不均匀气隙结构异步起动永磁同步电机优化设计与退磁分析

发布时间：2018-04-13 03:01

本文选题：永磁电机 + 不均匀气隙　；参考：《合肥工业大学》2017年硕士论文

【摘要】：相比于普通感应电机,异步起动永磁同步电机(Line-Start Permanent Magnet Synchronous Motor,LSPMSM)具有高效率和高功率因数的显著优势,而相比于调速永磁同步电机它又具有自起动的特性,因此,异步起动永磁同步电机在工业生产中的应用具有广泛的前景。但是,异步起动永磁同步电机的气隙磁场波形类似于方波,磁场谐波复杂,高气隙磁场谐波畸变率导致电机运行时铁心损耗大,电磁噪声高,给电机带来一系列不利后果。针对普通异步起动永磁同步电机气隙磁场谐波复杂的不良特性,本文提出了一种不均匀气隙结构的异步起动永磁同步电机。围绕该不均匀气隙结构电机,展开的主要研究工作如下:1.给出了不均匀气隙结构电机气隙长度的表达式,利用磁动势乘以磁导的气隙磁场传统解析理论,研究了转子磁极偏心距与气隙磁场波形的关系。为了得到最小的气隙磁场波形畸变率,优化设计了转子磁极偏心距的尺寸。2.不变气隙是不均匀气隙长度函数的重要组成部分,分析设计了电机的不变气隙长度,使电机性能满足设计任务要求的指标。3.对不均匀气隙结构电机的转矩特性展开了理论分析与有限元仿真。分析了磁极偏心距与齿槽转矩的关系,得到齿槽转矩最小时磁极的偏心距离;从减小转矩脉动主要次谐波入手,研究了反电动势谐波与转矩脉动的关系,从而使电机转矩脉动最小化。4.分析了影响不均匀气隙结构异步起动永磁同步电机退磁的因素,研究了负载转矩和转动惯量与永磁体退磁的关系,提出了获得永磁体最小工作点的研究方法。5.研究了电机非正常运行工况对永磁体退磁的影响,为永磁体合理的防失磁设计提供依据。本文通过对不均匀气隙结构异步起动永磁同步电机的研究,得到了抑制气隙磁场谐波含量的方法,采用了磁极偏心的方案减小了齿槽转矩和电机的转矩脉动,分析总结了永磁体退磁的规律,为异步起动永磁同步电机工程实践提供了有价值的参考方案。
[Abstract]:Compared with the ordinary induction motor, the asynchronous starting permanent magnet synchronous motor (Line-Start Permanent Magnet Synchronous Motor LSPMSM) has the remarkable advantages of high efficiency and high power factor, while compared with the speed regulating permanent magnet synchronous motor, it has the characteristics of self-starting.Asynchronous starting permanent magnet synchronous motor (PMSM) is widely used in industrial production.However, the air-gap magnetic field waveform of asynchronous starting permanent magnet synchronous motor is similar to that of square wave. The magnetic field harmonics are complex, and the high air gap magnetic field harmonic distortion rate leads to a large loss of iron core and high electromagnetic noise, which brings a series of adverse consequences to the motor.In view of the complex harmonic characteristics of the air gap magnetic field of the common asynchronous starting permanent magnet synchronous motor, a non-uniform air-gap structure asynchronous starting permanent magnet synchronous motor is proposed in this paper.The main research work around the non-uniform air-gap motor is as follows: 1.The expression of air gap length of non-uniform air-gap structure motor is given. The relationship between rotor magnetic pole eccentricity and air gap magnetic field waveform is studied by using the traditional analytic theory of air-gap magnetic field with magnetic EMF times magnetic conductance.In order to obtain the minimum distortion rate of air gap magnetic field, the size of rotor pole eccentricity is optimized.The invariant air gap is an important part of the non-uniform air gap length function. The constant air gap length of the motor is analyzed and designed to make the performance of the motor meet the requirements of the design task.The torque characteristics of non-uniform air gap motor are analyzed theoretically and simulated by finite element method.The relationship between magnetic pole eccentricity and grooving torque is analyzed, the eccentric distance of magnetic pole is obtained when the tooth slot torque is minimum, and the relationship between the harmonic of backEMF and torque ripple is studied by reducing the main harmonics of torque ripple.Thus, the torque ripple of the motor is minimized. 4.The factors affecting demagnetization of asynchronous starting permanent magnet synchronous motor with non-uniform air-gap structure are analyzed. The relationship between load torque and moment of inertia and permanent magnet demagnetization is studied. The research method of obtaining the minimum working point of permanent magnet is put forward.The effect of abnormal operating condition of motor on demagnetization of permanent magnet is studied, which provides the basis for the reasonable design of permanent magnet.Based on the research of asynchronous starting permanent magnet synchronous motor with non-uniform air gap structure, the method of restraining harmonic content of air gap magnetic field is obtained in this paper. The scheme of magnetic pole eccentricity is adopted to reduce the torque of tooth slot and torque ripple of motor.The law of permanent magnet demagnetization is analyzed and summarized, which provides a valuable reference scheme for the engineering practice of asynchronous starting permanent magnet synchronous motor (PMSM).
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM341

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