Analysis Of Temperature Field Of Air-cooled Permanent Magnet Synchronous Motor

With the continuous development of the motor industry and people’s increasing demand for new energy motors,permanent magnet synchronous motors featuring small size and good performance are increasingly used in transportation,mining,and robotics industries.At the same time,as people’s requirements for the use performance of permanent magnet synchronous motors gradually increase,more and more high electromagnetic loads and the use of thermal load materials easily lead to excessive internal temperatures during the operation of the motor,thereby causing permanent magnets.Demagnetization at high temperatures accelerates the aging of the insulator,resulting in accidents such as winding short circuits,which seriously affect the reliability of the motor’s service life.In this paper,a 9.5kW air-cooled permanent magnet synchronous motor for traction is taken as an example to establish a three-dimensional model of the motor.The knowledge of fluid mechanics and heat transfer is used.The finite element analysis method is used for the air-cooled permanent magnet synchronous motor.The steady-state flow field of the internal air was simulated by three-dimensional numerical simulation,and the flow velocity and the flow law of the cooling fluid on the surface of the air-cooled permanent magnet synchronous motor,the surface of the stator windings,and the rotor core were obtained.Based on the simulation results of the flow field and the related principles of heat transfer,the finite element simulation software was used to solve the steady-state temperature field and transient temperature field of the air-cooled permanent magnet synchronous motor.The distribution of temperature rise of stator core,stator winding,and rotor core and winding,and the reason of distribution of temperature field are analyzed according to the characteristics of the flow of the heat transfer fluid.At the same time,the fan structure of the air-cooled permanent magnet synchronous motor was changed.Using the same flow field and temperature field solving method,the original radial fan structure and the flow field and temperature field inside the motor after changing to a diagonal fan structure were compared and analyzed.Simulation analysis was performed on the end sound fields of two different fan structures.The temperature rise distribution of various components inside the air-cooled permanent magnet synchronous motor under the influence of different fan structures during the whole temperature rise and normal operation,as well as the end noise under the influence of two different fan structures,combined with the requirements for heat dissipation and noise Different conditions indicate that each of the two fan structures is more suitable for its use environment.