Checking and Preventing Measures of Short-Circuit Current Breaking Level of 220kV Circuit Breaker

In order to solve the serious problems caused by the system short-circuit current exceeding the standard and the circuit breaker cannot reliably break the short-circuit current, this paper proposes a method to check the short-circuit current breaking capacity of the circuit breaker in 220kV and above substations. The first step is to compare the short-circuit current in actual working conditions with the effective value of the AC component of the circuit breaker’s rated short-circuit current. The second step is to calculate the DC component time constant under actual working conditions and compare the amplitude of the most half-wave current with the duration of the most half-wave. Multiply the product and type test T100a test value to check the circuit breaker’s ability to break short-circuit current. Finally, the corresponding preventive measures for circuit breakers and the means to limit short-circuit current are proposed, which provide a reference for the safe operation of the power grid.