Title Page
ABSTRACT
국문 초록
PREFACE
Contents
CHAPTER 1. INTRODUCTION 20
1.1. Motivations 20
1.2. Literature reviews 24
1.3. Scopes & purpose of the proposed method 26
1.4. Contributions of the Dissertation 29
1.5. Dissertation Outline 31
CHAPTER 2. Characteristics of frequency response resources and closed loop frequency prediction model 33
2.1. Classification according to response characteristics of frequency response resources. 33
2.2. Inertial energy of synchronous generator 35
2.3. CLOSED FORM FREQUENCY RESPONSE PREDICTION MODEL 40
2.4. Establishing the closed form frequency response prediction model 47
CHAPTER 3. Characteristics of JEJU power system and its frequency response resources 49
3.1. Jeju power system and two HVDCs interconnected 49
3.2. Effect of frequency resources to nadir frequency in the HVDC connected Jeju system 54
3.3. Effect of ESS on Jeju's nadir frequency and control interference 55
3.4. Effect of flywheel-connected synchronous condensers to Jeju's nadir frequency and its limitation. 60
CHAPTER 4. Verification of proposed method with Jeju Power system 63
4.1. Closed loop frequency response prediction model for Jeju power system. 63
4.2. Verifying the closed form FRP model through time domain simulation 66
4.3. Analysis of synchronous condenser's inertia constant to nadir frequency 70
4.4. Analysis of synchronous condenser's capacity to nadir frequency 73
4.5. Considerations for inertial constant and capacity of synchronous condenser to secure frequency stability 75
CHAPTER 5. CONCLUSION & Future work 79
5.1. Conclusion 79
5.2. Future work 81
REFERENCES 83
Table 1. Increase of curtailments due to the Jeju system's increased renewable energy sources 50
Table 2. Details of 4 RMRs in Jeju power system 51
Table 3. Details of Jeju HVDC #1, #2 52
Table 4. Inertia resources of Jeju Power system 55
Table 5. Main parameters of Jeju power system's ESS 57
Figure 1. The scope and purpose of the proposed method; complement to time domain simulation 28
Figure 2. Time scale of each frequency response resources 33
Figure 3. Classification according to response characteristics of frequency response resource 34
Figure 4. Power balance of synchronous machine 37
Figure 5. The change in the output of each resource and the process of frequency recovery after the failure 38
Figure 6. Diagram of frequency control in power systems wherein the HVDCs are more dominant than the governor response 40
Figure 7. Procedure for developing the frequency response model 47
Figure 8. Configuration of the Jeju system's power generation resource and HVDCs 50
Figure 9. Block diagram of frequency control logic of HVDC #2 53
Figure 10. Block diagram of frequency control logic of HVDC #1 53
Figure 11. Frequency and each resource's power change after most severe contingency in Jeju power system 54
Figure 12. Fast Frequency Response Resources of Jeju Power system 55
Figure 13. Resource's response after Namjeju TP #2,#3 Trip : (a) System frequency (b) Power deviation of synchronous generators (c)... 56
Figure 14. Simulation results with updated ESS parameters 59
Figure 15. Simulation results with original ESS parameters 59
Figure 16. Nadir frequency in major contingency failures according to the inertial constant of the flywheel-connected synchronous condenser 61
Figure 17. Changes in-out and frequency according to the inertial constant of the flywheel connected synchronous condenser 62
Figure 18. Response of HVDC #1 for step function of 0.01 pu 63
Figure 19. Transfer function of HVDC by input functions 64
Figure 20. The result of HVDCs' curve fitting by the various RoCoFs 65
Figure 21. Validation of proposed method through PSSE simulation. 66
Figure 22. Comparison of nadir frequency and nadir frequency time of the proposed method according to the applied RoCoF for curve fitting 68
Figure 23. Analysis of synchronous condenser's inertia constant to nadir frequency by the proposed method and simulated result 71
Figure 24. Analysis of synchronous condenser's inertia constant to nadir frequency by the proposed method and simulated result[내용없음] 18
Figure 25. Analysis of synchronous condenser's capacity to nadir frequency by the proposed method and simulated result 73
Figure 26. Analysis of synchronous condenser's capacity to nadir frequency by the proposed method and simulated result[내용없음] 19
Figure 27. Contour line graph of frequency nadir of Jeju power system according to capacity and inertia constant of synchronous condenser 76
Figure 28. Contribution of the system inertia of Jeju power system and HVDCs on the nadir frequency 77
Figure 29. Contribution of the system inertia of Jeju power system and HVDCs on the nadir frequency[내용없음] 19
Figure 30. Diagram for turbine governor frequency control system 81