Effect of Opening Speed on Voltage Distribution of Double-break Vacuum Circuit Breaker

The advantages of the short vacuum gap, such as fast insulation recovery and low carbon emissions, can be fully developed by multi breaks in series. However, there is a problem of uneven voltage distribution on the breaks. Too high grading capacitance on both ends of the interrupter will increase the post-arc current and limit the breaking capacity of the double-break vacuum switch. The purpose of this paper is to find a self grading method to reduce the use of grading capacitors. The influence of different breaking speeds on the voltage distribution during the arcing phase is studied in the condition that two sets of contacts in the same vacuum environment. A double-break detachable vacuum interrupter is designed. The voltage distribution is simulated with Maxwell at a static state. A synthetic loop experimental platform for double-break vacuum circuit breaker with one chamber was built. The voltage distributions in different breaking processes are tested, including double-break opening at the same or different speeds. The experimental results show that different speed breaking can improve the voltage distribution uniformity of the double-break vacuum circuit breaker, which provides a reference for improving the breaking capacity of the double-break vacuum circuit breaker. © 2021, Power System Technology Press. All right reserved.