某变电站35 kV电压并列装置烧毁的原因分析

Cause Analysis of 35 kV Voltage Paralleling Device Burning in Certain Substation

针对地区电网中某变电站一起35kV电压互感器并列装置烧毁的现象,从电压并列装置的原理出发,结合故障现象,运用戴维南等效电路原理阐述了电力系统铁磁谐振机理,通过分析电磁油浸式电压互感器的原理与内部结构,得出了单相接地及其过程引起的铁磁谐振过电压窜入二次侧回路是导致该电压并列装置两次烧毁的实际原因。给出了消除或抑制电压互感器铁磁谐振的多种应对措施,为今后确保电网安全稳定运行提供参考。

In allusion to a case of35kV voltage transformer burning phenomenon of regional grid substation devices,starting from the principleof the voltage paralleling device and combining with the fault phenomenon,this paper adopted Thevenin equivalent circuit principle to expound theferromagnetic resonance mechanism of electrical power system.Analysis was made to the principle and interior structure of electromagnetism oilimmersed voltage transformer.The one-phase ground was obtained and its process that created ferromagnetic resonance overvoltage plunging intothe circuit at secondary side was the actual cause of the voltage paralleling device twice burning.This paper gave a variety of measures to eliminateand suppress the voltage transformer ferromagnetic resonance,which provides references for safe and stable operation of the power grid in future.