Modified Space Vector PWM Sequences for High Power Drives

Abstract

The inbuilt advantage of the space vector based pulse width modulation (SVPWM) strategy lies in the ease in choosing different switching sequences to generate the required reference vector than with the conventional triangle comparison approach. However, SVPWM technique involves various steps which are mathematically intense. In order to reduce this complexity, a simplified algorithm is proposed here. This work aims at reducing of harmonic distortion in high-power drives, which operate at significantly lower switching frequencies.  In this paper, conventional SVPWM (CSVPWM) and Modified SVPWM (MSVPWM) sequences are applied to a three level neutral point clamped (NPC) inverter fed V/f controlled induction motor drive. The two performance measuring parameters weighted total harmonic distortion (WTHD) of the line voltages and total harmonic distortion (THD) in no-load stator current for odd and even samples are compared for different sequences employing simplified algorithm.

Keywords:ADPWM, CSVPWM, DPWM, MSVPWM