A new space vector pulsewidth modulation strategy for reducing ground to stator-neutral voltage in inverter-fed AC motor drives

Abstract

This paper proposes a new two-phase PWM scheme that can reduce the ground to stator neutral voltage in three-phase diode rectifier/inverter system with corner grounded delta-connected input source. According to the sign of voltage difference between ground and DC-bus midpoint voltage, the proposed PWM use only one zero space vector in one control period. Thus, the peak-to-peak value of ground to stator neutral voltage can be reduced to 2/3 compared with conventional three-phase SVPWM. Without any degradation of control performance of inverter, the proposed PWM scheme can be easily implemented in software and requires no extra hardware except a simple neutral voltage measurement circuit.