摘要
空气间隙操作冲击特性对外绝缘设计有重要参考价值。在我国西电东送的大环境下,建设高海拔超特高压输电线路必然要面临复杂大气环境下的外绝缘设计和施工。本文在查阅国内外有关研究状况的基础上,利用重庆大学高电压与电工新技术教育部重点实验室的大型多功能人工气候室对低气压条件下棒-板空气间隙正极性操作冲击放电特性及电压校正进行了研究,并选择多个高海拔现场进行试验比对。本文主要进行了以下研究工作:
(1)在大型多功能人工气候室模拟低气压条件,选择500、1000、1500mm长度的棒-板空气间隙进行正极性操作冲击放电试验,对其放电特性、电压校正方法进行研究;
(2)选择1000mm长度棒-板空气间隙进行湿度对正极性操作冲击放电影响的试验,对不同气压条件下湿度对其放电特性、50%放电电压的影响进行研究;
(3)在人工气候室模拟低气压试验研究的基础上,提出基于相对气压和基于g参数法的空气间隙放电电压大气校正方法;
(4)进行高海拔现场棒-板空气间隙正极性操作冲击放电试验,对新的校正方法进行校验和比较,就湿度对空气间隙放电的影响和机理进行探讨。
通过人工气候室试验和现场试验本文得出以下结论:
(1)相对气压校正方法未考虑湿度的附加影响,气压越低,湿度对放电的作用越显著,其校正误差越大。在相对气压校正方法的基础上,引入湿度附加影响参数,能准确地反映湿度在棒-板空气间隙放电过程中的作用,50%放电电压是考虑绝对湿度附加影响后相对气压的幂函数;
(2)在温湿度范围偏离标准参考大气条件较小的条件下,采用基于g参数的校正方法可以适用于海拔超过2000m的地区,但在温湿度范围偏离标准参考大气条件较大时,其误差较大;
(3)利用大型人工气候室模拟低气压条件下棒-板空气间隙放电试验得到的校正公式能够反映大气参数对间隙放电的影响,所得结论适用于高海拔现场条件;
(4)在不同的气压条件下绝对湿度的增加会提高棒-板空气间隙的50%放电电压,但其存在饱和特性,在不同气压下,其饱和趋势及程度不同;
(5)湿度的增加提高了流注的初始场强,减小了流注的发展时间,击穿时间缩短,放电电压提高;湿度进一步增加,击穿时间继续减小,放电电压则降低。
Switching impulse flashover performance in the air gap is very important to external insulation design. In the stratagem of the power transmission from the west to the east in China, designing and constructing UHV or EHV overhead transmission lines must get across in these complex climate western areas of high altitudes. Refering to abundant inland and oversea data and using the large scale artificial climate chamber of the Key Laboratory of High Voltage Engineering and Electrical New Technology of The Education Ministry in Chongqing University,this essay carries a series of experimentations of positive switching impuls flashover performance and correction in the rod-plane air gap under lower atmospheric pressure and compares with real spot. The main research of this dissertation are as followed:
(1) Carrying the test of positive switching impulse flashover in the rod-plane air gap of the 500, 1000 mm and 1500 mm three kinds of length in the artificial climate chamber under lower atmospheric pressure, the flashover performance and 50% flashover voltage correction methods are researched.
(2) Choosing the rod-plane air gap of 1000mm length, The influences of humidity to flashover performance and 50% flashover voltage under positive switching impulse are researched in different lower atmospheric pressure.
(3) Based on research in the artificial climate chamber, new correction motheds are put forward according to P/P0 and g parameter mothed.
(4) Testing in high altitude area spots and comparing the results from the artificial climate chamber. Researching the influence of humidity in rod-plane air gap flashover according to the results in high altitude area and the artificial climate chamber.
Through simulating and spot tests, the main conclusion of the analyze results are as follows:
(1) The deviation increases adopting the correction mothed of P/P0 at lower atmospheric pressure derived from humidity and it has a bigger error the pressure lower. Considering the additional influence of the absolute humidity, the 50% flashover voltages are more exact than before.
(2) The results of g parameter correction method is suitable above altitude 2000m when environmental parameters are close to the standard reference conditions. Its error increases when temperature and humidity deviate more from the standard reference
引文
[1] 孙才新,司马文霞,舒立春,大气环境与电气外绝缘,北京,中国电力出版社,2002.
[2] 中电联统计信息部,全国电力工业生产简况,中国电力,2006,Vol.39,No.2:100-104.
[3] 张运州,我国区域电网未来主网架结构特点与发展趋势,中国电力,2005,Vol.38,No.1:1-5.
[4] 陈琴生译,绝缘实验方法手册,北京,水利电力出版社,1987.
[5] 马乃详,长间隙放电,北京,中国电力出版社,1998.
[6] 陆宠惠,王凤鸣,特高压线路外绝缘特性的探讨,高电压技术,1996,Vol.22,No.1:31-34.
[7] 孙才新,蒋兴良,司马文霞等,海拔 4000m 以上短间隙交流放电特性及电压校正,中国电机工程学报,2002,Vol.22,No.10:116~120.
[8] A.Pigini,G.Sartorio,M.Moreno,et al,Influence of air density on the impulse strength of external insulation,IEEE Transon Power Apparatus and Systems,1985,Vol.PAS-104.
[9] Zhang Renyu,Zheng Jianchao,Progress in outdoor insulation research in China,IEEE Transactions on Electrical insulation,1990,Vol.25,No.6:1125-1137.
[10] P.N.Mikropoulos,C.A.Stassinopoulos,Influence of humidity on the breakdown mechanism of medium length rod-plane gaps stressed by positive impulse voltages,IEE Proceedings:Science,Mesaurement and Technology,1994,Vol.141,No.5:407-417.
[11] P.A.Calva,V.del Moral et al, New proposal of correction factors for dc Voltages,2003 Annual Report conference on electrical insulation and dielectric Phenomena,IEEE,2003.
[12] P.A.Calva,A.Robledo-Martinez,Effect of Humidity On DC Breakdown Voltages in Ambient Air At High Altitude , Conference on Electrical Insulation and Dielectric Phenomena(CEIDP),Annual Report,1996,Vol.2:567-570.
[13] Boutlendj M.,Allen N.L.,Lightfoot H.A.,Neville R.B.,Positive DC corona and sparkover in short and long rod-plane gaps under variable humidity conditions,Science, Measurement and Technology, IEE Proceedings,1991,Vol.138,No.1:31-36.
[14] 梁曦东,陈昌渔,周远翔,高电压工程,北京,清华大学出版社,2003.
[15] J.Willett,D.A.Davis,P.Laroche,An experimental study of positive leaders initiating rocket-triggered lightning ,Atmosph Res,Vol.1999,No.51:189-219.
[16] V.Idone,The luminous development of Florida triggered lightning ,Res Lett Atmos Electr,1992,No.12:23-28.
[17] I.Fofana,A.Beroual,Model for long air gap discharge using an equivalent electricalnetwork,IEEE Transacations on Dielectrics and Electrical Insulation,1996,Vol.3,No.2:273-282.
[18] Allen,N.L.,Boutlendj,M.,Lightfoot,H.A.,Dielectric breakdown in nonuniform field air gaps,Electrical Insulation,IEEE Transactions,1993,Vol.28,No.2:183 -191.
[19] A.Bondiou,I.Gallimberti,Theoretical modelling of the development of the positive spark in long gaps,1994,Vol.27,No.6:1252-1266.
[20] Gallimberti.G.Bacchiega,Anne Bondiou-Clergerie,Philippe Lalande,Fundamental processes in long air gap discharges ,C.R.Physique, 2002,Vol.3:1335-1359.
[21] Zahraee,H.H.,Proposed theory for streamer-to-leader-transition in non-uniform field air gaps subjected to positive switching-impulse,Industry Applications Society Annual Meeting,Conference Record of IEEE,1993,Vol.3:1653-1657.
[22] Gallimberti.I,Bacchiega,G.,Bondiou-Clergerie et al.,Fundamental processes in long air gap discharges,Comptes Rendus Physique,2002,Vol.3,No.10:1335-1359.
[23] Allen,N.L., Boutlendj, M.,Lightfoot H.A.,Dielectric breakdown in nonuniform field air gaps,Electrical Insulation,IEEE Transactions ,1993,Vol.28,No.2:183 – 191.
[24] 张海燕,王文端,长间隙放电流注发展的新的计算模型,北京动力经济学院学报,1995, Vol.12,No.3:8-13.
[25] IEC,IEC6006011:High voltage techniques Part 1:General definitions and test requirements,1989.
[26] T.A.Philips,L.M.Robertson,A.F.Rohlfs,R.L.Thompson,Influence of air density on electrical strength of transmission line insulation,IEEE Trans,1967, Vol.PAS-86,No.8:948-961.
[27] T.Harada,T.Aoshima,T.Ishida,Y.Ichihara,K.Anjo,N.Nimura,Influence of air density on flashover voltages of air gaps and insulators,IEEE Trans,1970, Vol.PAS-89,No.6:1192-1202.
[28] E.M Bazelyan,T.G.Valamat-Zade,A.V.Shkilev,A long spark in the presence of reduced air density,Izvestiya Akademii Nauk SSSr,En.i.Trans,1975,Vol.13,No.6:149-154.
[29] A.Pigini,G.sartorio,M.Moreno,M.Ramirez,R.Cortina,E.Garbagnati,A.C.Britten and K.J Sadurski,Influence of Air Density on the Impulse Strength of Air Insulation,IEEETrans,1985,Vol.PAS-104,No.10:2888-2900.
[30] Farouk A.M.Rizk,Critical switching impulse strength of long air gaps:modeling of air density effects,IEEE Transactions on Power delivery,1992,Vol.7,No.3:1507-1515.
[31] José García,Fernando Herrera,Helmuth Ortiz,Study of the breakdown voltage of the air in high altitudes applying lightning impulses(1.2/50μS)under conditions of controlledhumidity and temperature , IEE Conference Publication , 1999 , Vol.3 , No.467 :3.55.S7-3.58.S7.
[32] 云南电力试验研究所,高原超高压输电线路外绝缘的试验研究,云南电力技术, 1994,Vol.22,No.1:4-13.
[33] 郑增泰,高海拔对外绝缘放电电压影响的研究小结,云南电力技术,1993,No.1:27-30.
[34] B.Yang,L.M.Wang,Z.C.Guan,et al.,Research on transition condition between streamer and leader in 1m plane-rod gap under switching impulse voltage,Proceedings of International Symposium on Electrical Insulating Materials(ISEIM 2001),2001:266-269.
[35] J.Schmid,Influence of absolute humidity on the electrical breakdown in air,European Transactions on Electrical Power Engineering,1992,Vol.2,No.5:327-331.
[36] Allen,N.L.,Boutlendj,M.,Study of the electric fields required for streamer propagation in humid air,Science,Measurement and Technology,IEE Proceedings A,1991,Vol.138, No.1:37-43.
[37] Raj Mohan Bharadwaj, B.R.Prabhakar,Effect of humidity on the breakdown of air gaps under oscillatory switching impulse voltages,Conference Record of IEEE International Symposium on Electrical Insulation,1996,Vol.1:320-323.
[38] P.N.Mikropoulos,C.A.Stassinopoulos,Influence of humidity on the breakdown mechanism of medium length rod-plane gaps stressed by positive impulse voltages,IEE Proc.Sci.Meas.Technol,1994,Vol.141,No.5:407-417.
[39] Yoshibumi Yamagata,Akio Oe,Kunihiko Miyake,Yoshinori Aihara et al.,Phase-to-ground and phase-to-phase sparkover characteristics of external insulation at the entrance of a UHV substation,IEEE Transactions on Power delivery,2002,Vol.17,No.1:223-232.
[40] 刘有为,郑健超,冲击电压下沿面闪络与空气湿度的关系,中国电机工程学报,1999, Vol.19,No.4:50-53.
[41] J.Kucera,T.W.Liao,A.F.Rohlfs,Atmospheric Correction Factors for High Voltage Testing ,Electra,1970,No.21:74-85.
[42] M.Ramirez,M.Moreno,A.Pigini,G.Rizzi,E.Garbagnati,Air density influence on the strength of external insulation under positive impulses:experimental investigation up to an altitude of 3000 m a.s.l.,IEEE Transactions on Power Delivery,1990,Vol.5,No.2:730-736.
[43] IEC,High voltage test techniques,Part 1:definition and test requirements,IEC Publication 60-1,1973.
[44] 宿志一,尚涛,王代荣,换流站直流场空气间隙放电特性的高海拔校正,电力设备,2005,Vol.6,No.8:25-28.
[45] 第一机械工业部,水利电力部,高压电气设备绝缘试验电压和试验方法,GB311-64,1964.
[46] 中华人民共和国机械工业部,高压电器使用于高海拔地区的技术要求,JB/Z102-71,1971.
[47] IEC,Common Specifications for High Voltage Switchgear and control gear Standards,IEC60694-1996,1996.
[48] IEC,Insulation coordination Part 2 Application Guide,IEC600071-2-1996,1996.
[49] 万启发,陈勇,谷莉莉等,高海拔外绝缘海拔校正因数的初步探讨,电压技术,2003,Vol.29,No.5:6,51.
[50] 蒋兴良,于亮 ,胡建林等,棒-板长空气间隙在低气压下雷电冲击特性及电压校正,中国电机工程学报,2005,Vol.25,No.11:152-156.
[51] 蒋兴良,孙才新,舒立春等,正棒-板短间隙雷电冲击放电电压的海拔修正,重庆大学学报,2003,Vol.26,No.3:77-81.
[52] 孙才新,舒立春,蒋兴良等,高海拔、污秽、覆冰环境下超高压线路绝缘子交直流放电特性及闪络电压校正研究,中国电机工程学报,2002,Vol.22,No.11:115-120.
[53] Sun Caixin,Jiang Xingliang,Sima Wenxia,et al,Study of flashover performance and voltage correction of DC insulator in icing districts of altitude of 2500m and below,power con 2002,International Conference,2002,Vol.3:1871-1874.
[54] Jiang Xingliang,Sun Caixin,Sima Wenxia,et al,AC flashover performance and voltage correction of 27.5 and 110kV iced copposite insulator at 4000~5500m high altitude districts,Power System Technology Proceedings,2002,Vol.3:1890-1894.
[55] Zhang Jianhui,Shu Lichun,Sun Caixin,et al,DC flashover performance of iced insulators under pressure and pollution conditions,properties and applications of dielectric materials ,Proceedings of the 3rd International Conference,1991,Vol.2:957-960.
[56] 于亮,低气压下 110kV 系统棒-板空气间隙冲击放电特性及电压校正研究,硕士学位论文,重庆大学,2005.
[57] P.A.Calva,F.P.Espino,Correction factors for Positive dc voltages,IEEE Transactions on Dielectrics and Electrical Insulation,1998,Vol.5,No.4:541-544.
[58] Gedenhuys H.J.,The positive streamer gradient over apractical range of air density and humidity,CIGRE,Report,1989,Vol.(WG03)18 IWD:22-89.
[59] 龙玉华,高海拔地区的空气湿度对操作波放电的影响,高电压技术,1994,Vol.20,No.2:58-60.
[60] 王秉钧编,数理统计在高电压技术中的应用,北京,水利电力出版社,1990.
[61] 中国国家标准,高电压试验技术第一部分:一般试验要求,GB/T16927.1-1997,北京,中国标准出版社,1997.
[62] 邹进上,刘长盛,刘文保,大气物理学基础,北京,气象出版社,1982.
[63] 杨津基,气体放电,北京,科学出版社,1983.