特高壓直流輸電系統(tǒng)單極接地過(guò)電壓的研究
[Abstract]:With the increase of power load level in our country, and the distribution of energy and load areas is seriously uneven, long-distance, high-power, cross-regional transmission lines more and more appear in the power system of our country, but the direct current transmission system has good economy. It is very suitable for long distance and high power transmission due to its reliable operation performance and the absence of stability problems of AC transmission systems. It is of great significance to study the overvoltage of HVDC transmission system and determine the insulation level of HVDC transmission lines to determine the energy security of our country and ensure the economic development of our country. DC grounding fault is the most common fault on DC line, and it will produce the most serious overvoltage on the line. Therefore, it is necessary to calculate the unipolar grounding overvoltage of HVDC transmission system. In this paper, the principle of unipole grounding overvoltage in HVDC system is analyzed theoretically, and the related factors affecting overvoltage are found out. Then the equivalent circuit of HVDC system is treated, according to the equivalent circuit diagram, the state differential equations of voltage and current at each point are listed, and the single-pole grounding overvoltage of typical HVDC transmission system is calculated by improved Euler method. The results show that when the fault point is at the midpoint of the line, the highest overvoltage will be generated at the non-fault pole. The shorter the line is, the higher the over-voltage level on the line is, and the fault grounding resistance can reduce the transient component of the voltage wave caused by the fault, the larger the fault grounding resistance, the smaller the overvoltage amplitude. In order to accurately calculate and analyze the unipolar grounding overvoltage of HVDC system, the simulation model of UHV HVDC system is established according to the actual parameters of Yunguang UHVDC transmission system by using PSCAD software. The effects of DC filter, flat-wave reactor, line length, fault grounding resistance, load level, earth resistivity and fault location on unipolar overvoltage of HVDC transmission system are calculated in detail. And the overvoltage of the equipment in the converter station when the fault. The calculation results show that the DC filter, load level and earth resistivity have a certain influence on the overvoltage when the maximum overvoltage occurs at the fault point. The higher the load level, the greater the overvoltage, the higher the earth resistivity and the lower the overvoltage. However, the influence of the inductance and configuration of the flat-wave reactor on the overvoltage is great. The larger the inductance, the smaller the overvoltage, and the smaller the overvoltage is when all of them are installed on the pole busbar and the neutral bus, respectively. The effect of line length and fault grounding resistance on overvoltage is consistent with the results obtained by the improved Euler method. When the line length is 800km, the maximum overvoltage on the line is 1.7 pu. it is worthy of attention. When grounding fault occurs, a certain overvoltage will be generated on the converter station equipment. Because the DC filter is closer to the line end, it will be greatly affected. When the fault point is near the converter station, it will cause a larger overvoltage on its inductance. The threat to its insulation deserves attention. For the measures to limit the overvoltage, the lightning arrester can be installed at the midpoint of the line, which can effectively limit the overvoltage.
【學(xué)位授予單位】:廣西大學(xué)
【學(xué)位級(jí)別】:碩士
【學(xué)位授予年份】:2014
【分類號(hào)】:TM721.1
【參考文獻(xiàn)】
相關(guān)期刊論文 前10條
1 史六如;±500千伏直流輸電線上的過(guò)電壓研究[J];電網(wǎng)技術(shù);1987年01期
2 葉會(huì)生,何俊佳,李化,林福昌;雷擊高壓直流線路桿塔時(shí)的過(guò)電壓和閃絡(luò)仿真研究[J];電網(wǎng)技術(shù);2005年21期
3 朱藝穎;蔣衛(wèi)平;吳雅妮;;特高壓直流輸電控制保護(hù)特性對(duì)內(nèi)過(guò)電壓的影響[J];電網(wǎng)技術(shù);2008年08期
4 吳婭妮;蔣衛(wèi)平;朱藝穎;李新年;咼虎;;特高壓直流輸電線路故障過(guò)電壓的研究[J];電網(wǎng)技術(shù);2009年04期
5 黃萬(wàn)永,霍繼安,曾南超,孟慶東;跨省電網(wǎng)以直流相聯(lián)是全國(guó)聯(lián)網(wǎng)的最佳模式[J];電網(wǎng)技術(shù);1999年01期
6 朱韜析;歐開健;;高壓直流輸電系統(tǒng)線路接地故障過(guò)程研究[J];廣東電力;2008年10期
7 荊勇,任震,楊晉柏,李立mg,陳葛松,林集明;天廣直流輸電系統(tǒng)運(yùn)行過(guò)電壓的研究[J];高電壓技術(shù);2002年04期
8 舒印彪;中國(guó)直流輸電的現(xiàn)狀及展望[J];高電壓技術(shù);2004年11期
9 曾南超;高壓直流輸電在我國(guó)電網(wǎng)發(fā)展中的作用[J];高電壓技術(shù);2004年11期
10 黃燕艷,張穎,施圍;不同額定電壓等級(jí)避雷器對(duì)操作過(guò)電壓的影響[J];高壓電器;2003年04期
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