一起220kV倒置式电流互感器事故原因分析

对一台220kV油浸倒置式电流互感器的故障进行了分析,介绍了故障分析与诊断的过程,并结合故障产生的原因提出了相应的预防措施。     

基于FRA的发电机转子绕组匝间短路故障仿真研究

基于频率响应法(FRA)理论,对发电机转子绕组匝间短路故障进行仿真研究。采用有限元软件计算某1000MW汽轮发电机转子绕组正常工作及匝间短路故障下的分布电容、电感参数,从而搭建发电机转子绕组二端口网络模型。结果显示,绕组频响曲线谐振峰主要集中在150kHz附近,匝间短路使谐振峰往高频方向移动,且短路越严重,谐振峰位置变化越明显。同时,不同线槽绕组由于分布参数的差异,频响曲线在谐振峰位置和幅值上有明显不同。     

变压器箱体螺栓异常发热的原因分析与处理方法

通过红外测温巡检发现变压器箱体多个连接螺栓发热严重.通过理论分析变压器正常运行过程中的漏磁通分布,结合现场实际经验,找出异常发热原因,提出了采用不锈钢螺栓或导流铜排进行磁通短路处理的措施.     

直流串联电弧故障的检测方法研究(英文)

It is difficult to detect and extinguish direct current(DC)arc in power electronics systems,and the arc could easily lead to a fire and cause great damage to surrounding equipment.A DC arc generation simulation unit is established,in which DC series arcs are generated by dragging the moving electrode away from the fixed one with the help of the stepper motor.In addition,a ferrite rod antenna is used to receive the electromagnetic radiation signals induced by the arcs.Based on experiments using the unit,the general characteristics of DC arc,including the pulse characteristics of arc current and source output in corresponding time window,and the frequency-domain characteristics of arc current,are studied.With discussion on three detection methods,it is concluded that the variation of current and voltage of arc,the spectrum of the arc current during the discontinuous intervals and the radiating electromagnetic signal are all features that can be adopted for detecting DC series arc.Therefore,a synthetic judgment method is suggested for further study.