正立式电流互感器膨胀器异常分析

Abnormal Analysis of Positive Current Transformer Expander

2019年,某省电网连续发生多起正立式电流互感器膨胀器异常拉伸和部分膨胀器顶部盖板跌落在地的事件,给电网安全稳定运行带来严重危害。通过对该类型电流互感器进行比对分析,发现其色谱数据普遍异常,氢气、甲烷、乙烷、总烃超标,部分互感器存在微量乙炔,但不涉及一氧化碳、二氧化碳。此外,对发生此类故障的正立式电流互感器返厂解体检查,难以发现放电点。为此,以一起220 kV某线路故障电流互感器A相返厂解体案例为例,对该类型电流互感器的故障原因进行了深入分析,对后期电流互感器运维提出了针对性的建议。

In 2019, a number of positive current transformer expanders in a power grid in a province continued to stretch abnormally,which brought serious harm to the safe and stable operation of the power grid. Through the comparison and analysis of this type of current transformer, it is found that the chromatographic data are generally abnormal, for example, hydrogen, methane, ethane, total hydrocarbon exceed the standard, and some transformers have trace acetylene, but do not involve carbon monoxide and carbon dioxide. In addition, it is difficult to find the discharge point through the breakdown by returning to the factory. In this paper, the fault reason of the current transformer of this type is analyzed and summarized based on the case study of a 220 kV line current transformer A phase breakdown when returned to factory, and the corresponding suggestions are put forward for the operation and maintenance of the current transformer.