Random Switching Period SVPWM Technique with Variable Sampling Frequency for Three‐Phase Power Converters

To improve the pulse width modulation (PWM) harmonic suppression effect of the three-phase VSI-fed PMSM system, this paper proposed a novel random switching period (RSP)-Space Vector Pulse Width Modulation (SVPWM) technique for the three-phase power converter. First, the proposed technique replaces the 10-bit linear feedback shift register pseudorandom number generator (LFSR-PRNG) with a Tiny Mersenne Twister (MT)-PRNG to quickly generate high-quality pseudorandom number sequences. Then, to reduce the sampling error caused by the current ripple, this paper analyzes the sampling timing under different modulation techniques. Based on the interrupted update mechanism of the Infineon AURIX-TC264, the variable frequency sampling of the RSP-SVPWM technique is implemented to ensure the best sampling of the motor phase current. Finally, the simulation and experimental results show that the proposed technique can effectively disperse PWM harmonic energy. Meanwhile, the RSP-SVPWM technique based on variable sampling frequency effectively improves the phase current quality of the PMSM system. The proposed technique shows great potential for suppressing PWM harmonics in integrated PMSM systems. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.