本文選題：諧振接地系統(tǒng) + 消弧線圈　； 參考：《中國礦業(yè)大學(xué)》2014年碩士論文

【摘要】：目前，我國配電網(wǎng)中性點大多采用中性點不接地或經(jīng)消弧線圈接地的方式運行，統(tǒng)稱之為小電流接地系統(tǒng)。按照消弧線圈調(diào)諧方式的不同，消弧線圈可分為預(yù)調(diào)式與隨調(diào)式兩種；按照對電網(wǎng)電容電流補償程度的差異，消弧線圈的工作狀態(tài)可分為全補償、欠補償和過補償三種�，F(xiàn)有消弧線圈自動跟蹤補償設(shè)備僅能補償接地電流中的有功分量。因而，對于絕緣老化較為嚴重、架空線為主或電力線路網(wǎng)絡(luò)較大的電網(wǎng)有必要測量其線路絕緣阻抗。實際運行中，中性點位移電壓普遍存在，特別是消弧線圈全補償時的諧振過電壓，而較大中性點位移電壓對系統(tǒng)安全運行顯然是有害的，需通過增加電網(wǎng)阻尼率或脫諧度的方式實現(xiàn)中性點位移電壓的限制。但是目前抑制零序電壓的方法僅給出大致的控制范圍，未給出將中性點位移電壓限制至某一定值的精確控制條件。電網(wǎng)單相接地故障時往往伴隨一定值的過渡電阻，過渡電阻弱化故障特征，降低保護裝置的靈敏度，因而有必要根據(jù)電網(wǎng)故障前后的特征預(yù)估過渡電阻值的大小。 本文針對諧振接地系統(tǒng)現(xiàn)有中性點位移電壓抑制方法的不足，提出電網(wǎng)正常運行時脫諧度和阻尼率的最優(yōu)控制條件。分析隨調(diào)式消弧線圈不同脫諧度和預(yù)調(diào)式消弧線圈不同阻尼率下的零序電壓軌跡。根據(jù)電網(wǎng)絕緣參數(shù)和當(dāng)前消弧線圈支路阻抗下的零序電壓值，可計算出限制中性點位移電壓的精確控制條件。針對消弧線圈并阻尼接地的電網(wǎng)，本文根據(jù)阻尼電阻調(diào)節(jié)前后零序電壓的特性實現(xiàn)消弧線圈補償狀態(tài)的判斷。 本文提出基于“失諧量”的消弧線圈調(diào)諧方法，可實現(xiàn)電網(wǎng)電容電流的跟蹤測量，該方法適用于消弧線圈并阻尼接地電網(wǎng)；提出消弧線圈變阻尼跟蹤調(diào)諧方法，該方法不僅可實現(xiàn)電網(wǎng)電容電流的測量還可精確測量電網(wǎng)絕緣總電阻；提出消弧線圈變參調(diào)諧通用方法，該方法不受消弧線圈調(diào)諧變參方式的限制，實現(xiàn)電網(wǎng)電容電流和絕緣電阻的精確測量，在預(yù)調(diào)式和隨調(diào)式消弧線圈中均可適用。 本文分別針對中性點不接地和諧振接地的電網(wǎng)，根據(jù)單相接地故障前后中性點電壓的位移度，判斷過渡電阻的分布區(qū)間。 最后針對本文提出的中性點電壓精確控制方法、消弧線圈跟蹤調(diào)諧控制方法和過渡電阻的識別進行了仿真實驗研究。仿真實驗的結(jié)果均證明了所提理論的正確性和有效性。
[Abstract]:At present, the neutral point of distribution network in our country is mostly operated by neutral point ungrounded or grounded by arc-suppression coil, which is called small current grounding system. According to the different tuning modes of the arc-suppression coil, the arc-suppression coil can be divided into two types: presetting type and accompanying mode, and the working state of arc-suppression coil can be divided into three types: full compensation, undercompensation and over-compensation according to the difference of compensation degree of capacitor current in power network. The existing arc suppression coil automatic tracking compensation equipment can only compensate the active power component in the grounding current. As a result, it is necessary to measure the insulation impedance of the power grid with the main overhead line or the larger power line network for the serious insulation aging. In actual operation, the neutral displacement voltage is widespread, especially the resonant overvoltage when the arc suppression coil is fully compensated, but the larger neutral displacement voltage is obviously harmful to the safe operation of the system. It is necessary to limit the neutral displacement voltage by increasing the damping ratio or detuning degree. However, at present, the method of suppressing zero-sequence voltage only gives the approximate control range, and does not give the accurate control condition to limit the neutral displacement voltage to a certain value. Single phase grounding fault of power network is usually accompanied by a certain value of transition resistance, which weakens the fault characteristics and reduces the sensitivity of the protective device, so it is necessary to estimate the magnitude of the transition resistance according to the characteristics of the power network before and after the fault. In this paper, the optimal control conditions of detuning degree and damping rate are proposed to overcome the deficiency of the existing neutral point displacement voltage suppression methods in resonant grounding system. The zero-sequence voltage trajectories with different detuning degrees and different damping ratios of preset arc-suppression coil are analyzed. Based on the insulation parameters of the power network and the zero sequence voltage values under the current impedance of the arc-suppression coil branch, the accurate control conditions limiting the displacement voltage of the neutral point can be calculated. According to the characteristics of zero-sequence voltage before and after damping resistor adjustment, the compensation state of arc-suppression coil is judged in this paper for the power network with arc-suppression coil and damping grounding. In this paper, a tuning method of arc-suppression coil based on detuning is proposed, which can be used to track and measure the capacitance current of power network. This method is suitable for arc-suppression coil and damping grounding power network, and a variable damping tracking and tuning method for arc-suppression coil is proposed. This method can not only measure the capacitance current of power network but also measure the total insulation resistance of power network accurately, and put forward a general method of tuning arc suppression coil, which is not limited by the tuning method of arc-suppression coil. The accurate measurement of capacitance current and insulation resistance can be used in presetting and adjusting arc suppression coils. In this paper, according to the voltage displacement of neutral point before and after single-phase grounding fault, the distribution range of transition resistance is judged for the grid with neutral point ungrounded and resonant grounding respectively. Finally, simulation experiments are carried out on the precise control method of neutral voltage proposed in this paper, the tracking tuning control method of arc suppression coil and the identification of transition resistance. The simulation results show that the proposed theory is correct and effective.
【學(xué)位授予單位】：中國礦業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TM475

【參考文獻】

相關(guān)期刊論文 前10條

1 田銘興,勵慶孚;磁飽和式可控電抗器的等效電路及仿真分析[J];電工技術(shù)學(xué)報;2003年06期

2 徐波;張建文;蔡旭;管珊蓮;姚勇;;電網(wǎng)不對稱條件下小電流接地系統(tǒng)接地相辨識[J];電工技術(shù)學(xué)報;2011年12期

3 徐玉琴,陳志業(yè),李鵬;晶閘管投切電容式消弧線圈的設(shè)計與應(yīng)用研究[J];電力系統(tǒng)自動化;2001年13期

4 蔡旭,李仕平,杜永忠,陳剛;變阻尼調(diào)匝式消弧線圈及接地選線綜合控制器[J];電力系統(tǒng)自動化;2004年05期

5 陳忠仁;吳維寧;張勤;陳家宏;;調(diào)匝式消弧線圈自動調(diào)諧新方法[J];電力系統(tǒng)自動化;2005年24期

6 蔡旭，，李偉民;自動跟蹤電網(wǎng)電容電流動態(tài)補償系統(tǒng)研究[J];電力系統(tǒng)自動化;1995年08期

7 趙牧函,紀延超;消弧線圈自動調(diào)諧原理的研究[J];電力系統(tǒng)及其自動化學(xué)報;2002年04期

8 邵國君;蔡旭;;基于DSP和FPGA的消弧線圈數(shù)字勵磁調(diào)節(jié)器[J];電力自動化設(shè)備;2006年08期

9 張建文;蔡旭;;快速自勵式消弧線圈研究及應(yīng)用[J];電力自動化設(shè)備;2006年09期

10 鄧金啟;智能消弧線圈接地裝置及其應(yīng)用[J];電網(wǎng)技術(shù);2001年10期

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