Analysis And Calculation Of Electromagnetic Noise For Transverse Flux Permanent Magnet Motor

Electromagnetic noise of motor affects not only human health, but service life of the motor. In some special occasions, the standard of motor noise is more stringent. As one of the most important indexes for measure motor performance, in the last few years, considerable attention has been paid to vibration noise level of motor. Recently, with the fast development of high-power electrical drive technology, it is increasingly urgent to demand for motor with high torque density and low speed. Meeting the above requirements, transverse flux permanent magnet motor has already become one of research hotspot. However, it still leaves some room for improvements of this kind of motor. To the best of author knowledge, up to now, there has few literatures studying electromagnetic noise. Motor noise usually consists of mechanical noise, aerodynamic noise and electromagnetic noise. Generally speaking, electromagnetic noise is the main component of motor noise. In this paper, the problem of the calculation and analysis method of electromagnetic noise from transverse flux permanent magnet motor is studied.When the motor running, it can result in the change of air-gap field and produce alternating electromagnetic force. Moreover, the force leads to vibration of every part of the motor. Noise level is determined by electromagnetic force and motor vibration performance. Therefore, it becomes a key issue that analyse components of electromagnetic force and natural model for studying electromagnetic noise. Transverse flux permanent magnet motor has three-dimensional distribution magnetic circuit, so the computing method of two dimensional magnetic field is no longer applicable. By using the Pro/Engineer softwares, this paperconstructs three-dimensional models of transverse flux permanent magnet motor to analyze air gap field and components of electromagnetic force with Ansys Maxwell 2015, and calculate motor natural model with Ansys Workbench. Then through electromagnetic force loading on the motor stator system, vibration response and electromagnetic noise are investigated.Finally, with the computation analysis, the electromagnetic noise source of transverse flux permanent magnet motor has been found, and vibration characteristic is obtained. By using direct coupling approach, this analysis process reduces the difficulty of calculating electromagnetic noise and improves the accuracy. Therefore, this paper is not only the basis of the further work for suppressing noise of transverse flux permanent magnet motor, but has some reference for the practical engineering.