CARRIER BASED HYBRID PWM ALGORITHM WITH REDUCED COMMON MODE VOLTAGE FOR THREE PHASE VOLTAGE SOURCE INVERTER FED INDUCTION MOTOR DRIVES

This paper proposes a simple carrier based hybrid P WM algorithm (HPWM) to mitigate the common mode voltage (CMV) variations. Though the sp ace vector PWM (SVPWM) gives, it results in large CMV values. Hence, to reduce the CMV and complexity, which is involved in the SVPWM technique, this paper presents simple scalar based PWM techniques. By adding the zero sequence voltage to the phase voltages, the modulating signals are derived for the active zero state PWM (AZSPWM) techniques. Also, to reduce the harmonic distortion further, a HPWM technique is presented based on the concept of the stator flux ripple. As the proposed AZSPWM and HPWM techniques do not use zero states, the CMV variations can be minimized from 2 dc V ± to 6 dc V ± when compared with the SVPWM algorithm. To evaluate the proposed algorithm simulation studies have been carried on v/f control led induction motor drive and the results are presented