文档介绍：学生毕业设计(论文)
题目: 变压器电流差动保护方法研究
学生姓名:
院别: 信息与控制工程学院
专业年级: 2009级电气工程及其自动化一班
指导教师:
2013年 6 月 20 日
摘要
变压器是电力系统中的重要设备,随着科技的进步和电力系统的不断完善,采用先进的保护方案来加强变压器运行的可靠性和预警性是技术人员的不懈努力目标。本文首先从电力系统继电保护的一些问题出发,对电力变压器继电保护技术作出了相应的概述,并对电力变压器继电保护的现状和趋势作了简单的分析;结合当前的变压器空载试验,对励磁涌流的特征进行定性的分析,结合当前的一些励磁涌流识别的方法,作出了比较详细的分析和论述。通过对电力变压器的等效电路和磁路定量分析,从中发现电力变压器故障电流和励磁涌流之间的特征和差异,并建立相应的物理模型。通过对变压器模型在正常运行、接地短路和线圈短路的定量分析,列出状态方程,在这些方程的基础上提出电力变压器继电保护的方案。本方案根据保护方程式实际差值与设定动作设定值相对比,来区别故障电流和励磁涌流。采用涌流识别对变压器进行改造,大大提升了变压器的稳定运行。同时也可以防止误动作,增加变压器差动保护的准确性。
关键词:变压器;差动保护;涌流技术;防误动
ABSTRACT
The transformer is an important power system equipment, and its direct impact on the reliability of electricity transport and development. With the advancement of technology and the constant improvement of the power system, the use of advanced transformer protection programs to enhance the reliability and early warning is the tireless efforts of technical staff goals. Firstly, power system protection from some of the problems starting on the power transformer protection status and trends of a simple analysis; combined with the current transformer no-load tests on the characteristics of inrush current qualitative analysis, the current Some inrush current identification method and the ponents, making a more detailed analysis and discussion. In the equivalent circuit of power transformers and ic premise quantitative analysis found that power transformer fault current and inrush current characteristics and differences between, and establish a corresponding physical model. Running through the transformer model, shorted to ground, coil short quantitative analysis of the equations listed in three states, on the basis of proposed power transformer protection scheme. The program under the Protection of the actual difference pared with the preset action, to distinguish between the fault current and inrush current. Inrush current identification for transformer protection using transformation, greatly enhance the stable operation of