【作者】 谷君；

【导师】 刘万顺；

【作者基本信息】 华北电力大学（北京） ， 电力系统及其自动化， 2007， 硕士

【摘要】 长期以来,差动保护一直是变压器的主保护,该保护中最关键和困难的问题是如何防止励磁涌流所导致的差动保护误动。近年来,出现了多起和应涌流引起变压器差动保护误动的事故,影响到电力系统的安全稳定运行。所以研究和应涌流引起差动保护误动的原因并最终提出识别和应涌流的方法具有十分重要的意义。论文研究的主要工作有:1.建立和应涌流仿真模型,分析和应涌流的产生机理并找出和应涌流引起差动保护误动的根本原因。2.深入分析了两台Y/△接线方式的变压器产生和应涌流情况,提出利用时差法对和应涌流进行鉴别。3.提出了一种基于平方根滤波法参数辨识的变压器保护方法,该方法能正确区分变压器内、外部故障及涌流状态(包括励磁涌流与和应涌流)。更多还原

【Abstract】 Differential protection has been a major protection of transformer in a long time. How to prevent the inrush causing malfunction in differential protection is a key and difficult problem. These years, there are instances of sympathetic inrush resulting in the malfunction of transformers’differential protection, the security and stability of power system is greatly affected. Considering the reasons of the malfunction of differential protection, the research for new algorithm of identifying the sympathetic inrush, is in highly demand. The major combustions of this dissertation are as follows:1. The simulation models of sympathetic inrush are developed. The principle and the reasons of the malfunction of differential protection are analyzed in the dissertation.2. The principle of sympathetic inrush in two transformers connected in wye-delta mode is analyzed. A new method of identifying the sympathetic inrush which is based on the time differential method is put forward.3. A new transformer protection method of identifying the winding parameter based on the square-root algorithm is put forward, this method could identify the internal、external fault、inrush (including sympathetic inrush ) correctly.更多还原