Investigations of transient processes at vacuum circuit breaker switching and development of technical requirements for 6–35 kV vacuum circuit breakers

The paper explains the necessity of the development of additional technical requirements for medium voltage vacuum circuit breakers (VCB). Based on experimental investigations, possibility of significant difference in electrical and mechanical characteristics for VCB of various manufacturers is stated. It is shown that associated parameters of electrical and mechanical transient processes at VCB switchings influence on insulation of switched equipment. As an example, results of full-scale tests of vacuum and oil circuit breakers in the operational network of Novosibirsk CHP plant No.4 are presented. Importance of determination of optimal VCB parameters is confirmed.