铁道车辆牵引系统用永磁同步电机比较

永磁体的采用,使永磁同步电机即使在空转的时候也能产生反电势,并且随着转速的升高反电势亦升高。当永磁同步电机作为铁道车辆牵引电机时,由于铁道车辆特有的惰行工况,必须解决永磁同步电机在铁道车辆惰行时的高反电势,以及由此带来的重投困难。如果仅从控制的角度,在电机高速运行时施加直轴负向电流,从而减弱合成气隙磁场,以降低反电势,但由此将带来惰行的铜耗,并且对控制器和逆变器的可靠性提出了更高的要求。本文从降低电机高速惰行时的反电势出发,提出了几种永磁电机方案,从而为铁道车辆牵引用永磁同步电机的选择提供一定参考。

Comparison of Permanent Magnet Synchronous Motors Applied to Railway Vehicle Traction System

In use of the permanent magnet material,the permanent magnet synchronous motor(PMSM) can generate the back EMF even when rotating without load.The railway vehicle has the special working condition of costing.When PMSM is applied to the railway traction system,the problem of the high back EMF during costing and the difficulty of re-closing must be resolved.Reducing the synthesized air-gap flux linkage by adding the negative d-axis current can reduce the back EMF,but the copper loss is increased and the reliability of the control unit and inverter must be enhanced.In this paper,several PMSM designing schemes are put forward from the point of reducing the back EMF.This gives a reference for selecting PMSM for the railway vehicle traction system.