Design And Optimize On The Cooling Structure For Electric Vehicle Motor

The oil shortage and atmosphere pollution are becoming increasingly serious.So in order to solve these problems,The new energy vehicles have to be developed.The electric vehicles are clean,quiet and economical.Nowadays,electric vehicles are becoming more and more popular.The motor is one of the most important parts of electric vehicles.The performance of the motor is very important to driving requirement for electric vehicles.The motors for electric vehicles need to be high power density,but the installation space was narrow.These factors caused high temperature rising rapidly in the motor.The motor would burnout,the windings and the magnets would fail to work if the temperature were too high.And the motors life would be shorted inevitably.So an effective cooling system is critical to reduce the temperature rise of the motor.This dissertation was based on the technology roadmap as below: ‘Determined the heat distribution of the motor—Calculated the temperature rise of the motor—Designed and optimized cooling structure—Analyzed the cooling performance—Determined a suitable cooling structure of the motor'.This study was focused on the effects of different cooling structures on temperature rise of the motor.1)Based on the heat transfer,a thermal network model of the motor is established.The model was used for calculating the loss of the motor,researching the heat transfer process in the motor.The temperature rise and temperature distribution of stator,windings,magnets and rotor were also analyzed.2)Based on the CFD(Computational fluid dynamics)method,the flow distribution inside the motor was Calculated applying the existing mainstream CFD mathematical model.The influence of the flow distribution in the cooling fin on the temperature rise of the motor is analyzed.3)Focused on the prototype,a forced air-cooled cooling scheme was proposed.This scheme provided the ventilation structure and vent location,the size of cooling fan was calculated.The different influence of forced air cooling structure and nature air cooling structure on temperature rise of prototype was analyzed.4)A parallel jacket was designed and optimized considering its structure,the different influence of temperature rise before and after optimization was compared.In the end,the result of the simulation which can provide some reference for the cooling structure design of the motor was analyzed and some advice was proposed.