Modulated Frequency Triangular Carrier Based Space Vector PWM Technique for Spreading Induction Motor Acoustic Noise Spectrum

Abstract

To spread the motor acoustic noise, various PWM techniques have been proposed for Voltage Source Inverter (VSI) fed Induction Motor Drives. Random PWM techniques are the most useful techniques to reduce motor acoustic noise. It is difficult for real-time implementation, unpredictable switching losses and the motor suffers from shaft torque dynamics due to adventitious excitation of natural frequencies. The Constant Frequency Triangular Carrier (CFTC) based Space Vector PWM technique will inject switching frequency harmonics into the Variable Frequency Drive, where the harmonics are concentrated at integral multiples of switching frequency which generate audible acoustic noise. To spread the audible harmonic spectrum, this paper presents a Modulated Frequency Triangular Carrier (MFTC) based SVPWM technique, in which the carrier frequency is modulated accordingly. Both the CFTC and the proposed MFTC based PWM techniques are simulated using MATLAB/Simulink. The experiments are conducted on a low-cost TMS320F28379D controller. The proposed MFTC based PWM technique shows better performance in spreading the motor acoustic noise spectrum as compared to the CFTC based SVPWM technique.