Analysis Of Temperature Field And Performance Of Hairpin Motor

As a new generation of high-performance motors,the hairpin motor has the technical characteristics of small size,high slot full rate,and high efficiency,which fully meets the requirements of new energy vehicles for drive motors.However,as the output power increases,the motor requires a high electromagnetic load design,which causes the motor to generate a lot of heat during operation.Therefore,the cooling of the hairpin motor has become one of the technical difficulties and hotspots in the development of the hairpin motor.This paper takes a card issuing motor with a power of 125 KW in a certain company as the research object.In the design stage,it designs and provides a water-cooled structure,simulates and analyzes the temperature field distribution and calculates the strength of the motor structure to ensure the key performance of the card issuing motor,and use experiments to verify the simulation.reliability.Performance analysis of the motor.The laboratory module is used in Motor-CAD to calculate the external characteristics and efficiency of the motor according to the vector current control principle.The results show that the distribution of the highest efficiency zone of the motor meets the requirements and the high efficiency of the entire motor meets the design requirements,constant torque zone and constant power The area distribution meets the design requirements.Analysis of the temperature field of the motor.First,on the basis of finite element theory,use Maxwell software to establish a two-dimensional finite element model of electromagnetic field,calculate iron core loss and permanent magnet eddy current loss through transient electromagnetic field model,and calculate winding copper loss through empirical formula method;the calculation result represents the sum of copper loss The stator core loss accounts for about 99% of the total loss.Secondly,design and choose the watercooling structure of the motor.Based on the CFD method,using the fluent module in ANSYS to analyze the flow field and temperature field of different water-cooled structures,the spiral water channel has a more uniform flow velocity distribution and better heat dissipation performance under the same boundary conditions.Then calculate the convective heat transfer coefficient of the motor.The motor model is simplified,and the heat transfer coefficient is used for convective heat transfer compensation.Calculate the effective thermal conductivity of the gap,the heat transfer coefficient of the stator end,the heat transfer coefficient of the winding end,the heat transfer coefficient of the rotor end,and the heat transfer coefficient of the shell surface through the empirical formula method.Finally,an electromagnetic thermal fluid-solid coupling analysis model is established,and the steadystate temperature field under rated conditions is calculated using the fluent module in ANSYS.Through parametric modeling in Motor-CAD,the two modules of electromagnetic calculation and thermal calculation are used for unidirectional coupling to calculate the transient temperature field under peak torque and peak speed conditions.The simulation calculation results show that the motor high temperature area Concentrated at the end of the winding,the temperature field of the entire motor meets the design requirements.Strength analysis of the motor.The analysis results of the previous steady-state temperature field are mapped to the corresponding parts of the motor,and the Static Structural module in ANSYS is used for static dynamic analysis.Considering the interference fit between the shaft and the rotor core during assembly,the housing and the stator are subjected to constant The torque is affected,and the calculation results show that the deformation of the motor is within a reasonable range and the strength meets the requirements.Card issuing motor performance test experiment and reliability experiment.According to the corresponding national standards of the motor performance test experiment and reliability test experiment,the motor performance test experiment is carried out.The simulation results are compared and analyzed with the test results.The simulation results and the calculation results are in good agreement,which verifies the credibility of the model,shows that the calculation results have practical significance,and provides a reliable calculation model for future product development.And calculation method.