Common mode voltage elimination PWMs for a dual two-level VSI with single inverter switching

This paper discusses two new pulse width modulation (PWM) switching methods for eliminating common mode voltage (CMV) in the dual two-level voltage source inverter (VSI). Both the PWM methods also ensures that the switching power loss is limited to one inverter only at all instants of time. Analytical expressions for switching times of the phase switching devices of the two inverters are developed to force the CMVs in a dual two level VSI configuration to zero which enables the dual-inverter drive to be driven from a single DC power supply. The implementation of the proposed PWM algorithm depends only on the instantaneous magnitudes of the reference space vector on the stationary reference axes. The implementation totally avoids use of sector identification and also the use of look up tables.