On-line reduction of switching losses and common-mode voltages of multi-level PWM inverter by a new space vector modulation

A new space-vector modulation method is proposed to reduce common-mode voltages and switching losses simultaneously in multi-level inverters. The basic principle involves elimination of the common-mode voltage by limiting the combinations of the output phase voltage levels, and optimum selection of switching vector (SV) pattern based on a new two-phase modulation. The selected SV pattern minimizes an estimation function based on switching losses considering phase currents among possible reduction patterns for one switching cycle. A five-level inverter example is investigated and validated for the results of the proposed method.