分段供电直线感应电机动子不对称模型及参数计算

摘要

对于分段供电直线感应电动机,由于动子两端开断,动子等效互感存在较大的不对称,仅控制定子电流对称,不能消除动子负序电流引起的两倍转差频率力波动.基于动子涡流产生的机理,提出了动子等效绕组的形式,推导了动子不对称分布参数模型,得出在动子行程的大部分阶段,电机的不对称参数是基本恒定的.提出了动子不对称参数的计算方法,通过有限元建模进行推力仿真,并在大功率加速实验平台上开展动态试验,计算了动子不对称电感参数,仿真和实验计算结果与理论值吻合良好.动子不对称参数计算方法,可以为分段供电直线感应电机的电磁设计和优化控制提供参考.%For segment-powered linear inductive motor, there is a major asymmetry among the equivalent mutual inductance for discontinuity of mover.Double slip frequency thrust ripple caused by negative sequence component of mover current cannot be eliminated by just controlling primary current symmetrical.Based on the mechanics of eddy currents, the form of mover equivalent windings is proposed, mover asymmetrical distributed parameter model was derived.In most of mover travel distance, the asymmetrical parameters are mainly constant.Finally the method of calculating mover asymmetrical parameter by making use of thrust data was presented, The mover asymmetrical parameter was validated by finite element simulation and experiment,and the simulated and experimental results matched well with analytical results.The method provides a useful reference to the electromagnetic design and optimize control of segment-powered linear induction motor.