Research On Rail-driven Direct-drive Pivot Module Combination Traction Permanent Magnet Motor

Aiming at the disadvantages of the current rail transit traction system in China,the asynchronous motor or permanent magnet motor combined with the gearbox leads to low transmission efficiency and complex transmission structure.This paper proposes a new traction drive system for direct drive axle-type module combined traction permanent magnet motor.Compared with the traditional traction drive system,the transmission system has the advantages of high transmission efficiency,simple transmission structure,small maintenance workload,and easy maintenance and assembly.The main research contents are as follows:Firstly,the advantages of the direct drive axle-type module combined traction permanent magnet motor traction system and the traditional traction system are compared and analyzed,the transmission structure of the gearbox simplified traction system is omitted,and the problem of difficult maintenance and disassembly of the motor is solved.In order to ensure that the motor's electromagnetic torque does not change before and after the motor is cut off,the rated parameters of the replaced direct drive axle-type module combined traction permanent magnet motor are converted according to the performance parameters of the original traction motor used in the subway.Secondly,the splitting rules and stator winding module splitting rules of the direct drive crankshaft module combined traction permanent magnet motor stator unit module are derived.The stator slot splitting and stator of the q=0.4 permanent magnet motor commonly used in the slot matching are summarized.Number of winding split modules.A stator-driven modular permanent magnet motor with a stator splitting into three unit modules and a stator winding with 9 coils cut off is designed.Finally,the operation characteristics of the direct-drive axle-type module combined traction permanent magnet motor under different operating conditions are analyzed:the normal operation of three unit modules,one unit module failure and two unit module failures are carried out with no-load and load simulation.Verify the fault tolerance of the motor.In order to improve the stability of train operation,the influence of the structure with different degrees of uneven air gap ratio on the harmonic pulsation of the motor is analyzed.Considering that the size of the traction motor is limited,the temperature rise of the motor is also not negligible.By comparing and analyzing the influence of the number of slots on the water channel on the cooling effect of the motor,the water channel design of the motor is finally determined.The vector control method of the direct drive axle-type module combined traction permanent magnet motor is introduced.The system simulation model based on MTPA vector control is built in Simulink.The simulation results verify that the controller design can meet the control requirements.