本文選題：小電流接地系統(tǒng) + 單相接地故障�。� 參考：《山東大學(xué)》2015年碩士論文

【摘要】：隨著社會經(jīng)濟的快速發(fā)展,電力用戶對供電可靠性的要求越來越高,對整個電力系統(tǒng)的安全性和可靠性提出了新的、更高的要求。目前,國內(nèi)6kV～35kV配電網(wǎng)大多數(shù)采用小電流接地系統(tǒng),主要包括中性點不接地系統(tǒng)、中性點經(jīng)消弧線圈接地系統(tǒng)和經(jīng)中電阻接地系統(tǒng)。在配電網(wǎng)中,發(fā)生單相接地故障的機率占80%以上,當(dāng)小電流接地系統(tǒng)發(fā)生單相接地故障時,由于無法形成短路回路,故障僅為線路對地的容性電流,電流值一般較小。因單相接地時系統(tǒng)線電壓仍保持對稱,所以允許系統(tǒng)可帶故障運行1-2小時,但長時間的帶接地故障運行會對配電網(wǎng)及設(shè)備產(chǎn)生負面影響。這就要求在配電線路發(fā)生單相接地故障時,要盡可能快速、準確地判斷出故障線路并隔離處理,這也推動了配電線路單相接地故障選線技術(shù)的進一步發(fā)展。本課題研究基于暫態(tài)、穩(wěn)態(tài)、高頻及“S注入”法的多種選線原理的優(yōu)缺點,研究自適應(yīng)動態(tài)貢獻率算法,根據(jù)對算法適用域的特征量分析,解決了多種算法的權(quán)重動態(tài)分配問題,使系統(tǒng)中的多種算法能夠動態(tài)的自適應(yīng)不同的運行方式和接地方式,達到對各種算法動態(tài)貢獻率的分析,最終得到準確的故障饋線。通過各種對穩(wěn)態(tài)量、暫態(tài)量、高頻特征量及注入法中各故障分量的互相關(guān)分析,得到故障饋線與非故障饋線的相互關(guān)系,達到祛除對故障電流門檻的依賴,解決困擾多年以來零序電流門檻的設(shè)定帶來的麻煩。同時也降低了對零序電流互感器精度的要求,符合目前變電站的實際情況。利用小電流系統(tǒng)單相接地時的各特征量,給出小電流接地選線總體設(shè)計方案,同時完成小電流接地選線系統(tǒng)的硬件、軟件方案設(shè)計,建立小電流接地系統(tǒng)單相接地故障選線系統(tǒng),最后通過測試來檢驗該系統(tǒng)的有效性和實用性。
[Abstract]:With the rapid development of social economy, the demand of power supply reliability is becoming higher and higher, which puts forward new and higher requirements for the security and reliability of the whole power system. At present, small current grounding systems are mostly used in 6kV~35kV distribution networks in China, including neutral ungrounded system, neutral grounding system through arc-suppression coil and mid-resistance grounding system. In the distribution network, the probability of single-phase grounding fault is more than 80%. When the single-phase grounding fault occurs in the low-current grounding system, the fault is only capacitive current of the line to the ground, and the current value is generally small because the short-circuit can not be formed. Because the line voltage of single-phase grounding system is still symmetrical, the system can run with fault for 1-2 hours, but the long-time operation with grounding fault will have a negative impact on the distribution network and equipment. This requires that the fault line should be judged and treated as quickly and accurately as possible when the single-phase grounding fault occurs on the distribution line, which also promotes the further development of the single-phase grounding fault line selection technology of the distribution line. Based on the advantages and disadvantages of transient, steady, high-frequency and "S-injection" methods, the adaptive dynamic contribution algorithm is studied in this paper. It solves the problem of dynamic weight allocation of various algorithms, and makes various algorithms in the system dynamically adapt to different operation modes and grounding modes, so that the dynamic contribution rate of various algorithms is analyzed, and the accurate fault feeder is finally obtained. Through the cross-correlation analysis of steady state, transient, high frequency characteristic and each fault component in injection method, the relationship between fault feeder and non-fault feeder is obtained, and the dependence on fault current threshold is eliminated. Solve the trouble caused by the setting of zero-sequence current threshold for many years. At the same time, the precision requirement of zero sequence current transformer is reduced, which accords with the actual situation of substation. Based on the characteristics of single-phase grounding of small current system, the overall design scheme of line selection for small current grounding is given, and the hardware and software design of line selection system with small current grounding is also completed. The single-phase grounding fault line selection system of small current grounding system is established. Finally, the validity and practicability of the system are tested.
【學(xué)位授予單位】：山東大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TM862

【參考文獻】

相關(guān)博士學(xué)位論文 前3條

1 齊鄭;小電流接地系統(tǒng)單相接地故障選線及定位技術(shù)的研究[D];華北電力大學(xué)（北京）;2005年

2 朱珂;中性點非有效接地系統(tǒng)單相接地故障選線新方法研究[D];山東大學(xué);2007年

3 王念彬;基于小波神經(jīng)網(wǎng)絡(luò)的小電流接地系統(tǒng)故障選線方法的研究[D];中國礦業(yè)大學(xué)（北京）;2010年

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本文編號：1848691