Water Cooling System Design And Temperature Analysis Of PMSM In Electrical Vehicle

The drive motor in electric vehicle usually got a high temperature rise as it is typically be with high power density, which will have a significant influence on motor operation performance, efficiency and life. Water cooling is an effectively way for the reduction of temperature. The temperature of water cooling motor is both related with the complex thermal model inner the motor and the rheological properties of cooling medium inner the cooling structure. The research of high-performing cooling structure has important theoretical significance and applied value to the improvement of power density and operation reliability in the motor.A kind of high efficient parallel V-type water cooling structure was researched. Firstly, based on the basic theory of hydromechanics, the3D fluid and temperature fields were analyzed numerically using the finite element method. The structure of the water channels was optimized for the targets of improving the flow uniformity, increasing the convective heat transfer surface and reducing the flow resistance. The comparison was present before and after the optimization.Secondly, based on the basic theory of heat transfer, the thermal field of the motor in radial cross section was scattered into25lumped parameter nodes using the equivalent thermal network method, a set of heat transfer equations were listed and analyzed. The3D steady thermal finite element model of the motor was established and the numerical analysis was done, the result of25nodes were verified, the temperature distribution and heat transfer characters inner the PM motor were system analyzed and the height of the cooling ribs and the water inflow were researched as the thermal sensitivity factor.Finally, the15kW water cooling PMSM in electric vehicle was based on a prototype. The water cooling-temperature test bench was built, the flow field characteristics in the cooling structure were researched and the temperature experimental plan was put forward. The cooling structure has been used in the practical motor products and got a good cooling effect.