本文選題：特高壓直流輸電 + 大氣顆粒物　； 參考：《華北電力大學(xué)(北京)》2017年博士論文

【摘要】：電暈放電引起的離子流場是反映特高壓直流輸電線路電磁環(huán)境的重要參數(shù),它與離子流密度、無線電干擾、可聽噪聲等物理量共同決定著輸電導(dǎo)線的類型、對地高度、極間距、分裂間距與走廊寬度等線路設(shè)計指標(biāo)。我國北方地區(qū)的特定季節(jié)出現(xiàn)了灰霾天氣。灰霾中的大氣顆粒物將因特高壓直流輸電線路的電暈放電而發(fā)生荷電,進(jìn)而對輸電線路離子流場和離子流密度產(chǎn)生影響。本文通過顆粒物存在時離子流場的建模計算,以及對直流導(dǎo)線離子流場的測量實驗,研究了大氣顆粒物的質(zhì)量濃度、粒徑、介電常數(shù)等物理量對離子流場的影響機(jī)理和規(guī)律。首先,研究了電暈放電產(chǎn)生的空間電荷對地面離子流場測量準(zhǔn)確性的影響,以及直流電場儀探頭對其周圍離子流場的畸變規(guī)律。通過計算和測量獲得了平行電極間離子流場、離子流密度、空間電荷密度的分布規(guī)律,得到了空間電荷對直流電場儀測量準(zhǔn)確性的影響程度。提出了圓柱坐標(biāo)系內(nèi)離子流場的通量有限元方法,計算了離子流場在直流電場儀表面的分布,定量分析了直流電場儀對離子流場的畸變規(guī)律,并通過實驗加以驗證。提出了一種與電場儀配合使用的附加電極的設(shè)計方案,可明顯抑制電場儀周圍離子流場的畸變。通過理論計算和實驗測量驗證了附加電極的有效性。其次,分別提出了在平板電極和圓柱電極內(nèi)的直流離子流場中測量大氣離子遷移率的兩種方法,并將所提方法應(yīng)用于含顆粒物空氣的等效離子遷移率的測量研究。建立了室內(nèi)封閉實驗室,在其中搭建平板電極的電暈放電實驗平臺,定量研究了燃香煙塵顆粒的質(zhì)量濃度改變時,空氣與燃香煙塵顆粒所組成的混合體系的等效遷移率的變化規(guī)律。再次,提出了計算離子流場的上流邊界元方法,用來精確計算場域邊界或電極表面的電場強(qiáng)度。使用邊界單元和上流單元分別求解Poisson方程和電流連續(xù)性方程,迭代計算離子流場大小和空間電荷密度。通過離子流場的測量實驗對所提計算方法的有效性進(jìn)行驗證。最后,在離子流場的上流邊界元算法中計入顆粒物的場致荷電和擴(kuò)散荷電效應(yīng),通過實驗和計算獲得了大氣顆粒物的質(zhì)量濃度、粒徑、介電常數(shù)對高壓直流導(dǎo)線離子流場的影響機(jī)理和規(guī)律。在室內(nèi)封閉實驗室中,測量了存在燃香煙塵顆粒時高壓直流導(dǎo)線下方離子流場的分布,驗證所提計算方法的有效性。通過測量和計算,獲得了荷電顆粒物與空氣中的小離子對總的空間電荷密度的貢獻(xiàn),以及荷電顆粒物對離子流場的貢獻(xiàn)。針對±1100k V特高壓直流輸電線路的結(jié)構(gòu),計算了大氣顆粒物的質(zhì)量濃度、粒徑、介電常數(shù)對輸電線路下方地面處離子流場的影響規(guī)律。
[Abstract]:The ion current field caused by corona discharge is an important parameter to reflect the electromagnetic environment of UHVDC transmission line. It determines the type of transmission wire, ground height, polar distance together with physical parameters such as ion current density, radio interference, audible noise, etc. Line design index such as split spacing and corridor width. There is haze in the northern part of China during the special season. The atmospheric particles in the haze charge the corona discharge of the HVDC transmission line and then affect the ion flow field and ion current density of the transmission line. In this paper, the influence mechanism and law of mass concentration, particle size and dielectric constant of atmospheric particles on ion flow field are studied through modeling and calculation of ion flow field in the presence of particulate matter and the measurement experiment of ion flow field in direct current conductor. Firstly, the influence of space charge generated by corona discharge on the accuracy of surface ion flow measurement and the distortion of ion flow field around it by the probe of DC electric field instrument are studied. The distribution of ion current field, ion current density and space charge density between parallel electrodes are obtained by calculation and measurement. The degree of influence of space charge on the accuracy of DC field meter is obtained. The flux finite element method of ion flow field in cylindrical coordinate system is presented. The distribution of ion current field on the surface of DC field is calculated. The distortion law of ion current field is quantitatively analyzed and verified by experiments. A design scheme of the additional electrode used in conjunction with the electric field meter is proposed, which can obviously suppress the distortion of the ion flow field around the electric field meter. The effectiveness of the additional electrode is verified by theoretical calculation and experimental measurement. Secondly, two methods of measuring atmospheric ion mobility in DC ion flow field of flat electrode and cylindrical electrode are proposed, and the proposed method is applied to the measurement of equivalent ion mobility in air containing particulate matter. An indoor closed laboratory was established, in which the corona discharge experimental platform of flat electrode was set up, and the change of mass concentration of cigarette dust particles was studied quantitatively. The change of equivalent mobility of the mixed system composed of air and cigarette dust particles. Thirdly, an upper current boundary element method is proposed to calculate the electric field intensity of the field boundary or electrode surface. Poisson equation and current continuity equation are solved by boundary element and upper current element respectively. The size of ion flow field and space charge density are calculated iteratively. The validity of the proposed method is verified by measuring the ion flow field. Finally, the field charge and diffusion charge effects of particles are taken into account in the upper current boundary element algorithm of ion flow field. The mass concentration and particle size of atmospheric particles are obtained by experiments and calculations. The influence mechanism and law of dielectric constant on ion flow field of HVDC conductor. In an indoor closed laboratory, the distribution of ion flow field beneath the high voltage direct current conductor was measured in the presence of cigarette dust particles, and the validity of the proposed method was verified. Through measurement and calculation, the contribution of charged particles and small ions in air to the total space charge density and the contribution of charged particles to the ion flow field are obtained. According to the structure of 鹵1100kV UHV HVDC transmission line, the influence of mass concentration, particle size and dielectric constant of atmospheric particles on the surface ion flow field under the transmission line is calculated.
【學(xué)位授予單位】：華北電力大學(xué)(北京)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2017
【分類號】：TM75

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 涂功銘;宋薔;陳奎續(xù);姚強(qiáng);;帶電顆粒流動過程中電荷損失的研究[J];中國電機(jī)工程學(xué)報;2016年16期

2 汪l，

本文編號：2038297