Computation of power line structure surge impedances using the electromagnetic field method

On Tower Impedances for Transient Analysis

“…If the response to a unit step function, that is, the surge impedance is needed, it can be determined from the harmonic impedance [9]. If we write (6) then, the response to a unit step function (surge impedance) is [23] (7)…”

“…If the tower is represented as an ideal transmission line, the following formula [19] may be used for the characteristic impedance: (9) where and are the height and the radius of the tower, respectively.…”

“…In general, approaches to the problem may be categorized as: 1) Theoretical a) in time domain [4]- [6]; b) in frequency domain [7]- [9]. Based on: i) circuit and transmission-line theory [7], [10], [13], [15]; ii) waveguide theory [11]; iii) electromagnetic-field theory [5], [6], [8], [9].…”

“…Based on: i) circuit and transmission-line theory [7], [10], [13], [15]; ii) waveguide theory [11]; iii) electromagnetic-field theory [5], [6], [8], [9]. 2) Experimental a) on scaled models [12]- [14], [16]; b) on actual towers [14].…”

“…• line integral of electric field from the ground surface to the tower top [5]; • difference of potentials between the top and the bottom [9]; • measured along a given path from the top of the tower to a "distant" point at the ground surface [18]. The aim of this paper is to explore possibilities for a systematized approach to the analysis and uniquely defined quantities that characterize the transient response of towers.…”