Carrier-Based Modulation Strategies With Reduced Common-Mode Voltage for Five-Phase Voltage Source Inverters

Two modulation strategies based on carrier-based modulation (CBM) scheme (named RCMV-CBM1 and RCMV-CBM2) are proposed to reduce the common-mode voltage (CMV) of a five-phase voltage source inverter. The basic characteristic of them is that two kinds of carriers with opposite phase are adopted. By applying the opposite carrier to some specific phases, the switching states with higher CMV absolute value can be avoided. In RCMV-CBM1, the output phase with the third largest modulated signal uses the opposite carrier, and the peak-to-peak value of CMV is reduced by 40%. In RCMV-CBM2, the output phases with the second largest and fourth largest modulated signals use the opposite carrier, and the peak-to-peak value of CMV is decreased by 80%. However, the ripple analysis reveals that RCMV-CBM1 has an advantage over RCMV-CBM2 in current quality. In addition, the optimized RCMV-CBM1 and RCMV-CBM2 are presented for reducing the output current ripple. Finally, a scaled-down prototype is built to verify the correctness and effectiveness of the proposed modulation strategies.