电压稳定毕业设计

论文编号:JD191     字数:22916,页数:56  

摘 要
电力系统中很多电压崩溃事故往往是由一些故障引起的，切负荷是使故障后的系统恢复电压稳定的有效方法。本文对故障切负荷的策略作了一些研究，提出了一种切负荷的方法。为了更准确地描述电力系统在非正常运行情况的状态，本文提出了一种新型的潮流算法，它同时考虑了系统的网络方程和动态元件的稳态特性，使计算结果更接近系统实际运行状态。另外还设计了基于延拓法的连续潮流算法，用于求取系统的稳定极限，和计算节点的电压稳定灵敏度。在此基础上，本文提出了选取切负荷地点和确定最小切负荷量的方法。
关键词：电力系统 电压稳定 电压崩溃 连续潮流 切负荷。
Abstract
In power system, many voltage collapse incidents are caused by some fault, load shedding is a efficient way to restore the stability of a system after fault. In this paper we make some study on load shedding strategy after fault and a load shedding method is presented. In order to describe the state of a power system under abnormal operation condition more accurately, a novel load flow algorithm is developed in which both network equation and the steady characteristic of dynamic elements in power systems are considered. Also we developed a continue-power-flow (CPF) program based on the method which is used to calculate the stability limit of a power system and the voltage stability sensitivity of a special bus. Based on the above, a method used to select the location and determine the amount of a load shedding strategy is presented.
Keywords: Power system Voltage stability Voltage collapse Continue power flow Load shedding.

目 录
摘要........................................................................ 1
目录 ........................................................................3
第一章   绪论................................................................5
1.1 电压稳定研究概述..........................................................5
1.1.1 电压稳定问题的概念......................................................5
1.1.2 电压稳定的分析方法 .....................................................5
1.2 切负荷对系统电压稳定的作用................................................6
1.2.1 预防性切负荷措施........................................................6
1.2.2 校正性切负荷措施........................................................6
1.3 切负荷策略研究中的问题................................................... 6
1.4 本文的工作 ...............................................................7
第二章改进的潮流算法.........................................................9
2.1 引言..................................................................... 9
2.2. 系统模型 ................................................................9
2.2.1 发电机模型 .............................................................9
2.2.2 负荷模型................................................................11
2.2.3 网络方程................................................................11
2.2.4 通用的微分－代数方程模型................................................12
2.3 潮流方程的求解............................................................13
2.3.1 方程的结构 .............................................................13
2.3.2 雅可比矩阵的形成 .......................................................13
2.3.3 原始数据与解............................................................19
2.3.4 各种限制与OLTC分接头动作的考虑..........................................20
2.4 小结 .....................................................................22
第三章连续潮流算法与灵敏度分析 ..............................................23
3.1. 负荷增长方式与发电机功率增长的分配 ......................................23
3.2. 采用延拓法的潮流算法.....................................................25
3.2.1 潮流方程以及雅可比矩阵的修改............................................25
3.2.2 预测和校正过程..........................................................26
3.3 灵敏度分析 ...............................................................30
3.3.1 基于连续潮流的简单灵敏度分析............................................30
3.3.2 基于特征值－特征向量的灵敏度与稳定性分..................................31
3.4. 小结 ....................................................................32
第四章故障情况下的甩负荷方案.................................................33
4.1. 电压稳定性故障 ..........................................................33
4.1.1 线路停运 ...............................................................33
4.1.2 发电机的停运 ...........................................................34
4.1.3 故障类型与甩负荷策略....................................................34
4.2. 切负荷地点的确定.........................................................35
4.2.1 概述 ...................................................................35
4.2.2 负荷类型的考虑..........................................................36
4.3. 切负荷量的确定...........................................................36
4.3.1切负荷的理论目标量 ......................................................36
4.3.2 实际切负荷量 ...........................................................37
4.4. 最佳切负荷方案...........................................................38
第五章测试系统与计算结果 ....................................................40
5.1. 测试系统.................................................................40
5.1.1 系统接线图..............................................................40
5.1.2 正常运行状态的潮流分布..................................................40
5.2. 连续潮流计算结果........................................................ 41
5.2.1 不考虑发电机各种极限时的计算结果........................................41
5.2.2 考虑发电机原动机输出极限时的计算结果 ...................................45
5.2.3 考虑发电机电枢电流极限时的计算结果 .....................................46
5.2.4 影响负荷功率极限的因素 .................................................47
5.3. 故障切负荷计算结果 ......................................................48
5.3.1 线路故障算例 ...........................................................48
5.3.2 发电机故障算例..........................................................50
总  结 .......................................................................52
参考文献..................................................................... 54
附录 ........................................................................56