A Z-source inverter accepting rapid reverse current flow

This paper proposes a bi-directional Z-source inverter which has the reduced voltage stress on the circuit elements when the reverse current flow occurs. A Z-source inverter has a unique impedance network between the inverter bridge and the voltage source, which can boost the input voltage. A bidirectional Z-source inverter for electric vehicles has the state which the inductor currents direction chages rapidly at the instant time when the power flow is switched to the reverse power flow. This phenomenon may cause a rapid voltage increase on the circuit elements. The proposed circuit prevents the rapid change of the inductor current with only one passive device. The operation of the proposed inverter has been confirmed with PSIM simulation and in the circuit experiments.