220 kV油浸式电流互感器油色谱异常原因分析

Analysis of Abnormal Oil Chromatography of 220 kV Oil-Immersed Current Transformer

对某220 kV变电站油浸倒置式电流互感器进行油色谱分析试验,试验结果发现乙炔含量异常,初步分析判断故障类型为低能量瞬时放电。通过试验、返厂解体及后续根据厂家对倒置式系列电流互感器雷电截波冲击试验的试验结果和本例电流互感器在变电站所处间隔位置,验证分析结果的正确性,并提出运行维护措施。研究结果表明,二次绕组与铁芯罩壳间在冲击电流作用下的低能量局部放电是造成此类型油浸倒置式电流互感器油色谱异常的主要原因,并且发现此现象多出现在母联间隔,本研究为油浸倒置式电流互感器绝缘性能研判提供一定参考。

The oil chromatographic analysis test is carried out on the oil-immersed inverted current transformer of a 220 kV substation.The test results find that the acetylene content is abnormal.The preliminary analysis shows that the fault type is low-energy instantaneous discharge.The test results of a series of current transformers in the lightning chopper impact test and the interval position of the current transformer in the substation in this example verify the correctness of the analysis results,and put forward operation and maintenance suggestions.The research results show that the low-energy partial discharge between the secondary winding and the iron core casing under the action of the inrush current is the main reason for the abnormal oil chromatogram of this type of oil-immersed inverted current transformer,and it is found that this phenomenon often occurs in the bus tie interval.The research provides some reference for the research and judgment of insulation performance of oil-immersed inverted current transformer.