• G. V. Bezprozvannych National Technical University "Kharkiv Polytechnic Institute", Ukraine https://orcid.org/0000-0002-9584-3611
  • V. M. Zolotaryov Private Joint-stock company Yuzhcable works, Ukraine
  • Y. A. Antonets Private Joint-stock company Yuzhcable works, Ukraine




bare conductor, protected wire, cross-linked polyethylene insulation, oxide insulation, thermal resistance, optimal insulation thickness, heat balance, effective heat transfer coefficient, current carrying capacity


Introduction. The main direction of technical policy in the design, construction and technical re-equipment of transmission lines is the modernization of electrical networks and increase their energy efficiency in order to increase the throughput and reliability. Problem. Existing calculation methods do not take into account the influence of insulation thickness on the long-term current load of the wires according to the values of the maximum permissible working temperature of the conductors. Purpose. The investigation of the influence of insulation thickness of the protected wires of high-voltage electric transmission lines on their current carrying capacity. Methodology. The long operating temperature of the wire when the rated load current flows is determined based on the heat balance equation. Results. A method has been developed for determining the optimum thickness of polyethylene cross linked and oxide insulation to provide the lowest thermal resistance to the heat transfer of protected wires, the use of which allows increasing the current carrying capacity by 20 % compared to bare wires. It is shown that the internal temperature drop in cross linked polyethylene insulation is an order of magnitude smaller in comparison with the oxide insulation at identical values of the dielectric loss tangent. Originality. The calculations take into account the presence on the surface of a non-insulated aluminum conductor of a natural dense film based on aluminum oxide, which protects it from further contact with air. The capacitance of a single phase conductor with insulation is determined on the basis of the calculation of the electric field in a piecewise homogeneous medium by the method of secondary sources.


1. Enterprise standard. Technical policy of SE «NEK» UKRENERGO» in the field of development and operation of in trunk and interstate electric networks. SOU NEC 20.261. Kyiv, 2017. 84 p. (Ukr).

2. Catalog of LLC «Sim-Ross-Lamifil». Energy-efficient wires of a new generation for power lines. 2014. 26 p. (Rus).

3. DSTU 4743: 2007. Provody samoutrymni izolovani ta zakhyshcheni dlia povitrianykh linii elektroperedavannia. Zahalni tekhnichni umovy [State Standard of Ukraine DSTU 4743: 2007. Wires self-supporting insulated and protected for overhead transmission lines. General specifications]. Kyiv, 2007. 26 p. (Ukr).

4. Shcherba A.A., Peretyatko Yu.V., Zolotaryov V.V. Samonesushchie izolirovannye i vysokovol'tnye zashchishchennye provoda [Self-supporting insulated and high-voltage protected wires]. Institute of Electrodynamics of the NAS of Ukraine, National Technical University of Ukraine «KPI», Private Joint-stock company Yuzhcable works Publ., 2008. 271 p. (Rus).

5. Guide for qualifying high temperature conductors for use on overhead transmission lines. CIGRÉ TB 426. 2010. 44 p.

6. IEC 60287-1-1:2006 Electric cables – Calculation of the current rating – Part 1-1: Current rating equations (100 % load factor) and calculation of losses. General specifications.

7. Bezprozvannych G.V., Naboka B.G., Moskvitin E.S. Substantiation of electrophysical characteristics of high-voltage power cable semiconducting screens with stitched insulation. Electrical engineering & electromechanics, 2010, no.3, pp. 44-47. (Rus). doi: 10.20998/2074-272X.2010.3.10.

8. Bezprozvannych G.V., Naboka B.G. Matematicheskie modeli i metody rascheta elektroizoliatsionnykh konstruktsii [Mathematical models and methods of calculation of electrical designs]. Kharkiv, NTU «KhPI» Publ., 2012. 108 p. (Rus).

9. Carslaw H.S., Jaeger J.C. Conduction of heat in solids. Second Ed. Clarendon Press, London, 2003. 510 p.

10. Hunter M., Fowle P. Natural and thermally formed oxide films on aluminium. Journal of the Electrochemical Society, 1956, vol.103, no.9, pp. 482-485. doi: 10.1149/1.2430389.

11. Naboka B.G. Raschety elektrostaticheskikh polei v elektroizoliatsionnoi tekhnike: uchebnoe posobie dlia studentov elektroenergeticheskikh spetsial'nostei [Settlements electrostatic fields in the insulating technique: a textbook for students of electric power specialties]. Kiev, IEDL Publ., 1995. 120 p. (Rus).

12. Bezprozvannych A.V. High electric field and partial discharges in bundled cables. Technical electrodynamics, 2010, no.1, pp. 23-29. (Rus).



How to Cite

Bezprozvannych, G. V., Zolotaryov, V. M., & Antonets, Y. A. (2018). EFFECT OF THE THICKNESS OF INSULATION OF PROTECTED WIRES OF HIGH-VOLTAGE OVERHEAD TRANSMISSION LINES TO THEIR CURRENT CARRYING CAPACITY. Electrical Engineering & Electromechanics, (2), 41–46. https://doi.org/10.20998/2074-272X.2018.2.07



Engineering Electrophysics. High Electric and Magnetic Field Engineering