发电机定子绕组单相接地故障的定位方法  

LOCATION DETECTION FOR THE STATOR SINGLE-PHASE GROUND FAULT OF A GENERATOR

作　　者：毕大强[1] 王祥珩[1] 李德佳 余高旺 王维俭[1] 

机构地区：[1]清华大学电机系,北京市100084 [2]核电秦山联营有限公司,浙江省海盐县314300 [3]许继电气保护及自动化事业部,河南省许昌市461000

出　　处：《电力系统自动化》2004年第22期55-57,94,共4页Automation of Electric Power Systems

基　　金：中国博士后科学基金资助项目(2004035022)

摘　　要：对发电机定子单相接地故障进行故障定位,能够扩展目前定子单相接地保护的功能,有利于尽早发现和排除接地故障。提出了一种针对中性点经配电变压器高阻接地的发电机定子单相接地故障定位方法。由基波零序电压启动故障定位功能,根据发生单相接地故障后故障相机端对地电压最低的特点,判断出故障相别。进一步利用故障位置与发电机零序电压、故障相相电压、对地电容以及接地故障过渡电阻之间的关系,计算出具体的故障位置,其中,接地故障过渡电阻值由外加20 Hz电源定子单相接地保护计算得到。此故障定位方法简单易行,无需另外增加设备。动模试验结果验证了此故障定位方法的正确性和有效性。Fault location for ground fault of a generator will extend the present function of ground fault protection and greatly help the fast detection and clearance of the ground fault. This paper proposes a method to detect the location of stator ground fault for a generator, whose neutral is grounded via the distribution transformer with a parallel resistance at secondary winding. After the zero-sequence fundamental voltage enables the function of fault localization, the fault phase is determined according to the characteristic that the terminal voltage of fault phase is the lowest. Furthermore, in terms of the relationship among the fault location, zero-sequence fundamental voltage, fault phase voltage, winding capacitance to ground and grounding transient resistance, which is obtained by the injection 20 Hz voltage protection, the fault location is calculated. The proposed method of fault localization in the paper is simple and practicable, and does not need additional equipment. The experimental results demonstrate that the method is correct and valid.

关 键 词：发电机 定子单相接地故障 外加电源 零序电压 故障定位 

分 类 号：TM31[电气工程—电机]