Measurement of zero-zone voltage for vacuum circuit breaker with oscillation zero-crossing circuit

Abstract

Vacuum Circuit Breaker (VCB) with oscillation zero-crossing circuit is wildly used to interrupt high direct current, especially in the magnet quench protection system. The injection time of reverse current is the critical factor that affect the breaking result. During the current breaking period, the voltage of VCB varies in a wide range, while the arc voltage in zero-zone is very small and changes rapidly. Therefore, the conventional methods cannot meet the voltage measurement requirements. In this paper, a bi-directional zero-zone voltage measurement scheme for VCB was proposed. According to the variation characteristics of transient voltage during the breaking process, the design and simulation verification of the measurement device were completed. Then the high voltage impulse experiment and arcing measurement testing were carried out by the developed prototype of the arc voltage measurement device. The experimental results indicated that the device has fast response and high measurement accuracy, which meets the measurement requirements of VCB zero-zone voltage.