Comprehensive Decision of Distribution Network Line Selection Based on Credibility Evaluation Index

Abstract

小电流接地的配电系统故障选线技术是保证配电网安全可靠运行的重点。关于配电网选线技术研究主要集中于选线原理，且受配电系统网架结构、中性线接地方式、出线类型、负荷等因素影响，各方法均有局限性，目前缺乏对选线方法的综合评价的研究。本文针对三种不同选线方法，包括零序电流比幅法、谐波法和零序电流有功分量法，将每种选线方式的影响因素进行量化分析，定义了不同方法能够正确选线的可信度评价指标，并对其进行可信度等级划分，通过构造欧式距离量化指标评价体系，建立了综合评价指标，给出基于可信度评价的选线方式综合决策。最后，采用算例验证了该方法的可行性和实用性。 The fault line selection technology of distribution system with small current grounding is the key to ensure the safe and reliable operation of distribution network. The research on the technology of line selection in distribution network mainly focuses on the principle of line selection. Due to the influence of the grid structure of distribution system, the way of neutral grounding, the outlet type, load and other factors, each method has its limitations. Currently, there is a lack of the study on comprehensive evaluation methods of line selection. In this paper, three different line selection methods, including zero-sequence current amplitude method, harmonic method and zero-sequence current active component method, are used to quantitatively analyze the influencing factors of each line selection method. The credibility evaluation index of different methods is defined and classified according to the credibility level. The comprehensive evaluation index is established through the construction of Euclidean distance quantitative index evaluation system, and the comprehensive selection of line selection method based on credibility evaluation is given. Finally, an example is given to verify the feasibility and practicability of this method.