基于单相接地故障类型的选线方法研究

发布时间：2018-04-12 23:30

本文选题：故障类型 + 故障选线　；参考：《中国矿业大学》2017年硕士论文

【摘要】：在配电网发生的故障中,单相接地故障占其中的绝大多数。单一的选线判据在解决选线问题时,由于受到复杂多变的工况等因素的影响,准确率较低。融合的选线方法在一定程度上提高了选线的准确率,但同时面临着数据处理量大、信息冗余度大的问题。本文通过研究接地故障时的特点,将单相接地故障分类。根据不同类型的故障,选择对应的方法,保证选线的准确性、快速性。首先,本文建立了一种符合实际情况的电弧模型,分析单相电弧接地时的特点,利用故障相电压小波高频重构分量峭度系数作为特征量,将电弧故障与普通故障区分开来;根据不同故障工况下,暂态零序电流小波高频能量占比不同的特点,将普通故障再分为强暂态、中等暂态、弱暂态三种故障类型。其次,在ATP/EMTP中建立配电网仿真模型,选取了几种典型的稳态和暂态选线方法对不同故障初相角、不同过渡电阻、不同中性点接地方式下的工况进行仿真分析,研究了各种方法的特点及适用的情况。再次,本文根据各种方法的特点,建立各自的故障测度函数。研究根据不同的故障类型,选择最契合故障情况的选线方法。对于必须使用融合选线法的故障情况,采取利用仙农模糊熵构造信度分配函数的改进D-S证据理论,来进行选线方法的融合。通过算例说明了先进行故障分类再进行选线的步骤,并通过对比,验证该方法的优越性和容错性。而后用大量不同工况下的选线结果验证了该方法的有效性。最后,利用实验室的硬件平台和LabVIEW的虚拟仪器集成环境,实现了本文研究的基于单相接地故障类型的选线保护系统。
[Abstract]:In the distribution network fault, single-phase grounding fault accounts for the majority of them.When a single line selection criterion is used to solve the problem, the accuracy rate is low due to the influence of complex and changeable working conditions.The fusion line selection method improves the accuracy of line selection to a certain extent, but at the same time, it faces the problems of large data processing and large information redundancy.In this paper, single-phase grounding faults are classified by studying the characteristics of grounding faults.According to different types of faults, select the corresponding method to ensure the accuracy and speed of line selection.Firstly, a kind of arc model is established, and the characteristics of single-phase arc grounding are analyzed. The kurtosis coefficient of high-frequency reconstruction component of fault phase voltage wavelet is used as the characteristic quantity to distinguish arc fault from ordinary fault.According to the characteristics of high frequency energy ratio of transient zero-sequence current wavelet under different fault conditions, common faults are divided into three types: strong transient, medium transient and weak transient.Secondly, the simulation model of distribution network is established in ATP/EMTP, and several typical steady-state and transient line selection methods are selected to simulate and analyze the conditions of different fault initial phase angle, different transition resistance and different neutral grounding mode.The characteristics and application of various methods are studied.Thirdly, according to the characteristics of various methods, this paper establishes their fault measure functions.According to different fault types, the selection of the most suitable fault line selection method.For the fault cases where the fusion line selection method must be used, the improved D-S evidence theory, which uses Shannon fuzzy entropy to construct reliability distribution function, is adopted to fuse the line selection method.An example is given to illustrate the steps of fault classification and line selection, and the advantages and fault tolerance of the method are verified by comparison.Then, the effectiveness of the method is verified by a large number of results of line selection under different working conditions.Finally, the hardware platform of the laboratory and the virtual instrument integration environment of LabVIEW are used to realize the line selection protection system based on single-phase grounding fault type studied in this paper.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM862

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