Rush-current breaking properties of IGBT-type DC model circuit breaker with different time constants of gate-emitter voltage

The model DC circuit breaker composed of an insulated gate bipolar transistor has been constructed. Consideration was given to the current-limiting process, i.e., to establish a method for limiting the direct current to zero. This method was achieved by decreasing gate-emitter voltage with a passage of time at a certain time-constant τ_GE. The breaking experiment of the rush-current interruption of 80 to 200 A was made to find out the current interrupting properties for τ_GE of 10, 5 and 1 ms. The model circuit breaker designed with 5 ms proved to achieve the current interruption even for 200 A and not to cause very high excessive overvoltage during the current interruption process. As far as the present experiment conditions are concerned, τ_GE of 5 ms is considered to be sufficient value.