Methodology for Lightning Protection Device Placement in Medium Voltage Overhead Lines with Covered Conductors
2018
Viesturs Zimackis

Defending
18.12.2018. 10:00, Rīgas Tehniskās universitāte, Enerģētikas un elektrotehnikas fakultāte, Āzenes ielā 12 k 1, 212. auditorijā

Supervisor
Sandra Vītoliņa

Reviewers
Imants Matīss, Vilnis Krēsliņš, Saulius Gudžius

The dissertation is devoted to the development of a methodology for the placement frequency of lightning protection devices in medium voltage overhead lines with covered conductors. Effectively positioned protective devices increase the reliability of the power supply and reduce the SAIDI and SAIFI values. Within the framework of the dissertation, a computer simulation model is developed for lightning discharge in medium voltage overhead lines with covered conductors. The compilation and analysis of lightning statistics in the territory of Latvia, as well as tables and curves for shielding factor of objects close to the power line have been developed. Developed a structure of the power line element critical flashover voltage values. Evaluated the power line depreciation impact on critical flashover value and developed critical flashover reduction factor curves for operating period of medium voltage overhead lines with covered conductors. The methodology for determining the frequency of lightning protection device placement is proposed, in which a new criterion, the flashover frequency ζ, has been introduced in addition to currently in practice used insulation flashovers from direct and indirect lightning stokes F. This value has been introduced to have a direct connection to the lifetime of the power line, expressed in years, and could be used in addition criteria that are the predicted effect of the depreciation on the flashover frequency of the medium voltage overhead lines with covered conductors and the analysis of alternatives. Within the framework of the dissertation, thresholds for this criterion have been verified using various possible scenarios. The methodology developed in the doctoral thesis consists of 7 calculation blocks that take into account: 1) regional lightning statistics; 2) parameters depending on the route of the power line; 3) determination of critical flashover voltage of the power line; 4) the choice of type of protection device; 5) insulation flashover; 6) power line depreciation impact forecast 7) analysis of alternatives. As a result of the proposed methodology, the user obtains the recommended frequency of placement of protective devices for the power line in question. The proposed methodology can be applied both at the project stage and in the existing medium voltage overhead line with covered conductors. The dissertation describes in detail an example that can be used as a guide to the application of the methodology. The dissertation is written in Latvian, it contains an introduction, 6 chapters, main results and conclusions, bibliography and 22 annexes. The total volume of dissertation is 135 pages, containing 64 figures, 32 tables and 23 annex pages. In the bibliography 130 sources of literature are given.


Keywords
Zibensizlāde, izolēto vadu līnijas, zibensaizsardzība

Zimackis, Viesturs. Methodology for Lightning Protection Device Placement in Medium Voltage Overhead Lines with Covered Conductors. PhD Thesis. Rīga: [RTU], 2018. 135 p.

Publication language
Latvian (lv)
The Scientific Library of the Riga Technical University.
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