Improved quasi-Z-source dual-inverter for open-end winding induction motor drives

An improved quasi-z-source dual-inverter for open-end winding induction motor drives is presented in the paper. The improved quasi-z-source dual-inverter can not only realize boost/buck function, but also suppress DC-link bus overshoot voltage, which is suitable for medium/high-power level. The topology allows shoot-through state, so that the dead-time effect cannot be existed. The dual-inverter belongs to the three-level drive system. The utilization rate of DC-link bus voltage is accordingly improved. The proposed topology has high reliability, strong fault tolerance and single-stage boost/buck voltage function, bidirectional energy flow, except simple structure and low cost of open-end winding induction motor. Due to strong fault tolerance and boost function in the proposed topology, the dynamic performance of the drive system can be significantly improved. The operating mode and the modulation method are analyzed in this paper. The simulation and experimental results can verify the feasibility of the improved topology for the motor drives.