Study On Loss And Thermal Characteristics Of Permanent Magnet Synchronous Motor

With the development of industry,permanent magnet synchronous motor(PMSM)is applied more and more widely.Compared with electric excitation motor,its efficiency is higher,power density is bigger,structure is relatively simple,and durability is higher.Therefore,the permanent magnet synchronous motor(PMSM)is used as a dynamic component in many situations,and the normal operation of the motor is very important at this time.If the motor temperature rises too high,the permanent magnet will be demagnetized and the winding insulation will fall off.When the motor rotates,the stress of the permanent magnet and rotor will also increase,so it is very important for the research of the temperature rise of the motor.In this paper,the loss,temperature rise and stress of a 5.5kW synchronous motor are analyzed and calculated.First,a 5.5kW line start permanent magnet synchronous motor(PMSM)is designed.Main size,air gap,stator slot,winding and rotor are determined,and the no-load and loaded conditions are simulated,and the starting performance of the motor can be seen.Secondly,the normal and tangential components of the tooth and yoke are analyzed,and the iron consumption of the tooth and yoke is calculated.The rotor core loss and the permanent magnet eddy current loss are calculated,and the effect of the numbers of permanent magnet sections on the eddy current loss is analyzed.Then,the loss calculated at rated load is used as heat source,and the motor is properly simplified.The mesh is generated and the boundary conditions and material properties are determined.The three-dimensional temperature field of the motor is calculated,and the temperature distribution results of all parts of the motor are obtained.Meanwhile,the insulation material,cooling gas velocity and cooling gas temperature of motor are changed,and the distribution of motor temperature under different conditions is obtained.The influence of these parameters on motor temperature and cooling effect is analyzed.Finally,according to the calculated temperature of permanent magnet and rotor,the radial stress,tangential stress and equivalent stress of permanent magnet and rotor are calculated.At the same time,the stress size of the permanent magnet and rotor at the rated speed of the motor at different temperatures was calculated,and the regulation was obtained.