A Random Pulse Position Modulation Method Based on Markov Chain for Noise Suppression in PMSM Drive System

The presence of electromagnetic noise in permanent-magnet synchronous motor (PMSM) drive systems significantly reduces user experience. In response to this challenge, the paper proposes a solution in the form of a random pulse position modulation technique grounded in Markov chain. Firstly, the sideband harmonic currents during the operation of PMSM are investigated. Subsequently, the variations electromagnetic force wave (EFW) within the motor under the influence of sideband harmonics are analyzed, and the mechanism of electromagnetic noise generation in PMSM is revealed. Following this, a strategy for suppressing noise based on the random pulse position modulation method is introduced, and optimization of this strategy is carried out by using Markov chain. The feasibility of the proposed method is verified through simulations.