Space Vector Pulse Width Modulation with Reduced Common Mode Voltage and Current Losses for Six-Phase Induction Motor Drive with Three-Level Inverter

Common-mode voltage (CMV) generated by the inverter causes motor bearing failures in multiphase drives. On the other hand, presence of undesired z-component currents in six-phase induction machine (SPIM) leads to extra current losses and have to be considered in pulse width modulation (PWM) techniques. In this paper, it is shown that the presence of z-component currents and CMV in six phase drive system are two major limiting factors in space vector selection. The calculated voltage space vectors for both symmetrical and asymmetrical SPIM drive system with three-level inverter are illustrated in the decoupled subspaces and described in terms of undesirable voltage components and CMV value. Several space vector pulse width modulation (SVPWM) techniques are investigated based on CMV and z-component currents generation. Then, a modified SVPWM technique with minimum current distortion, undesired current components and CMV with a modest torque ripple is proposed based on the simulation results.