Space Vector Based Variable Delay Random Pwm Algorithm for Direct Torque Control of Induction Motor Drive for Harmonic Reduction

The conventional SVPWM algorithm gives good performance for control of induction motor drive, but it produces more acoustical noise resulting in increased total harmonics distortion. The random pulse width modulation (RPWM) techniques has become an established means for mitigation of undesirable side effects in PWM converters, the use of voltage source inverters in adjustable speed ac drives in particular. Hence, to minimize these anomalies of the drive, this paper presents a novel variable delay random pulse width modulation (VDRPWM) algorithm with constant switching frequency for direct torque controlled induction motor drive. The Simplicity of this technique is its easy implementation and requires only low-end processors. The conventional VDRPWM preserves both the quality switching of the conventional space-vector PWM (SVPWM) method and minimized harmonic mitigation of the variable switching frequency PWM technique. To validate the proposed conventional VDRPWM algorithm for the considered drive, simulation studies have been carried out and results are presented. The simulation results confirmed the feasibility of proposed VDRPWM algorithm strategy in terms of acoustical noise and harmonic distortion as compared with conventional DTC and SVPWM based induction motor drive.