Design And Thermal Analysis Of Amorphous Metal High-speed Permanent Magnet Motor

The high-speed permanent magnet synchronous machines(HSPMSMs)have become a hot topic in the research of motor science in recent years due to the excellent performance(high power density,high efficiency,excellent control performance,high reliability).With the development of new amorphous metal(AM)soft magnetic materials,applying it to the stator core of HSPMMs can reduce the core loss significantly and improve the efficiency greatly of the motor with its low-loss characteristics.Firstly,the magnetization performance and loss performance of the AM material are affected by the processing seriously,and the magnetization and loss performance of the AM core after processing is seriously deteriorated.Based on the magnetic property measurement system of German BROCKHAUS company,the magnetization characteristics and loss characteristics of AM ribbon and laminated AM cores after processing were tested in this paper.Then,the modified method for the AM core loss based on the AM ribbon loss characteristics is obtained.The accuracy of the obtained modified method for the AM core loss was verified by comparing the results of the finite element calculation with the no-load iron loss experimental data of an AM HSPMSM prototypeSecondly,it is consider that the loss of the motor material(copper,NdFeB)will change with the temperature variations,and the loss change will in turn affect the temperature rise of the HSPMSMs.An electromagnetic-thermal bi-directional coupling model that can comprehensively consider the influence of temperature on the parameters of windings and NdFeB materials is introduced in this paper.Based on the finite element software,multiple iterative convergence calculations of electromagnetic field and temperature field are performed to consider the effect of motor material loss on temperature At the same time,the assembly gap of the motor is considered,which improves the accuracy of the motor loss and temperature rise calculation results.By comparing the results of the finite element calculation with the test data of an AM HSPMSM prototype,the accuracy of the proposed electromagnetic-thermal bi-directional coupling method is verified.Finally,based on the research on the key technology of AM HSPMSMs,the AM HSPMSMs with two types of rotor pole structures,interior permanent-magnet(IPM)and surface-mounted permanent-magnet(SPM)are designed in this paper,respectively.Firstly,the electromagnetic part is designed,including the determination of the stator and rotor dimension,air gap length,selection of permanent magnets and the size of the sleeve material.Then the mechanical strengths of the two rotor structures were checked,respectively.The "一" shape magnet of IPM rotor is divided into two sections,and the safety factor of motor can reach 1.57.When the SPM rotor structure selects the interference 0.12mm between the sleeve and the magnets,the safety factor of motor can reach 2.04.Finally,the fluid-solid coupling Fluent software is used to calculate and analyze the temperature field and fluid field of the two rotor structure motors.The temperature rise of each motor component is within the safe range of materials.The relevant design parameters can provide a reference for AM HSPMSMs of similar specifications.