Novel random SVPWM technique based on Tiny Mersenne Twister PRNG to reduce PWM harmonic

Abstract

To suppress pulse width modulation (PWM) harmonics in the permanent magnet synchronous motor (PMSM) systems, a novel random pulse position space vector PWM (RPP-SVPWM) technique is proposed in this paper. In the proposed RPP-SVPWM technique, a high-performance Tiny Mersenne Twister (MT) algorithm is used instead of a linear feedback shift register (LFSR) to construct a pseudo-random number generator (PRNG). Meanwhile, the technique takes into account the effect of the modulation index (MI). A random pattern of pulse positions is chosen according to the magnitude of the modulation index. When MI >= 0.5, the random degrees of freedom are increased by randomizing the action time of the zero vector. Accordingly, the diffusion effect is improved at high modulation indexes. Then, the impact of LFSR-PRNG and Tiny MT-PRNG on the PWM harmonic suppression effect under different modulation indexes is investigated. Finally, simulation results are analyzed to evaluate the performance. This study is expected to provide a reference for the random pulse position SVPWM technique to suppress PWM harmonics in integrated PMSM drive systems.