Harmonic Cancellation Technique of Four Pole Induction Motor Drive by using Phase Shifted Carrier Space Vector PWM Technique

The conventional two-level inverter fed induction motor drive causes pulsating torque because of harmonics present in the inverter output voltage. Therefore, minimization of harmonics content is the major challenge in two-level inverter supplied drives. In this paper, a harmonic reduction technique for multiple pole-pair induction motor drive is presented. A modified carrier based space vector PWM technique is used with suitable phase shift between different (modulating and carrier) signals to cancel the harmonic content. In order to use this PWM technique, each pole-pair winding coil of a four-pole induction motor is supplied with two-level inverters separately as dual inverter fed drives. Two dc voltage sources are used to feed all these two-level inverters and by connecting in proper sequence zero sequence currents can be eliminated. By using proposed PWM technique to the inverter configuration, all harmonics will appear at four times of the switching frequency. The proposed inverter concept is tested with 5hp four-pole induction motor in MATLAB/Simulink and experimentally also verified with laboratory prototype. Simulation and experimental results demonstrate the performance of the proposed inverter topology and also show the improvement in harmonic profile.