Research on Closing Resistance of 750 kV Circuit Breaker Based on ATP-EMTP

In 750 kV transmission line, all kinds of circuit breaker closing operations, such as three-phase null line of circuit breaker and single-phase reclosing when single-phase ground fault occurs, will produce a high overvoltage on the transmission line. The value of this overvoltage often exceeds the required value of system insulation coordination, causing certain damage to the transmission line. In order to solve the above problems, this paper takes Shanghai Miao Converter Station - Shahu 750 kV transmission line as an example, based on the ATP-EMTP electromagnetic transient simulation software to establish a 750 kV circuit breaker three-phase closing and single-phase reclosing operation overvoltage calculation model. The influence of closing resistance of metal oxide arrester and circuit breaker on 2% statistic overvoltage of three-phase closing and single-phase reclosing is calculated and analyzed. Finally, the arrester configuration limiting the operating overvoltage and the closing resistance value of the circuit breaker are determined.