Research On The Problem Of Traction For The New Mid-to-low Speed Maglev Train Using Synchronous Motor

Low velocity and low tractive efficiency are the main defects of low-spee maglev train. Complex system, large swerving radius, and high investment are the main defects of high-spee maglev train. In order to make up the defects of the exiting maglev train, reserve their advantages, and widen the application field of maglev train, the new mid-to-low speed maglev train(CMST) is studied. Halbach permanent magnet+ironless coil typed synchronous motor is applied in the CMST system. The dissertation focuses on the optimization design and performance analysis of the new motor, the control method of vehicle traction. The details of this dissertation are listed as follows.1. The optimization design of the new motor is researched. The calculation method of tractive force is studied. The calculation method is verified using finite element method. The accelerating ability is analyzed. The calculation methods of tractive efficiency and power supply capacity is studied. The impacts on tractive efficiency and power supply capacity caused by structure parameters, such as motor stator size, space width are detailed. Studies show that in order to improve tractive efficiency, stator length should be reduced, stator width should be increased, space width should be decreased on the premise that the accelerating ability is enough. Moreover, the design example of new motor is given,2. The performance of the new motor is analyzed. The performance of new motor using ironless coil and iron coil is compared. The magnetic field intensity, electromagnetic force, traction efficiency and power factor are calculated. Then the calculation methods of the most energy-saving speed, average efficiency and energy consumption are studied. The study shows that when the speed is 110~130km/h, the traction efficiency of the CMST is highest. Additionally, the magnetic field intensity and traction force of the new motor are measured, and its accelatation nearly reaches 1.1 m/s2.3. The traction control system of CMST is studied. Analyze the impacts on control effect induced by Halbach permanent magnet+ironless coil. The control system is studied. The strategy that 0di ? is used to guarantee the normal force is zero. The decoupling current loop is designed. The control parameters are adjusted according to the stator length. Finally, the design is verified through simulation.