| 引用本文: | 刘柱揆,曹敏,董涛.基于波形相似度的小电流接地故障选线[J].电力系统保护与控制,2017,45(21):89-95.[点击复制] |
| LIU Zhukui,CAO Min,DONG Tao.Fault line selection of neutral indirectly grounding system based on waveform similarity[J].Power System Protection and Control,2017,45(21):89-95[点击复制] |
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| 摘要: |
| 提出一种基于零序电流波形相似性的配网小电流接地系统故障选线方法，以解决小波等暂态方法难以确定能量频段等问题。通过对小电流接地系统零序电流分析，发现非故障线路零序电流波形相似，而与故障线路电流波形有明显差别。提出了基于互近似熵的选线方法，通过直接计算同一母线的两条出线之间零序电流采样值的互近似熵值，判断两条线路零序电流波形的相识度，从而筛选出故障线路。仿真结果表明，该方法实现简单、选线准确率高，且不易受高电阻接地、电网结构和故障初始条件差异等复杂因素的影响。 |
| 关键词: 小电流接地 选线 波形 相似度 熵 |
| DOI：10.7667/PSPC161765 |
| 投稿时间：2016-10-24修订日期：2017-03-19 |
| 基金项目: |
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| Fault line selection of neutral indirectly grounding system based on waveform similarity |
| LIU Zhukui,CAO Min,DONG Tao |
| (Electric Power Research Institute, Yunnan Power Grid Co., Ltd., Kunming 650217, China) |
| Abstract: |
| To solve the problem of transient method like wavelet difficult to determine the power frequency, this paper proposes a fault line selection method for neutral indirectly grounding system based on the waveform similarity of zero-sequence current. Based on the analysis of zero-sequence current for neutral indirectly grounding system, zero-sequence current waveform of non-fault lines are similar and very different from the fault line. This paper introduces mutual approximate entropy for fault line selection, by computing the mutual approximate entropy value of zero-sequence current sampling value between two outgoing lines with the same bus. Then the fault line is selected by judging the zero-sequence current waveform similarity of two lines. Simulation result shows the method shares the merit of being easy to implement, almost not effected by the high grounding resistance or power gird structure and fault initial condition, and accurate fault line selection. |
| Key words: neutral indirectly grounding system fault line selection waveform similarity entropy |
