Test Analysis of Commutating Process for Hybrid Current-limiting Circuit Breakers with High Rising Rate Current

A novel hybrid current-limiting circuit breaker based on high speed electro-magnetic driven switch and bi-directional thyristor switch is presented.A 3 kA/320 V current-limiting circuit breaker is developed and the commutating process is analyzed with high rising rate current.The equivalent circuit model and calculating formulas are obtained.The experimental results by different di/dt values show that the equivalent circuit model is correct.By reducing inductance of commutating circuit and delayed time of electro-magnetic driven switch,the current of 13.6 kA is transferred within 100 μs successfully.