摘要：6～10kV 属于小电流供电系统，而实际中也多采用这类电网。其优点是单相故障时， 故障电流小，对人身没有较大危害同时也可保护设备。而小电流系统发生不同故障情况是 所出现的特征量变动也是不同的。所以本课题将对架空线路和电力电缆这两种线路进行多 种故障分析与推导，为系统故障后的选线提供基础的理论依据与参考。66253

另外也会介绍中性点三种不同的接地方式的工作原理和优缺点，分析系统故障时引发 的参数变化和波动对电网的影响。之后，使用 MATLAB 对电力系统进行搭载，并进行故障 时的模拟仿真，最后将理论推导的结果与仿真波形相结合，来验证理论分析的准确性与可 行性，为日后配电网建设的中性点选择、电网故障的处理和电网的继电保护系统的实施提 供可行的理论依据。

毕业论文关键词： 中性点接地方式；故障分析；MATLAB 仿真；

6 ~ 35kV Power Grid Fault Analysis

Abstract:6 ~ 10kV is a small current power supply system, and in practice this kind of power grid is used. The advantage is that the fault current is small in single phase fault, which is not harmful to the person, but also protects the equipment. And the variation of the characteristics of the small current system is different. So this topic will be for the two kinds of overhead line and power cable lines to a variety of fault analysis and derivation, provides the basis for system failure after the line selection theory basis and reference.

Also introduces neutral point the work of three different kinds of earthing ways of the principle and advantages and disadvantages of analysis system failure caused by the parameters change and fluctuation influence to power grid. After, the use of MATLAB to carry electricity system, and fault simulation, finally combining the results of the theoretical derivation and simulation waveforms, to verify the feasibility and accuracy of theoretical analysis, for the future of the construction of the distribution network neutral point selection, power grid failure handling and power grid relay protection system implementation to provide feasible theory basis.

Key Words: point grounding Neutral;Fault Analysis;MATLAB simulation

目 录

摘要 1

Abstract 1

1 绪论 1

1.1 课题的提出与意义 1

1.2 国内外研究综述 1

1.2.1 国外的研究现状 1

1.2.2 国内研究现状 2

1.3 课题的主要研究内容 2

2 6～35kV 电网架空线路故障分析 4

2.1 单相接地故障 4

2.1.1 中性点不接地系统 4

2.1.2 中性点消弧线圈接地系统 11

2.1.3 中性点小电阻接地系统 13

2.2 相间短路故障 15

2.2.1 中性点不接地系统 15

2.2.2 中性点消弧线圈接地系统 18

2.2.3