Hybrid PWM Algorithm for Induction Motor Drive with Reduced Computational Burden

This paper presents a generalized pulse width modulation (GPWM) algorithm for induction motor drives. In the proposed approach, by varying a constant )(2k value from zero to one, various DPWM algorithms can be generated along with the SVPWM algorithm. As the proposed approach uses instantaneous phase voltages only for the calculation of gating times of the inverter, the complexity burden involved is very less when compared with the classical space vector approach. Then, the rms stator flux ripple, which is a measure of ripple in line current characteristics have been plotted for all the DPWM and SVPWM algorithms. From which, it is concluded that the SVPWM algorithm gives superior performance at low modulation indices, whereas the DPWM algorithm gives superior performance at higher modulation indices. Hence, to achieve the superior waveform quality at all modulation indices, a hybrid PWM (HPWM) algorithm has been presented in this paper. To validate the proposed algorithms, several numerical simulation studies have been carried out and results have been presented and compared.