The Figure Shows the Current and Voltage Waveforms. When the DCCB (Direct Current Circuit Breaker) is in Normal Operation (Circuit Breaker S1 and Residual Current Circuit Breaker S2 are Closed, S3 is Open), the Opening Sequence Begins. The Circuit Breaker is Triggered by a Protective Relay. Here, the Relay Time is Assumed to be 2ms. After Receiving the Trip Signal, Switch S1 Starts to Operate. When It Reaches a Sufficient Distance to Withstand the Transient Voltage Applied During the Interruptio