Study on a New Single Coil-Type Axial Magnetic Field Contact for High-Voltage Vacuum Interrupters

A new single coil-type axial magnetic field (AMF) contact for high-voltage vacuum interrupters is introduced. Its AMF characteristics were studied by a finite element method, taking the eddy current effect into account. Vacuum arc appearance of the new single coil-type AMF contact was observed by a high-speed charge-coupled device video camera. Capacitors and reactors (LC) discharging current interruption tests up to 45.0 kA were done with a single frequency LC oscillating circuit. Vacuum arc appearance of the single coil-type and slot-type AMF contacts was compared. The research results show that the new single coil-type AMF contact is more suitable for high-voltage vacuum interrupters than the slot-type AMF one

I. Introduction

At present, circuit breakers have predominance in the high-voltage (greater than or equal to 72.5 kV) circuit breakers field. Because of the greenhouse effect of , it is important to develop “green” high-voltage circuit breakers. Vacuum circuit breakers have a minimum environmental impact. With the accumulated knowledge of both manufacturing technology and the study of vacuum arcs, the development of high-voltage vacuum circuit breakers has aroused considerable interest [1]–[13].