Comparative evaluation of carrier-based PWM strategies with zero-sequence signal injection for B6-VSI fed induction motor drives

Pulsewidth modulation (PWM) variable speed drives are increasingly applied in many industrial applications that require superior performance. The carrier-based PWM strategy can be improved by adding different zero sequence signals to the reference sinusoidal phase voltages. This paper presents a comparative evaluation of five carrier-based PWM techniques with zero-sequence signal injection for a six-switch three-phase inverter (B6) fed an open-loop induction motor (IM) drives over the linear modulation and overmodulation ranges. The carrier-based PWM strategies under consideration are tested and are verified by experiments using a test bench. Several experimental results are presented to validate this study. The characteristics of the PWM methods are analyzed and compared based on four criteria such as the variation of the root mean square values of stator voltages and currents, mechanical speed and slip versus the stator frequency using the open-loop scalar control.