直线电机不均匀气隙磁场解析计算方法

直线感应电机运行时，其初级和次级之间可能因不平行而形成不均匀气隙，从而造成电机磁场分布变化。对于这种不均匀气隙的电机磁场分布的计算，沿用传统的基于均匀气隙的公式则会使误差增大。为解决此问题，首先基于电磁场理论，提出了一种不均匀气隙直线感应电机磁场的解析计算公式；其次根据直线电机特性对解析公式进行修正；最后将解析公式计算结果与有限元方法计算得到的气隙磁场分布结果进行了对比。对比结果表明，这种考虑了气隙不均匀的解析磁场计算方法相比不考虑气隙不均匀的计算，其平均误差减小50%以上,为直线感应电机的设计和控制效果的提升提供了一种有益的参考。

An Analytical Calculation Method of Flux Density for Uneven Air-gap Linear Induction Motor

The linear induction motor(LIM)may lead to an uneven air-gap between its primary and secondary during operation.This uneven air-gap will bring the variation of flux distribution in the LIM.The traditional calculation method for electric machine flux will enhance error when not considering the uneven air-gap.Aiming to this problem,this paper firstly presented an analytic calculating method of the flux density based on Maxwell’s theory,secondly provided a correction method considering the uniqueness of LIM,finally compared the results with the results of the finite element method(FEM).The comparison illustrates that the analytic method reduces the calculation error over 50%than the calculation without considering the uneven air-gap.This method provides a useful reference for the future design and control of LIMs.