Fault Characteristics and Protection Actions of Modular Multilevel Converter in 500kV Sunan UPFC

摘要

Unified Power Flow Controller (UPFC) project in Suzhou 500kV southern power grid is the highest voltage class and largest capacity UPFC project in the world, and it is used to solve the problems of uneven power flow distribution, over-limited sectional flow, poor dynamic reactive support ability, et al. In this paper, the fault characteristics of sub-modular, including open circuit, control pulse loss and falsely closed, and the converter protection of Modular Multilevel Converter (MMC) in 500kV Sunan UPFC project are discussed in detail. Fault simulation platform based on Matlab/Simulink is applied to analyze the corresponding relationship between several kinds of sub-modular faults and converter protection, which will be useful for operation and maintenance workers to locate fault area quickly.