小电流接地系统间歇性弧光接地过电压影响因素分析

Analysis of Influencing Factors on Intermittent Arc Grounding Overvoltage in Small Current Grounding System

摘要:

弧光接地过电压作为小电流接地系统中最常见的内部过电压之一，对电力系统的安全稳定运行产生巨大威胁。弧光过电压的产生往往伴随着间歇性，通过分析间歇性弧光过电压的暂态特征以及影响因素能够为防治该现象提供必要的参考。为此，考虑了包括电弧重燃时刻、燃弧时长、熄弧时长、电弧电阻在内的几个不同影响因素，通过搭建中性点不接地系统的仿真平台分析间歇性弧光接地过电压的暂态特征，并对比各影响因素的作用程度。结果表明在中性点不接地系统的间歇性接地能够产生明显的过电压，并且过电压的幅值主要受重燃时刻和电弧电阻影响，而燃弧时长、熄弧时长对过电压幅值影响较小。

Abstract:

As one of the most common internal overvoltages in small current grounding system, arc grounding overvoltage poses a great threat to the safe and stable operation of power system, and the generation of arc overvoltage is often accompanied by intermittency. The analysis of transient characteristics and influencing factors of intermittent arc overvoltage can provide a necessary reference for preventing and controlling this phenomenon. For this reason, several different influencing factors are considered, including arc reignition time, arc duration, arc extinction time and arc resistance. By building a simulation platform for ungrounded neutral system, the transient characteristics of intermittent arc grounding overvoltage are analyzed, and the effects of various influencing factors are compared. The results show that the intermittent grounding in ungrounded neural system can produce obvious overvoltage, and the magnitude of overvoltage is mainly affected by the reignition time and arc resistance, while the arc duration and arc extinction time have little influence on the magnitude of overvoltage.