Fault case analysis and simulation research of neutral‐bus arresters multi‐column parallel connected in converter station

High-voltage DC arrester is one of the key equipment for overvoltage protection of ultra-high voltage DC (UHVDC) transmission system. This device plays a decisive role in the insulation level of the whole process. The current distribution between resistance pieces of multi-column parallel arresters is non-uniform, which affects the overall energy absorption capacity of arresters. First, a real failure case of ±500 kV Xiluodu-Nuozhadu HVDC project is introduced. Then, the analysis of the specific failure case is proposed. Finally, a corresponding model is built on PSCAD/EMTDC to study the current distribution characteristics.