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.