A space vector PWM scheme for an open-end winding induction motor drive with a reduced power loss

Abstract

The dual-inverter fed open-end winding induction machine drive is a promis ing power circuit for medium-voltage, high-power industrial applications. This drive accomplishes 3-level inversion using a couple of ordinary 2-level voltage source inverters. Several PWM schemes were proposed for this drive to obtain a good harmonic performance. In this paper, an improvised space vector PWM (SVPWM) scheme is presented, which is named the phase clamped and alter nate switched (PCAS) PWM strategy. This PWM scheme brings in a consider able reduction in the switching power loss in the dual-inverter system. The PCAS-SVPWM strategy switches only two phases of the switching inverter in any given sampling time period, unlike the other SVPWM schemes, wherein all the three phases of the switching inverter undergo a switching action. In addition, the proposed SVPWM achieves the waveform symmetries and reduces the common-mode voltage. Simulation results suggest that this PWM scheme results in a reduction of the overall power loss, which is in the range of 4.5% to 11% across the entire range of modulation, depending upon the rat ing of the machine. The effectiveness of the proposed PCAS-SVPWM scheme is assessed with simulation studies and is experimentally validated with labora tory prototype