基于PEEC法的发电机定子绕组线棒高频电路模型

建立合理的电机定子绕组电路模型,对于研究定子绕组绝缘局部放电信号的传播规律,了解局部放电信号的特征具有重要意义.部分元等效电路(PEEC)法是基于电磁场方程推导出来的等值电路模型,能够对一些用传统方法难以建模的复杂物理结构建立合理的电路模型,并且所建模型可以方便地与其它模型(比如传输线模型)综合连接、计算仿真,该方法还能够综合考虑外部测量电路的影响,在集成电路高频电路模型建立中有广泛的应用.本文采用PEEC法原理,建立了电机定子绕组单根线棒高频电路模型和双根线棒的耦合传播模型,此方法克服了以往多导体均匀传输线理论在电机定子绕组电路模型建立中的不足.模型中的部分电感、部分电容等参数由PEEC原理结合相关计算软件求得.模型的仿真计算与实验结果比较,证实了所建模型的有效性及参数的准确性.

HF Circuit model of generator stator bar based on PEEC

Modeling an accurate circuit of generator stator windings is significant for researching Partial Discharge(PD) propagation in stator windings and the characteristics of PD.There are mainly three faults about the stator windings circuit model based on the multi-conductor transmission line theory: firstly,the signal propagating in stator windings is not strictly a TEM mode;secondly,it is difficult to set up a reasonable end-windings circuit model with transmission line theory;and finally it is impossible to establish a complex coupling circuit model of the stator windings and the PD sensors.This paper develops a new HF circuit model of single stator bar and a coupling circuit model of two coupled bars on the basis of Partial Element Equivalent Circuit(PEEC) method,which has an advantage over the multi-conductor transmission line theory in modeling circuit of generator stator windings.The partial inductance matrices and partial capacitance matrices in the model are calculated by using PEEC theory and FastModel-a special calculating software developed by MIT.The consistency between the experiment results and the simulation results shows that the PEEC model and the parameters are feasible and accurate enough within the frequency range under test.