选择性powerformer定子单相接地保护方案 stator winding single-phase grounding faults protection scheme for powerformer with selectivity.pdfVIP

技术与应用 王媛媛1杨博林2龙立宏2 (1．长沙理工大学，长沙520225；2．湖南省电力勘测设计院，长沙410007) 摘要 为解决高压发电机的选择性问题，分析了定子单相接地故障前后高压发电机机端零序 电流基波分量和三次谐波故障分量的变化特征。通过比较各高压发电机零序电流的大小、方向和 能量判断单相接地点是否在本发电机定子绕组内部。仿真分析结果表明：该保护方案可实现100％ 定子接地保护，能可靠地识别出发电机内、外部的定子接地故障，判断故障发电机；该方案构成 原理较简单，具有鲁棒性强的特点。 关键词：高压发电机；定子绕组单相接地故障；零序电流；选择性 ator Faults WindingSingle-PhaseGrounding forPowerformerwith ProtectionScheme Selectivity Bolin2 WangYuanyuaniYang LongLihon92 of 1O11 (1．ChangshaUniversityScience＆Technology，Changsha，44； 2．HunanElectricPower 41 DesignInsititue，Changsha0007) AbstractInordertoresolvetheselective forPowerforlTlerwithmorethanone protection a characteristicsofthestator bus，the generatordirectlyconnecting windingphase-to-ground fundamentalandthird-harmonicfault zero—sequencecurrent(zero—sequencecomponent component)are inthis thedirectionof of analyzed paper．Throughcomparing zero—sequencecurrents，magnitude fault stator faultscanbedetected currents，and zero—sequence pointenergydissipation，thegrounding occurredin stator ornot．Simulationresultsshowthatthe generatorwinding fundamental component andthethird—harmonicfault of currentarecombinedtorealize1 of componentleakage 00％coverage fau