Analysis Of Temperature Field And Water Cooling Of High Speed Permanent Magnet Synchronous Motor For Centrifuge

In recent years,high-speed permanent-magnet synchronous motors(HSPMSM)have been rapidly developed.And HSPMSM without gears and other speed-reducing mechanisms.The high speed and relatively small volume make the output power proportional to the rotational speed under a certain motor torque,and the AC asynchronous motor is gradually replaced in many occasions,and the energy consumption relative to the asynchronous motor is small.It is the focus of great development at present.But,the characteristics of high frequency and high frequency of permanent magnet synchronous motor cause a gradual increase in the temperature rise of the motor,which is small in volume and difficult to dissipate heat,especially when the high temperature rise in the full closed motor leads to the irreversible demagnetization of the permanent magnet.At first,construction of motor model and loss calculation.This paper built a HSPMSM model for Centrifuge has 300kW,18000rpm,and the finite element analysis(FEA)is carried out by Ansoft-Maxwell to obtain the distribution of copper,core and eddy current loss of high speed permanent magnet synchronous motor.Secondly,analysis of temperature field caused by the flow field and flow field of the motor.According to the finite element model of Ansoft-Maxwell,establish a HSPMSM model equivalent gap flow field.The flow state of air gap is judged by the Reynolds number of the flow field in the air gap of the motor,and the rationalization conditions of the fluid simulation and set up the boundary condition of the fluid simulation.By using the method of computational fluid dynamics(CFD),the Fluent fluid multi-physics and coupling analysis through software,flow field of HSPMSM in different speed circumstances are analyzed.Through the calculation of the equivalent heat dissipation coefficient between the stator slots and windings of the motor and the contact surfaces of the motor,the temperature field model of the HSPMSM is established,and the motor at different speeds is obtained under the temperature field module in the ANSYS-Workbench classic interface.Thirdly,overall temperature field analysis of the motor.The temperature rise of each part of the motor caused by copper,core,eddy current loss and air gap flow field of HSPMSM is analyzed by the finite element analysis of the motor,based on heat transfer,the overall distribution of the motor temperature field obtained by multi-physics and coupling analysis.Finally,verify the rationality of the new water cooling method and perform water cooling analysis.According to the temperature rise of 300 kW,18000rpm HSPMSM for Centrifuge,a new type of water cooling structure was used to suppress the stator yoke in the stator of the motor.The distribution of magnetic density and magnetic force flux of the motor under the stator yoke with different cooling slots was analyzed,combined with the motor cooling effect under different cooling slot number is suitable for the motor cooling effect best pipe number and verify the rationality of the structure of water cooling.The distribution of the temperature field of the stator,windings,and permanent magnets of the motor after the cooling of the motor is obtained by the methods of computational fluid dynamics,heat transfer and multi-physics and coupling analysis.