轮缘推进永磁电机-护套-介质系统建模与仿真

Modeling and Simulation of Rim-Driven Thruster Permanent Magnet Motor-Sheath-Dielectric System

为了降低轮缘推进器永磁电机的涡流损耗,研究护套材料与厚度对永磁电机涡流损耗的影响,基于有限元电磁分析软件ANSYSElectronicsDesktop,建立电机-护套-介质系统模型,并通过仿真结果与数值计算结论的对比验证模型准确性;计算永磁电机定转子护套、永磁体涡流密度分布,分析护套材料与厚度对涡流损耗的影响规律。结果表明:护套材料电导率较高时护套中的涡流密度远大于永磁体中的,电导率较低时两者大小相近;采用电导率较低的护套材料时电机产生的涡流损耗远小于采用电导率较高的护套材料;护套材料对护套单位体积涡流损耗影响较大,对永磁体影响较小;定转子护套的厚度比与产生的涡流损耗呈正相关;随着护套厚度比增大,采用电导率较低的护套对永磁体及护套单位体积涡流损耗影响较小,而电导率较高的护套因为屏蔽作用能够通过降低永磁体的涡流密度来降低永磁体涡流损耗;气隙介质在空气、淡水、海水中的变化对电机的磁通密度分布没有显著影响。研究成果可为轮缘推进器永磁电机护套设计提供参考。

In order to reduce the eddy current loss of the permanent magnet motor of the rim thruster,study the influence of the sheath material and thickness on the eddy current loss of the permanent magnet motor,based on the finite element electromagnetic analysis software ANSYS Electronics Desktop,establish the motor-sheath-dielectric system model,and verify the model accuracy by comparing the simulation results with the conclusion of the numerical calculations;calculate the stator-rotor sheath of the permanent magnet motor,calculate the eddy current density distribution of permanent magnet,and analyze the influence of the sheath material and thickness on the eddy current loss.The results show that:the eddy current density in the sheath is much larger than that in the permanent magnet when the conductivity of the sheath material is higher,and the size of the two is similar when the conductivity is lower;the eddy current loss generated by the motor is much smaller than that by the sheath material with higher conductivity when the sheath material with lower conductivity is used;the sheath material has a greater influence on the eddy current loss per unit volume of the sheath,and a smaller influence on the permanent magnet;the thickness ratio of the stator-rotor sheath is positively correlated with the eddy current loss generated;as the thickness ratio of the sheath increases,the eddy current density in the sheath becomes higher,and the eddy current density in the permanent magnet becomes lower.Positive correlation;as the thickness ratio of the sheath increases,the use of lower conductivity of the sheath on the permanent magnets and the sheath unit volume eddy current loss has less impact,and higher conductivity of the sheath because of the shielding effect can be reduced by reducing the eddy current density of the permanent magnets to reduce the permanent magnet eddy current loss;changes in the air gap medium in the air,fresh water,sea water,the motor's magnetic flux density distribution does not have a significant effect.The research results can provide a reference for the design of permanent magnet motor sheaths for rim thrusters.