Performance Enhancement Method for Power Electronic Switch in Hybrid DC Circuit Breaker Based on Partial Precooling

Insufficient current capability is the most serious problem faced by power electronic devices in hybrid dc circuit breaker (HCB), where the junction temperature rise is the main restriction. This letter proposes a novel performance enhancement method for power electronic switch in HCB based on partial precooling. By applying thermoelectric cooling technology, the temperature of power electronic devices and their surrounding region can be reduced in advance in the steady state of the HCB, allowing the devices to achieve superior current performance. Then, a 4.5 kV power electronic switch module prototype with a low-cost integrated precooling unit was developed, which can provide a temperature drop of 15 °C for the power electronic device within, resulting in approximately 10% improvement in current performance.