电磁式电压互感器故障分析及防控措施

Failure Analysis and Prevention and Control Measures of Electromagnetic Voltage Transformer

电磁式电压互感器在我国10 kV配电网中广泛应用。其励磁电感呈现非线性,系统扰动时容易发生铁磁谐振,由此引起的PT炸裂情况时有发生,对电网正常运行带来严重的安全隐患。本文针对中性点不接地系统中PT铁磁谐振进行分析,结合实例阐述其产生机理及引发的危害,并对现有的几种消谐方法进行探讨。

Electromagnetic voltage transformer(PT)is widely used in my country's 10kV distribution network.Due to its non-linear excitation inductance,ferromagnetic resonance is prone to occur when the system is disturbed,and the resulting PT bursting occurs from time to time.The normal operation of the power grid brings serious security risks.This paper analyzed the PT ferromagnetic resonance in the neutral point ungrounded system,explained its generation mechanism and the harm caused by the case analysis,and discussed several existing resonance elimination methods.