FAA Lightning Protection Study: Lightning Induced Transients on Buried Shielded Cables: Numerical Analysis and Results.
Abstract
This report is primarily concerned with analysis of induced transient current and voltage pulses on buried shielded transmission lines, due to earth conduction effects of nearby lightning discharges. A numerical method is presented in this report to determine the amount of coupling between a lightning discharge to ground and an earth-return transmission line. The transmission line is assumed to be a long straight horizontal coaxial cable with an inner shield and an outer armor, terminated on both ends with typical communication equipment load impedances. The general case is considered here, in which the outermost conductor is not necessarily in perfect contact with the conducting earth but has a contact impedence with the earth, as in cables with an outer dielectric covering for corrosion or water protection. Indirect strikes to the cable via conductive coupling mechanisms through the earth are considered. Several average lightning channel conditions and several representative buried cable geometries are examined. The results are conveniently displayed via numerous graphs of the time histories and frequency spectra of the resulting transient current and voltage surges. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1977
- Accession Number
- ADA041319
Entities
People
- Chin-lin Chen
- John D. Nordgard
Organizations
- Rome Laboratory