成都理工大学工程技术学院毕业论文
电力系统短路计算的程序实现
作者姓名：孔 祥 天
专业名称：电气工程及其自动化
指导教师：赵 熹 讲师
电力系统短路计算的程序实现
摘要
短路电流计算是电气设计中最基本的计算之一，在发电厂、变电所以及整个电力系统的设计和运行工作中，都必须事先进行短路计算，以此作为合理选择电气接线、电气设备选型、继电保护整定计算、确定限制短路电流措施、在电力系统中合理地配置各种继电保护并整定其参数等的重要依据。掌握短路发生以后的物理过程以及计算短路时各种运行参量(电流、电压等)的计算方法是非常必要的。本文介绍了短路电流计算实用的数学模型、计算原理和方法。用MATLAB语言编写了计算程序，应用起来方便、快捷、准确，提高了效率和准确度。
关键词 ：短路电流 电气设计 继电保护 程序 电网
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电力系统短路计算的程序实现
Abstract
Electrical short-circuit current calculation is the calculation of the basic design of one of the power plants, substations and the power system design and operation of work, short-circuit must be calculated in advance, a reasonable choice as electrical wiring, electrical equipment, the election type, relay setting calculation to determine the measures to limit short-circuit current in the power system configuration in a reasonable range of relay and its parameters, such as setting an important basis. Have occurred after short-circuit as well as the calculation of the physical processes at a variety of short-run parameters (current, voltage, etc.) the calculation is very necessary. In this paper, short-circuit current calculation and practical mathematical model, principles and methods of calculation. MATLAB language with the computer program, application to convenient, fast, accurate, and improve the efficiency and accuracy.
Keywords:Short-circuit current, Electrical Design, Relay Protection, Procedures, Power Grid.
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电力系统短路计算的程序实现
目录
摘要 ............................................................................................................ I Abstract .................................................................................................... II 目录 ......................................................................................................... III 前言 ........................................................................................................... 1 1电力系统短路故障分析的基本知识 .................................................... 3
1.1短路故障分析概述 ...................................................................... 3 1.1.1短路的概念及类型 ................................................................ 3 1.1.2短路产生的原因 .................................................................... 3 1.1.3短路的危害及限制措施 ........................................................ 4 1.2计算短路电流的目的 .................................................................. 6 1.3短路计算的作用 .......................................................................... 6 1.4短路计算的基本步骤 .................................................................. 7 1.5标幺制 .......................................................................................... 7 1.5.1标幺值的概念 ........................................................................ 7 1.5.2基准值的选取 ........................................................................ 7 1.5.3基准值改变时标幺值的换算 ................................................ 8 1.5.4不同电压等级网络中各元件参数标幺值计算 .................... 9 2电力系统三相短路分析计算 .............................................................. 11
2.1恒定电势源的三相短路电流分析 ............................................ 11 2.1.1三相短路的暂态过程分析 .................................................. 11 2.1.2短路冲击电流和最大有效值电流 ...................................... 14 2.2同步发电机突然三相短路的物理分析 .................................... 17 2.3电力系统三相短路的实用计算 ................................................ 18 2.3.1三相短路实用计算的基本假设 .......................................... 18 2.3.2起始次暂态电流和冲击电流的实用计算 .......................... 19 2.3.3短路电流计算曲线及其应用 .............................................. 20 2.3.4短路电流周期分量的近似计算 .......................................... 23
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