直流电压下SF_6中环氧复合绝缘的表面电荷积聚与衰减特性
|
摘要
为了研究直流电压下聚合物绝缘材料表面电荷的积聚和衰减特性,选择环氧复合绝缘材料为实验试品,采用对称平面压接电极,施加不同幅值的直流电压,利用静电探头测量了大气压SF_6气体中不同充电时间下绝缘材料的表面电位分布。实验结果表明:在直流电压作用下,环氧复合绝缘表面会发生同极性电荷积聚,电极中心线上表面电位呈钟形分布,表面电位的峰值和半峰值宽度随电压幅值增加不断增加。在相同幅值电压下,低幅值时(<10 kV),正极性下表面电荷密度较负极性下高;高幅值时(>10 kV),负极性下表面电荷密度较正极性下高。随充电时间增加,电极中心线表面电位仍然呈钟形分布,和外施电压同极性的表面电荷密度较高且分布较为集中。表面电位的衰减分为两个阶段,符合双指数函数规律,初期衰减快,后期衰减慢,正电荷衰减速度大于负电荷,电压幅值越高,起始电位衰减越快,衰减完全所需要的时间越长。结合实验结果,分析认为表面电荷主要通过表面电导衰减。
In order to study the accumulation and decay characteristics of surface charges on polymeric insulation materials under DC voltage, the epoxy composite insulating material was selected as the experimental samples with symmetric planar electrodes. After the samples being charged under different voltage amplitudes with different duration in SF_6 of atmospheric pressure, the surface potential distribution was measured with a Kelvin electrostatic probe. The results reveal that charges of the same polarity as applied voltage accumulate on the insulation surface. The surface potential of the center of electrode presents a bell-shaped distribution. The peak and half peak width of surface potential increase with the applied voltage amplitudes. When the applied voltage is low(<10 kV), the density of positive surface charge is higher than that of negative one under the same voltage magnitude, which is opposite when the applied voltage is high. When charging duration increases, the surface potential of the center of electrode also presents a bell-shaped distribution. The density of surface charge of the same polarity as applied voltage is higher and distributed intensively. There are two stages of surface charge decay, which satisfies a double exponential model. The decay rate is fast at earlier stage and slow at later stage. The initial decay rate is faster when the voltage amplitude is higher, but it takes much longer time to decay completely. The experimental results reveal that the surface charge decays mainly because of the contribution of surface conduction.
In order to study the accumulation and decay characteristics of surface charges on polymeric insulation materials under DC voltage, the epoxy composite insulating material was selected as the experimental samples with symmetric planar electrodes. After the samples being charged under different voltage amplitudes with different duration in SF_6 of atmospheric pressure, the surface potential distribution was measured with a Kelvin electrostatic probe. The results reveal that charges of the same polarity as applied voltage accumulate on the insulation surface. The surface potential of the center of electrode presents a bell-shaped distribution. The peak and half peak width of surface potential increase with the applied voltage amplitudes. When the applied voltage is low(<10 kV), the density of positive surface charge is higher than that of negative one under the same voltage magnitude, which is opposite when the applied voltage is high. When charging duration increases, the surface potential of the center of electrode also presents a bell-shaped distribution. The density of surface charge of the same polarity as applied voltage is higher and distributed intensively. There are two stages of surface charge decay, which satisfies a double exponential model. The decay rate is fast at earlier stage and slow at later stage. The initial decay rate is faster when the voltage amplitude is higher, but it takes much longer time to decay completely. The experimental results reveal that the surface charge decays mainly because of the contribution of surface conduction.
引文
[1]李鹏,颜湘莲,王浩,等.特高压交流GIL输电技术研究及应用[J].电网技术,2017,41(10):3161-3167.LI Peng,YAN Xianglian,WANG Hao,et al.Research and application of UHVAC gas-insulated transmission line[J].Power System Technology,2017,41(10):3161-3167.
[2]汤广福,庞辉,贺之渊.先进交直流输电技术在中国的发展与应用[J].高电压技术,2016,36(7):1760-1771.TANG Guangfu,PANG Hui,HE Zhiyuan.R&D and application of advanced power transmission technology in China[J].High Voltage Engineering,2016,36(7):1760-1771.
[3]刘振亚.特高压交直流电网[M].北京:中国电力出版社,2013:11-12.LIU Zhenya.Ultra-high voltage AC and DC grid[M].Beijing,China:China Electric Power Press,2013:11-12.
[4]ZHOU H Y,MA G M,LI C R,et al.Impact of temperature on surface charges accumulation on insulators in SF6-filled DC-GIL[J].IEEETransactions on Dielectrics&Electrical Insulation,2017,24(1):601-610.
[5]许安,何大猛,刘守豹,等.±500 kV德阳换流站支柱绝缘子放电故障电场计算分析[J].电磁避雷器,2014(3):12-19.XU An,HE Dameng,LIU Shoubao,et al.The electric field analysis on±500 kV post insulator with discharge failure in Deyang converter station[J].Insulator and Surge Arresters,2014(3):12-19.
[6]汪沨,方志,邱毓昌.高压直流GIS中绝缘子的表面电荷积聚的研究[J].中国电机工程学报,2005,25(30):105-109.WANG Feng,FANG Zhi,QIU Yuchang.Study of charge accumulation on insulator surface in HVDC gas-insulated switchgear[J].Proceedings of CSEE,2005,25(30):105-109.
[7]YAMANO Y,OHASHI A,KATO K,et al.Charging characteristics on dielectric surface by different charging processes in vacuum[J].IEEETransactions on Dielectrics and Electrical Insulation,1999,6(4):464-468.
[8]XUE J Y,WANG H,LIU Y Q,et al.Surface charge distribution patterns of a truncated cone-type spacer for HVDC GIL/GIS[J].IETScience,Measurement&Technology,2018,12(4):436-442.
[9]JING T.Surface charge accumulation:an inevitable phenomenon in DC GIS[J].IEEE Transactions on Dielectrics and Electrical Insulation,1995,2(5):771-778.
[10]刘志民,邱毓昌,冯允平.对绝缘子表面电荷积聚机理的讨论[J].电工技术学报,1999,14(2):65-68.LIU Zhimin,QIU Yuchang,FENG Yunping.The discussion about accumulation mechanism of surface charge on insulating spacer[J].Transactions of China Electrotechnical Society,1999,14(2):65-68.
[11]IWABUCHI H,MATSUOKA S,KUMADA A,et al.Influence of tiny metal particles on charge accumulation phenomena of GIS model spacer in high-pressure SF6 gas[J].IEEE Transactions on Dielectrics and Electrical Insulation,2013,20(5):1895-1901.
[12]李庆民,王健,李伯涛,等.GIS/GIL中金属微粒污染问题研究进展[J].高电压技术,2016,42(3):849-860.LI Qingmin,WANF Jian,LI Botao,et al.Review on metal particle contamination in GIS/GIL[J].High Voltage Engineering,2016,42(3):849-860.
[13]邓军波,薛建议,张冠军,等.SF6/N2混合气体中沿面放电实验研究的现状与进展[J].高电压技术,2016,42(4):1190-1198.DENG Junbo,XUE Jianyi,ZHANG Guanjun,et al.Current status of experimental research on surface discharge in SF6/N2 mixture gas[J].High Voltage Engineering,2016,42(4):1190-1198.
[14]ZHANG B Y,ZHANG G X.Interpretation of the surface charge decay kinetics on insulators with different neutralization mechanisms[J].Journal of Applied Physics,2017,121(10):105105.
[15]KUMARA J R S S,SERDYUK Y V,GUBANSKI S M.Surface potential decay on LDPE and LDPE/Al2O3 nano-composites:measurements and modeling[J].IEEE Transactions on Dielectrics and Electrical Insulation,2016,23(6):3466-3475.
[16]DENG J B,KUMADA A,HIDAKA K,et al.Residual charge density distribution measurement of surface leader with feedback electrostatic probe[J].Applied Physics Letters,2012,100(19):1-4.
[17]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.
[18]MIN D,CHO M,KHAN A R,et al.Surface and volume charge transport properties of polyimide revealed by surface potential decay with genetic algorithm[J].IEEE Transactions on Dielectrics&Electrical Insulation,2012,19(2):600-608
[19]高宇,杜伯学.伽玛线辐射对环氧树脂表面电荷消散特性的影响[J].高电压技术,2012,38(4):824-830.GAO Yu,DU Boxue.Effect of Gamma-ray irradiation on surface charge decaying characteristic of epoxy resin[J].High Voltage Engineering,2012,38(4):824-830.
[20]NAKANISHI K,YOSHIOKA A,SHIBUYA Y,et al.Charge accumulation on spacer surface at DC stress in compressed SF6 gas[M].Oxford,UK:Pergamon Press,1982:365-372.
[21]WANG Q,ZHANG G X,WANG X X.Characteristics and mechanisms of surface charge accumulation on a cone-type insulator under dc voltage[J].IEEE Transactions on Dielectrics and Electrical Insulation,2012,19(1):150-155.
[2]汤广福,庞辉,贺之渊.先进交直流输电技术在中国的发展与应用[J].高电压技术,2016,36(7):1760-1771.TANG Guangfu,PANG Hui,HE Zhiyuan.R&D and application of advanced power transmission technology in China[J].High Voltage Engineering,2016,36(7):1760-1771.
[3]刘振亚.特高压交直流电网[M].北京:中国电力出版社,2013:11-12.LIU Zhenya.Ultra-high voltage AC and DC grid[M].Beijing,China:China Electric Power Press,2013:11-12.
[4]ZHOU H Y,MA G M,LI C R,et al.Impact of temperature on surface charges accumulation on insulators in SF6-filled DC-GIL[J].IEEETransactions on Dielectrics&Electrical Insulation,2017,24(1):601-610.
[5]许安,何大猛,刘守豹,等.±500 kV德阳换流站支柱绝缘子放电故障电场计算分析[J].电磁避雷器,2014(3):12-19.XU An,HE Dameng,LIU Shoubao,et al.The electric field analysis on±500 kV post insulator with discharge failure in Deyang converter station[J].Insulator and Surge Arresters,2014(3):12-19.
[6]汪沨,方志,邱毓昌.高压直流GIS中绝缘子的表面电荷积聚的研究[J].中国电机工程学报,2005,25(30):105-109.WANG Feng,FANG Zhi,QIU Yuchang.Study of charge accumulation on insulator surface in HVDC gas-insulated switchgear[J].Proceedings of CSEE,2005,25(30):105-109.
[7]YAMANO Y,OHASHI A,KATO K,et al.Charging characteristics on dielectric surface by different charging processes in vacuum[J].IEEETransactions on Dielectrics and Electrical Insulation,1999,6(4):464-468.
[8]XUE J Y,WANG H,LIU Y Q,et al.Surface charge distribution patterns of a truncated cone-type spacer for HVDC GIL/GIS[J].IETScience,Measurement&Technology,2018,12(4):436-442.
[9]JING T.Surface charge accumulation:an inevitable phenomenon in DC GIS[J].IEEE Transactions on Dielectrics and Electrical Insulation,1995,2(5):771-778.
[10]刘志民,邱毓昌,冯允平.对绝缘子表面电荷积聚机理的讨论[J].电工技术学报,1999,14(2):65-68.LIU Zhimin,QIU Yuchang,FENG Yunping.The discussion about accumulation mechanism of surface charge on insulating spacer[J].Transactions of China Electrotechnical Society,1999,14(2):65-68.
[11]IWABUCHI H,MATSUOKA S,KUMADA A,et al.Influence of tiny metal particles on charge accumulation phenomena of GIS model spacer in high-pressure SF6 gas[J].IEEE Transactions on Dielectrics and Electrical Insulation,2013,20(5):1895-1901.
[12]李庆民,王健,李伯涛,等.GIS/GIL中金属微粒污染问题研究进展[J].高电压技术,2016,42(3):849-860.LI Qingmin,WANF Jian,LI Botao,et al.Review on metal particle contamination in GIS/GIL[J].High Voltage Engineering,2016,42(3):849-860.
[13]邓军波,薛建议,张冠军,等.SF6/N2混合气体中沿面放电实验研究的现状与进展[J].高电压技术,2016,42(4):1190-1198.DENG Junbo,XUE Jianyi,ZHANG Guanjun,et al.Current status of experimental research on surface discharge in SF6/N2 mixture gas[J].High Voltage Engineering,2016,42(4):1190-1198.
[14]ZHANG B Y,ZHANG G X.Interpretation of the surface charge decay kinetics on insulators with different neutralization mechanisms[J].Journal of Applied Physics,2017,121(10):105105.
[15]KUMARA J R S S,SERDYUK Y V,GUBANSKI S M.Surface potential decay on LDPE and LDPE/Al2O3 nano-composites:measurements and modeling[J].IEEE Transactions on Dielectrics and Electrical Insulation,2016,23(6):3466-3475.
[16]DENG J B,KUMADA A,HIDAKA K,et al.Residual charge density distribution measurement of surface leader with feedback electrostatic probe[J].Applied Physics Letters,2012,100(19):1-4.
[17]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.
[18]MIN D,CHO M,KHAN A R,et al.Surface and volume charge transport properties of polyimide revealed by surface potential decay with genetic algorithm[J].IEEE Transactions on Dielectrics&Electrical Insulation,2012,19(2):600-608
[19]高宇,杜伯学.伽玛线辐射对环氧树脂表面电荷消散特性的影响[J].高电压技术,2012,38(4):824-830.GAO Yu,DU Boxue.Effect of Gamma-ray irradiation on surface charge decaying characteristic of epoxy resin[J].High Voltage Engineering,2012,38(4):824-830.
[20]NAKANISHI K,YOSHIOKA A,SHIBUYA Y,et al.Charge accumulation on spacer surface at DC stress in compressed SF6 gas[M].Oxford,UK:Pergamon Press,1982:365-372.
[21]WANG Q,ZHANG G X,WANG X X.Characteristics and mechanisms of surface charge accumulation on a cone-type insulator under dc voltage[J].IEEE Transactions on Dielectrics and Electrical Insulation,2012,19(1):150-155.