Generalized PWM algorithm for VSI fed induction motor drives using the only sampled reference phase voltages

This paper presents a simple generalized pulse width modulation (GPWM) algorithm for a 3-phase, 2-level voltage source inverter fed induction motor drives. The space vector approach requires angle and sector estimation for the calculation of gating times of the inverter and hence increases the complexity of the PWM algorithm. However, the proposed algorithm uses the instantaneous phase voltages only. Hence, the complexity will be reduced. Moreover, the proposed approach gives the realization of various carrier based PWM algorithms that include both space vector PWM (SVPWM) and various discontinuous PWM (DPWM) algorithms by using a generalized control algorithm and is obtained via unequal sharing of zero states. In the proposed approach, by varying a constant (k ) value from zero to one, various DPWM algorithms can be generated along with the SVPWM algorithm under both the linear and over modulation regions. To validate the proposed GPWM algorithm, several numerical simulation studies have been carried out and the results have been presented. The simulation results show the effectiveness of the proposed algorithm.