The development of space vector PWM for four switch three phase inverter fed induction motor with DC - link voltage imbalance

This paper is to present a new space vector pulse width modulation (PWM) algorithm for four switch three phase inverter (FSTPI) fed induction motor under DC-link voltage imbalance. By using reasonable mathematical transform, space vector PWM (SVPWM) technique for FSTPI under DC-link voltage imbalance or ripples have been solved, which is based on the establishment of basic space vectors and modulation technique in similarity with six-switch three-phase inverters. This approach has a very important sense to solve hard problems for FSTPI under DC-link voltage imbalance, for example ensuring the required voltage for undermodulation mode and overmodulation mode 1 and 2, extended to six-step mode. Matlab/Simulink is used for the simulation of the proposed SVPWM algorithm for undermodulation, overmodulation mode 1 and 2. This SVPWM approach is also validated experimentally using DSP TMS320LF2407a in FSTPI-IM system.