鼠笼式永磁交流电机的分析、优化与无传感器控制

发布时间：2018-07-17 15:51

【摘要】：常见的永磁交流电机包括电网供电的自起动永磁同步电机、逆变器供电的永磁同步电机(变频永磁无刷交流电机)与永磁无刷直流电机。本文主要研究鼠笼式永磁无刷直流电机和自起动永磁同步电机。鼠笼式永磁无刷直流电机结合了永磁电机和异步电机的双重特点。从电机本体结构上看,这类电机转子上安装了鼠笼,因而该电机与传统自起动永磁同步电机结构类似,但是控制方式并不相同。该类电机具有良好的起动性能和较高的稳态运行效率及功率密度。由于与自起动永磁同步电机工作方式不同,鼠笼绕组对电机性能和控制策略的影响也不相同。因此研究该类电机的优化设计以及控制规律具有较高的学术价值,值得深入研究。本文简单介绍了鼠笼式永磁无刷直流电机的工作原理,并介绍了高速电机的研究现状,总结了目前高速永磁电机研究方面取得的主要学术成果,针对鼠笼式高速永磁无刷直流电机研究具体展开了以下一些工作,取得了一些较有价值的成果：首先,本文详细整理了现有文献关于自起动永磁同步电机的数学模型,并且推导了鼠笼式永磁无刷直流电机在定子坐标系下的数学模型；通过MATLAB软件,编写了鼠笼式永磁无刷直流电机的仿真模型。仿真模型从数学角度解释了电机参数对电机运行性能的影响。相比有限元软件,该仿真模型的分析时间大大缩短,为鼠笼式永磁无刷直流电机的优化设计提供了较大的便利。其次,以一台中等功率高速永磁无刷直流电机为例,综合考虑电机加工成本、加工工艺、电磁性能、机械强度等因素,给出了优化设计方法与规律,完成了样机的电磁设计方案和实物样机加工,开展实验研究,验证了设计方案的可行性。设计规律可以推广应用于中等功率高速永磁无刷直流电机的优化设计。再次,详细分析了鼠笼绕组对永磁电机退磁性能的影响,找出了永磁电机永磁体局部不可逆退磁扩散的规律,从数学模型层面解释了鼠笼绕组在提高永磁体抗退磁能力时发挥的作用。提出了四种有效提高永磁体抗退磁能力的优化措施,以一台自起动永磁同步电机为例,使用Ansoft有限元软件分析了四种优化措施对永磁体堵转退磁的影响,最后制作了样机,堵转退磁实验数据与有限元仿真数据吻合。最后,研究了鼠笼绕组对永磁电机磁链观测器的影响,推导了在同步速坐标系下永磁电机磁链观测原理。由于在同步速坐标系下,电机内物理量的基频分量均为直流量,而谐波分量为交流量,由于鼠笼绕组的电流为谐波电流,因此,通过简单的一阶低通滤波器可以将鼠笼电流对定子电流、磁链的影响滤除。而转子的位置仅与转子磁链的基频分量有关,因此,使用同步旋转坐标系下的磁链观测原理可以计算得到准确的转子位置信息。通过对鼠笼式永磁无刷直流电机的有限元仿真结果进行数值计算,验证了该磁链观测原理的准确性,在此基础上,完成了硬件磁链观测器的制作,用于控制样机运行,实验效果良好。
[Abstract]:The common permanent magnet AC motor includes the self starting permanent magnet synchronous motor (PMSM) powered by the power grid, the permanent magnet synchronous motor (VVVF permanent magnet brushless AC motor) powered by the inverter and the permanent magnet brushless DC motor. This paper mainly studies the squirrel cage permanent magnet brushless DC motor and the self starting permanent magnet synchronous motor.
The squirrel cage permanent magnet brushless DC motor combines the dual characteristics of the permanent magnet motor and the asynchronous motor. From the main structure of the motor, the squirrel cage is installed on the motor rotor, so the motor is similar to the traditional self starting permanent magnet synchronous motor, but the control mode is not the same. The motor has good starting performance and high stability. The effect of the squirrel cage winding on the performance and control strategy of the motor is different from that of the self starting permanent magnet synchronous motor. Therefore, the study of the optimal design and control law of this kind of motor has a high academic value. It is worth studying in depth.
This paper briefly introduces the working principle of the squirrel cage permanent magnet brushless DC motor, introduces the research status of the high speed motor, summarizes the main academic achievements in the research of high speed permanent magnet motor, and has made some work on the study of the squirrel cage high speed permanent magnet brushless DC motor. Achievements:
First, the mathematical model of the self starting permanent magnet synchronous motor (PMSM) in the existing literature is arranged in detail, and the mathematical model of the squirrel cage permanent magnet brushless DC motor in the stator coordinate system is derived. The simulation model of the squirrel cage type permanent magnet brushless DC motor is written by the MATLAB software. The simulation model explains the motor reference from the mathematical angle. Compared with the finite element software, the analysis time of the simulation model is greatly shortened, which provides a great convenience for the optimization design of the squirrel cage permanent magnet brushless DC motor.
Secondly, taking a medium power high speed permanent magnet brushless DC motor as an example, the optimization design method and law are given in consideration of the machining cost, processing technology, electromagnetic performance and mechanical strength. The electromagnetic design and the prototype of the prototype are completed and the experimental research is carried out. The feasibility of the design scheme is verified. The law can be applied to the optimization design of medium power high speed permanent magnet brushless DC motor.
Thirdly, the effect of the squirrel cage winding on the demagnetization performance of permanent magnet motor is analyzed in detail. The law of local irreversible demagnetization and diffusion of permanent magnet permanent magnet is found out. The role of the squirrel cage winding in improving the anti demagnetization ability of permanent magnets is explained from the mathematical model level. Four optimization measures to improve the anti demagnetization ability of permanent magnets are proposed. Taking a self starting permanent magnet synchronous motor as an example, Ansoft finite element software is used to analyze the effect of four optimization measures on the degaussing of the permanent magnet. Finally, the prototype is made. The experimental data of the degaussing and demagnetization are in agreement with the finite element simulation data.
Finally, the influence of the squirrel cage winding on the flux observer of the permanent magnet motor is studied. The principle of the magnetic chain observation of the permanent magnet motor under the synchronous speed coordinate system is derived. The fundamental frequency component of the physical quantity in the synchronous speed coordinate system is all direct flow, and the harmonic component is the AC flow, and the current of the squirrel cage winding is harmonic current. The single first order low pass filter can remove the effect of the squirrel cage current on the stator current and magnetic chain. The position of the rotor is only related to the basic frequency component of the rotor flux. Therefore, the accurate rotor position information can be calculated by the principle of magnetic chain observation under the synchronous rotating coordinate system. The result of the element simulation is calculated to verify the accuracy of the principle of the magnetic chain observation. On this basis, the hardware flux observer is made, which is used to control the operation of the prototype, and the experimental results are good.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM34

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