发电机转子匝间短路故障电磁场数值分析研究  

Electromagnetic Field Study on Rotor Winding Inter-turn Short Circuit Fault of Generator based on Numerical Analysis

作　　者：李天辉 夏彦卫 臧谦 武玉才[2] 顾朝敏 张达 田霖 张志猛 LI Tianhui;XIA Yanwei;ZANG Qian;WU Yucai;GU Chaomin;ZHANG Da;TIAN Lin;ZHANG Zhimeng(State Grid Hebei Electric Power Research Institute,Shijiazhuang 050021,China;School of Electrical and Electronic Engineering,North China Electric Power University,Baoding 071003,China)

机构地区：[1]国网河北省电力有限公司电力科学研究院,石家庄050021 [2]华北电力大学电气与电子工程学院,河北保定071003

出　　处：《大电机技术》2023年第5期7-12,共6页Large Electric Machine and Hydraulic Turbine

基　　金：国网河北省电力有限公司科技项目(kj2019-067)。

摘　　要：掌握气隙磁场的分布情况,是实现转子绕组匝间短路故障诊断的重要手段。考虑到短路故障会引起绕组电路拓扑结构的改变,本文通过机理分析推导,得到气隙磁场、定子电流、电磁转矩等一系列电气量的变化特征,并采用有限元数值分析法对故障状态的电磁场及电磁特性进行研究。以一台同步发电机为例,首先建立二维场路耦合有限元电磁场计算模型,通过仿真分析对比了电机额定工况时发生短路故障前后磁场分布的差异;然后对匝间短路故障下产生在电机气隙磁密中不同频率的谐波、定子支路中的电流及电机电磁转矩的变化规律进行了深入分析;最后重点针对故障对电机运行性能的影响进行了探讨。本文可为同步发电机早期故障诊断提供理论依据,为工程实际提供参考。It is important to know the distribution of the air gap magnetic field for the fault diagnosis of inter-turn short circuit,which occurs in excitation winding of synchronous generator.Considering that the short circuit fault will cause a series of changes of the topological structure of winding circuit,this paper obtains the variation characteristics of a series of electrical quantities such as air gap magnetic field,stator current and electromagnetic torque through theoretical analysis and derivation.The electromagnetic field and electromagnetic characteristics of the rotor inter-turn short circuit fault are numerically analyzed and verified by the finite element method.Taking a synchronous generator as an example,the two-dimensional field-circuit coupling finite element electromagnetic field calculation model of the generator is established.Firstly,the difference of magnetic field distribution before and after the short circuit fault under the rated operation condition of the generator is compared.Secondly,we deeply analyze and obtain the variation rules of air gap flux density harmonics,stator branch current and electromagnetic torque under inter-turn short circuit fault.Finally,the influence of fault on the operation performance of the generator is analyzed.This paper can provide a theoretical basis for early short circuit fault diagnosis of synchronous generator rotor and reference for engineering practice.

关 键 词：同步发电机 匝间短路 有限元方法 故障诊断 电磁场 

分 类 号：TM301.4[电气工程—电机]