A novel zero-sequence current elimination PWM scheme for an open-end winding motor drive with dual two-level inverter

This paper introduces a novel pulse width modulation (PWM) scheme for an open-end winding motor drive with dual two-level three-phase inverter which can achieve zero sequence current (ZSC) elimination effect in ideal condition. Based on normal SPWM modulation scheme with appropriate phase-shift, the common mode voltage (CMV) in different inverters can keep the same and cancel out with each other which can realize the zero sequence voltage (ZSV) elimination effect finally. In this condition, the dual inverters can share the same DC power and simplify the structure of drive system. The phase current of the novel scheme can reach the maximum value as same as other ZSC elimination schemes while the THD can be reduced. In addition, the double frequency effect of proposed method can also decrease the requirement of DC side capacitor. To verify the analysis, both simulation and experimental results are presented to validate the superiority of proposed method.