低矫顽力永磁体磁滞特性实验研究

Experimental Research on Hysteresis Characteristics of Low Coercivity Permanent Magnet

低矫顽力永磁体是记忆电动机气隙磁场调节的功能元件,但其非线性磁滞特性导致在调磁过程后不易准确获取磁滞参数,影响记忆电动机精确调磁调速控制。分析低矫顽力永磁体的磁滞特性,建立低矫顽力永磁体的Preisach磁滞模型。通过设计调磁装置,采用有限元仿真研究在施加正弦波和方波等外部磁场过程中的低矫顽力永磁体磁滞特性。仿真结果表明,低矫顽力永磁体的剩磁通密度随所施加外部磁场的变化而变化。制作调磁装置样机,搭建调磁装置控制系统,实验研究在施加不同外部磁场过程中的低矫顽力永磁体磁滞特性。该实验为建立适合记忆电动机设计和优化用的调磁模型提供一种研究方法。

Low coercivity permanent magnet is the functional element of the memory machine for air-gap flux-regulation,but its nonlinear hysteresis characteristic makes it difficult to obtain accurate hysteresis model after the process of flux-regulation.As a result,the accurate air-gap flux-regulation and speed control of the memory machine is affected.Firstly,the hysteresis characteristics of low coercivity permanent magnet materials are analyzed,and the Preisach hysteresis model of low coercivity permanent magnet is established.Then,the flux-regulation device is designed and the hysteresis characteristics of low coercivity permanent magnet in the process of applying external magnetic fields such as sine wave and square wave are studied by finite element simulation.The results show that the residual flux density of low coercivity permanent magnet accordingly changes with the applied external magnetic field.Finally,the prototype of the flux-regulation device is fabricated,and its control system is built,the hysteresis characteristics of the low coercivity permanent magnet in the process of applying different external magnetic fields are experimentally studied.The research findings provide a research method for establishing the flux-regulation model suitable for the design and optimization of memory machine.