论文总字数：82250字

摘 要

16012207 李云倩

指导教师 陈中

近年来由于工业的发展，越来越多的企业拥有了自己的自备孤网电力系统，为生产运行提供电力能源。因此企业孤网电力系统的稳定性问题受到重视，对于这一问题的研究直接关乎企业的生产和可持续性发展。另一方面，孤立电网的概念比较新颖，国内外所做研究不多，对于企业孤网稳定性的研究多基于实际的企业电力系统。本文采用同样的方式，以鲁西新材料产业园企业孤网电力系统作为主要研究对象，利用中国电科院研发的PSASP程序进行仿真与探索，找出潜在的不稳定溃网因素并提出应对策略，改善该孤网系统的稳定性问题。

本文首先对该企业孤网系统不发生故障的情况仿真，进行了潮流计算和静态安全分析，确定其没有溃网的风险，能够保持稳定；之后对发生故障的情况做了分析，由于在孤网系统中频率问题的重要性大于其他问题，所以将研究的重点放在频率稳定上，主要选取三种对频率有重大影响的具有典型意义的故障状态，分别为最大容量发电机退出系统（故障Ⅰ）、带最大负荷的馈线跳闸故障（故障Ⅱ）和期间联络线跳闸故障（故障Ⅲ）。按顺序进行研究，故障Ⅰ将引起系统的低频问题，因此采用减载策略，制定减载顺序并确定百分比；故障Ⅱ将引起系统的高频问题，因此采用切机策略，确定切机的台数和百分比；故障Ⅲ将引起系统的部分高频问题与部分低频问题，采用减载与切机相结合的方法制定策略。

除此之外，本文还对该企业孤网系统中性点接地方式的选择、电压稳定问题和未来并网规划做了一定的讨论。在中性点接地方式的选择部分分别对中性点不接地、经消弧线圈接地和经小电阻接地做了比较，最终得出中性点经小电阻接地方式最适合于该企业孤网的结论。在电压稳定分析部分，对静态电压稳定和动态电压稳定分别做了研究，得到了静态电压稳定裕度和改良方案，并对ZIP负荷静特性模型和感应电动机负荷模型分别做了故障分析，得到了故障切除的极限时间结果。而在未来并网规划部分，对该孤网系统未来的扩大机组并网方式进行了研究和评估，选择出了能够保持稳定性且适合可持续发展的并网方式。

关键词：企业孤网；频率稳定；电压稳定；中性点；PSASP

Abstract

With the rapid development of the industry in recent years, more and more enterprises have their self-provided generating sets, which provide electricity for production efficiently. Therefore, the stability of enterprise self-provided isolated power grid is more important than before, and the sustainable development of enterprises also depends on researches to the issue. On the other hand, the concept of isolated power grid is new to some extent, there are not a lot of researches. Most of them are based on one entity enterprise power system, so this paper uses the same method. Using the program PSASP which explored by Chinese EPRI, this paper focuses on the actual network structure of LuXi New Material Industrial Park, searching the potential instable factor that could cause network collapse ,putting forward solutions to that and improving the stabilities of this enterprise-owned isolated power grid.

At first, this paper simulates the non-fault situation of the enterprise isolated power system and makes both power flow calculation and static security analysis, confirming that the electricity grid can keep steady in the situation. Then the situation of several faults is simulated. In isolated power network, the importance of frequency stability is bigger than other problems, so this paper mainly focuses on the problem of frequency stability. Three kinds of fault type which are typical and have great effect on frequency stability are selected to simulate, including the generation which has biggest capacity dropping out the system (fault Ⅰ), the feeder which supplies the heaviest load tripping (fault Ⅱ)and the feeders which connect different phases tripping (fault Ⅲ). Research them in order, there are some findings: fault Ⅰ could cause low frequency problems so the chapter puts forward the strategy of load shedding which defines the order and percent in detail; fault Ⅱ could cause high frequency problems so the chapter proposed the strategy of generation cutting which formulates the quantity and percent; fault Ⅲ could cause both high and low frequency problems, therefore combining load shedding and generation cutting to formulate a suitable strategy.

Besides, this paper also discusses some other issues, such as the choice of neutral grounding modes, the analysis of voltage stability and the planning of grid-connected in the future. In the part of neutral grounding, the chapter compares three modes and concludes that neutral point through small resistance grounding is the suitable one. In the part of voltage stability, the chapter researches the static and academic voltage stabilities. It proposes both the margin of static voltage stability and the improvement programs. Then it analyses the fault situation of ZIP load static characteristic model and introduction motor loads, arriving at the limit time of cutting fault. In the part of grid-connected, the chapter evaluates different schemes and chooses the plan that can maintain stability and sustainability.

Key words: enterprise isolated power system; frequency stability; voltage stability; neutral point; PSASP

目 录

第一章 绪论 1

1.1 研究背景与现状 1

1.1.1 研究背景 1

1.1.2 研究现状 2

1.2 技术路线 3

1.3 研究内容和难点 4

1.3.1 关键问题 4

1.3.2 具体研究内容 5

1.4 研究应用意义 6

1.5 章节安排 6

第二章 企业孤网系统现状分析 8

2.1 电网现状介绍 8

2.1.1 用电负荷数据 8

2.1.2 电网电气图 9

2.2 潮流计算 9

2.2.1 电网拓扑图与潮流运行图 9

2.2.2 潮流计算数据结果 10

2.3 本章小结 14

第三章 企业孤网系统静态安全分析 15

3.1 软件仿真部分 15

3.1.1各方案结果展示 15

3.1.2 部分方案计算数据结果 16

3.2 本章小结 19

第四章 企业孤网系统暂态稳定分析 20

4.1 软件仿真部分 20

4.1.1 故障点单相接地短路故障仿真 20

4.1.2 1#、2#期联络线故障仿真 22

4.1.3 2#、3#期联络线故障仿真 24

4.2 本章小结 26

第五章 企业孤网系统低频减载分析 27

5.1 原理分析 27

5.2 软件仿真部分 28

5.2.1 丢失最大一台发电机的故障仿真 28

5.2.2 考虑现有低频减载装置的故障仿真与策略制定 29

5.2.3 不考虑现有低频减载装置的故障仿真与策略制定 30

5.3 本章小结 33

第六章 企业孤网系统高频切机分析 34

6.1 原理分析 34

6.2 软件仿真部分 34

6.2.1 带最大负荷馈线跳闸的故障仿真 34

6.2.2 馈线跳闸的切机策略仿真 35

6.2.3 馈线单相接地短路故障的切机策略仿真 36

6.2.4 策略的多样性 38

6.3 本章小结 39

第七章 企业孤网系统联络线跳闸问题分析 41

7.1 各联络线跳闸仿真分析概览 41

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