Analysis and Control of Current Ripples of Z-Source Inverters

Load current ripple is an important issue in the design and control of inverters since it influences the torque ripple and noise amplitude of a motor drive. The current ripple of Z-source inverter (ZSI) is analyzed in this paper. The expression of current ripple is derived and the current ripples of ZSI and voltage-source inverter (VSI) are compared. A variable DC-link voltage and switching frequency method was adopted to reduce conduction and switching losses without increasing the predicted peak current ripple. These theoretical findings were further verified by simulations and experiments.