Selecting a Grounding Scheme for Screens of Power Cable Lines

The choice of a grounding scheme for the screens of power cable lines is a complex engineering and economic task that affects the efficiency, safety and cost-effectiveness of the operation of electrical networks. Existing approaches are often based on individual technical or economic criteria without taking them into account comprehensively. The purpose of this work is to develop a method for selecting the optimal grounding scheme for screens based on the criterion of minimum reduced costs, taking into account technical limitations on induced voltage and line capacity. The paper examines three basic grounding schemes (one-sided, two-sided, transposition), for which capital costs, annual operating costs, induced currents and voltage on the shields, and long-term permissible cable load currents were calculated. The maximum length of a cable line with one-sided grounding is determined based on the induced voltage condition. The areas of applicability of various schemes are indicated: one-sided grounding is applicable for short lines (up to 0.5–1.5 km depending on the cross-sectional area of the conductors); two-sided grounding is optimal for lines with a small current load; transposition of screens is recommended for long lines with a relatively high current load. It has been established that the transition from double-sided grounding to single-sided grounding or transposition for 110 kV cables increases the capacity of the cable line by 1–26 % depending on the cross-sectional area of the core and screen. The development of software to automate the process of selecting the optimal grounding scheme for screens seems relevant. The practical application of the developed methodology allows optimizing technical solutions in the design of cable lines, reducing capital and operating costs of electrical networks.

1. Czapp S., Dobrzynski K. (2020) Safety Issues Referred to Induced Sheath Voltages in HighVoltage Power Cables–Case Study. Applied Sciences, 10 (19), 6706. https://doi.org/10.3390/app10196706.

2. Antonov A., Gusev O., Gusev Yu. Monakov Yu., Oknin E., Cho G. Ch. (2016) Methods of Grounding Cable Screens. Elektroenergiya. Peredacha i Raspredelenie = Electric Power. Transmission and distribution, (5), 86–91 (in Russian).

3. Zhao T. (2023) Sheath Bonding Equipment for AC Transmission Cable Systems. Accessories for HV and EHV Extruded Cables. Vol. 2: Land and Submarine AC/DC Applications. Cham: Springer International Publishing, 487–571. https://doi.org/10.1007/978-3-030-80406-0_8.

4. IEEE Std 575-2014. IEEE Guide for Bonding Shields and Sheaths of Single-Conductor Power Cables Rated 5 kV through 500 kV. IEEE. https://doi.org/10.1109/IEEESTD.2014.6905681.

5. Dmitriev M. (2013) Selection and Implementation of Grounding Schemes for Shields of Single-Phase Cables 6-500 kV. Elektroenergiya. Peredacha i Raspredelenie = Electric Power. Transmission and distribution, (6), 90–97 (in Russian).

6. Bure I. G., Khevsuriani I. M., Bystrov A. V. (2016) Influence of the Shield Grounding System on the Selection of the Cross-Section of a Cable Line with Cross-Linked Polyethylene Insulation. Elektrotekhnika [Electrical Engineering], (11), 72–78.

7. Bystrov A. V., Khevsuriani I. M. (2014) Selection of a Shield Grounding System When Calculating the Cross-Section of 6-500 kV Cables. Promyshlennaya Energetika = Industrial Power Engineering, (7), 19–23 (in Russian).

8. Gouda O. E., Farag A. A. (2011) Factors Affecting the Sheath Losses in Single-Core Underground Power Cables with Two-Points Bonding Method. International Journal of Electrical and Computer Engineering (IJECE), 2 (1). https://doi.org/10.11591/ijece.v2i1.115.

9. Vysotski M. E. (2024) The Choice of a Construction Arrangement for Cable Lines with a Voltage of 10 kV According to the Criterion of the Minimum Expected Cost. Energetika. Izvestiya Vysshikh Uchebnykh Zavedenii i Energeticheskikh Ob’edinenii SNG = Energetika. Proceedings of CIS Higher Education Institutions and Power Engineering Associations, 67 (6), 488–500. https://doi.org/10.21122/1029-7448-2024-67-6-488-500 (in Russian).

10. IEC 60287-1-1:2023. Electric Cables – Calculation of the Current Rating. Part 1–1: Current Rating Equations (100 % Load Factor) and Calculation of Losses General. Available at: https://standards.iteh.ai/catalog/standards/iec/164f72dc-b67a-496b-af43-97e28a944a7b/iec-60287-1-1-2023.

11. Bronguleeva M. N., Gorodetsky S. S. (1963) High Voltage Cable Lines. Leningrad–Moscow, Gosenergoizdat Publ. 512 (in Russian).

12. Podgaysky S. I. (2022) Power Electric Cables with Cross-Linked Polyethylene Insulation

13. [Dissertation]. Minsk, Belarusian National Technical University. 154 (in Russian).

14. Dmitriev M. V. (2021) High Voltage Cable Lines. Saint Petersburg, Polytekh-Press Publ. 688 (in Russian).

15. IEC 60287-2-1:2023. Calculation of the Current Rating. Part 2–1: Thermal Resistance – Calculation of Thermal Resistance. Available at: https://standards.iteh.ai/catalog/standards/iec/9a2a6795-afb1-4194-97ae-9eef8d36e808/iec-60287-2-1-2023.

16. Gerasimenko A. A., Fedin V. T. (2023) Electrical Systems and Networks. Rostov-on-Don, Fenix Publ. 473 (in Russian).

17. IEC 60287-3-2:2012. Electric Cables – Calculation of the Current Rating. Part 3–2: Section on Operating Conditions – Economic Optimization of Power Cable Size. Available at: https://standards.iteh.ai/catalog/standards/iec/22c648b0-31da-4b8b-a73c-90355e4d7914/iec-60287-3-2-2012.