Study of ultra-high-speed power switching-off of SSCB for coal mine low-voltage system

This paper analyses the reality of traditional three phase AC contactless switch, and points out the inherence break time is over 10ms. It puts forward using IGBT as the main component of solid state circuit breaker for the transformer neutral point's contactless switch. This enables that the operating time of ultra-high-speed short circuit protection is less than 1ms. In addition, this paper has proposed a transient mathematical model for a turning-off process of transformer neutral point SSCB. The total switching-off time has been obtained by theoretical analysis and validated by tests.