基于广域信息的选择性漏电保护研究

发布时间：2018-04-10 11:24

本文选题：选择性漏电保护 + 广域信息　；参考：《安徽理工大学》2017年硕士论文

【摘要】：煤炭在我国能源中占主要地位,我国矿井众多且矿井电网大部分采用电缆供电。电缆在井下环境中容易损坏,电缆的损坏极大可能会引起漏电事故,从而影响井下工作的进度与效率。煤矿井下发生漏电故障的时候,为了快速定位故障区域,避免越级跳闸,本文根据广域继电保护的分区结构原理,针对井下供电系统提出一种基于广域信息下的的选择性漏电保护的新方法。该方法根据煤矿井下供电系统的特点,结合广域继电保护的分区方案,在井下实际供电线路中按馈电开关的安装位置进行区域划分,在每个划分的区域里通过安装在馈电开关处的零序互感器得到零序信息。以零序电压作为判断线路是否存在故障的依据,在此基础上再以相邻区域的零序电流的差值作为特征量,并以该特征量在故障线路与非故障线路相位和幅值上的差异作为判据,比较不同区域零序电流特征量的广域信息,最终得出故障点所在区域。考虑到井下零序电流信息容易受到干扰,本文针对故障信号采取一种基于经验模态分解(Empirical Mode DecompositionEmpirical,EMD)的滤波降噪方案,将故障信号分解成若干分量,挑取其中部分信号分量进行重新组合,获得降噪后的新信号。为了探讨本论文方法的可行性,本文以实际矿井采区供电系统图为参考模型,利用MATLAB simulink进行仿真模型搭建。对本文提出的故障判据进行仿真验证,同时还考虑了过渡电阻对仿真波形的影响。Matlab仿真效果表明,本文提出的选线方法不仅能够确定故障线路,而且可以进一步得到故障所在的区域,有助于提高了井下检修的效率,具有较强的实用价值。
[Abstract]:Coal is the main source of energy in our country. There are many mines in our country and most of mine power networks are supplied by cable.The cable is easy to be damaged in underground environment, and the damage of cable may cause leakage accident, which will affect the progress and efficiency of underground work.In order to locate fault area quickly and avoid over-grade tripping when leakage fault occurs in coal mine, this paper is based on the principle of zone structure of wide area relay protection.A new method of selective leakage protection based on wide area information is proposed for underground power supply system.According to the characteristics of underground power supply system in coal mine and combined with the zoning scheme of wide area relay protection, the method is divided according to the installation position of feeder switch in actual underground power supply line.Zero sequence information is obtained by the zero sequence transformer installed at the feed switch in each divided area.The zero-sequence voltage is taken as the basis for judging whether there is a fault or not on the basis of which the difference of zero sequence current in adjacent regions is taken as the characteristic quantity, and the difference in phase and amplitude between the fault line and non-fault line is taken as the criterion.The wide area information of zero sequence current characteristic quantity in different regions is compared, and the fault point is finally obtained.Considering that the zero sequence current information is easy to be interfered with, a filtering and noise reduction scheme based on empirical Mode decomposition (EMD) is proposed in this paper. The fault signal is decomposed into several components.Pick out some of the signal components to recombine to obtain the new signal after noise reduction.In order to discuss the feasibility of this method, this paper takes the power supply system diagram of actual mine mining area as the reference model, and uses MATLAB simulink to build the simulation model.The simulation results of the fault criterion proposed in this paper and the influence of transition resistance on the simulation waveform show that the proposed line selection method can not only determine the fault line, but also take into account the influence of transition resistance on the simulation waveform.Furthermore, the fault area can be further obtained, which is helpful to improve the efficiency of downhole maintenance and has strong practical value.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD611.5

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