Research on Electromagnetic Transient Simulation of 500kV Unified Power Flow Controller

As the most versatile flexible AC transmission system to date, the unified power flow controller(UPFC) not only controls the AC line power flow, but also provides reactive power compensation to the system. At present, UPFC has been developed to 500 kV voltage level, and the converters’ structure is modular multilevel converter(MMC). The special structure of UPFC’s series side transformer makes the control strategy and fault characteristics of UPFC different from the existing MMC-HVDC project, and electromagnetic transient simulation research is urgently needed. Based on the published data of 500 kV UPFC project in Suzhou Southern Power Grid, this paper conducts electromagnetic transient simulation research on 500 kV MMCUPFC in PSCAD, which can provide support for the control strategy, protection scheme and the overvoltage and insulation cooperation of UPFC.