Novel strategy for soft-switching PAM inverter system

In this paper, a new soft-switching utility pulse amplitude modulation (PAM) inverter system for motor drive is proposed. In general, an induction motor driven by the nonsinusoidal pulse width modulation (PWM) voltage generates a torque ripple. Therefore, the inverter for the motor drive generally improves the output voltage waveform by removing the lower-order harmonics. Although the output voltage waveform is a nonsinusoidal waveform, the motor driven by the proposed modulating signal produces approximately constant torque. It is possible to reduce the number of commutations, to increase the amplitude of the fundamental component and to reduce the torque ripple in the new PWM strategy