
4.3.4. Simulation Results and Discussion 96
CHAPTER Ⅴ. Conclusion and Future Work 102
5.1. Conclusion 102
5.2. Future Work 103
References 104
개요 111
Table 3.1. Power Coefficients (Cₚ) αij[이미지참조] 39
Table 3.2. PI-optimized parameters 44
Table 3.3. Wind Turbine Parameters 46
Table 3.4. DFIG-WTG Parameters 46
Table 3.5. PI Controllers' Gain 50
Table 3.6. Synchronous Generator (SG) Parameters 53
Table 3.7. Generating Unit Model Type 54
Table 3.8. Steam Turbine Model Parameters 56
Table 3.9. Exciter Model ST4B Parameters 61
Table 3.10. PSS Model PSS2B Parameters. 63
Table 3.11. Parameters of the ESS. 72
Table 3.12. System conditions for general simulation. 72
Table 3.13. Parameters for the transformers. 73
Table 4.1. System condition for Scenario 1 simulation. 75
Table 4.2. The grid frequency responses with generator trip event 77
Table 4.3. Pgrid output response[이미지참조] 78
Table 4.4. Pgen output response[이미지참조] 79
Table 4.5. Pₑₛₛ output response 80
Table 4.6. SoC limitation response 81
Table 4.7. The grid frequency responses with load change event 82
Table 4.8. Pgrid output response with load change[이미지참조] 83
Table 4.9. Pgen output response with load change[이미지참조] 84
Table 4.10. Pₑₛₛ output response with load change 85
Table 4.11. SoC limitation response with load change 86
Table 4.12. System condition for Scenario 2 87
Table 4.13. Grid frequency results with generator trip event 89
Table 4.14. Grid active power results with generator trip event 90
Table 4.15. Generator active power results with generator trip event 92
Table 4.16. Grid frequency response with load change event 97
Table 4.17. Grid active power response with load change event 98
Table 4.18. Gen active power response with load change event 99
Figure 2.1. Wind turbine types configuration. 27
Figure 2.2. Type 3 (DFIG-WT) model structure. 28
Figure 2.3. Power system; (a) typical frequency response, and (b) frequency control classification 33
Figure 3.1. Wind power Cp curves. 39
Figure 3.2. Wind turbine operating regions. 42
Figure 3.3. Pitch angle control system. 44
Figure 3.4. Structure of the energy storage system (ESS). 48
Figure 3.5. ESS - PCS operation mode. 49
Figure 3.6. Control block diagram of inverter controller P/Q. 50
Figure 3.7. Active and reactive power (P/Q) control structure with ESS. 51
Figure 3.8. Control element of the generating unit. 53
Figure 3.9. A small signal model of SG governor with droop. 55
Figure 3.10. The IEEEG1 steam turbine transfer function block diagram. 55
Figure 3.11. Frequency-power (f-p) droop characteristics. 58
Figure 3.12. Droop control loop structure. 58
Figure 3.13. Governor speed-droop control block diagram. 59
Figure 3.14. IEEE ST4B excitation system transfer function. 61
Figure 3.15. Block diagram of IEEE power system stabilizer (PSS2B) transfer function. 62
Figure 3.16. FR with/without the ESS and governor; (a) conventional and (b) proposed method; (c) Detailed proposed adaptive control of ESS operation with SG for FR and SoC. 67
Figure 3.17. Flow chart of the control algorithm of the proposed method for FR. 69
Figure 3.18. Flow chat of the pitch limit condition for FR-ESS control. 70
Figure 3.19. Test power system network with ESS and WT. 71
Figure 4.1. Test power system without wind power integration. 75
Figure 4.2. Comparison of grid frequency responses for the control methods. 77
Figure 4.3. Comparison of the system's active power for the control methods. 78
Figure 4.4. Comparison of the generator's active power for the control methods. 79
Figure 4.5. Comparison of ESS active power with CS2 and CS3 methods. 80
Figure 4.6. Comparison of ESS SoC limits with CS2 and CS3 methods. 81
Figure 4.7. Grid frequency responses with load change for the control methods. 82
Figure 4.8. Comparison of grid's active power with control modes for load change. 83
Figure 4.9. Comparison of generator's active power with control modes for load change. 84
Figure 4.10. Comparison of ESS active power with CS2 and CS3 during load change. 85
Figure 4.11. Comparison of SoC limits of ESS for CS2 and CS3 during load change. 86
Figure 4.12. Grid frequency response comparison with generator trip for wind speed; (a) low 3 m/s (b) rated 11 m/s (c) high 20 m/s 88
Figure 4.13. Grid active power response comparison with generator trip for wind speed; (a) low 3 m/s (b) rated 11 m/s (c) high 20 m/s. 90
Figure 4.14. Generator active power response comparison with generator trip for wind speed; (a) low 3 m/s (b) rated 11 m/s (c) high 20 m/s. 91
Figure 4.15. ESS active output power comparison with CS2 and CS3 for wind speed; (a) low 3 m/s (b) rated 11 m/s (c) high 20 m/s. 93
Figure 4.16. 50% initial SoC comparison with CS2 and CS3 for wind speed; (a) low 3 m/s (b) rated 11 m/s (c) high 20 m/s. 94
Figure 4.17. Comparison of pitch angle with control modes for wind speed (a) low 3 m/s (b) rated 11m/s (c) high 20 m/s. 95
Figure 4.18. Comparison of WTG active power with control modes for wind speed (a) low 3 m/s (b) rated 11 m/s (c) high 20 m/s. 96
Figure 4.19. Grid frequency deviation with load change at rated wind speed. 97
Figure 4.20. Grid active power with load change at rated wind speed. 98
Figure 4.21. Comparison of generator active power with control modes at rated wind speed. 99
Figure 4.22. Comparison of ESS active power response with control modes at rated wind speed 100
Figure 4.23. Comparison of WT active power with control modes at rated wind speed 101
Figure 4.24. Comparison of the pitch angle of DFIG WTG with load change event at rated wind speed 101