电气工程及其自动化毕业设计-小电流接地系统故障自动选线仿真及研究.docx

1、本科毕业论文（20 届）小电流接地系统故障自动选线仿真及研究所在学院专业班级 电气工程及其自动化学生姓名指导教师i完成日期ii目 录摘要 .IAbstract.II1 引言 .11.1 课题研究的背景及其意义 .11.2 小电流接地系统单相接地故障选线研究现状 .11.2.1 国外研究现状 .11.2.2 国内研究现状 .12 小电流接地系统单相接地故障特征分析 .22.1 电力系统中性点接地方式概述 .22.2 小电流接地系统单相接地故障稳态特征分析 .22.2.1 中性点直接接地系统 .22.2.2 中性点不接地系统 .22.2.3 中性点经消弧线圈接地系统 .52.3 小电流接地系统单相

2、接地故障暂态特征分析 .72.3.1 暂态电容电流 .82.3.2 暂态电感电流 .92.3.3 暂态接地电流 .93 小电流接地系统选线方法综述 .103.1 利用电网稳态电气量提供的故障信息构成的自动选线法 .103.1.1 零序电流比幅法 .103.1.2 零序电流群体比幅比相法 .103.1.3 基于五次谐波分量的选线方法 .103.1.4 零序电流有功分量法 .11iii3.1.5 零序电流无功功率方向法 .113.1.6 最大 或( sinI)法 .11siI3.1.7 能量法 .113.2 利用电网暂态电气量提供的故障信息构成的自动选线法 .123.2.1 基于小波分析的选线方法

3、 .123.2.2 首半波法 .123.3 其他方法 .123.3.1 拉线法 .123.3.2 注入信号法 .124 小电流接地系统自动选线仿真 .124.1 基于零序电流比幅法原理选线的仿真 .124.1.1 多回路的架空线路仿真 .124.1.2 多回路电缆线路仿真 .154.2 基于零序功率方向法原理选线的仿真 .184.2.1 架空线路的仿真 .184.2.2 电缆线路的仿真 .194.3 基于五次谐波电流法原理选线的仿真 .204.3.1 接地电阻为 100 时 .204.3.2 接地电阻为 400 时 .215 结论 .23参考文献 .24致谢 .25附录 .26ivvConte

4、ntsAbstract.II1 Introduction.11.1 Background and significance of the research .11.2 Research status of single phase grounding fault line selection for small current grounding system .11.2.1 Foreign research status quo.11.2.2 Domestic research status quo.12 Analysis of single phase grounding fault in

5、 small current grounding system .22.1 Overview of neutral point grounding in power system .22.2 Analysis of the steady state characteristics of single-phase grounding fault in small current grounding system.22.2.1 Neutral point direct earthing system.22.2.2 Neutral point is not grounded system .22.2

6、.3 Earthing system of the neutral point via the arc suppression coil .52.3 Transient characteristic analysis of single phase to earth fault in small current grounding system .72.3.1 Transient capacitance current .82.3.2 Transient inductance current.92.3.3 Transient grounding current.9vi3 Overview of

7、 the selection of small current grounding system .103.1 Automatic wire selection method based on the fault information provided by power grid steady electrical quantity .103.1.1 Zero sequence current ratio method.103.1.2 Zero sequence current group ratio phase method .103.1.3 Line selection based on

8、 five harmonic components .103.1.4 Active component method for zero sequence current .113.1.5 Zero sequence current reactive power direction method .113.1.6 The maximumor sinI( iI)method.113.1.7 Energy method.113.2 Automatic wire selection method based on the fault information provided by power grid

9、 transient electric quantity.123.2.1 Line selection based on wavelet analysis .123.2.2 First half wave method .123.3 Other methods.123.3.1 Pull method.123.3.2Injection signal method.124 Automatic wire selection simulation for small current grounding system .124.1 Simulation of line selection based o

10、n zero sequence current ratio method .124.1.1 Simulation of multi circuit overhead line .124.1.2 Simulation of multi circuit cable line .154.2 Simulation of the line selection based on zero sequence power direction method.184.2.1 Simulation of aerial line.184.2.2 Simulation of cable line .19vii4.3 S

11、imulation of line selection based on five harmonic current method.204.3.1 Ground resistance of 100.204.3.2 Ground resistance of 100 .215 Conclusion .23Reference .24Acknowledgement .25Appendix.26I小电流接地故障系统自动选线仿真及研究摘要：本文首先论述了课题的背景和意义，概括国内和国外的研究状况，分析了小电流单相接地故障的特征，包括暂态和稳态故障信息，并对基于此故障信息的选线方法，对其进行了包括原理在内的

12、简要介绍和比较，随后选取了几种选线方法，运用 Matlab 中的 Simulink 软件包进行了仿真，根据仿真结果和分析，分析当前自动选线法存在的问题及今后的展望。关键词：小电流接地系统 单相接地故障 选线 注入法 MatlabIISimulation and Research of Automatic Wire Selection for Small Current Fault SystemAbstract First of all, this paper discusses the background and significance of the topic, throughout t

13、he domestic and foreign research situation, analyzes the small current single phase grounding fault features, including the steady state and transient fault information, and based on the methods of fault line selection in the fault information and the the principle, brief introduction to and compari

14、son, then select the several methods of fault line selection and use a kind of software package for the simulation in MATLAB, according to the simulation results and analysis, analysis of problems and future prospect of the automatic line selection method.Keywords: the small current grounding system; single phase ground fault; line selection; injection method; Matlab