A high-performance PWM algorithm for vector controlled induction motor drive for reduced current ripple

This paper presents a high performance pulse width modulation (HPPWM) algorithm for vector controlled induction motor drive. Due to the requirement of angle and sector information, the complexity involved in classical space vector approach is more. In this paper, a simple generalized PWM (GPWM) algorithm has developed by using the imaginary switching times, which simplifies the control algorithm. In the proposed generalized PWM algorithm the actual gating times are generated from the instantaneous sampled reference phase voltages only. In this algorithm, a unified expression is derived for offset time from which by varying a parameter various PWM algorithms can be generated. Further, the proposed HPPWM algorithm has been developed based on the mean square current ripple characteristics. This algorithm uses the sequence which results in reduced harmonic distortion in current over a subcycle and hence it improves the performance of the drive system. To verify the proposed algorithm, numerical simulation studies have been carried out on a vector controlled induction motor drive and results have been presented.