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

•Zero-zone voltage measuring device design is the key problem of quench protection system for superconducting magnets.•This paper analyzes in detail the variation characteristics of transient voltage during the breaking process and designs zero-zone voltage measuring device.•The designed bi-directional zero-zone voltage measurement device meets the requirements of measuring the zero-zone voltage generated during the breaking of VCB, and has the advantages of rapid response, high reliability and accurate measurement.•The zero-zone voltage measurement device developed in this paper can provide strong support for improving the breaking reliability of VCB and improve the reliability of the quench protection system of fusion devices.