次级断续时直线感应牵引电机的分段式等效电路与特性分析

A Piecewise Equivalent Circuit and Characteristic Analysis of Linear Induction Traction Motor when the Secondary is Discontinuous

提出分段式等效电路模型,分析了次级断续时直线感应牵引电机特有的电磁现象及其特性。首先,建立次级断续时直线感应电机的物理模型,根据初级、次级的耦合情况将初级通过断续区域的过程分为九个阶段。其次,提出分段式等效电路模型,分析次级断续时等效电路参数的变化情况。然后,考虑初级铁心有限长、横向和纵向端部效应、趋肤效应和初级半填充槽的影响,根据电磁场分析模型和各阶段求解时的积分区间,求出次级断续时推力、气隙传递的无功功率、次级板涡流损耗、机械效率和等效电路参数。最后,将不同频率和速度下计算的推力、次级断续时推力和效率的动态变化曲线与实验测量结果对比,分析了电机的特性变化情况,验证了等效电路的正确性。

A piecewise equivalent circuit model is proposed,and the electromagnetic phenomena and characteristics of linear induction traction motor with discontinuous secondary are analyzed.Firstly,the physical model of linear induction motor with discontinuous secondary is established.According to the coupling situation of primary and secondary,the process of primary passing through discontinuous region is divided into nine stages.Secondly,a piecewise equivalent circuit model is proposed,and the variation of equivalent circuit parameters are analyzed when the secondary discontinuity occurs.Then,the effects of the finite length of primary core,transverse and longitudinal end effects,skin effect and half-filled slots of primary are considered.According to the electromagnetic field analysis model and the integral interval of each stage,the thrust,reactive power transferred by air gap,eddy current loss of secondary plate,mechanical efficiency and equivalent circuit parameters are calculated.Finally,thrust under different frequencies and speeds,the dynamic curves of thrust and efficiency,are compared with the experimental results,and the characteristics of the motor are analyzed,which verify the correctness of the equivalent circuit.