Noise Suppression Technology for DTP-PMSM Based on Dual Random Modulation Strategy

Randomized modulation technology can effectively suppress high frequency noise in motor drive application. This paper is devoted to issues in synthesis of randomized modulation schemes and proposes a dual random PWM technology based on two-state Markov chain and pseudo-random binary sequence (PRBS). This combined type of randomized modulation can make the switching cycle more evenly distributed and significantly suppress the high frequency noise focused on the switching frequency and its integer multiples. We focus on the power spectra of certain associated waveforms. Furthermore, the DTP-PMSM model with random PWM has been built to evaluate the effect with random PWM modulations based on four methods including conventional method, Markov chains, PRBS and the method combining Markov chain with PRBS. The simulation results prove that proposed PWM strategy possesses excellent harmonic power spreading ability and high frequency noise suppression capability.