【摘要】：接地系統(tǒng)是保證風(fēng)電場安全運(yùn)行的重要組成部分之一,接地網(wǎng)雷電沖擊電流入地點(diǎn)處的電位較高問題一直是威脅設(shè)備及人身安全的主要問題之一,為了有效降低接地網(wǎng)雷電沖擊電流注入點(diǎn)處的電壓,并對接地網(wǎng)的沖擊電位分布進(jìn)行改善,本文對風(fēng)電場圓環(huán)接地網(wǎng)的沖擊特性進(jìn)行研究分析。本文首先建立了圓環(huán)接地網(wǎng)的幾何模型,然后在考慮雷電流的高頻效應(yīng)基礎(chǔ)上,忽略導(dǎo)體的電阻,建立合理的雙π型等效電路下的數(shù)學(xué)模型,對圓環(huán)接地網(wǎng)在沖擊電流入地點(diǎn)處的電壓用電磁暫態(tài)程序(ATP-EMTP)進(jìn)行仿真,并將得到的結(jié)果與方孔接地網(wǎng)進(jìn)行對比分析。在此模型的基礎(chǔ)上,對影響沖擊特性的其它因素進(jìn)行仿真分析,并用仿真的方法對圓環(huán)接地網(wǎng)的沖擊特性進(jìn)行優(yōu)化研究。分析結(jié)果表明：圓環(huán)形接地網(wǎng)雷電流沖擊入地點(diǎn)處的電壓只有方形接地網(wǎng)的二分之一左右。當(dāng)雷電流沖擊入地點(diǎn)位于圓環(huán)接地網(wǎng)中心位置時(shí),其入地點(diǎn)處電壓只有位于邊緣處的三分之一左右。雷電流幅值升高時(shí),沖擊接地點(diǎn)處的電壓也隨之升高,并且隨著雷電流幅值的增加,沖擊點(diǎn)處電壓隨時(shí)間變化越快。不等間距同心圓環(huán)接地網(wǎng)在沖擊入地點(diǎn)處的電壓比等間距同心圓環(huán)接地網(wǎng)低13.3%左右。根據(jù)分析結(jié)果可得出以下結(jié)論：圓環(huán)接地網(wǎng)在降低沖擊電流入地點(diǎn)處的電壓方面比方孔地網(wǎng)好,在保護(hù)設(shè)備及人身安全方面效果明顯。在接地網(wǎng)設(shè)計(jì)時(shí),應(yīng)該盡量將接地引下線布置在接地網(wǎng)的中心處,以降低沖擊點(diǎn)處的電壓,并應(yīng)采用不等間距同心圓布置圓環(huán)接地網(wǎng)。
[Abstract]:Grounding system is one of the important components to ensure the safe operation of wind farm. The high potential of lightning impulse in the grounding grid is always one of the main problems that threaten the safety of equipments and people. In order to effectively reduce the voltage at the injection point of lightning impulse current in grounding grid and improve the impulse potential distribution of grounding grid, the impact characteristics of circular earthing grid in wind farm are studied and analyzed in this paper. In this paper, the geometric model of the toroidal grounding grid is first established, and then, on the basis of considering the high frequency effect of the lightning current, the resistance of the conductor is ignored, and a reasonable mathematical model of the double 蟺 equivalent circuit is established. The voltage of toroidal grounding grid is simulated by electromagnetic transient program (ATP-EMTP), and the results are compared with that of square hole grounding grid. On the basis of this model, the other factors affecting the impact characteristics are simulated and analyzed, and the impact characteristics of the ring grounding grid are optimized by the simulation method. The analysis results show that the current impact voltage of the circular grounding grid is only about 1/2 of that of the square grounding grid. When the lightning current impinges at the center of the ring grounding grid, the voltage at the incoming location is only about 1/3 of that at the edge. When the lightning current amplitude increases, the voltage at the impulse grounding point also increases, and with the increase of lightning current amplitude, the voltage at the impulse point changes faster with time. The voltage of the concentric ring grounding grid with unequal spacing is 13.3% lower than that of the concentric ring grounding grid with equal spacing at the impact site. According to the analysis results, the following conclusions can be drawn: the ring grounding grid is good in reducing the voltage of the impulse electric inflow site, such as the hole-to-ground network, and the effect is obvious in the protection of equipment and personal safety. In the design of the grounding grid, the grounding lead-down line should be arranged at the center of the grounding grid as far as possible to reduce the voltage at the impact point, and the ring grounding grid should be arranged with unequal spacing concentric circle.
【學(xué)位授予單位】：長沙理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TM614

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 孫結(jié)中,劉力;運(yùn)用等值復(fù)數(shù)鏡像法求解復(fù)合分層土壤結(jié)構(gòu)的格林函數(shù)[J];中國電機(jī)工程學(xué)報(bào);2003年09期

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本文編號(hào)：2471452