Space Vector Based Dual Zero-Vector Random Centered Distribution Pwm Algorithm for Direct Torque Control of Induction Motor Drive For Reduced Acoustical Noise

Abstract

The direct torque control (DTC) technique has been recognized as the viable solution to achieve precise and quick torque response but it suffers from few drawbacks such as high ripple in torque, flux and stator current resulting in increased vibrations and acoustic noise. The conventional SVPWM algorithm gives good performance for control of induction motor drive, but it also produces considerable acoustical noise resulting in increased total harmonics distortion. The deterministic pulse width-modulation (PWM) method adopted in induction-motor drives causes Acoustical noise due to the switching frequency. This paper presents a novel dual zero-vector random centered distribution PWM algorithm for direct torque controlled induction motor drive. The proposed PWM algorithm uses two zero voltage vectors. When the operating modulation index is less than the critical modulation index, the proposed PWM algorithm uses V₀ (000) as zero voltage vector. Otherwise, when the operating modulation index is greater than the critical modulation index, the proposed PWM algorithm uses V₇ (111) as zero voltage vector. To verify the proposed PWM algorithm, a numerical simulation studies have been carried out and results are presented and compared with classical SVPWM algorithm. The simulation results confirm the effectiveness of the proposed DZRCDPWM algorithm for the considered drive.

Key words: DTC, DZRCDPWM, RPWM, SVPWM, Acoustic noise.