Fundamental study of an intelligent power routing switch based on SiC DC-DC converter for next generation DC distribution network

A power routing switch using SiC-MOSFET has been developed for the future DC distribution network. The routing switch behaves as an intelligent relay, a circuit breaker and an inrush avoiding circuit. The circuit configuration of the routing switch is based on the non-isolated hard-switching DC-DC converter, and the surge voltage across the SiC-MOSFET is minimized by managing circuit parasitic parameters to prevent malfunction of peripheral equipment. The high frequency digital control has been applied, and the fault current has been interrupted within several microseconds after the accident. A 5 kW and DC 380 V prototype has been fabricated and the performance as the circuit breaker and the inrush avoiding circuit has been evaluated experimentally. The fault current of 37 A has been interrupted within 5 μs after the detection of the fault current of 22 A, suppressing the overshoot voltage of the SiC-MOSFET lower than 500 V. The inrush current has been also avoided by the PWM soft-start operation for the capacitive load without any external protection equipment. The developed switch works as the multifunction circuit protection device and realizes the flexible intelligent power routing by taking the control strategy for the next generation DC network into account.