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.