小電流接地系統(tǒng)故障選線新方法研究

論文編號:ZD1384  論文字?jǐn)?shù):28788,頁數(shù):45

論文題目：小電流接地系統(tǒng)單相接地故障選線的研究
摘　要
 電流接地系統(tǒng)在提高供電可靠性上具有優(yōu)越性，從而在我國的配電網(wǎng)中得到廣泛應(yīng)用。該系統(tǒng)發(fā)生單相接地故障的機(jī)率最高，當(dāng)小電流接地系統(tǒng)發(fā)生單相接地故障時(shí)，長時(shí)間的接地運(yùn)行極易形成兩點(diǎn)或多點(diǎn)接地短路，弧光接地還會(huì)引起全系統(tǒng)過電壓，破壞系統(tǒng)的安全運(yùn)行，因此如何快速準(zhǔn)確的排除故障線路，對系統(tǒng)的運(yùn)行具有重要的意義。但是由于單相接地故障產(chǎn)生的故障電流很小等諸多原因，單相接地故障選線問題一直沒有得到很好的解決。本文針對這個(gè)問題開展研究工作，旨在發(fā)現(xiàn)現(xiàn)有選線方式存在的不足，進(jìn)一步探索故障選線方法。作為研究工作的基礎(chǔ)，首先本文系統(tǒng)地分析了小電流接地系統(tǒng)發(fā)生單相接地故障的特點(diǎn)，從暫態(tài)和穩(wěn)態(tài)兩方面研究了故障特征量在正常線路和故障線路上的差異，為本文的后期工作提供理論基礎(chǔ)。在理論分析的基礎(chǔ)上，對現(xiàn)有的選線方法進(jìn)行了簡單的研究，分析了各種選線方法的局限性，總結(jié)了目前選線困難的主要原因。最后，指出了基于單一選線方法都具有其各自的局限性，應(yīng)對各選線方法合理地進(jìn)行綜合，發(fā)揮各種選線方法之間的互補(bǔ)性，形成多判據(jù)的綜合選線方法。本文對已提出的綜合選線方法加以改進(jìn)，以故障測度為基準(zhǔn)，融合了零序電流群體比幅法、注入信號法、基于零序電流諧波畸變率特性選線法、暫態(tài)零序電流互積求和法、衰減直流分量選線法以及小波包分析選線法等六種選線方法，構(gòu)造了一種基于模糊理論的多判據(jù)綜合選線方法。對各種單一選線方法設(shè)定了故障測度隸屬函數(shù)和各判據(jù)的權(quán)重系數(shù)隸屬函數(shù)。根據(jù)系統(tǒng)結(jié)構(gòu)以及多種故障特征量，通過模糊決策得到最終的選線結(jié)果。并對所改進(jìn)的綜合選線方法進(jìn)行了數(shù)字仿真，取得了預(yù)期的結(jié)果，證明了它的正確性、可靠性。最后，針對目前傳統(tǒng)的選線方法只利用待測故障的故障信息選線，而沒有利用到已有故障樣本中含有大量對故障選線有利的信息，本文在基于對已有故障樣本的故障信息分析的基礎(chǔ)上，提出了利用灰關(guān)聯(lián)分析對新的待測故障進(jìn)行選線，建立了基于注入信號和小波包分解的灰關(guān)聯(lián)分析故障選線方法。且通過大量的數(shù)字仿真實(shí)驗(yàn)，驗(yàn)證所建立的選線體系的可行性。基于灰關(guān)聯(lián)分析的選線方法從選線思路上有別于傳統(tǒng)的選線方法，開辟了一條新的故障選線道路，與所改進(jìn)的基于模糊理論多判據(jù)綜合選線方法相結(jié)合，能起到有效的驗(yàn)證作用，選線的精度將得到大大加強(qiáng)，針對目前小電流接地電網(wǎng)單相接地故障選線困難具有一定的現(xiàn)實(shí)意義。
關(guān)鍵詞：小電流接地系統(tǒng)；故障選線；故障測度；信息融合：模糊理論；灰關(guān)聯(lián)分析

 
Title: Single phase small current grounding system of fault line selection
 
ABSTRACT
 Small current grounding system to improve power supply reliability in the superiority, which in our distribution network has been widely used. The system is single phase ground fault at the highest risk, when a small current grounding system, single-phase ground fault occurs, the formation of a long ground run two or more points easily ground short circuit, grounding can also cause system-wide arc over voltage, damage the safe operation of the system, how to troubleshoot quickly and accurately route, the operation of the system is significant. However, due to single-phase ground fault resulting fault current is very small, and many other reasons, the single phase to ground fault line problem has never been solved. In this paper, this research work aims to find ways of existing shortcomings in alignment, and further explore the fault line selection method. As a basis for research work, the first systematic analysis of this small current grounding system fault occurs the characteristics of single phase, from both transient and steady state characteristics of the fault and fault lines in the normal amount of the difference in line for this article provide a theoretical basis for later work. In the theoretical analysis, based on the alignment of the existing methods of a simple, analyzes the limitations of a variety of line selection, summarized the main reason the current alignment difficulties. Finally, it was based on a single line selection methods have their respective limitations, address the method to select reasonably comprehensive, method to select between a variety of play complement each other, forming an integrated multi-line selection criteria. This paper has proposed a comprehensive method to select improved to failure as the benchmark measure, the integration of groups than the amplitude of zero sequence current law, injecting signal, based on zero sequence current harmonic distortion characteristics of line selection method, the transient zero sequence current summation of each product, decaying line selection method and the wavelet packet analysis of six Line selection method to select, construct a multi-criteria based on fuzzy comprehensive method to select. A variety of single fault line selection method set membership function and the criterion measure of the weight coefficients of the membership function. According to the system structure and the amount of a variety of fault feature, the fuzzy decision-making to get the final alignment result. And the improved method to select for the integrated digital simulation, and achieved the expected results, proof of its validity and reliability. Finally, the current traditional method to select only the information by the fault under test fault line selection, without samples used to have trouble on the Fault Line contains a lot of favorable information, this paper has been based on fault samples of fault information Based on the analysis presented, Grey relational analysis tested the new fault line selection, established based on the injection signal and the wavelet packet decomposition of the gray relational analysis method of fault line. And through a large number of digital simulation experiments to verify the established alignment system is feasible. Grey relational analysis method to select the train of thought from the choice of lines is different from the traditional method to select, has opened up a new fault line the road, with the improved multi-criteria based on fuzzy comprehensive method to select the combination can play an effective role in verification, the accuracy of alignment will be greatly enhanced, the small current grounding power for the current single-phase to ground fault line has a certain practical significance difficult. Key words： small current grounding system; fault line; failure measure; information fusion: fuzzy theory; Grey relational analysis
 
 
 目錄
1 緒論  1
 1．1本文的研究意義 1
 1．2國內(nèi)外研究現(xiàn)狀 2
 1．3本文的主要工作 2
2小電流接地系統(tǒng)單相接地故障分析 5
 2．1電力系統(tǒng)中性點(diǎn)接地方式介紹 5
 2．1．1中性點(diǎn)不接地 5
 2．1．2中性點(diǎn)經(jīng)消弧線圈接地 6
 2．1．3中性點(diǎn)經(jīng)高阻接地 7
2．2小電流接地系統(tǒng)單相接地故障基本特征 7
 2．2．1中性點(diǎn)不接地系統(tǒng)單相接地故障特征 7
 2．2．2中性點(diǎn)經(jīng)消弧線圈接地系統(tǒng)單相接地故障特征 10
 2．2．3小電流接地系統(tǒng)單相接地故障的暫態(tài)分析 11
3 選線方法分析及解決思路 15
3．1現(xiàn)有選線方法概述 15
 3．1．1穩(wěn)態(tài)選線方法 15
 3．1．2暫態(tài)選線方法 17
3．2選線的誤判問題 18
3．3選線的局限及解決思路 19
 3．3．1選線局限性 19
 3．3．2選線解決思路 20
4 基于模糊理論的多判據(jù)綜合選線方法 23
4．1信息融合與故障選線 23
4．2模糊理論 23
4．3故障測度和判據(jù)權(quán)重系數(shù) 25
4．4基于模糊理論的多判據(jù)綜合選線體系 25
 4．4．1多種單一判據(jù)的選取 25
 4．4．2故障測度隸屬函數(shù)和權(quán)重系數(shù)隸屬函數(shù)的建立 26
4.5仿真及數(shù)據(jù)分析 29
 4．5．1仿真模型的建立 29
 4．5．2中性點(diǎn)不接地系統(tǒng)故障仿真及數(shù)據(jù)分 29
5 基于灰關(guān)聯(lián)分析的故障選線方法 31
 5．1灰關(guān)聯(lián)分析理論 31
 5．2基于灰關(guān)聯(lián)分析的故障選線方法 31
 5．3本章小結(jié) 32
6 結(jié)論與展望 33
致  謝 35
參考文獻(xiàn) 36