Small signal modeling and controller design of a bidirectional Quasi-Z-Source inverter for electric vehicle applications

This paper presents the small signal modeling and controller design of a bidirectional Quasi-Z-Source inverter (BQ-ZSI) for electric vehicle (EV) applications. The derived small signal model shows that the Quasi-Z-Source network (QZSN) is prone to oscillate when there is a disturbance from the dc input voltage. Since the battery pack voltage in an EV is easy to fluctuate because of the battery´s internal impedance and rapid change of the load current, a dedicated voltage controller with feed forward compensation is designed to reject the disturbance and stabilize the dc-link voltage during non-shoot-through state. Simulation and experimental results are both presented to prove the effectiveness of the proposed controller.