4) A lightning strikes a 30-m unshielded over-head transmission line following parameters: the Surge impedance of the tower 10 2 Surge impedance of lightning channel at tower top 500 2 Tower-footing resistance = 10 2 Tower height 30 m Cross-arm height= 27 m 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. iv) Draw the voltage lattice diagram with proper labels of the time. v) Ignoring the phase voltage, determine the insulator voltage after 2 µs.

4) A lightning strikes a 30-m unshielded over-head transmission line following parameters: the Surge impedance of the tower 10 2 Surge impedance of lightning channel at tower top 500 2 Tower-footing resistance = 10 2 Tower height 30 m Cross-arm height= 27 m 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. iv) Draw the voltage lattice diagram with proper labels of the time. v) Ignoring the phase voltage, determine the insulator voltage after 2 µs.

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

Chapter4: Transmission Line Parameters

Section: Chapter Questions

Problem 4.13P: A single-phase overhead transmission line consists of two solid aluminum conductors having a radius...

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