大型发电机及其机端外接元件单相接地故障定位  

Ground Fault Location of Large Generator and External Components

作　　者：赵思腾 桂林[1] 张琦雪[2] 王祥珩[1] ZHAO Siteng;GUI Lin;ZHANG Qixue;WANG Xiangheng(State Key Laboratory of Control and Simulation of Power System and Generation Equipments(Department of Electrical Engineering,Tsinghua University),Beijing 100084,China;NR Electric Co.,Ltd.,Nanjing 211102,China)

机构地区：[1]电力系统及发电设备控制和仿真国家重点实验室(清华大学电机系),北京100084 [2]南京南瑞继保电气有限公司,江苏南京211102

出　　处：《中国电力》2020年第3期119-125,共7页Electric Power

基　　金：国家自然科学基金资助项目(51277103);中国广核集团公司科技项目(3100077009)~~

摘　　要：为了区分大型发电机及其机端外接元件的单相接地故障,提出了一种基于零序方向判别原理的定位方案,将发电机及其机端外接元件划分为发电机本体、励磁变高压绕组、高厂变高压绕组和剩余外接元件4个区域,采用排除法依次排查并确定故障位置。该定位方案的关键在于机端零序电流和励磁变/高厂变高压侧零序电流的测量,需要结合故障区域选择不同的电流互感器。采用现场故障案例对所提定位方案进行了验证,表明该方案能够实现发电机及其外接元件接地故障的准确定位,缩短了故障检修时间,保证了发电机及时恢复供电。该故障定位方法具有推广应用价值。A fault location method is proposed to distinguish the ground faults of large generators and their external components.It divides the generator and its external components into four regions:the generator,the high-voltage winding of excitation transformer,the high voltage winding of unit auxiliary transformer,and the remaining external components.According to the zero-sequence direction discrimination principle,the exclusion method is used to check and determine the location of the fault.The key to this location method is to measure the zero-sequence current of generator terminal and high-voltage side of excitation transformer/unit auxiliary transformer.It’s necessary to select the TA according to different regions where the fault occurs.The location method was verified by a series of real fault cases,which proved that the method can accurately locate the ground fault of the generator and its external components,with shortened troubleshooting time and in-time power recovery of the generator.The proposed fault location method has the value of popularization and application.

关 键 词：发电机 机端外接元件 接地故障定位 零序方向判别原理 排除法 

分 类 号：TM862[电气工程—高电压与绝缘技术] TM31