A Novel PWM Strategy for Current Ripple and Output Harmonic Minimization of Current-Fed Trans-Quasi-Z-Source Inverters

The recently proposed current-fed trans-quasi-Z-source inverter (CF-trans-qZSI) can buck or boost voltage and provide a bidirectional power flow. Thus, it has received much attention. To minimize the current ripples and output harmonics, this paper presents a novel space vector pulse width modulation (SVPWM) strategy for the CF-trans-qZSI. The switching sequence in this SVPWM strategy for the boost mode is realized by partitioning equally the short zero state time into four parts; while, for the buck mode, it is implemented by dividing the short zero state time and open zero state time into more parts, where the time interval of each part is not equal. In both modes, the divided short zero state time, open zero state time, and two-active-state time are symmetrical in one switching cycle. Simulation and experiments are performed to validate the performance of the proposed strategy. The results show that the proposed SVPWM algorithm can improve the performance of the CF-trans-qZSI in terms of reducing the DC inductor current ripples and output current harmonics in both modes.