一起220kV CVT的铁磁谐振故障分析

Fault Analysis on Ferromagnetic Resonance of 220 kV CVT

为研究某变电站一起220 kV电容式电压互感器铁磁谐振故障的原因,通过对220 kV电容式电压互感器的结构原理、内部稳态谐振、暂态谐振及其抑制措施进行了探讨,在分析了电容量、介质损耗、录波图后,初步判断该电容式电压互感器出现铁磁谐振且不能有效阻尼的故障。研究后将故障电容式电压互感器返厂进行准确度试验、铁磁谐振检验,其中铁磁谐振检验项目不合格,验证了分析的正确性。最后总结了电容式电压互感器发生铁磁谐振的外部条件及阻尼器失效的原因,就如何避免电容式电压互感器发生铁磁谐振提出了若干建议。

For studying the reason of ferromagnetic resonance fault in 220 k V capacitor voltage transformer（CVT）, through the discussion of structure principle, internal steady resonance, transient resonance and its suppression measures, and after the analysis of capacitance, dielectric loss and oscillogram, the initial judgment is CVT cause ferromagnetic resonance, and the fault cannot be effectively damped. After the study,the faulty CVT is returned to the manufacturer for accuracy test, ferromagnetic resonance check. The item of ferromagnetic resonance check is unqualified and the correctness of the analysis is verified. Finally,the external condition causing ferromagnetic resonance of CVT and the damping invalidity are summarized,also many suggestions on how to avoid the ferromagnetic resonance of capacitor voltage transformer are proposed.