永磁同步电机温度场分析及冷却系统研究

发布时间：2018-03-27 16:24

本文选题：永磁同步电机　切入点：温度场　出处：《湘潭大学》2017年硕士论文

【摘要】：由于永磁同步电机具有体积小、质量轻、功率密度高、形状和尺寸灵活多样等一系列优点,使其得到了广泛应用。随着工业技术发展,永磁电机的单机容量不断增加,内部损耗也随其增加,致使电机内部温升越来越高,直接影响电机的可靠运行。因此,对于电机温度场的分析计算及电机冷却系统的设计研究尤为重要。本文主要用不同的温度场分析方法对不同冷却方式的两款永磁同步电机进行温度场分析,实现对不同冷却形式的永磁同步电机温度场的精确分析,并针对不同实际情况选择最为合适的温度场计算方法。首先,以320kW自然冷却永磁同步发电机为例,用公式计算法和Ansoft Maxwell软件分析法对永磁同步电机的损耗进行分析计算,得到电机的损耗分布情况,尤其是针对永磁体涡流损耗的分析计算。基于传热学的基本理论,采用FEM对样机进行温度场分析,用ANSYS Workbench软件对样机电磁场、温度场进行耦合分析,得到样机温度场的分布情况。并通过对有无涡流损耗影响的样机温度场分布情况进行对比分析,验证永磁体涡流损耗的重要性。其次,采用LPTN对样机进行温度场分析,根据电机各部位散热路径设置节点,建立能反映电机整体传热情况的热网络结构,由热传导和热对流计算公式计算各节点热阻,通过MATLAB编写热平衡方程计算程序,计算电机内部各节点的温度。对样机进行温升测试,通过对FEM、LPTN和温升测试的结果进行对比可知,在误差允许范围内,LPTN和FEM的计算结果均正确。最后,以100kW水冷永磁同步电动机为例,对其水冷系统进行分析设计。为了解决传统冷却结构在电机长期运行过程中容易出现漏液和散热不均的问题,提出一种新型冷却结构。以传热学和流体力学基本理论为基础,计算样机损耗发热和散热处于平衡状态时的水流量和流速。用CFD方法分析冷却介质的流动特性,并对样机进行流场和温度场耦合分析,得到样机的温度场分布情况。通过对比有无冷却结构样机温度场分布情况,验证水冷结构设计的合理性及实用性。
[Abstract]:Permanent magnet synchronous motor (PMSM) has been widely used because of its advantages of small size, light weight, high power density, flexible shape and size, etc. With the development of industrial technology, the single machine capacity of PMSM has been increasing. With the increase of internal loss, the internal temperature rise of the motor becomes higher and higher, which directly affects the reliable operation of the motor. It is very important to analyze and calculate the temperature field of the motor and to design the cooling system of the motor. In this paper, the temperature field of two permanent magnet synchronous motors with different cooling modes is analyzed with different temperature field analysis methods. The temperature field of permanent magnet synchronous motor (PMSM) with different cooling forms is analyzed accurately, and the most suitable temperature field calculation method is chosen according to different actual conditions. Firstly, taking 320kW natural cooling PMSG as an example, The loss distribution of permanent magnet synchronous motor (PMSM) is analyzed and calculated by formula calculation method and Ansoft Maxwell software analysis method, and the loss distribution of PMSM is obtained, especially for the analysis and calculation of eddy current loss of permanent magnet. Based on the basic theory of heat transfer, The temperature field of the prototype is analyzed by FEM, and the electromagnetic field and temperature field of the prototype are analyzed by ANSYS Workbench software. The distribution of the temperature field of the prototype is obtained, and the importance of the eddy current loss of the permanent magnet is verified by comparing and analyzing the temperature field distribution of the prototype with or without eddy current loss. Secondly, the temperature field of the prototype is analyzed by LPTN. According to the heat dissipation path of the motor, the node is set up, and the heat network structure reflecting the whole heat transfer of the motor is established. The thermal resistance of each node is calculated by the formula of heat conduction and heat convection, and the calculation program of heat balance equation is compiled by MATLAB. The temperature of each node inside the motor is calculated. The temperature rise test of the prototype is carried out. By comparing the results of the FEM-LPTN and the temperature rise test, it can be seen that the calculation results of both the LPTN and the FEM are correct within the range of errors permitted. Finally, Taking 100kW water-cooled permanent magnet synchronous motor as an example, the water cooling system is analyzed and designed. A new cooling structure is proposed. Based on the basic theories of heat transfer and hydrodynamics, the flow rate and velocity of water are calculated when the heat dissipation and heat dissipation are in equilibrium. The flow characteristics of cooling medium are analyzed by CFD method. The temperature field distribution of the prototype is obtained by the coupled analysis of the flow field and the temperature field, and the rationality and practicability of the water-cooled structure design are verified by comparing the temperature field distribution of the prototype with or without cooling structure.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM341

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