7th International Conference on Electric Power Equipment– Switching Technology (ICEPE 2024)

130 / 2024-04-14 15:37:16

DC Short-Circuit Current Transfer of Parallel Vacuum Switches with Different Intervals

vacuum switch,time intervals,DC circuit breaker

With the advancement of renewable energy source such as photovoltaic plant and wind farm, the capacity of DC grid is increasing rapidly. Larger grid capacity results in higher requirements of current load and interruption capacity in DC circuit breaker (DCCB). However, the capacity of single vacuum switch is limited to load several kiloampere system current. Parallel vacuum switches are needed to achieve higher load capacity. In this paper, to analyze the current transfer in parallel vacuum switches, a DC short-circuit experimental model is established with DCCB consisting of two parallel vacuum switches. The short-circuit current transfer between parallel vacuum switches and interruption characteristics of DCCB with different fault current and opening time intervals are investigated. From the experimental results, with the same opening time interval, higher short-circuit current results in longer current transfer time. With larger opening time interval, higher voltage in pre-charged capacitor is needed to interrupt the same fault current. In DC system with high load current, parallel vacuum switches can be used in DCCB with short opening time interval.