Analysis of the ionized field around HVDC transmission lines

(1994) Analysis of the ionized field around HVDC transmission lines. PhD thesis, King Fahd University of Petroleum and Minerals.


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In this dissertation, novel iterative finite-element based algorithms are proposed for the analysis of ionized field around monopolar and bipolar high voltage direct current (HVDC) transmission lines. One of the problems associated with HVDC transmission is the corona on the transmission line conductors. The proposed algorithms are aimed to waive Deutsch's assumption, wherein, the space-charges are assumed to affect only the magnitude but not the direction of the electric field. Moreover, ion diffusion has been considered in the analysis of monopolar ionized fields, and for the first time, in bipolar ionized fields. For bipolar fields, the effect of ion penetration and unequal corona onset and ion mobility values is also studied. The artificial boundary imposed around the transmission line to define the boundaries of the finite-element grid extend over distances that reach 3.5-5.5 times the transmission line height above the ground plane. In this dissertation, a technique is proposed to simulate this artificial boundary at infinity. Unlike all previous attempts reported in the literature, the proposed algorithms implement directly the electric field at the coronating conductor(s) surface as a boundary condition in the finite-element formulation. The proposed algorithms are tested through their application to different laboratory and full-scale transmission line configurations with smooth and rough conductor surfaces. The V-I characteristics, the current density as well as the electric field profiles at the ground plane are found to be in better agreement with the measured values than the previous attempts reported in the literature. Laboratory models of monopolar and bipolar transmission lines were built to check the accuracy of the proposed algorithms. The proposed algorithms are characterized by their quick convergence and simplicity in programming.

Item Type: Thesis (PhD)
Subjects: Electrical
Department: College of Engineering and Physics > Electrical Engineering
Committee Advisor: Abdel-Salam, Mazen
Committee Members: Al-Shehri, Abdallah M. and Attili, Basem Saleem and Zedan, Fareed M. and Soliman, F. and Mufti, A.
Depositing User: Mr. Admin Admin
Date Deposited: 22 Jun 2008 13:53
Last Modified: 01 Nov 2019 13:53