a) A lightning strikes a 30-m unshielded over-head following parameters: Surge impedance of the tower 100 2 Surge impedance of lightning channel at tower top = 500 2 Tower-footing resistance = Tower height 30 m Cross-arm height = 27 m 10 2 %3D The lightning strike current is assumed to be a constant 30 kA for a duration of 20 us. The traveling wave propagation speed in the tower is 1.2 x 10 m/s. i) Determine the voltage reflection coefficients at tower top and tower foot. ii) Determine the time of travel from tower top to tower foot. iii) Determine the time of travel from cross arm to tower foot.

a) A lightning strikes a 30-m unshielded over-head following parameters: Surge impedance of the tower 100 2 Surge impedance of lightning channel at tower top = 500 2 Tower-footing resistance = Tower height 30 m Cross-arm height = 27 m 10 2 %3D The lightning strike current is assumed to be a constant 30 kA for a duration of 20 us. The traveling wave propagation speed in the tower is 1.2 x 10 m/s. i) Determine the voltage reflection coefficients at tower top and tower foot. ii) Determine the time of travel from tower top to tower foot. iii) Determine the time of travel from cross arm to tower foot.

Power System Analysis and Design (MindTap Course List)

6th Edition

ISBN:9781305632134

Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Publisher:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Chapter3: Power Transformers

Section: Chapter Questions

Problem 3.33MCQ: The direct electrical connection of the windings allows transient over voltages to pass through the...

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