本文選題：沿面閃絡 + 電暈老化��； 參考：《華北電力大學》2017年碩士論文

【摘要】：沿面閃絡電壓的研究一直是個熱點課題,發(fā)展了各種理論,基于實驗的研究,提出了很多提高沿面閃絡電壓的方法。在各種研究因素中,空間電荷對沿面閃絡電壓的影響研究較少,隨著材料老化程度的增加,材料內(nèi)陷阱密度變大,空間電荷入陷形成空間電荷層,一方面形成了材料內(nèi)附加電場,另一方面蘊藏了大量的極化能量,空間電荷對沿面閃絡電壓影響不能被忽略。對沿面閃絡電壓的影響研究,能夠為材料改性方面提供指導意義,進一步提高絕緣材料沿面閃絡電壓,探索空間電荷對沿面閃絡過程的作用關系,有助于拓展絕緣材料沿面閃絡的相關機理。本文通過人工電暈老化的方法,老化了不同時長的硅橡膠試樣,隨著老化時間的增加,材料內(nèi)部陷阱密度變大,通過電極注入電荷被陷阱俘獲,形成蘊含空間電荷數(shù)由少到多的試樣,在指狀電極下進行沿面閃絡電壓測試,探究空間電荷對沿面閃絡電壓的影響。首先搭建了人工電暈老化試驗裝置,獲取具有不同陷阱數(shù)目的老化試樣。并且搭建了沿面閃絡電壓測試平臺,編寫了恒定升壓速率的升壓控制軟件,基于單片機控制的高壓直流電源能夠以均勻的升壓速率輸出電壓,減小了電壓波形對沿面閃絡電壓的影響,大大降低了實驗數(shù)據(jù)的分散性,是實驗成功進行的保障。其次利用電導電流曲線粗略的反映老化材料內(nèi)陷阱密度。電導電流對數(shù)坐標系下曲線的斜率代表空間電荷入陷速率。電導電流測試受多種因素影響,重復性較差,對升壓梯度和升壓間隔較敏感。為此開發(fā)了基于單片機平臺的等梯度、等間隔升壓系統(tǒng),通過讀取采樣電阻上的電壓值,經(jīng)集成運放放大后,自動將運算后的電導電流值發(fā)送至電腦端。最后通過曲線擬合得到電老化閾值,估算材料內(nèi)陷阱密度情況。研究結果表明,空間電荷對沿面閃絡流柱發(fā)展存在重要影響,一方面空間電荷層形成的空間電場,對表面流柱內(nèi)電荷有力的作用,加速了流柱內(nèi)正負粒子的分離速度,正負粒子形成的空間電場對電極間的電場有削弱的作用;另一方面空間電荷層使電極間的電場向材料表面彎曲,使流柱沿著材料表面前進,受材料表面形貌的影響變大,沿面閃絡電壓在一度程度內(nèi)會升高。大量積聚的空間電荷蘊含了大量的極化能量,空間電荷釋放時大量能量參與到沿面閃絡中,同時表面電荷受空間電荷引力的作用,表面電荷消散相對較難。使沿面閃絡電壓急劇下降。提高沿面閃絡電壓需要抑制表面電荷的積累,也要兼顧空間電荷的分布與空間電荷量蘊含的極化能量。
[Abstract]:The study of flashover voltage along the surface has been a hot topic. Various theories have been developed. Based on the experimental research, many methods to improve the flashover voltage along the surface have been proposed. Among all the factors studied, the influence of space charge on flashover voltage along the surface is less studied. With the increase of aging degree of materials, the density of traps in materials becomes larger, and space charges sink in to form space charge layers. On the one hand, the additional electric field in the material is formed, on the other hand, there is a large amount of polarization energy, so the influence of space charge on the flashover voltage can not be ignored. The study on the effect of flashover voltage can provide guidance for material modification, improve the flashover voltage of insulating material, and explore the relationship between space charge and flashover process. It is helpful to expand the mechanism of insulator flashover along the surface. By means of artificial corona aging, the samples of silicone rubber with different ages were aged. With the increase of aging time, the trap density of the material increased, and the charge injected into the electrode was captured by the trap. The flashover voltage was measured under the finger electrode to investigate the influence of space charge on the flashover voltage. First, artificial corona aging test device was built to obtain aging samples with different number of traps. A flashover voltage test platform is built, and a constant boost control software is developed. The voltage output of HVDC power supply based on single-chip microcomputer can be uniform at the booster rate. The influence of voltage waveform on flashover voltage along the surface is reduced, and the dispersion of experimental data is greatly reduced, which is the guarantee of successful experiment. Secondly, the conductance current curve is used to roughly reflect the trap density in aging materials. The slope of the curve in logarithmic coordinate system of conductance current represents the rate of entrapment of space charge. The measurement of conductance current is affected by many factors, and its repeatability is poor, and it is sensitive to the voltage gradient and the booster interval. In this paper, an equal-gradient, equal-interval voltage booster system based on single-chip microcomputer is developed. By reading the voltage value on the sample resistor and amplifying by integrated operational amplifier, the calculated conductance current value is automatically transmitted to the computer. Finally, the electrical aging threshold was obtained by curve fitting, and the trap density in the material was estimated. The results show that space charge has an important influence on the development of flashover flow column along the surface. On the one hand, the space electric field formed by the space charge layer has a force on the charge in the surface flow column, which accelerates the separation speed of positive and negative particles in the flow column. The space electric field formed by the positive and negative particles weakens the electric field between the electrodes; on the other hand, the space charge layer bends the electric field between the electrodes towards the surface of the material, making the flow column advance along the surface of the material, which is greatly affected by the surface morphology of the material. The flashover voltage along the surface increases at one degree. A large amount of accumulated space charge contains a lot of polarized energy. When the space charge is released, a large amount of energy is involved in the flashover along the surface. At the same time, the surface charge is affected by the space charge gravity, so it is relatively difficult to dissipate the surface charge. A sharp drop in flashover voltage along the surface. To increase the flashover voltage along the surface, the accumulation of surface charge should be restrained, and the distribution of space charge and the polarization energy contained in the amount of space charge should be taken into account.
【學位授予單位】：華北電力大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TM216

【參考文獻】

相關期刊論文 前10條

1 梁英;靳哲;張君成;;硅橡膠在不同電暈老化階段下的表面電荷對沿面閃絡的影響[J];中國電機工程學報;2016年22期

2 黃成才;李永剛;汪佛池;張志猛;;基于電導電流測試的硅橡膠復合絕緣子傘群材料老化特性分析[J];電工技術學報;2016年02期

3 王亞林;吳建東;萬佳東;陳亞丁;尹毅;;低密度聚乙烯空間電荷與電導電流的聯(lián)合測量[J];南方電網(wǎng)技術;2015年10期

4 高巖峰;王家福;梁曦東;閻志鵬;劉瑛巖;;交直流電暈對高溫硫化硅橡膠性能的影響[J];中國電機工程學報;2016年01期

5 高宇;門業(yè)X;杜伯學;趙慶磊;;表面電荷對典型聚合物絕緣材料直流閃絡電壓的影響[J];高電壓技術;2015年05期

6 王飛風;張沛紅;高銘澤;;納米碳化硅/硅橡膠復合物非線性電導特性研究[J];物理學報;2014年21期

7 汪佛池;黃成才;李永剛;楊升杰;張志猛;;硅橡膠復合絕緣子老化狀態(tài)評估新判據(jù)[J];電網(wǎng)技術;2014年11期

8 吳建東;蘭莉;尹毅;李U，

本文編號：2102513