贴壁式贯流机组定子绕组击穿故障处理关键技术

Key Technologies for Treating Breakdown Faults of Holistic Bulb Turbine Generator Stator Winding

针对贴壁式铁心无通风沟定子绕组槽内接地时利用传统的接地故障查找方法无法应用的问题,以广西大埔水电站为例,分别从定子线棒安装试验中击穿、发电机运行中定子线棒击穿两种不同情形分析研究故障查找及处理方案,提出了直流电位故障查找法,并在传统方法基础上优化球间隙放电故障法。当汛期机组出现接地故障而无法立即拆除故障线棒时,计算分析了采用引桥跨接法将故障线棒排除在支路外的影响,并研究了采取引桥跨接处理后机组运行参数变化对机组运行效果的影响。结果表明,贴壁式贯流机组定子绕组接地后,可采取临时处理方法--引桥跨接法绕开故障线棒,再根据机组参数变化量确定是否可临时满负荷运行。

The holistic stator core has no ventilation groove,and the traditional grounding fault finding methods can-not be applied when grounding in the stator slot.This article introduces the testing and detection methods for finding grounding bars during the installation process of stator bars in holistic stator core units,as well as the methods for han-dling faulty bars.Secondly,the binary method was used to analyze the grounding position of the stator winding during the operation of the unit.When a grounding fault occurs during the flood season and the faulty bar cannot be immediately removed,the impact of using the approach bridge crossing method to exclude the faulty bar from the winding branch was analyzed.The impact of changes in operating parameters of the unit after adopting the approach bridge crossing treatment on the operating performance of the unit was studied.The results indicate that after the stator winding of the holistic sta-tor core bulb turbine unit is grounded,a temporary treatment method can be adopted-the bridge crossing method to by-pass the faulty bar,and then determine whether it can temporarily operate at full load based on the change of unit parameters.