中性点非有效接地系统电磁式电压互感器铁磁谐振问题研究  

Comprehensive analysis on ferroresonance of electromagnetic potential transformer for power system with invalid neutral grounding modes

作　　者：许贵民 姚帅 尹红霞 XU Guimin;YAO Shuai;YIN Hongxia(Kashi Power Supply Company,State Grid Power Corporation,Kashi 844000,China)

机构地区：[1]国网喀什供电公司,新疆喀什844000

出　　处：《电气应用》2020年第5期53-60,共8页Electrotechnical Application

摘　　要：主要对中性点非有效接地系统电磁式电压互感器铁磁谐振问题进行研究。首先介绍了电压互感器铁磁谐振产生的根本原因,即铁磁材料磁导率随着所施加电压或流过电流的持续增大反而降低,引起励磁电抗急剧减小,从而引发谐振;接着介绍了铁磁谐振分类,包括基频谐振、高频谐振和分频谐振;然后重点分析了电压升高与电流增大对谐振的影响,分别介绍了中性点非有效接地系统单向接地时的中性点电压变化轨迹,并给出了可能产生谐振的区间范围,介绍了电压互感器三相励磁电抗不同饱和程度对铁磁谐振产生的影响;最后介绍了几种常用的谐振消除方法。所介绍内容能够为电网运维检修人员以及互感器设计人员提供理论参考和经验借鉴。A comprehensive analysis on ferroresonance of electro-magnetic potential transformer for power system with invalid neutral grounding modes is given.First of all,it introduces the basic cause for ferroresonance of electro-magnetic potential transformer:the magnetic permeability of ferromagnetic materials reduces with the increase on applied voltage and current,causing a sharp decrease on excitation reactance and leading to the occurrence of ferroresonance.Then it presents the classification which includes fundamental frequency,high frequency and di-vided frequency.The key analysis is on infuence of voltage increasing and current augment on ferroresonance.It gives a detailed introduction on variation of zero sequence voltage of single-phase earth fault in invalid neutral grounding modes and offers a reasonable interval which could cause ferroresonance;it analyses the impact of saturation of excitation reactance on ferroresonance.In the end,some ferroresonance elimination methods are provided.It could provide theoretical reference and experience for maintainer of power system and designer of potential transformer.

关 键 词：电压互感器 谐振 单相接地 饱和 消谐 

分 类 号：TM451[电气工程—电器]