配电系统单相接地保护存在问题及改进措施

作者：邬莉娜1，彭建州2 日期：2008-06-23/span> 浏览：4135 查看PDF文档

配电系统单相接地保护存在问题及改进措施

邬莉娜1，彭建州2
（1.浙江大学 电气工程学院,浙江 杭州 310027； 2.杭州华章电气工程有限公司,浙江 杭州 310012）

摘要：三相四线配电系统中变压器低压侧单相接地短路有多种保护方式。为了简化二次回路和减少初投资，通常用过流保护兼作单相接地短路保护，但在保护配置和整定上都存在保护灵敏度和选择性难以兼顾的问题。提出了一种利用负序保护功能实现的变压器低压单相接地保护方法，并详细给出了保护计算方法及具体实施技巧。研究结果表明，该方法能在不增加设备投资和接线的情况下，妥善地解决单相接地保护的难题。
关键词：低压配电；接地保护；负序保护；灵敏度分析
中图分类号：TN421文献标识码：A文章编号：1001-4551(2008)06-0051-03

Existing problems and improving measures of singlephase grounding protection for power distribution system
WU Lina1, PENG Jianzhou2
(1.College of Electrical Engineering, Zhejiang University, Hangzhou 310027, China;
2.Hangzhou Huazhang Electrical Engineering Limited Company, Hangzhou 310012, China)
Abstract: In threephase fourwire system, there are various protection methods for singlephase ground short circuit in lowvoltage side of transformer. Overcurrent protection concurrently works as singlephase ground shortcircuit protection for the sake of simplifying secondary loop and reducing initial investment, but there is problem of giving consideration to protection sensitivity and selectivity in protection configuration and setting. Singlephase ground protection method in lowvoltage side of transformer using negativesequence protection function was presented. Protection calculating method and concrete implementing technique were given in detail. The results show that, the problem of singlephase ground protection is solved properly without increasing equipment investment and wiring by this method.
Key words: lowvoltage distribution; grounding protection; negativesequence protection; sensitivity analysis
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