Energy efficiency optimization through THD and switching losses reduction in continuous and discontinuous digital modulation techniques

This paper analyzes the way to increase the energy efficiency of three phase converters applied to control AC motor drives, through the reduction of the total harmonic distortion (THD) of the output voltage and the reduction in the switching losses in the PWM inverter. The aim is to develop a system which selects the most adequate modulation technique required to simultaneously optimize the harmonic distortion and the commutation losses in the electronic switches that constitute the power converter. The developed modulation techniques are the sinusoidal pulse width modulation (SPWM), the sinusoidal pulse width modulation with the injection of a third harmonic of zero sequence (THIPWM), the space vector pulse width modulation (SVPWM) and different discontinuous modulation techniques (DPWM2, DPWMMAX and PWMMIN). The validation of the proposed method has been carried out on an experimental system based on the digital signal processor DSP56F807 from the commercial firm Motorola.