Analysis on Electromagnetic Vibration of Synchronous Reluctance Motors under Different Drive Methods

Abstract

Sine-wave drive and square-wave drive are two common motor control strategies. This study constructs a mathematical model capable of predicting the distribution of electromagnetic force waves in synchronous reluctance motors (SynRMs) under these two drive methods, and comparatively analyzes the vibration phenomena induced by electromagnetic forces under different drive methods. It aims to provide an effective tool for predicting the distribution of electromagnetic force waves in SynRMs, while exploring the influence of drive modes on their vibration characteristics. The study focuses on a 4-pole, 36-slot 5.5 kW SynRM. Based on the magnetomotive force (MMF)-permeance method, incorporating the special rotor structure and the characteristics of current harmonics under square-wave drive, an air-gap flux distribution function is established. Meanwhile, Maxwell's stress tensor method is adopted to analyze how the air-gap flux density relates to electromagnetic excitation force waves. Subsequently, this analysis is applied to forecast the spatiotemporal distribution features of radial electromagnetic force waves. Finite element simulations are conducted to compute the modal and vibration responses of the SynRM, followed by a comparative analysis of the vibration characteristics under the two drive methods. Additionally, a 6-pole, 36-slot SynRM is used for additional comparative verification. Ultimately, the effectiveness of the simulation results is verified through experiments.