Outline of Guide for Application of Transmission Line Surge Arresters 42 to 765 kV

Effective December 6, 2006, this report has been made publicly available in accordance with Section 734.3(b)(3) and published in accordance with Section 734.7 of the U.S Export Administration Regulations As a result of this publication, this report is subject to only copyright protection and does not require any license agreement from EPRI This notice supersedes the export control restrictions and any proprietary licensed material notices embedded in the document prior to publication Outline of Guide for Application of Transmission Line Surge Arresters—42 to 765 kV Extended Outline 1012313 Outline of Guide for Application of Transmission Line Surge Arresters—42 to 765 kV Extended Outline 1012313 Technical Update, October 2006 EPRI Project Manager A Phillips ELECTRIC POWER RESEARCH INSTITUTE 3420 Hillview Avenue, Palo Alto, California 94304-1338 PO Box 10412, Palo Alto, California 94303-0813 USA 800.313.3774 650.855.2121 askepri@epri.com www.epri.com DISCLAIMER OF WARRANTIES AND 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YOUR SELECTION OR USE OF THIS DOCUMENT OR ANY INFORMATION, APPARATUS, METHOD, PROCESS, OR SIMILAR ITEM DISCLOSED IN THIS DOCUMENT ORGANIZATION(S) THAT PREPARED THIS DOCUMENT Kinectrics North America, Inc NOTE For further information about EPRI, call the EPRI Customer Assistance Center at 800.313.3774 or e-mail askepri@epri.com Electric Power Research Institute and EPRI are registered service marks of the Electric Power Research Institute, Inc Copyright © 2006 Electric Power Research Institute, Inc All rights reserved CITATIONS This report was prepared by Kinectrics North America Inc 800 Kipling Avenue Toronto, Ontario, Canada Principal Investigator W.A Chisholm This report describes research sponsored by the Electric Power Research Institute (EPRI) This publication is a corporate document that should be cited in the literature in the following manner: Outline of Guide for Application of Transmission Line Surge Arresters—42 to 765 kV: Extended Outline EPRI, Palo Alto, CA: 2006 1012313 iii PRODUCT DESCRIPTION Lightning flashovers are the most frequent cause of transmission line outages Transmission line surge arresters (TLSA) limit lightning overvoltages between phase conductors and towers, and thus eliminate most outages on protected structures This guide provides a tutorial on the relevant lightning phenomena, with an in-depth look at the operation, application, and placement of TLSA to maximize flashover protection and minimize capital investment The guide also describes ways to improve tower grounding for better performance of overhead groundwires Results and Findings The guide contains an in-depth description of the following areas: • The parameters that influence transmission line lightning performance / parameters Lightning incidence scales performance in all regions With overhead groundwires, lightning currents act against local soil resistivity to create insulator stress Adding arresters reduces the influence of grounding When OHGW are removed, leaving only arresters, the lightning charge replaces peak current as a dominant stress The section also discusses other transmission line features that affect line lightning performance, including line, tower, insulator and arrester air gap geometries; tower impedance; and nonlinear corona effects • TLSA selection/specification Before selecting a TLSA, utility engineers should consider a number of design questions concerning arrester operating characteristics and rating, temporary overvoltages, arrester protective levels and insulation coordination, TLSA energy capability, arrester failures, TLSA housings, and TLSA installation and handling Selecting an arrester system (possibly including a series gap or insulator) for a particular transmission line is the process of simultaneously satisfying these concerns with a single arrester type • Placement of arresters for improved lightning performance The efficient application of TLSA to improve line performance requires the investigation of all available mitigation options and weighing of the performance benefits against real cost Estimating the effects of changes in tower structure and design, shielding, grounding, and arresters on the lightning performance of transmission lines is crucial to this process This section discusses backflashover protection, unshielded applications, and transmission lines over varying terrain Challenges and Objectives One difficulty in focusing this report is the wide range of technical backgrounds of the readers Electrical engineers will be most interested in insulation coordination and risk management Civil engineers will be more interested in what will be gained and lost if a new line is designed without overhead groundwires (OHGW) and with compact insulation, protected by TLSA While v these readers will find what interests them, the main focus of this report is a utility project manager facing a decision to replace existing overhead groundwires (OHGW), the fastestdecaying transmission line component, with a typical life of 25 to 55 years What has changed in ten years is that the decision to put up TLSA in place of OHGW is commercially and technically viable in many areas Having this new alternative, with its reduced visual impact and peak-load loss reduction, can help the utility bottom line, especially considering that the OHGW conductors represent 4% of the total line investment Applications, Values, and Use New lines with reduced visual impact are already taking advantage of TLSA to replace overhead groundwires So far, these applications have been made in areas of difficult grounding and low lightning incidence However, the alternative of buried transmission cable looms like the sword of Damocles, motivating overhead line engineers to deliver more reliability with fewer resources EPRI Perspective Lightning causes power outages that cost utilities more than $1 billion per year directly, in damaged or destroyed equipment The indirect damage to customers from all power quality problems is estimated to exceed $100 billion per year, with more than half of these disturbances having lightning as a root cause This guide presents TLSA theory and design information to enable utilities to minimize the number outages due to lightning EPRI developed this guide with the understanding that users may not be familiar with either TLSA or the current standards that do, or should, apply to them The guide is tutorial in nature and does not anticipate every situation or utility need In general, however, experience has shown that properly designed, installed, inspected, and maintained hardware such as TLSA, counterpoise, and overhead groundwires can significantly improve system reliability and power quality Approach In 1997, EPRI delivered a TLSA application guide (TR-108913), consolidating literature with results of a survey of 31 EPRI-member utilities EPRI also supported arrester energy and mechanical tests at the EPRI Power Delivery Center-Lenox The state of the art of TLSA has advanced considerably since the last EPRI guide was published Line arresters have proved themselves as technically and economically feasible for improving performance of conventional lines with overhead groundwires TLSA have also been used on 230-kV and 400-kV lines without overhead groundwires, where the extra surge duties raise new electrical reliability concerns Most of the difficulties found in applying TLSA relate to the spotty reliability of mechanical components This can be addressed by ensuring that TLSA components meet the same high reliability standards that apply to other line components This document is an extended outline that will be built upon and refined over the new few years to develop a completed guide Keywords Reliability Lightning and weather impacts Power quality Transmission lines vi ABSTRACT In most areas, flashovers from lightning are by far the most frequent cause of transmission line outages Transmission line surge arresters (TLSA) limit the lightning over-voltages between phase conductors and the tower structure This prevents flashovers and insulation damage on that structure This guide provides a tutorial of the relevant lightning phenomena, in general, and offers an in-depth look at the operation, application, and placement of TLSA to maximize flashover protection and minimize capital investment The guide also considers other mitigation measures, including improved tower grounding and the application of overhead groundwires EPRI developed this guide with the understanding that users may not be familiar with either TLSA or the current standards that or should apply to them The guide, therefore, is tutorial and does not anticipate every situation or utility need Overall, however, experience has shown that properly designed, installed, inspected, and maintained hardware such as TLSA, counterpoise, and overhead groundwires can significantly improve system reliability and power quality This document is an extended outline that will be built upon and refined over the new few years to develop a completed guide i Case Studies Figure 8-11 TLSA on AEP 765-kV Line for Switching Surge Control 8-14 REFERENCES ANSI/ IEEE Std 4-1992 Standard Techniques for High-Voltage Testing ANSI/ IEEE-62.11-1993 "Standard for Metal Oxide Surge Arresters for Alternating Current Power Circuits" CEI/IEC 99-4 1991-11 "International Standard: Surge Arresters Part Metal Oxide Surge Arresters without Gaps for AC Systems" ANSI/ IEEE C62.22-1991 "IEEE Guide for the Application of Metal-Oxide Surge Arresters for Alternating-Current Systems" ANSI/ IEEE C62.1-1989 "Standard for Gapped Silicon-Carbide Surge Arresters for AC Power Circuits" ANSI/IEEE C62.2-1987 "Guide for the Application of Gapped Silicon-Carbide Surge Arresters for AC Systems" IEEE Standard 1243/1997, "Guide for Improving the Lightning Performance of Transmission Lines" CEI/IEC 99-1 1991 "Part 1: Non-Linear Resistor Type Gapped Surge Arresters for AC Systems" V Mazur and L Ruhnke, “Evaluation of Lightning Protection System at the WSR-88D Radar Sites”, NOAA Final Report, May 2001 Combined Satellite- and Surface-Based Estimation of the Intracloud–Cloud-to-Ground Lightning Ratio over the Continental United States DENNIS J BOCCIPPIO, KENNETH L CUMMINS, HUGH J CHRISTIAN AND STEVEN J GOODMAN, Monthly Weather Review Vol 129, January 2001 R Zemeckis and R Gale, “Back to the Future”, 1985 The Cost of Power Disturbances to Industrial and Digital Economy Companies, EPRI, Palo Alto, CA, June 2001 TR-findout J.G Anderson, "Lightning Performance of Transmission Lines," Chapter 12, Transmission Line Reference Book - 345 kV and Above, Second Edition, Electric Power Research Institute, Palo Alto, CA, 1987 9-1 References Guide for Improving the Lightning Performance of Transmission Lines, IEEE Standard 1243/1997 Dept., 445 Hoes Lane, Piscataway, NJ 08855-1331 CIGRE Working Group 01 (Lightning) of Study Committee 33 (Overvoltages and Insulation Coordination), Guide to Procedures for Estimating the Lightning Performance of Transmission Lines, CIGRE Brochure #63, October 1991, Paris Appendix of Reference K Berger, "The Earth Flash," Chapter 5, Lightning, Vol 1, Edited by R H Golde, Academic Press, New York, 1977 W Chisholm, Y L Chow, K D Srivastava, "Travel Time of Transmission Towers," IEEE Trans PWRD, Vol PAS-104, No 10, October 1985, pp 2922-2928 R.L Witzke, T J Bliss, "Coordination of Lightning Arrester Location with Transformer Insulation Level," AlEE Trans., Vol 69, Part 1,1950, pp 964-975 P Chowdhuri, Electromagnetic Transients in Power Systems, John Wiley & Sons, New York, NY USA M Darveniza, "Further Experience with the Integration Method of Estimating Non-Standard Impulse Insulation Strength," Proceedings of Sixth intl Symposium on High Voltage Engineering, paper 22.15, New Orleans, LA, 1989 10 A.M Mousa, "The Soil Ionization Gradient Associated with Discharge of High Currents into Concentrated Electrodes," lEEE Trans on Power Delivery, Vol 9, No 3, July 1994, pp 16691677 11 K.H Weck, "Remarks to the Current Dependence of Tower Footing Resistances," CIGRE Working Group Report, No 33-85 (WGO1)IWD 12 A.V Korsuncev, "Application of the Theory of Similitude to the Calculation of Concentrated Earth Electrodes," Elektrichestvo, No 5, May 1958, pp 31-35 13 F Popolansky, "Generalization of Model Measurement Results of Impulse Characteristics of Concentrated Earths," CIGRE Working Group Report, No SC33-80 (WGO1) IWD, August 1980 14 ANSI/IEEE 62.11, Standard for Metal Oxide Surge Arresters for AC Power Circuits 15 J Williams, "Transmission Line Arrester Energy Study for Lightning Surges," Distributed at the EPRI TLSA Workshop, July 1994 16 E.R Whithead, "CIGRE Survey of the Lightning Performance of Extra-High Voltage Transmission Lines," Electra, No 33, March 1974 9-2 References 17 C.H Shih, B.J Ware, J.G Anderson, J.J LaForest, "The Effect of Metal Oxide Arresters on Switching Overvoltages on EHV Systems," CIGRE Paper 33-03,1982 Tarasiewicz, E., Rimmer, F and Morched, A.S., “Transmission Line Arrester Energy, Cost, and Risk of Failure Analysis for Partially Shielded Transmission Lines”, IEEE Trans PWRD Vol 15 No.3, Jul 2000, p.919 International Telecommunications Union Recommendation ITU-R P.368-7, Ground-Wave Propagation Curves for Frequencies between 10 kHz and 30 MHz 1992 International Telecommunications Union Recommendation ITU-R P.832-2, World Atlas of Ground Conductivities 1999 Kenji TSUGE, Hiroaki YAMADA, “Application Technology of Lightning Arrester for 275kV Transmission Line”, ICLP 2006 Teru ARAYA, Naoto TAMURA, Kazuo KUMATA, “Effective Partial Installation of Line Surge Arresters for 275kV Transmission Lines in winter lightning area”, ICLP 2006 Kundu, Debu, “Lightning Protection and Its Effects on Industrial Plants and Electrical Systems”, May 8-9, 2000 Seminar, Toronto, Ontario Jim Sanders and Kevin Newman, “Polymer Arresters as an Alternative to Shield Wire”, 24th Annual Transmission & Substation Design and Operation Symposium, EU1413-H, 1992 B RICHTER, W SCHMIDT K KANNUS, K LAHTI, V HINRICHSEN C NEUMANN W PETRUSCH, K STEINFELD, “LONG TERM PERFORMANCE OF POLYMER HOUSED MO-SURGE ARRESTERS”, CIGRE 2004 A3-110 Loudon, D, Kjell Halsan, Jonsson, Karsson, Stenstrøm and Lundquist, “A compact 420 kV line utilising line surge arresters for areas with low isokeraunic levels”, CIGRE 1998, 22/33/36-08 In addition, it is noted that the v1.0 gridded satellite lightning data (see Figure 4-3) were produced by the NASA LIS/OTD Science Team (Principal Investigator, Dr Hugh J Christian, NASA / Marshall Space Flight Center) and are available from the Global Hydrology Resource Center 9-3 A TLSA MECHANICAL PERFORMANCE TESTS To better understand the mechanical limitations for the installation of TLSA, an evaluation of the components comprising a TLSA was conducted Two manufacturers, noted as A and B, provided disconnectors and arrester bodies for mechanical evaluation This evaluation included static tension and bending tests of arrester bodies, static tension and shear tests of arrester disconnects, and fatigue testing of disconnects The goal was to develop strength data for the arrester components and thus the arrester assembly This will allow utility engineers to compare arrester strength with line design parameters to determine if a sufficient level of reliability exists for the anticipated arrester installation Line Disconnector Testing Figure A-1 Shear and Tension Tests on TLSA Disconnects A-1 TLSA Mechanical Performance Tests Arrester Body Testing Figure A-2 Arrester Body Bending Test Setup Table A-1 Observed TLSA Failure Loads Manufacturer Tension Bending A (5085 lb) (330 lb) B (5594 lb) (540 lb) Evaluation of Different Arrester Installation Configurations A-2 B TLSA ENERGY WITHSTAND TEST DATA Definition of Withstand Criteria Tests of 63-mm TLSA to Destruction Tests of 8.4-kV MCOV Samples to Thermal Runaway B-1 C TRANSMISSION LINE LIGHTNING PERFORMANCE CASE STUDIES C-1 D MECHANICAL FORCE ANALYSIS FOR GAPLESS TLSA INSTALLATIONS Figure D-1 Example of Typical Conductor to Pole Suspension D-1 Mechanical Force Analysis for Gapless TLSA INstallations Figure D-2 Example of Typical Conductorto Tower Mast Suspension D-2 Export Control Restrictions The Electric Power Research Institute (EPRI) Access to and use of EPRI Intellectual Property is granted with the specific understanding and requirement that responsibility for ensuring full compliance with all applicable U.S and foreign export laws and regulations is being undertaken by you and your company This includes an obligation to ensure that any individual receiving access hereunder who is not a U.S citizen or permanent U.S resident is permitted access under applicable U.S and foreign export laws and regulations In the event you are uncertain whether you or your company may lawfully obtain access to this EPRI Intellectual Property, you acknowledge that it is your obligation to consult with your company’s legal 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800.313.3774 • 650.855.2121 • askepri@epri.com • www.epri.com 1012313 ... Outline of Guide for Application of Transmission Line Surge Arresters 42 to 765 kV Extended Outline 1012313 Technical Update, October 2006 EPRI Project Manager... the literature in the following manner: Outline of Guide for Application of Transmission Line Surge Arresters 42 to 765 kV: Extended Outline EPRI, Palo Alto, CA: 2006 1012313 iii PRODUCT DESCRIPTION... System Voltage of 100 to 230 kV System Voltage of 275 to 765 kV Typical Impulse Insulation Strength (CFO) No effect on strength 150 to 550 kV 550 to 1100 kV 1100 to 2200 kV 0.3 to m to m to m Induced