Mechanical Calculation of Flexible Wires of Overhead Lines with Barrage Balls

Aerial barrage balls serve for marking high-voltage wires in order to visually warn pilots of civil and military aviation about the presence of overhead lines. The present article deals with the mechanical calculation of flexible overhead wires of overhead lines, in which aerial warning barrage balls are installed. The wire is considered as a homogeneous flexible thread having the outline of a parabola and a chain line. The load from the aerial barrage balls must not be substituted with a distributed one by simple division of the total load into the span length, since it can cause incorrect results. The formulas for determining the sag are given for a different number of aerial barrage balls as a function of their number and the coefficient of concentrated forces. The acceptable accuracy of mechanical calculation is demonstrated when using the model of wire in the form of a parabola adopted in the design practice, provided that the components of concentrated forces are correctly determined. The equation of state is recorded, taking into account the weight and wind loads on the wire, as well as load coefficients in two planes, depending on the number of barrage balls. The performed calculations demonstrate an acceptable accuracy of the determination of the stress at various loadings of the span. For more accurate calculation of mechanical stresses and sag arrows, a vector-parametric method for calculating the flexible wires of overhead lines is suggested, where the calculated model of wires in the form of a flexible elastic thread is put taking into account of the spatial arrangement of all structural elements. The results of mechanical calculation according to the program that had been developed and to the existing methods for a different number of aerial barrier balls moved along the span are presented.

1. Boshnyakovich A. D. (1975) Calculation of the Wires of Substations and Large Transitions of Transmission Lines. Leningrad, Energia Publ. 248 (in Russian).

2. Idel’chik V. I. (1989) Electrical Systems and Networks. Moscow, Energoatomizdat Publ. 592 (in Russian).

3. Bladyko Y. V. (2018) Mechanical Calculation of Flexible Wires when the Concentrated Forces are Replaced by a Distributed Load. Energetika. Izvestiya Vysshikh Uchebnykh Zavedenii i Energeticheskikh Ob’edenenii SNG = Energetika. Proceedings of the CIS Higher Educational Institutions and Power Engineering Associations, 61 (2), 97–107. https://doi.org/10.21122/1029-7448-2018-61-2-97-107 (in Russian).

4. Bladyko Y. V. (2018) Mechanical Calculation of Flexible Wires when a Concentrated Load is Being Replaced with a Distributed One Taking into Account the Structural Elements. Izvestiya Vysshikh Uchebnykh Zavedenii i Energeticheskikh Ob’edenenii SNG = Energetika. Proceedings of the CIS Higher Educational Institutions and Power Engineering Associations, 61 (3), 220–234. https://doi.org/10.21122/1029-7448-2018-61-3-220-234 (in Russian).

5. Strelyuk M. I., Sergey I. I., Bladyko Y. V. (1983) Numerical Method for Calculating the Statics of a Flexible Busbars of Open Distribution Devices in Various Modes of Climatic Influences. Energetika. Izvestiya Vysshikh Uchebnykh Zavedenii. = Energetika. Proceedings of the CIS Higher Educational Institutions, (8), 8–14 (in Russian).

6. Strelyuk M. I., Sergey I. I., Bladyko Y. V. (1988) Vector-Parametric Method of Mechanical Calculation of Flexible Current Wires of Electrical Installations of Power Systems. Mathematical Methods in the Electric Power Industry: Materials of the IInd International Symposium. Zakopane, 10–12 November 1988. Zakopane, (3–19), 173–181 (in Russian).

7. Sergey I. I., Bladyko Y. V., Panamarenka Y. G., Tsemekhman B. D., Tarasov V. E. (2012) Action Analysis for Ice, Wind and Electro Dynamic Loads in Spans with Arbitrary Wire Layout. Energetika. Izvestiya Vysshikh Uchebnykh Zavedenii i Energeticheskikh Ob’edenenii SNG = Energetika. Proceedings of the CIS Higher Educational Institutions and Power Engineering Associations, (1), 38–44 (in Russian).

8. Streliuk M. I., Sergey I. I., Bladyko Y. V. (1995) Computer Aided Program of Mechanical Calculation of Flexible Conductors for Substations and Overhead Lines Design. New Electrical and Electronic Technologies and their Industrial Implementation: Proc. Int. Conf, Lublin (Poland), 7–8 Sept. Lublin: Lublin Technical University, 15–19.

9. Strelyuk M. I., Sergei I. I., Bladyko Y. V. (1995) Numerical Method of Mechanical Calculation of Flexible Current Conductors of Power Units of Power Systems. Energetika. Izvestiya Vysshikh Uchebnykh Zavedenii = Energetika. Proceedings of the CIS Higher Educational Institutions, (3–4), 21–29 (in Russian).

10. Sergei I. I., Ponomarenko E. G., Bladyko Yu. V., Klimkovich P. I (2015) Software Package for Mechanical and Electrodynamic Calculation of Flexible Current-Carrying Structures. Metodicheskie Voprosy Issledovaniya Nadezhnosti Bol'shikh Sistem Energetiki. Vyp. 66: Aktual'nye Problemy Nadezhnosti Sistem Energetiki: Materialy Mezhdunarodnogo Seminara imeni Yu. N. Rudenko [Methodical Problems of Research of Reliability of Big Systems of Power Engineering, Issue 66. Actual Problems of the Reliability of Energy Systems: Materials of the International Seminar. Yu. N. Rudenko]. Minsk, Belarusian National Technical University, 404–410 (in Russian).

11. Sergey I. I., Bladyko Y. V., Abramenko M. V. (2017) Mechanical Calculation of Flexible Wires with Aerial Warning Spheres. Nauka – Obrazovaniyu, Proizvodstvu, Ekonomike: Materialy 15-i Mezhdunar. Nauch.-Tekhn. Konf. T. 1 [Science for Education, Production, and Economics. Materials of the 15th International Scientific and Technical Conference. Vol. 1]. Minsk, Belarusian National Technical University, 23 (in Russian).