Design and reliability analysis of a novel hybrid current-limiting circuit breaker

The hybrid current-limiting circuit breaker with both the static characteristics of a mechanical switch and dynamic characteristics of solid-state switch represents a new concept in international circuit breaker research. A novel hybrid current-limiting circuit breaker using the high power fast switching thyristor is proposed. A 2 kA/320 V hybrid current-limiting circuit breaker is developed for the low voltage situation. An analysis of the circuit breaker's operational reliability shows that the design of the key parameters is correct. With the parameters optimized, it is shown by the experimental results that the ultra fast mechanical repulsion switch is capable of opening the contact within 280 μs upon receiving the opening signal. The fault current is commutated onto the solid-state high power thyristor composed switch circuit, which can break the fault current of 10 kA in as short as 53 μs.