Lightning Back Flashover Analysis of 132 kV Overhead Transmission Lines

  • Nabeel Humood Al Afifi

Student thesis: Master's Thesis

Abstract

Transmission systems are vital for residential and commercial clients, and mostly for industrial plants. Hence, reliability and availability of transmission lines are essential requirements. Even with the best design, manufacturing, engineering, selection, installation, and maintenance of transmission line components such as tower structures and insulators, complete availability still cannot be guaranteed due to the uncontrolled factor; the lightning. The availability is drastically reduced for single circuit transmission lines due to lack of redundancy. Lightning is considered to be the most disturbing class of all faults to transmission lines. It is therefore the scope of this thesis to explain and discuss the various aspects and factors affecting the behavior of transmission line towers, insulators, and line inductors when lightning strikes the tower structures or shield wires. One of ADCO's 132 kV transmission lines was selected for the purpose of simulation. Excessive energy is usually carried by the lightning currents that, after striking a tower or shield wire, need to have a low impedance path to the ground to be discharged. Lightning currents encounter several surge impedances during its journey to ground. These are, as per the order of travel segments, the surge impedances of the lightning path in the atmosphere, the shield wire, tower structures, and grounding structure under these towers. Hence, surge impedance is a critical factor in the phenomena of lightning wave propagation. The surge impedances of shield wires, towers, and grounding underneath towers are dependent on their material, structure, and arrangement.
Date of AwardSep 2013
Original languageAmerican English
SupervisorRedy Mardiana (Supervisor)

Keywords

  • Applied sciences, Alternating-polyphase-computer programs., Electric currents, Electric power distribution -high tension--computer programs, Overhead transmission lines, Electrical engineering, 0544:Electrical engineering

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