强降雨条件下空气间隙长波前操作冲击放电特性
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摘要
超、特高压输电线路风偏设计中,空气间隙的操作冲击放电特性是操作过电压等值风速选取的重要依据,现有研究主要集中在标准操作冲击电压的放电特性,强降雨条件下长波前空气间隙操作放电特性研究涉及较少。为此,在实验室模拟强降雨环境,对3种间隙长度、4种降雨强度和4种雨水电导率下导线–杆塔和棒–板空气间隙的1 000μs长波前正极性操作冲击放电特性U50进行了试验研究,结果表明,在所试验的条件范围内,强降雨条件下棒–板空气间隙U50最大降低了11.2%,导线–杆塔空气间隙U50最大降低了7.45%;棒–板空气间隙U50因雨水电导率变化最大降低3.32%,导线–杆塔间隙最大降低1.94%。对棒–板和导线–板空气间隙存在悬浮雨滴的静电场仿真计算表明,降雨强度越大则雨滴尺寸越大,空气间隙电场畸变越严重,且雨滴使棒–板间隙的电场畸变程度大于导线–板间隙。
The discharge characteristics of air gap subject to switching impulse voltage is a critical design criterion in selecting the equivalent wind speed for Extra and Ultra High Voltage(EHV/UHV) transmission lines. Existing research work focuses on the discharge characteristics under standard switching impulse voltage, while the long frontwave switching impulse voltage generated by the EHV/UHV transmission lines is rarely considered, especially under the heavy rain condition. We simulated four different precipitation intensities with four different rainfall conductivities in the laboratory. The conductor-tower and rod-plane air gaps with three different length were tested under a switching positive impulse voltage. The results show that the U50 of the rod-plane air gaps is reduced by 11.2% due to the increased precipitation rate and the U50 of the conductor-tower ones is reduced by 7.45%. The U50 of the rod-plane air gaps will reduce by 3.32% due to the increased rainwater conductivity and by 1.95% due to the reduction of conductor-tower distance. In addition, an electrostatic simulation has been conducted to study the influence of water droplets presenting in the electric field. The results show that the larger size the water droplet is, the greater distortion the electric field will have. It is also observed that the water droplets have more impact on the rod-plane air gap rather than the conductor-plane air gap.
The discharge characteristics of air gap subject to switching impulse voltage is a critical design criterion in selecting the equivalent wind speed for Extra and Ultra High Voltage(EHV/UHV) transmission lines. Existing research work focuses on the discharge characteristics under standard switching impulse voltage, while the long frontwave switching impulse voltage generated by the EHV/UHV transmission lines is rarely considered, especially under the heavy rain condition. We simulated four different precipitation intensities with four different rainfall conductivities in the laboratory. The conductor-tower and rod-plane air gaps with three different length were tested under a switching positive impulse voltage. The results show that the U50 of the rod-plane air gaps is reduced by 11.2% due to the increased precipitation rate and the U50 of the conductor-tower ones is reduced by 7.45%. The U50 of the rod-plane air gaps will reduce by 3.32% due to the increased rainwater conductivity and by 1.95% due to the reduction of conductor-tower distance. In addition, an electrostatic simulation has been conducted to study the influence of water droplets presenting in the electric field. The results show that the larger size the water droplet is, the greater distortion the electric field will have. It is also observed that the water droplets have more impact on the rod-plane air gap rather than the conductor-plane air gap.
引文
[1]RIZK F A M.Influence of rain on switching impulse sparkover voltage of large-electrode air gaps[J].IEEE Transactions on Power Apparatus and System,1976,95(4):1394-1402.
[2]耿翠英,陈守聚,刘莘昱,等.雨水条件下空气间隙操作冲击闪络试验研究[J].河南电力,2008(4):32-33.GENG Cuiying,CHEN Shouju,LIU Xinyu,et al.The research on the operation impacting flashover between air-gaps under raining conditions[J].Henan Electric Power,2008,2008(4):32-33.
[3]孙利朋.棒-板空气间隙淋雨操作冲击击穿特性的研究[D].重庆:重庆大学,2008.SUN Lipeng.Study of swithing impulse discharge performance of rod-plane air gaps under rain[D].Chongqing,China:Chongqing University,2008.
[4]YOSHIBUMI Y,AKIO O.Phase-to-ground and phase-to-phase sparkover characteristics of external insulation at the entrance of a UHVsubstation[J].IEEE Transactions on Power Delivery,2002,17(1):223-232.
[5]PRUPACHER H R,BEARD K V.A wind tunnel investigation of the internal circulation and shape of water drops falling at terminal velocity in air[J].Quarterly Journal of the Royal Meteorological Society,1970(96):247-256.
[6]MAMORU K,RYUICHI Y,MASANORI H.DC flashover characteristics with floating electrodes in air gaps[C]∥Proceeding of the 4th International Conference on Properties and Applications of Dielectric Materials.Brisbane,Australia:[s.n.],1994:52-55.
[7]MAMORU K,RYUICHI Y.Breakdown characteristics in air gaps with artificial floating metals under DC voltage[J].IEEE Transactions on Dielectrics and Electrical Insulation,1995,2(1):155-166.
[8]KUBUKI M,YOSHIMOTO R,YOSHIZUMI K.Estimation of DCbreakdown mechanisms in air gaps containing floating metallic particles[J].IEEE Transactions on Dielectrics and Electrical Insulation,1997,4(1):92-101.
[9]杨长河.气水混合两相体放电现象及机制的理论与实验研究[D].武汉:华中科技大学,2005.YANG Changhe.A dissertation submitted in partial fulfillment of the requirements for the degree of doctor of philosophy in engineering[D].Wuhan,China:Huazhong University of Science and Technology,2005.
[10]蒋兴良,周龙武,袁耀,等.降雨对短空气间隙直流放电的影响分析[J].高电压技术,2015,41(7):2350-2355.JIANG Xingliang,ZHOU Longwu,YUAN Yao,et al.Analysis on DCdischarge performance of short air gap under rain conditions[J].High Voltage Engineering,2015,41(7):2350-2355.
[11]董冰冰,蒋兴良,黄俊,等.雾对棒-板空气间隙交流放电特性的影响[J].高电压技术,2014,40(5):1339-1344.DONG Bingjing,JIANG Xingliang,HUANG Jun,et al.Influence of fog on AC discharge characteristics of rod-plane air gaps[J].High Voltage Engineering,2014,40(5):1339-1344.
[12]刘振,周春雨,余芳,等.长空气间隙长波前操作冲击放电特性[J].高电压技术,2009,35(10):2401-2405.LIU Zhen,ZHOU Chunyu,YU Fang,et al.Characteristics of the long-fronted switching impulse discharge[J].High Voltage Engineering,2009,35(10):2401-2405.
[13]谢梁,叶奇明,罗晓庆,等.特高压交流串补装置相间操作冲击放电特性[J].高电压技术,2016,42(2):551-556.XIE Liang,YE Qiming,LUO Xiaoqing,et al.Phase-to-phase switching impulse discharge characteristics of UHVAC series compensation[J].High Voltage Engineering,2016,42(2):551-556.
[14]高电压实验技术-第一部分:一般实验要求:GB/T16927.1-2011[S],2011.High-voltage test techniques-Part1:General definitions and test requirements:GB/T 16927.1-2011[S],2011.
[15]胡毅.输电线路运行故障分析与防治[M].北京:中国电力出版社,2007.HU Yi.Fault analysis and prevention of transmission line operation[M].Beijing,China:China Electric Power Press,2007.
[16]刘伟.降雨对棒-板短空气间隙直流放电影响的仿真及试验研究[D].重庆:重庆大学,2011.LIU Wei.Study on rainfall’s influence on positive DC discharge of rod-plane short air gap by simulation&experiments[D].Chongqing,China:Chongqing University,2011.
[2]耿翠英,陈守聚,刘莘昱,等.雨水条件下空气间隙操作冲击闪络试验研究[J].河南电力,2008(4):32-33.GENG Cuiying,CHEN Shouju,LIU Xinyu,et al.The research on the operation impacting flashover between air-gaps under raining conditions[J].Henan Electric Power,2008,2008(4):32-33.
[3]孙利朋.棒-板空气间隙淋雨操作冲击击穿特性的研究[D].重庆:重庆大学,2008.SUN Lipeng.Study of swithing impulse discharge performance of rod-plane air gaps under rain[D].Chongqing,China:Chongqing University,2008.
[4]YOSHIBUMI Y,AKIO O.Phase-to-ground and phase-to-phase sparkover characteristics of external insulation at the entrance of a UHVsubstation[J].IEEE Transactions on Power Delivery,2002,17(1):223-232.
[5]PRUPACHER H R,BEARD K V.A wind tunnel investigation of the internal circulation and shape of water drops falling at terminal velocity in air[J].Quarterly Journal of the Royal Meteorological Society,1970(96):247-256.
[6]MAMORU K,RYUICHI Y,MASANORI H.DC flashover characteristics with floating electrodes in air gaps[C]∥Proceeding of the 4th International Conference on Properties and Applications of Dielectric Materials.Brisbane,Australia:[s.n.],1994:52-55.
[7]MAMORU K,RYUICHI Y.Breakdown characteristics in air gaps with artificial floating metals under DC voltage[J].IEEE Transactions on Dielectrics and Electrical Insulation,1995,2(1):155-166.
[8]KUBUKI M,YOSHIMOTO R,YOSHIZUMI K.Estimation of DCbreakdown mechanisms in air gaps containing floating metallic particles[J].IEEE Transactions on Dielectrics and Electrical Insulation,1997,4(1):92-101.
[9]杨长河.气水混合两相体放电现象及机制的理论与实验研究[D].武汉:华中科技大学,2005.YANG Changhe.A dissertation submitted in partial fulfillment of the requirements for the degree of doctor of philosophy in engineering[D].Wuhan,China:Huazhong University of Science and Technology,2005.
[10]蒋兴良,周龙武,袁耀,等.降雨对短空气间隙直流放电的影响分析[J].高电压技术,2015,41(7):2350-2355.JIANG Xingliang,ZHOU Longwu,YUAN Yao,et al.Analysis on DCdischarge performance of short air gap under rain conditions[J].High Voltage Engineering,2015,41(7):2350-2355.
[11]董冰冰,蒋兴良,黄俊,等.雾对棒-板空气间隙交流放电特性的影响[J].高电压技术,2014,40(5):1339-1344.DONG Bingjing,JIANG Xingliang,HUANG Jun,et al.Influence of fog on AC discharge characteristics of rod-plane air gaps[J].High Voltage Engineering,2014,40(5):1339-1344.
[12]刘振,周春雨,余芳,等.长空气间隙长波前操作冲击放电特性[J].高电压技术,2009,35(10):2401-2405.LIU Zhen,ZHOU Chunyu,YU Fang,et al.Characteristics of the long-fronted switching impulse discharge[J].High Voltage Engineering,2009,35(10):2401-2405.
[13]谢梁,叶奇明,罗晓庆,等.特高压交流串补装置相间操作冲击放电特性[J].高电压技术,2016,42(2):551-556.XIE Liang,YE Qiming,LUO Xiaoqing,et al.Phase-to-phase switching impulse discharge characteristics of UHVAC series compensation[J].High Voltage Engineering,2016,42(2):551-556.
[14]高电压实验技术-第一部分:一般实验要求:GB/T16927.1-2011[S],2011.High-voltage test techniques-Part1:General definitions and test requirements:GB/T 16927.1-2011[S],2011.
[15]胡毅.输电线路运行故障分析与防治[M].北京:中国电力出版社,2007.HU Yi.Fault analysis and prevention of transmission line operation[M].Beijing,China:China Electric Power Press,2007.
[16]刘伟.降雨对棒-板短空气间隙直流放电影响的仿真及试验研究[D].重庆:重庆大学,2011.LIU Wei.Study on rainfall’s influence on positive DC discharge of rod-plane short air gap by simulation&experiments[D].Chongqing,China:Chongqing University,2011.