Property of 126kV vacuum circuit breaker based on three 40.5kV fiber-controlled vacuum interrupter modules in series

Interest in the application of vacuum circuit breaker (VCB) with multiple breaks arises from technical and economic considerations. Based on analysis on previous work, a 126kV VCB with triple breaks based on fiber-controlled vacuum interrupter modules (FCVIMs) in series is presented in this contribution. A FCVIM is composed of its own outer insulation, vacuum interrupter, permanent magnetic actuator with its controller and power supply. In order to make a VCB with multiple breaks that can be used for higher voltages, the fiber-controlled vacuum interrupter module can be placed in series just like the building blocks. The fiber-controlled technology is used to control the modules at the low voltage area while permanent magnetic actuator operates at the high voltage area. The VCB with double or triple breaks based on FCVIMs in series were set up for research to obtain the dielectric and breaking capacity property. Dielectric experiments were carried out on a single break FCVIM and the VCB with triple breaks based on FCVIMs in series under lightning impulse voltage. It shows that the 126kV VCB with three breaks in series has a higher breakdown voltage improvement factor. As a result, the breaking capacity was verified and the VCB with triple-breaker are eligible to be applied in the power system.