WORLD MEETING ON LIGHTNING Lightning Performance Research on Mexican High Voltage Transmission Lines

Transcription

1 WORLD MEETING ON LIGHTNING 2016 Lightning Performance Research on Mexican High Voltage Transmission Lines Carlos ROMUALDO-TORRES, PhD (Eng) Instituto de Investigaciones Eléctricas MEXICO

2 This paper describes: Answer to question 1: Shielding and backflashover results for typical transmission lines. Answer to question 2: The experiences obtained by CFE and IIE during several years of use of surge arresters in transmission and distribution lines. 2

3 Ø Answer to question 1: Shielding and backflashover results for typical transmission lines. 3

4 Transmission line lightning caused failures for 2013 and 2014 years [1, 2] Year Transmission Line Operating Voltage (kv) % 45 % % 57 % 4

5 Ø Prediction methods are usually based on Monte Carlo simulation [4]: Ø Electrogeometrical model [5, 6] Ø Travelling wave analysis [7] Ø To simulate the lightning performance of a transmission line over a prescribed period of time to determine a failure rate of the lines [8]. 5

6 Figure 1. Electrogeometrical model [5, 9] 6

7 Figure 2. Stroke current at a tower splitting between groundwires and ground [ 5] 7

8 Figure 3. Simplified description of the Monte Carlo and Travelling Wave 8 method for shielding and backflasohover calculations [8]

9 Figure kv transmission line under study [9]. Figure 5. Shielding and backflashover failures for a 230 kv transmission line based on 1 stroke/ km 2 /year [9]. 9

10 Answer to question 2: The experiences obtained by CFE and IIE during several years of use of surge arresters in transmission and distribution lines. 10

11 Figure 6. Transmission line protecting methods against shielding failures and backflashovers [10, 13]. 11

12 The main philosophy used for the application of surge arresters on transmission lines is as follows [11]: a) Outage statistic records of the prospect transmission line, at least of the last five years or before. b) Grounding resistance measurements along conflictive line areas. c) Ground flash density along the line. d) Terrain topography through the transmission line route e) Exposed towers over elevated mountainous areas with slopes and ravines, long spans and scarce vegetation. 12

13 Surge arresters are commonly installed as follows [11]: a) On critical sections of the line, or in regions with rocky soil (high resistivity) b) Structures with high grounding resistance c) In lines with critical loads connected 13

14 Installation of 230 kv arresters with external series gap a) Ten surge arresters were installed on TED VTP transmission line in This line is 106 km in length [12]. b) Two critical regions with major lightning problems were chosen. c) Surge arresters were installed at the outer phase conductors of the line 14

15 Poor performance Better performance Figure 8. Outages rates for TED VTP transmission line [3, 13]. 15

16 Table I. Outage rates for TED VTP transmission line [13] Transmission line Outages pear year with no arresters Year Arrester installation Outages per year with arresters Outage reduction per year TED VTP

17 SOME FURTHER RESEARCH Update for a distribution stroke leader approach angle. Development of stroke current distributions for the first and subsequent positive and negative strokes respectively. Studies on multicircuit flashovers and coupling effects for more than two groundwires on transmission lines. 17

18 Fast transient rise times should be considered, to determine their influence on the tower top potential at various grounding resistance values as well as tower surge impedance values. Ø Neural networks and fuzzy logic can be used, for the location of surge arresters on transmission and distribution lines, in order to improve the reliability line with poor lightning [14] 18

19 CONCLUSIONS 1] The installation of surge arresters, improvement of footing resistance and an adequate shielding angle transmission lines have permitted obtaining good results in their lightning performance. 2] Surge arresters were mainly installed in structures located in critical areas selected according to tripout historical information. 19

20 3] Good results have encouraged CFE, to continue installing surge arrester on the most critical transmission lines to improve their lightning performance. 20

21 REFERENCES 1] Failures, Statistics and Relevant Works on Transmission Lines, Coordinación de Transmisión, Gerencia de Líneas de Transmisión, CFE, 2013 (in Spanish). 2] Failures, Statistics and Relevant Works on Transmission Lines, Coordinación de Transmisión, Gerencia de Líneas de Transmisión, CFE, 2014, (in Spanish). 3] Tower Catalogue: 400 kv, 230 kv and 115 kv, CFE, (In Spanish) 4] Anderson J. G. "Monte Carlo Computer Calculation of Transmission-Line Lightning Performance". AIEE Trans. Vol. 80, pp , August ] GUIDE TO PROCEDURES FOR ESTIMATING THE LIGHTNING PERFORMANCE OF TRANSMISSION LINES. Working Group 01 (Lightning) of CIGRE Study Committee 33 (Overvoltages and Insulation Coordination). October ] Whitehead E. R. LIGHTNING. Lightning Protection, Vol. 2, Chapter 22. Protection of Transmission Lines. Academic Press, 1977, (Book Edited by R. H. Golde), ISBN

22 7] Bewley L. V. Travelling Waves on Transmission Systems. 2nd Edition, John Wiley & Sons, Inc. N. Y., 1951, Book. 8] Romualdo Torres C. Lightning Outages Calculations for Transmission Lines.Eleventh International Symposium on High - Voltage Engineering. Conference Publication No Vol. 2. Topic C. Lightning, protection against strikes, earthing. London, U. K. The Institution of Electrical Engineers August, ] ROMUALDO TORRES C. Lightning Performance of Transmission and Distribution Lines. PhD Thesis, University of Manchester Institute of Science and Technology, Manchester, Inglaterra, ] Furukawa S., Usuda O. Isozaki T., Irie T., 11] Romualdo T. C., Fonseca M. F. Development and Application of Lightning Arresters for Transmission Lines. IEEE PWD, Vol. 4, No. 4, pp , October Field experience on the application of surge arresters on transmission lines. IEEE 2010 Transmission and Distribution Conference and Exposition. April 19-22, New Orleans, Louisiana. 22

23 12] Romualdo Torres C., C a m p o s Miramontes A. Lightning protection of 230 kv Transmission Lines with Surge Arresters. ALTAE 2007, Paper Number 60, Cuernavaca, Mor. México. (In Spanish). 13] Lightning Field Performance of 230 and 400 kv Transmission Lines and the Application of Alternative Protecting Methods, IIE, Internal project report 13704, November 2009, (in Spanish). 14] Romualdo T. C., Ramírez G. M., Escamilla P. A. Lightning Outage Transmission Line Reliability Improvement with Surge Arresters TRANSMISSION AND DISTRIBUTION CONFERENCE AND EXPOSITION Submitted for publication. 23

24 Mexican High Voltage Transmission Lines Contact: Carlos ROMUALDO TORRES, PhD (Eng) Tel: ext crt@iie.org.mx