Final tension approximation method for determining the maximum sag of a bare overhead conductor

Shaun McCarthy; Nirmal-Kumar C. Nair

Final tension approximation method for determining the maximum sag of a bare overhead conductor

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Author(s): Shaun McCarthy ¹ and Nirmal-Kumar C. Nair ¹
- Affiliations: 1: Department of Electrical and Computer Engineering, University of Auckland, Science Centre, 38 Princes Street, Auckland, New Zealand
Source: Volume 9, Issue 3, 19 February 2015, p. 249 – 255
DOI: 10.1049/iet-gtd.2014.0592 , Print ISSN 1751-8687, Online ISSN 1751-8695

Received 11/06/2014, Accepted 31/07/2014, Revised 23/07/2014, Published 10/09/2014

The non-linear general state-of-change equation used to describe tension change phenomenon is solved along with catenary's parabolic expression, to evaluate the maximum sag as per IEEE 605-2008. The existing solutions for obtaining sag are either through trial-and-error techniques or iterative methods. Hence, a direct solution method is proposed, which gives conservative but quick results. The mathematical proof and its approximation validity have been provided. The method has also been verified on two standard test cases. Future extensions of this method to handle other possibilities have also been clearly identified.

References

1. 1)
  - 15. Epperson, J.F.: ‘An introduction to numerical methods and analysis’ (Wiley, New York, 2002).
2. 2)
  - 2. Sag-tension Calculation Methods for Overhead Lines, CIGRE WG B2.12.3, 2007.
3. 3)
  - 11. Chen, S.L., Black, W.Z., Fancher, M.L.: ‘High-temperature sage model for overhead conductors’, IEEE Trans. Power Deliv., 2003, 18, (1), pp. 183–188 (doi: 10.1109/TPWRD.2002.801427).
4. 4)
  - 8. Awad, M.B., Huestis, H.W.: ‘Influence of short-circuit currents on HV and EHV strain bus design’, IEEE Trans. Power Appar. Syst., 1980, 99, pp. 480–487 (doi: 10.1109/TPAS.1980.319683).
5. 5)
  - 7. The mechanical effects of short-circuit currents in open air substations, CIGRE WG 23-11, 1996.
6. 6)
  - 12. Discussion and Closure of paper: ‘High temperature sag model for overhead conductors’, IEEE Trans. Power Deliv., 2003, 18, (4) p. 1600.
7. 7)
  - 6. Short-circuit currents – Calculation of effects – Part 1: Definitions and calculation methods, IEC 60865-1-2011.
8. 8)
  - 13. Kopsidas, K., Rowland, S.M., Bourmecid, B.: ‘A holistic method for conductor ampacity and sag computation on an OHL structure’, IEEE Trans. Power Deliv., 2012, 27, (3), pp. 1047–54 (doi: 10.1109/TPWRD.2012.2187464).
9. 9)
  - 9. Bayliss, C., Hardy, B.: ‘Transmission and distribution electrical engineering’ (Elsevier Ltd, 2007, 3rd edn.), p. 672.
10. 10)
  - 1. Maor, E.: ‘e: the story of a number’ (Princeton, New Jersey, 1994), pp. 140–141.
11. 11)
  - 14. Moore, G.F.: ‘Electric cables handbook’ (Blackwell, Oxford, 1997, 3rd edn.).
12. 12)
  - 10. Havard, D.G., Pon, C.J., Ewing, H.A., Dumol, G.D., Wong, A.C.: ‘Probabilistic short-circuit uprating of station strain bus system – mechanical aspects’, IEEE Trans. Power Deliv., 1986, PWRD-1, (3), pp. 104–110 (doi: 10.1109/TPWRD.1986.4307980).
13. 13)
  - 4. Douglass, D.A., Thrash, R.: ‘Sag and tension of conductor’, in Grigsby, L.L. (Ed.): ‘Electric power generation, transmission, and distribution’ (CRC Press, Florida, 2007), 2nd ed., Chapter 14.
14. 14)
  - 5. IEEE Guide for Bus Design in Air Insulated Substations, IEEE Standard 605-2008, May 2010.
15. 15)
  - 3. Miroschnik, R.: ‘Force safety device for substation with flexible buses’, IEEE Trans. Power Deliv., 2003, 18, pp. 1236–1240 (doi: 10.1109/TPWRD.2003.817491).

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Final tension approximation method for determining the maximum sag of a bare overhead conductor

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