Insulation coordination for phase selection closing of AC filter in converter station

Abstract

A converter station of ±1100kV is equipped with four types of filters. It includes BP11/BP13, HP24/36, SC and HP3.The main function is to filter the harmonics in the high voltage AC busbar and provide reactive power compensation for the entire converter station. The circuit breaker of the converter station adopts the closing resistor to suppress closing inrush current and overvoltage during the closing operation of the group filter. At present, the closing resistor of AC filter circuit breaker in converter station is abnormal frequently, and the design has defects. It is planned to carry out the phase selection closing of the AC filter circuit breaker of the whole station. However, the evaluation and demonstration of the relevant content of the AC filter insulation coordination after the phase selection closing transformation has not been carried out. This paper intends to simulate and verify the phase selection closing on overvoltage of the converter station.Then this paper analyzes the influence of the phase selection closing and switching angles on the action characteristics of the AC filter arrester, and propose an appropriate switching angles range to ensure that the arrester will not operate.