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1、<p>  外文標(biāo)題:Design and Application of Line Surge Arresters to Improve Lightning Protection Characteristics of Transmission Lines</p><p>  外文作者:JL He , R Zeng , J Hu , SM Chen , J Zhao</p><p>

2、;  文獻(xiàn)出處:Transmission & Distribution Conference & Exposition, 2008 :1-8</p><p>  英文4089單詞,20988字符,中文7298漢字。</p><p>  此文檔是外文翻譯成品,無(wú)需調(diào)整復(fù)雜的格式哦!下載之后直接可用,方便快捷!</p><p>  Design and

3、Application of Line Surge Arresters to Improve Lightning Protection Characteristics of Transmission Lines</p><p>  Jin-Liang He Senior Member, IEEE, Rong Zeng Senior Member, IEEE, Jun Hu, Shui-Ming Chen Seni

4、or Member, IEEE and Jie Zhao</p><p>  Abstract—The line surge arrester with series gap can effectively improve the lightning protection performance of the transmission line, and guarantee its safe operation.

5、 This paper discussed the design of two different series gap structures, and their influence on the line surge arresters. The so-called “transverse discharge” between the grading ring of the insulator to the upper discha

6、rging electrode of the series gap is discussed. At last, the paper introduced the application and effects of li</p><p>  Index Term—Metal oxide surge arrester, line surge arrester, series gap, lightning impu

7、lse, switching overvoltage, power frequency overvoltage, polymeric surge arrester</p><p>  INTRODUCTION</p><p>  Since 1980’s, the polymeric ZnO surge arresters have been developed and put into

8、operations on transmission lines in parallel with the insulators to improve the lightning withstand characteristics of transmission lines and increase the reliability of power supply based on their excellent performances

9、 [1]-[10]. Especially, in the regions where the lightning is exceedingly active or the grounding resistances of towers are difficult to be reduced due to the high soil resistivity, the lightning with</p><p>

10、  The metal oxide surge arresters for lightning protection of transmission lines have two different kinds of structures. The first kind is the gapless surge arrester, which is directly connected with the phase conductor.

11、 It is the technology extension of the surge arrester for substation, and has the merit of no discharging time delay for reliably absorbing surge energy. Another kind of line surge arrester has a series gap which is inse

12、rted between and isolates the surge arrester and the phase con</p><p>  The line surge arrester with series gap only operates when a lightning strikes the transmission line or the tower, and keeps out of wor

13、k, a state of “rest”, under all other situations even including the AC power frequency or switching overvoltage. That is to say, there is current passing through the arrester only within very short time duration of light

14、ning strike, which is about 1 to 2 power frequency cycles ordinarily. Thus, it makes the line surge arrester with series gap have longer life tim</p><p>  It is always a tough problem for the gapless surge a

15、rrester that the inside ZnO varistor failure directly does harm to the normal power transmission. Whereas, the line surge arrester with series gap will not affect the normal operation of the transmission line even if the

16、 inside ZnO varistors are already in</p><p>  degradation state.</p><p>  On account of so many merits, the line surge arresters with series gaps have been widely adopted now. However, the serie

17、s gaps of the surge arresters can also be designed with different structures. How does the gap structure have influence on the performance of the line surge arrester? This paper analyzed the influence of two different ga

18、ps on the lightning impulse discharging characteristics of line surge arresters with polymer housings, and introduced the application and effects of line surge </p><p>  STRUCTURE DESIGN OF LINE SURGE ARREST

19、ERS</p><p>  The Structure of Series Gap</p><p>  The line surge arrester consist of the series gap and the arrester unit. At present, two different series gap structures are available. The firs

20、t is the separated gap designed in Japan [1], [2], whose two discharging electrodes are isolated only by air. The second is called as fixed gap or integrated gap, with two discharging rings fixed by a composite insulator

21、 to keep their distance unchanged even if very strong wind blows on the arrester [3].</p><p>  The fixed gap means that the arrester unit and the series gap are assembled into a whole body as shown in Fig.1(

22、a). Ordinarily, a composite insulator is fixed on the bottom of the arrester unit, and two ring-shape discharging electrodes are fixed on two terminals of the composite insulator. The merit of this kind of series gap is

23、that the distance between two discharging electrodes is never influenced by external factors. The line surge arresters developed in China have adopted this kind of seri</p><p>  For the separated gap, one of

24、 its discharging electrodes is fixed on the bottom of the arrester unit, and the other electrode is fixed on the phase conductor. This separated gap should be considered for the influence of different external factors on

25、 the distance between two discharging electrodes. In order to keep the distance unchanged, the discharging electrodes should be manufactured as complicated arc shape as shown in Fig.1(b). In Japan, 77 kV, 275 kV and 500

26、kV line surge arresters used th</p><p>  As the fixed gap is supported by the composite insulator, the power frequency operating voltage applied on the arrester unit and the fixed gap in normal operation con

27、dition can be easily determined by their capacitances. The capacitance of the fixed gap of the 110 kV line surge arrester with length of 500 mm is calculated as 0.4 pF, and the capacitance per ZnO varistor disk with diam

28、eter of 70 mm is measured as 1040 pF. There are 28 pieces of disks used in the whole arrester unit, and its total </p><p>  B.The Structure of Arrester Unit</p><p>  As shown in Fig.2, the devel

29、oped line polymeric ZnO surge arresters has a whole-solid-insulation structure, all interior gaps are filled with middle-temperature silicon rubber material. There is not any gas gap inside the arrester, it is different

30、from those used in Japan which still have gaps inside arrester [1]. We know the main reason of arrester failure is due to moisture ingress, so the failure of the whole-solid-insulation arrester caused by moisture ingress

31、 is eliminated. The polymeric ho</p><p>  C. The Selection of Applied Voltage Ratio of Arrester Unit </p><p>  Generally, the applied voltage ratio is defined as the ratio of the maximum continu

32、ous operation voltage to the 1-mA DC referenced voltage of the ZnO surge arrester. The applied voltage ratio of the gapless surge arrester is recommended in the region from 0.6 to 0.8, due to the consideration of thermal

33、 stability. For example, that ratio value of 500 kV gapless ZnO surge arresters is designed as 0.712 in China. Contrastively, the applied voltage ratio of the line surge arrester with series gap ca</p><p>  

34、The line surge arrester only works during lightning strike, and the voltage applied on it is suppressed by the ZnO varistors inside the arrester. So, its leakage distance of the polymer housing could be shorter than that

35、 of the gapless surge arrester.</p><p>  DESIGN OF THE SERIES GAP</p><p>  The design of the series gap includes selecting the gap structure and determining the length of the series gap. The gap

36、 distance between two electrodes of the arrester should keep unchanged approximately under different external forces, such as wind blowing or conductor swinging, in order to keep the discharging voltage of the series gap

37、 stable within small dispersion.</p><p>  When line surge arresters are installed for lightning protection of transmission lines, the protected insulators should have no flashover during lightning strikes. S

38、o the lightning impulse voltage versus time characteristic curve of the surge arrester with series gap and that of the insulator string should be in parallel approximately, having no cross point at all.</p><p&

39、gt;  As illustrated in Fig.3, the required lengths of the series gap for different purposes are not the same. In order to suppress the lightning overvoltage, the length of the series gap should be shorter than L1. For bl

40、owing out the power frequency following current, the length of the series gap should be longer than L2. On the other hand, the length of the series gap should be longer than both L3 and L4 to guarantee that the arrester

41、does not operate when the switching or power frequency overvoltag</p><p>  A. Coordination of the 50% Lightning Impulse Discharging Voltages</p><p>  The influences of the series gap lengths on

42、the 50% lightning discharging voltages of the line surge arresters are shown in Figs.4 and 5, while Fig.4 is for the fixed gaps, and Fig.5 is for the separated gaps.</p><p>  When we determine the 50% lightn

43、ing impulse discharging voltages of the line surge arresters with series gaps, the scattered discharging characteristics of air gaps should be considered for the insulation coordination of the surge arrester with the ins

44、ulator string of transmission line. Ordinarily in China, the standard deviation of lightning discharging voltages in air is selected as 0.03 [12]. In order to realize the insulation coordination between the insulator str

45、ing and the line surge arres</p><p>  where, U50, A is the 50% lightning impulse discharging voltage of the line surge arrester, and U50, I is the 50% lightning impulse flashover voltage of the insulator str

46、ing. Thus, the insulation coordination coefficient between the line surge arrester and the insulator string is 20%, which means that the 50% discharging voltage of the insulator string should be 20% higher than that of t

47、he line surge arrester. However, as the actual maximum discharging deviation is smaller than 0.03, the suggeste</p><p>  B. Coordination of the Lightning Impulse Voltage Versus Time Characteristics</p>

48、<p>  The 50% discharging voltage can not completely describe the lightning impulse discharging characteristic, and the discharging time duration is another important factor of the lightning impulse discharging ch

49、aracteristic. The lightning impulse voltage versus time characteristic of the line surge arrester and that of the insulator string should coordinate, too.</p><p>  The tested lightning impulse voltage versus

50、 time characteristics of the line surge arresters with fixed and separated gaps and those of the insulator string are shown in Figs. 6 and 7 respectively, while the length of the separated gap is 520 mm and the length of

51、 the fixed gap is 650 mm. The lightning impulse voltage versus time characteristic curve of the line surge arrester is in parallel with that of the insulator string, and they have no cross point.</p><p>  Co

52、mparing the curves in Figs. 6 and 7, the lightning impulse discharging voltage versus time characteristics of the separated and fixed gaps have obviously difference, as shown in Table III. The discharging voltages of the

53、 line surge arresters with arresters with fixed gaps under the same conditions. This is caused by the effect of the composite insulator which fixes the two discharging electrodes. As a result, the length of the separated

54、 gap can be designed shorter than that of the fixed gap.</p><p>  C. The Withstand Capabilities of Power Frequency Overvoltages</p><p>  The power frequency overvoltage of 110 kV power system wi

55、th the neutral point grounded is suggested as 1.35 times of the maximum operating phase voltage, which is equal to 94 kV (110 1.1 1.35/ 3 ). When the arrester unit is failed, the series gap should withstand the power fre

56、quency overvoltage and cut the power frequency following current.</p><p>  The power frequency overvoltage withstand values of the series gaps are tested and shown in Table I. When the series gap is only 480

57、 mm in length, the line arrester can withstand 174 kV power frequency overvoltage if the arrester unit is failed. According to experimental results in [1], the line surge arrester with series gap can cut off the power fr

58、equency following current in 0.5 power frequency cycle when the series gap length is longer than 313 mm.</p><p>  D. Switching Overvoltage Withstand</p><p>  There always are two different viewp

59、oints on the line surge arrester suppressing the switching overvoltage. One opinion insists that the line surge arrester should not put into operation when a switching overvoltage emerges in the transmission line, and th

60、e other one does not consider whether the line surge arrester puts into operation in switching overvoltage condition. Similar with the lightning impulse discharging voltage, the 50% switching impulse discharging voltage

61、of the line surge arrest</p><p>  E. Determination of Series Gap Length</p><p>  Fig.3 illustrates the demanded series gap lengths of the line surge arresters to fulfill different purposes, incl

62、uding cutting off the power frequency following current, withstanding the switching impulse overvoltage without discharging and discharging reliably under lightning impulse. The detailed values of those demanded series g

63、ap lengths of the line surge arrester are shown in Table II, from which we can find that the determined gap lengths of the fixed and separated gaps for 110 kV line sur</p><p>  THE MINIMUM DISTANCE BETWEEN S

64、URGE ARRESTER AND INSULATOR</p><p>  Normally in China, the surge arrester with the fixed gap is too long to correspond with the length of the insulator string, and the special installing device is necessary

65、 to fix the arrester. The line surge arrester’s installing methods would affect the protection effect of line surge arrester. From simulation experiment in laboratory, the installing sites of line surge arresters affect

66、their protection effects whether they are installed to protect porcelain or composite insulators, when the dis</p><p>  As shown in Fig.8, if the line arrester is close to the insulator, when a lightning imp

67、ulse is applied on the connecting wire of surge arresters with separated and fixed gaps installed on transmission towers.</p><p>  APPLICATION EFFECT ANALYSIS OF LINE SURGE ARRESTERS </p><p>  O

68、rdinarily, the lightning withstand level (LWL) is used to measure the lightning protection performance of transmission line, which is the maximum lightning current that the transmission line can withstand without flashov

69、er. The purpose to install line arresters on transmission line towers is to increase the lightning withstand levels (LWLs). The best way to improve the LWL of a transmission line is to install line arresters in all tower

70、s, but the cost would be very high. So, ordinarily the line</p><p>  When the lightning strikes the protected transmission line region by arresters, there is not any flashover in this region;</p><

71、p>  (b)When the lightning strikes the transmission line beyond the protected transmission line region, there is no flashover in this protected region, too.</p><p>  The application effects of line surge a

72、rresters on the 500-kV compact transmission line were analyzed by EMTP. If three pieces of line surge arresters are installed on a tower, the influence of grounding resistance R1 of the transmission line tower stroke by

73、lightning is shown in Table III, and the grounding resistance of all other towers is 10 ?, the applied voltage ratio q is changed in our calculation. The lightning withstand level of 500-kV Chang-Fang compact transmissio

74、n line can be improve</p><p>  When the span between two towers is increased, the lightning withstand level will be increased if line surge arresters are installed as shown in Table IV, but the absorbed ligh

75、tning energy by the arrester will increase 53% when the span from 450 m to 800 m. It is still no problem for the surge arrester to withstand the effect of lightning.</p><p>  CONCLUSIONS</p><p>

76、  This paper introduced the design of polymeric surge arrester to improve the lightning protection characteristics of transmission lines. The influence of two different series gaps, named as separated gap and fixed gap,

77、on the lightning impulse discharging characteristics of line surge arresters with polymer housings are discussed.</p><p>  According to the demands on the series gap lengths of the line surge arresters to cu

78、t off the power frequency following current, withstand the switching impulse overvoltage without discharging, and discharge reliably under lightning impulse, the determined gap lengths of the fixed and separated gaps for

79、 110 kV line surge arresters are 550 mm and 500 mm respectively.</p><p>  The so-called “transverse discharge” between the grading ring of the insulator to the upper discharging electrode of the series gap i

80、s discussed, the minimum distance between the grading ring of the insulator and the upper discharging electrode of the series gap should be larger than 0.8 m for 110-kV line surge arrester, and 1.3 m for 220-kV line arre

81、ster.</p><p>  Up to present, more than 25000 pieces of line surge arresters with series gaps have been put into operation on 35 kV, 110 kV, 220 kV and 500 kV transmission lines in China, and the line surge

82、arrester has become the main lightning protection measures of transmission lines.</p><p>  REFERENCES</p><p>  S. Furukawa, O. Usuda, T. Isozaki, and T. Irie, “Development and application of lig

83、htning arresters for transmission lines,” IEEE Trans. Power Delivery, Vol. 4, no. 4, pp. 2121-2129, Oct. 1999.</p><p>  [2] K. Ishida, K. Dokai, T. Tsozaki, T. Irie, T. Nakayama, H. Fujita, K. Arakawa, Y. Ai

84、hara, “Development of a 500 kV transmission line arrester and its characteristics,” IEEE Trans. on PWRD, vol.7, no.3, pp.1265-1274, July 1992.</p><p>  [3] J. L. He, S. M. Chen, R. Zeng, J. Hu, and C. G. Den

85、g, “Development of Polymeric Surge ZnO Arresters for 500-kV Compact Transmission Line,” IEEE Transactions on Power Delivery, vol. 21, no.1, pp.113-120, Jan. 2006.</p><p>  [4] J. L. He, S. W. Han, H. G. Cho,

86、 “Lightning Overvoltage Protection of AC Railroad Vehicles by Polymeric Arresters,” IEEE Transactions on Power Delivery, vol.14, no.4, pp.1304-1310, Oct. 1999.</p><p>  [5] R.E. Koch, J.A. Timoshenko, J.G. A

87、nderson, and C. H. Shih, “Design of zinc oxide transmission line arresters for application on 138 kV towers,” IEEE Trans. Power Apparatus and System, Vol. 104, no. 10, pp. 2675-2680, Oct. 1985.</p><p>  [6]

88、E. J. Tarasiewicz, F. Rimmer, A. S. Morched, “Transmission line arrester energy, cost, and risk of failure analysis for partially shielded transmission lines,” IEEE Trans. on PWRD, vol.15, no.3, pp.919-924, July 2004.<

89、;/p><p>  [7] S. Sadovic, R. Joulie, S. Tartier, E. Brocard, “Use of line surge arresters for the improvement of the lightning performance of 63 kV and 90 kV shielded and unshielded transmission lines,” IEEE Tr

90、ans. on PWRD, vol.12, no.3, pp.1232-1240, July 1997.</p><p>  [8] T. Yamada, J. Sawada, E. Zaima, T. Irie, T. Ohashi, S. Yoshida, T.Kawamura, “Development of suspension-type arresters for transmission lines,

91、” IEEE Trans. on PWRD, vol.8, no.3, pp.1052-1060, July 1993.</p><p>  [9] J. L. He, R. Zeng, S. M. Chen, Z. C. Guan, “Potential distribution analysis of suspended-type metal-oxide surge arresters,” IEEE Tran

92、s. on PWRD, vol.18, no.4, pp.1214-1220, Oct. 2003.</p><p>  [10] J. L. He, R. Zeng, S. M. Chen, Y. P. Tu, “Thermal characteristics of high voltage whole-solid-insulated polymeric ZnO surge arrester,” IEEE Tr

93、ans. on PWRD, vol.18, no.3, pp. 1221-1227, July 2003.</p><p>  [11] W. G. Huang, “Study on conductor configuration of 500 kV Chang-Fang compact line,” IEEE Trans. on PWRD, vol.18, no.3, pp. 1002-1008, July 2

94、003.</p><p>  [12] China Standard of Power Electric Industry DL/T 620-1997, Overvoltage protection and insulation coordination of ac power apparatus.</p><p>  [13] China Standard of Power Electr

95、ic Industry DL/T 815-2002, Polymeric metal oxide surge arresters for a.c. power transmission lines.</p><p>  Rong Zeng (M’02) was born in Xunyang city, Shanxi Province, P. R. China in 1971. He received his B

96、. Sc., M. Eng., and Ph. D. degrees from the Department of Electrical Engineering, Tsinghua University in Beijing, China, respectively in July 1995, July 1997, and July 1999.Currently, he is the vice Dean of the Departmen

97、t of Electrical Engineering, Tsinghua University. He became a lecturer in the Department of Electrical Engineering, Tsinghua University in Beijing in August 1999, and an associate pr</p><p>  Jun Hu was born

98、 in Ningbo city, Zhejinag Province, P. R. China, in 1976. He received his B Sc. and M. Sc. degrees in electrical engineering from the Department of Electrical Engineering, Tsinghua University in Beijing, China, in July 1

99、998 and July 2000, where he is currently pursuing the Ph. D. degree in the Department of Electrical Engineering at Tsinghua University, Beijing China.His research fields include overvoltage analysis in power system and d

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