固–气界面电荷消散特性及其动力学过程
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摘要
直流电场下气体绝缘设备中固体绝缘介质表面电荷的积聚会导致固–气界面的局部电场畸变,从而降低系统的绝缘水平。研究固–气界面电荷的消散特性可为高压直流气体绝缘装置的研发提供重要的理论基础。利用针–板电极向绝缘材料表面注入电荷,在不同条件下进行固–气界面电荷消散实验。采用静电探头法测量试样表面的电位分布,并通过反演计算得到电荷密度分布。结果表明:处在气体氛围中的环氧树脂材料,其表面电荷主要是通过与气体中离子中和消散,消散过程与气体中电场的分布有关。处在开放空间中的试样,表面电荷密度越大的地方电场越集中,因而迁移至此的异号带电粒子更多,表面电荷消散也更快,最后在试样表面会逐渐形成"火山口"形的电荷分布。基于固–气界面电荷消散的三种途径,构建了固–气界面电荷消散的动力学模型,分别考察了通过体电导消散、面电导消散,以及与气体中离子中和消散3种不同消散机理主导下的固–气界面电荷消散特性。研究发现,对于体积电导率小于10?15S/m的材料,表面电荷主要通过与气体中离子中和消散;对于体积电导率大于10?14S/m的材料,表面电荷主要通过体电导消散,各处消散速率基本一致;未经特殊处理的绝缘材料,表面电导率较小,对表面电荷消散的作用有限。
Charge accumulation on a solid insulator under dc field will lead to the local field distortion along the gas-solid interface and decrease the insulation level of the system. To study the surface charge dissipation characteristics will provide an important basis for the development of HVDC gas-insulated equipment. In this paper, the needle-to-plate electrode was used to inject charges onto the surface of insulating material, and the charge dissipation was studied under different conditions. The electrostatic probe method was used to measure the potential distribution on the sample surface, from which charge density distribution was obtained by the inversion calculation. Results show that surface charge on an epoxy resin insulator in the gas is mainly dissipated by neutralization with gas ions, and the process is related to the electric field distribution in the gas. For the charged sample in a free volume, electric field is more concentrated where the surface charge density is the maximum.As a result, more hetero-charges migrate to this area, leading to faster charge decay. Finally, a crater-shaped charge distribution forms. Based on the three ways for the surface charge decay,i.e. bulk conduction, surface conduction, and neutralization with gas ions, a kinetic model was built and the charge dissipation characteristics through the three mechanisms were studied separately. It reveals that surface charge of materials with bulk conductivity less than 10?15 S/m is mainly dissipated by neutralization with gas ions; for bulk conductivity larger than 10?14 S/m, surface charges are mainly dissipated through bulk conduction with almost the same dissipation rate on the surface; an insulating material without special treatment has a small surface conductivity, which has limited effect on charge decay.
Charge accumulation on a solid insulator under dc field will lead to the local field distortion along the gas-solid interface and decrease the insulation level of the system. To study the surface charge dissipation characteristics will provide an important basis for the development of HVDC gas-insulated equipment. In this paper, the needle-to-plate electrode was used to inject charges onto the surface of insulating material, and the charge dissipation was studied under different conditions. The electrostatic probe method was used to measure the potential distribution on the sample surface, from which charge density distribution was obtained by the inversion calculation. Results show that surface charge on an epoxy resin insulator in the gas is mainly dissipated by neutralization with gas ions, and the process is related to the electric field distribution in the gas. For the charged sample in a free volume, electric field is more concentrated where the surface charge density is the maximum.As a result, more hetero-charges migrate to this area, leading to faster charge decay. Finally, a crater-shaped charge distribution forms. Based on the three ways for the surface charge decay,i.e. bulk conduction, surface conduction, and neutralization with gas ions, a kinetic model was built and the charge dissipation characteristics through the three mechanisms were studied separately. It reveals that surface charge of materials with bulk conductivity less than 10?15 S/m is mainly dissipated by neutralization with gas ions; for bulk conductivity larger than 10?14 S/m, surface charges are mainly dissipated through bulk conduction with almost the same dissipation rate on the surface; an insulating material without special treatment has a small surface conductivity, which has limited effect on charge decay.
引文
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[9]苑舜.营口华能电厂GIS盆式绝缘子沿面放电分析[J].东北电力技术,1996(5):36-37.Yuan Shun.Analysis of the surface flashover of a GIScone-type insulator at Yingkou Huaneng power plant[J].Northeastern Electric Power,1996(5):36-37(in Chinese).
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[11]Kumara S,Serdyuk Y V,Gubanski S M.Surface charge decay on polymeric materials under different neutralization modes in air[J].IEEE Transactions on Dielectrics and Electrical Insulation,2011,18(5):1779-1885.
[12]高文强,张博雅,张贵新.硅橡胶材料表面电荷消散现象[J].高电压技术,2017,43(2):468-475.Gao Wenqing,Zhang Boya,Zhang Guixin.Surface charge decay on silicone rubber material[J].High Voltage Engineering,2017,43(2):468-475(in Chinese).
[13]Leal Ferreira G F,Figueiredo M T.Corona charging of electrets:models and results[J].IEEE Transactions on Dielectrics and Electrical Insulation,1992,27(4):719-737.
[14]Sessler GM,AlquiéC,Lewiner J.Charge distribution in Teflon FEP(fluoroethylene-propylene)negatively coronacharged to high potentials[J].Journal of Applied Physics,1992,71(5):2280-2284.
[15]Batra I P,Kanazawa K D,Seki H.Discharge characteristics of photoconducting insulators[J].Journal of Applied Physics,1970,41(8):3416-3422.
[16]Perrin C,Griseri V,Inguimbert C,et al.Analysis of internal charge distribution in electron irradiated polyethylene and polyimide films using a new experimental method[J].Journal of Physics D:Applied Physics,2008,41(20):205417.
[17]Lederle Ch,Kindersberger J,Surface charge decay on insulators in air and sulfur hexafluorid-Part I:Simulation[J].IEEE Transactions on Dielectrics and Electrical Insulation,2008,15(4):941-948.
[18]Zhang B,Zhang G.Interpretation of the surface charge decay kinetics on insulators with different neutralization mechanisms[J].Journal of Applied Physics,2017,121(10):105105.
[19]Lederle Ch,Kindersberger J,Surface charge decay on insulators in air and sulfur hexafluorid-Part II:Measurements[J].IEEE Transactions on Dielectrics and Electrical Insulation,2008,15(4):949-957.
[20]杜伯学,高宇,刘彦君.聚萘二甲酸丁二醇酯试样表面电荷迁移与消散机理[J].电工技术学报,2009,24(3):36-54.Du Boxue,Gao Yu,Liu Yanjun.Charge migration and decay on polybutylene naphthalate surface[J].Transactions of China Electrotechnical Society,2009,24(3):36-54(in Chinese).
[21]马云飞,章程,李传扬,等.重频脉冲放电等离子体处理聚合物材料加快表面电荷消散的实验研究[J].中国电机工程学报,2016,36(6):1731-1738.Ma Yunfei,Zhang Cheng,Li Chuanyang,et al.Experimental study of accelerating surface charge dissipation on polymer treated by repetitively pulsed discharge plasmas[J].Proceedings of the CSEE,2016,36(6):1731-1738(in Chinese).
[22]张博雅,王强,祁喆,等.直流电压下聚合物表面电荷测量方法及积聚特性[J].中国电机工程学报,2016,36(24):6664-6674.Zhang Boya,Wang Qiang,Qi Zhe,et al.Measurement method and accumulation characteristics of surface charge distribution on polymeric material under DC voltage[J].Proceedings of the CSEE,2016,36(24):6664-6674(in Chinese).
[23]付洋洋,王强,张贵新,等.基于表面电位测量的表面电荷反演计算[J].高电压技术,2013,39(1):88-95.Fu Yangyang,Wang Qiang,Zhang Guixin,et al.Inverse calculation of surface charge based on surface potential measurement[J].High Voltage Engineering,2013,39(1):88-95(in Chinese).
[24]邓军波,王涵,薛建议,等.基于静电探头法的表面电荷密度分布及电场分布的改进反演算法研究[J].中国电机工程学报,2018,38(4):1239-1247.Deng Junbo,Wang Han,Xue Jianyi,et al.Improved reverse algorithm of surface charge density distribution and electric field distribution based on electrostatic probe[J].Proceedings of the CSEE,2018,38(4):1239-1247(in Chinese).
[25]Bracewell R.Fourier analysis and imaging,Chapter 6:The two-dimensional convolution theorem[M].New York:Springer,2003:204-221.
[26]冈萨雷斯,伍兹.数字图像处理[M].3版.阮秋琦等,译.北京:电子工业出版社,2011:207-210.Gonzalez R C,Woods R E.Digital image processing[M].3rd ed.Ruan Qiuqi,et al,translated.Beijing:Publishing House of Electronics Industry,2011:207-210(in Chinese).
[27]Zhang B,Gao W,Qi Zhe,et al.Inversion algorithm to calculate charge density on solid dielectric surface based on surface potential measurement[J].IEEE Transactions on Instrumentation and Measurement,2017,66(12):3316-3325.
[28]Zhou H,Ma G,Li C,et al.Impact of temperature on surface charges accumulation on insulators in SF6-filled DC-GIL[J].IEEE Transactions on Dielectrics and Electrical Insulation,2017,24(1):601-610.
[29]Boggs S,Wiegart N.Gaseous Dielectrics IV[M].New York:Pergamon Press,1984:531.
[30]Winter A,Kindersberger J.Transient field distribution in gas-solid insulation systems under DC voltages[J].IEEETransactions on Dielectrics and Electrical Insulation,2014,21(1):116-128.
[31]Coelho R,Levy L,and Sarrail D.On the natural decay of corona charged insulating sheets[J].Physica Status Solidi,1986,94(1):289-298.
[32]Straumann U,Schuller M,Franck M C.Theoretical investigation of HVDC disc spacer charging in SF6 gas insulated systems[J].IEEE Transactions on Dielectrics and Electrical Insulation,2012,19(6):2196-2205.
[33]Zhang B,Zhang G,Wang Q,et al.Suppression of surface charge accumulation on Al2O3-filled epoxy resin insulator under dc voltage by direct fluorination[J].AIP Advances,2015,5(12):127207.
[34]Li C,Hu J,Lin C,et al.Surface charge migration and DCsurface flashover of surface-modified epoxy-based insulators[J].Journal of Physics D:Applied Physics,2017,50(6):065301.
[2]齐波,张贵新,李成榕,等.气体绝缘金属封闭输电线路的研究现状及应用前景[J].高电压技术,2015,41(5):1466-1473.Qi Bo,Zhang Guixin,Li Chengrong,et al.Research status and prospect of gas-insulated metal enclosed transmission line[J].High Voltage Engineering,2015,41(5):1466-1473(in Chinese).
[3]Zhang B,Qi Z,Zhang G.Charge accumulation patterns on spacer surface in HVDC gas-insulated system:dominant uniform charging and random charge speckles[J].IEEE Transactions on Dielectrics and Electrical Insulation,2017,24(2):1229-1238.
[4]Zhang B,Gao W,Hou Y,et al.Surface charge accumulation and suppression on fullerene-filled epoxy-resin insulator under DC voltage[J].IEEETransactions on Dielectrics and Electrical Insulation,2018,25(5):2011-2019.
[5]唐炬,潘成,王邸博,等.高压直流绝缘材料表面电荷积聚研究进展[J].电工技术学报,2017,32(8):10-21.Tang Ju,Pan Cheng,Wang Dibo,et al.Development of studies about surface charge accumulation on insulating material under HVDC[J].Transactions of China Electrotechnical Society,2017,32(8):10-21(in Chinese).
[6]Ma G,Zhou H,Li C,et al.Designing epoxy insulators in SF6-filled DC-GIL with simulations of ionic conduction and surface charging[J].IEEE Transactions on Dielectrics and Electrical Insulation,2015,22(6):3312-3320.
[7]张博雅,王强,张贵新,等.SF6中绝缘子表面电荷积聚及其对直流GIL闪络特性的影响[J].高电压技术,2015,41(5):1481-1487.Zhang Boya,Wang Qiang,Zhang Guixin,et al.Surface charge accumulation on insulators in SF6 and its effects on the flashover characteristics of HVDC GIL[J].High Voltage Engineering,2015,41(5):1481-1487(in Chinese).
[8]Boggs A S,Wang Y.Trapped charge-induced field distortion on GIS[J].IEEE Transactions on Power Delivery,1995,10(3):1270-1275.
[9]苑舜.营口华能电厂GIS盆式绝缘子沿面放电分析[J].东北电力技术,1996(5):36-37.Yuan Shun.Analysis of the surface flashover of a GIScone-type insulator at Yingkou Huaneng power plant[J].Northeastern Electric Power,1996(5):36-37(in Chinese).
[10]MoliniéP,Goldman M,Gatellet J.Surface potential decay on corona-charged epoxy samples due to polarization processes[J].Journal of Physics D:Applied Physics,1995,28(8):1601-1610.
[11]Kumara S,Serdyuk Y V,Gubanski S M.Surface charge decay on polymeric materials under different neutralization modes in air[J].IEEE Transactions on Dielectrics and Electrical Insulation,2011,18(5):1779-1885.
[12]高文强,张博雅,张贵新.硅橡胶材料表面电荷消散现象[J].高电压技术,2017,43(2):468-475.Gao Wenqing,Zhang Boya,Zhang Guixin.Surface charge decay on silicone rubber material[J].High Voltage Engineering,2017,43(2):468-475(in Chinese).
[13]Leal Ferreira G F,Figueiredo M T.Corona charging of electrets:models and results[J].IEEE Transactions on Dielectrics and Electrical Insulation,1992,27(4):719-737.
[14]Sessler GM,AlquiéC,Lewiner J.Charge distribution in Teflon FEP(fluoroethylene-propylene)negatively coronacharged to high potentials[J].Journal of Applied Physics,1992,71(5):2280-2284.
[15]Batra I P,Kanazawa K D,Seki H.Discharge characteristics of photoconducting insulators[J].Journal of Applied Physics,1970,41(8):3416-3422.
[16]Perrin C,Griseri V,Inguimbert C,et al.Analysis of internal charge distribution in electron irradiated polyethylene and polyimide films using a new experimental method[J].Journal of Physics D:Applied Physics,2008,41(20):205417.
[17]Lederle Ch,Kindersberger J,Surface charge decay on insulators in air and sulfur hexafluorid-Part I:Simulation[J].IEEE Transactions on Dielectrics and Electrical Insulation,2008,15(4):941-948.
[18]Zhang B,Zhang G.Interpretation of the surface charge decay kinetics on insulators with different neutralization mechanisms[J].Journal of Applied Physics,2017,121(10):105105.
[19]Lederle Ch,Kindersberger J,Surface charge decay on insulators in air and sulfur hexafluorid-Part II:Measurements[J].IEEE Transactions on Dielectrics and Electrical Insulation,2008,15(4):949-957.
[20]杜伯学,高宇,刘彦君.聚萘二甲酸丁二醇酯试样表面电荷迁移与消散机理[J].电工技术学报,2009,24(3):36-54.Du Boxue,Gao Yu,Liu Yanjun.Charge migration and decay on polybutylene naphthalate surface[J].Transactions of China Electrotechnical Society,2009,24(3):36-54(in Chinese).
[21]马云飞,章程,李传扬,等.重频脉冲放电等离子体处理聚合物材料加快表面电荷消散的实验研究[J].中国电机工程学报,2016,36(6):1731-1738.Ma Yunfei,Zhang Cheng,Li Chuanyang,et al.Experimental study of accelerating surface charge dissipation on polymer treated by repetitively pulsed discharge plasmas[J].Proceedings of the CSEE,2016,36(6):1731-1738(in Chinese).
[22]张博雅,王强,祁喆,等.直流电压下聚合物表面电荷测量方法及积聚特性[J].中国电机工程学报,2016,36(24):6664-6674.Zhang Boya,Wang Qiang,Qi Zhe,et al.Measurement method and accumulation characteristics of surface charge distribution on polymeric material under DC voltage[J].Proceedings of the CSEE,2016,36(24):6664-6674(in Chinese).
[23]付洋洋,王强,张贵新,等.基于表面电位测量的表面电荷反演计算[J].高电压技术,2013,39(1):88-95.Fu Yangyang,Wang Qiang,Zhang Guixin,et al.Inverse calculation of surface charge based on surface potential measurement[J].High Voltage Engineering,2013,39(1):88-95(in Chinese).
[24]邓军波,王涵,薛建议,等.基于静电探头法的表面电荷密度分布及电场分布的改进反演算法研究[J].中国电机工程学报,2018,38(4):1239-1247.Deng Junbo,Wang Han,Xue Jianyi,et al.Improved reverse algorithm of surface charge density distribution and electric field distribution based on electrostatic probe[J].Proceedings of the CSEE,2018,38(4):1239-1247(in Chinese).
[25]Bracewell R.Fourier analysis and imaging,Chapter 6:The two-dimensional convolution theorem[M].New York:Springer,2003:204-221.
[26]冈萨雷斯,伍兹.数字图像处理[M].3版.阮秋琦等,译.北京:电子工业出版社,2011:207-210.Gonzalez R C,Woods R E.Digital image processing[M].3rd ed.Ruan Qiuqi,et al,translated.Beijing:Publishing House of Electronics Industry,2011:207-210(in Chinese).
[27]Zhang B,Gao W,Qi Zhe,et al.Inversion algorithm to calculate charge density on solid dielectric surface based on surface potential measurement[J].IEEE Transactions on Instrumentation and Measurement,2017,66(12):3316-3325.
[28]Zhou H,Ma G,Li C,et al.Impact of temperature on surface charges accumulation on insulators in SF6-filled DC-GIL[J].IEEE Transactions on Dielectrics and Electrical Insulation,2017,24(1):601-610.
[29]Boggs S,Wiegart N.Gaseous Dielectrics IV[M].New York:Pergamon Press,1984:531.
[30]Winter A,Kindersberger J.Transient field distribution in gas-solid insulation systems under DC voltages[J].IEEETransactions on Dielectrics and Electrical Insulation,2014,21(1):116-128.
[31]Coelho R,Levy L,and Sarrail D.On the natural decay of corona charged insulating sheets[J].Physica Status Solidi,1986,94(1):289-298.
[32]Straumann U,Schuller M,Franck M C.Theoretical investigation of HVDC disc spacer charging in SF6 gas insulated systems[J].IEEE Transactions on Dielectrics and Electrical Insulation,2012,19(6):2196-2205.
[33]Zhang B,Zhang G,Wang Q,et al.Suppression of surface charge accumulation on Al2O3-filled epoxy resin insulator under dc voltage by direct fluorination[J].AIP Advances,2015,5(12):127207.
[34]Li C,Hu J,Lin C,et al.Surface charge migration and DCsurface flashover of surface-modified epoxy-based insulators[J].Journal of Physics D:Applied Physics,2017,50(6):065301.