考虑实心体涡流影响的笼型实心转子电机起动工况导条电流分布的解析计算

Analytical Calculation of Rotor Bar Current Distribution in Starting Condition of Cage Solid-Rotor Machine Considering the Effect of Eddy Current in Solid-Rotor

笼型实心转子感应电机实心体与导条感应电流相互耦合,尤其是两极电机起动时,实心体涡流对导条电流分布产生很大影响,使导条电流密度由槽口至槽底呈现先减小后增大的不对称U型分布。传统计算方法会导致转子参数计算误差较大,严重影响电机设计的准确性。该文建立考虑磁场饱和效应的二维多层电磁场解析模型,求解两极笼型实心转子感应电机起动工况下的磁场分布。在此基础上,计及转子铁心轭部感应电流影响,建立转子导条电流解析计算模型,并求解电机在起动运行时笼型导条电流密度的分布。最后,通过与有限元仿真结果对比,验证不同电压下起动时,所求解的导条电流密度分布规律的准确性。结果表明所提出的计算方法适用于包括两极电机在内的各种极数笼型实心转子感应电机,为该类电机起动参数及性能的准确计算提供了参考。

The induced current of solid-rotor and rotor bar of cage solid-rotor induction machine coupled with each other.Especially during the start-up process of two-pole machine,the current density of rotor bar shows an asymmetric U-shaped distribution due to the current of solid-rotor,decreasing first and then increasing from the top to the bottom of the slot.The traditional calculation method leads to large calculation error,affecting the accuracy of machine design.In this paper,a two-dimensional multilayer electromagnetic field analysis model that considered the effects of magnetic field saturation is established to solve the magnetic field distribution under starting condition.On this basis,considering the influence of the induced current of the rotor core yoke,an analytical calculation model was established to solve the current density distribution of rotor bar during the starting operation.Finally,by comparing with the finite element simulation,the accuracy of the calculation of the current density distribution was verified when the machine was started at different voltages.The proposed analytical calculation method is applicable to cage solid-rotor induction machines with different pole-pairs and provides a reference for accurate calculation of starting parameters and performance of the machine.