Research and application of multiple STATCOMs to improve the stability of AC/DC power systems in China Southern Grid

This study presents the research and application of multiple static synchronous compensators (STATCOMs) in the China Southern Grid (CSG) to enhance the stability of its receiving-end power system. In this research, a practical methodology is developed for the optimal allocation of STATCOMs in a complex power system through both static and dynamic approaches. The allocation scheme for installing multiple STATCOMs in the CSG is determined using the proposed process. ±200 MVAr STATCOMs are developed based on cascaded H-bridge converters connected in the delta structure. A special system-level control strategy for fast voltage recovery applications is introduced in this study, and field test results and application effects are presented. Results of the real-time digital simulation are introduced to verify the application effects in the case where multiple STATCOMs are connected to the grid. Field test results and analysis of the recorded data for the system faults during actual operation also verify the application effects of multiple STATCOMs in the CSG.