TESTING METHOD FOR DC CIRCUIT BREAKER

Provided is a testing method for DC circuit breaker to verify a current breaking performance thereof using a testing device applied for a synthetic testing method for AC circuit breakers. A testing method is for a DC circuit breaker 1 to verify the current breaking performance using a testing device including a current source circuit A and a voltage source circuit B, and includes supplying an AC current from at least the current source circuit A to the DC circuit breaker 1, breaking the current by the DC circuit breaker 1 at a time the current becomes equivalent to the fault current due to the system accident in the DC system, applying a voltage to the DC circuit breaker 1, before the current breaking, by connecting the voltage source circuit B to the DC circuit breaker 1, and applying the recovery voltage from the voltage source circuit B simultaneously with the current breaking.