Design and Optimization of High Efficiency Flat wire Motor for Electric Vehicle

Permanent magnet synchronous motor (PMSM) is the driving component of electric vehicle, and its performance directly determines the power performance, reliability and economy of electric vehicle. Traditional round wire motors can not meet the needs of electric vehicles in terms of high efficiency range, heat dissipation performance and automatic production. Flat wire motor gradually replaces the traditional round wire motor because of its small size, high efficiency, strong heat dissipation and low noise. However, the ac loss of winding of flat wire motor was high under the influence of skin effect at high speed. Therefore, taking 65kW motor as an example, the size design and winding optimization of flat wire permanent magnet synchronous motor are carried out. Firstly, the main dimensions of ac motor are calculated by using the basic equations of ac motor design. Secondly, the mathematical model of ac resistance of flat wire conductor was calculated by Maxwell electromagnetic field equations, and the optimization method of flat wire winding was analyzed according to the model and verified by finite element simulation. Finally, comparing the running efficiency of flat wire motor and round wire motor under the test road conditions, the influence of different cooling systems on motor temperature rise under the test road conditions was analyzed. The results show that the ac loss was the lowest when the height of flat wire conductor was the critical point, which provides a certain basis for the design of flat wire winding conductor.