考虑铁心片间短路故障的均匀化建模方法

Simulation study of interlamination short-circuit fault in cores based on homogenization theory

铁心叠片绝缘故障导致片间短路问题,一直是影响大型高压电机安全稳定运行故障之一。现行复杂叠片短路故障模拟计算方法,未能充分考虑频率和磁通对垂直于冲片轧制方向集肤深度影响,同时存在因叠片网格剖分计算量大而不利于工程应用。提出一种针对片间故障的快速模拟方法,采用宏观结构等效电导率与磁导率的均匀连续体代替实际叠片,构建片间故障的快速模拟模型。使用T,ψ-ψ方程的三维涡流场对片间绝缘区域进行计算,并将实际叠片模型与均匀化模型的仿真结果对比。最后以大型高压电机YR630-12/1430的铁心为例,进行片间故障电流的检测实验。结果表明,有限元仿真结果与实验结果相近,该模型可以快速且有效仿真实际片间故障,满足工程需求。

The interlamination short-circuit problem caused by core lamination insulation faults affects the stable operation of large-scale high-voltage motors.At present,the simulation calculation method for lamination short-circuit fault of the influence of frequency and magnetic flux on the skin depths is not fully considered in the direction perpendicular to the punching rolling direction.At the same time,there is a large amount of computation caused by the mesh subdivision for detailed lamination,which is hardly acceptable to the application in the engineering.In this paper,a fast simulation method for interlamination short-circuit faults is proposed.Using the macroscopically equivalent uniform electric conductance and magnetic permeability continuum model,a fast simulation model of complex lamination faults was constructed.It was based on the finite-element method,using the 3D eddy current field dynamic T,ψ-ψformulation.The simulation results of the actual laminated model and the eddy current field of the homogenization model were compared and analyzed.Finally,the stator core of large-scale high-voltage motor YR630-12/1430 was taken as an example to test the short-circuit fault current electric conductance.The results show that the finite element simulation results are similar to the experimental ones.The simulation model can quickly and effectively simulate the actual interlamination short-circuit fault and meet the engineering requirements.