电机旋转磁场中磁致伸缩导致的振动频率特性

Frequency characteristics of vibration caused by magnetostriction in a rotating magnetic field of a motor

噪声抑制是电机设计和应用中亟待解决的重要问题,在大型电机中磁致伸缩效应引起的振动噪声占比较大。本文首先建立电机电磁—机械耦合数值模型,分析电机定子上的应力特性,发现引起电机定子齿顶部和根部的磁密分布比较集中,应力较大的原因是磁路转向和畸变。然后设计实验对仿真结果进行验证,测量电机定子上的振动,发现最大低频力波为电源供电频率的一倍频力波,在同样测量条件下,测量三相变压器铁心上的振动,发现变压器在铁心磁路转向处有明显的一倍频力波。

Noise suppression is a key issue in the design and application phases of the motor.The vibration caused by magnetostriction effect occupy a large proportion in large motors.The electromagnetic mechanical coupling numerical model of the motor firstly was established in this paper,and the stress of silicon steel sheet of motor stator core was analyzed by numerical simulation.It was found that the distribution of magnetic density at the top and root of the stator teeth was relatively concentrated,and high stress resulted from the magnetic circuit steering and distortion.Then an experiment was designed to verify the simulation results,and the vibration of the stator of the motor was measured.It was found that the maximum low-frequency force wave is single power frequency wave.Under the same measurement conditions,the vibration on the core of the three-phase transformer is measured,and it was found that the transformer has a distinct single power frequency wave at the turn of the core magnetic circuit.