Analysis on an UHV Converter Station AC Filter Circuit Breaker Phase Selection Closing Operation Risk

The incoming line circuit breaker of AC filter group in converter station mainly relies on closing resistance or phase selection closing to suppress closing inrush current. The phase selection closing angle is closely related to the overvoltage and closing inrush current of AC filter equipment. This paper mainly analyzes the influence of closing angle deviation after transforming closing resistance circuit breaker into phase selection closing form due to closing resistance fault in a converter station. The influence of different closing angles on the action times of filter arrester, the electrical transient stress and the insulation bearing capacity of filter equipment is analyzed. It is concluded that the long-term deviation of closing angle of AC filter group circuit breaker is too large. It may cause the external insulation flashover problem of the intermediate connection of HP3 AC filter L1 reactor. This conclusion is of great significance to the engineering design and daily operation and maintenance of converter station.