Soft-switched quasi-Z-source inverter topology for variable speed electric drives

A novel bidirectional soft switched quasi-Z-source inverter is presented in this paper. By using a resonant capacitor and coupled inductors, the proposed quasi-Z-source inverter topology provides a solution to hard-switching problems for hybrid electric applications. The presented topology allows soft switching operations which aims at reducing the inverter's active devices switching stresses as well as mastering the slew rate dv/dt that have a negative effect over the motor windings. The effectiveness of the proposed topology has been analytically studied and simulated in Matlab/Simulink and the results have been validated by experiment for both motoring and generating modes.