| Since the beginning of the 21 st century,urban rail transit has developed rapidly and has been widely popularized in many cities.Locomotives used in urban rail transit are frequently started in the section and short running time,which can generate considerable and recoverable braking energy.However,due to the insufficient development of energy storage technology,this part of the energy cannot be recycled.Therefore,the development of urban rail transit urgently needs an efficient energy storage technology.Flywheel Energy Storage System(FESS),as a high power density and pollution-free energy storage method,in fact,it not only helps to raise the braking energy utilization rate to a higher level,but also reduces the related voltage fluctuations,so it contains very clear room for development.High Speed Permanent Magnet Synchronous Motor(HSPMSM)is compatible with FESS by virtue of its high power density and simple structure.From the perspective of HSPMSM,in fact,it belongs to an indispensable and important part of FESS.Whether its performance is good or bad will have a key impact on the latter,and it is in FESS,the operating environment of HSPMSM is vacuum,which makes it difficult to dissipate heat,and the internal temperature rise of the motor is large,which is not conducive to the safe and stable operation of HSPMSM.Therefore,the paper focuses on the loss and temperature of HSPMSM.The main work and results are as follows:(1)According to the Alstom Type A car as the main body of the application,after the analysis,it was decided to model its dynamics model,analyze the relationship between resistance and traction/braking force,and calculate the specific power and energy during the start-stop phase of the vehicle group.And based on the simulation of the traction power supply system,it is explained that the energy recovery system is helpful to suppress the fluctuation of the grid voltage.After the above steps are completed,the detailed FESS configuration scheme and the basic performance parameters of the motor are obtained.(2)According to the matched rated parameters of the motor,the calculation of the key dimension parameters is completed,and the stator and rotor structures are designed based on the characteristics of the high-speed motor.Make full use of the relevant finite element software to design a motor with 130 k W and a speed of 20,000 r/min Material selection and size calculation were followed by a 2-D finite element motor model to analyze the electromagnetic characteristics under no-load conditions and verify the rationality of the motor design.(3)The stator iron loss calculation model was established on the basis of considering the rotating magnetization and various harmonics,and the value of the stator iron loss was calculated by using it,and the simulation test was performed using Maxwell software.The simulation results were compared with the analytical calculation values to verify whether the model was accurate;use the formula method to calculate and analyze the copper loss of the stator winding;efficient simulation of the loss of permanent magnets,which lays the foundation for the temperature field analysis in the next chapter.(4)The basic principles of heat transfer are explained,and three basic methods of heat conduction are introduced.On this basis,a three-dimensional finite element thermal model of HSPMSM is built,and the calculation method of thermal parameters and heat dissipation coefficient of HSPMSM material is given.The temperature field of HSPMSM under natural air cooling and vacuum conditions is analyzed,and the results show that the temperature rise under vacuum conditions is higher than that under natural air cooling conditions. |
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