| Low floor vehicles meet the needs of modern national transportation development because of their energy saving and economic characteristics,and have strong adaptability to most areas in China,and gradually become the mainstream of modern transportation.Permanent magnet synchronous motor has the characteristics of small volume,high power density and so on,and has high adaptability to low-floor vehicles.At the same time,the characteristics of small volume and high power density of permanent magnet synchronous motor will produce a large temperature rise.The insulation layer inside the permanent magnet motor is prone to aging at high temperature,and the permanent magnet material is very sensitive to temperature.Irreversible demagnetization may occur in the high temperature environment,which seriously affects the performance of the motor.Therefore,a lot of research work has been done in this paper for a low-floor permanent magnet synchronous motor with rated power of 46.6k W.The number of poles,groove type,winding,permanent magnet and other aspects of the motor are emphatically introduced.The basic parameters of the motor are optimized by electromagnetic method and the final scheme of the motor is given.The simulation parameters of permanent magnet motor under rated working condition are obtained by electromagnetic calculation,and the correctness is verified by comparing with the test values of actual production motor.Combined with the principle of finite element analysis,a two-dimensional model of permanent magnet motor was established,and the electromagnetic parameters of the motor under rated working conditions were obtained through two-dimensional electromagnetic simulation,and the reliability was verified by comparing with the original given value under rated working conditions.Based on the calculation theory of steady-state working performance and loss of S1,the performance parameters and loss of permanent magnet motor in the steady-state working condition of S1 were solved.Combined with the related theories of permanent magnet motor traction control,the traction characteristics of permanent magnet motor are explored.Based on the basis of heat transfer and fluid mechanics,the temperature-fluid coupling solution model of the original water-cooled motor was established to explore the cooling performance of the original water-cooling structure.The reliability of the simulation is verified by comparing with the temperature rise test results of the prototype.Three new water-cooling structure schemes were designed,and a temperature-fluid coupling solution model was established to explore the best water-cooling scheme.After determining the optimal water-cooling structure scheme,the optimal water-cooling structure scheme is optimized from the three aspects of inflow flow,channel thickness and channel width.There are 47 figures,19 tables and 58 references. |
