Which category of lightning stroke presents the greatest hazard?
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Answer: A. Direct stroke on line conductor
Explanation
A direct lightning stroke on a line conductor injects massive surge currents directly. Direct injection bypasses all transmission tower shielding and protective ground wires. The full magnitude of the lightning current enters the power system unimpeded. Lightning bolts carry tens to hundreds of kiloamperes of electrical surge energy. Overhead transmission lines utilize grounded shield wires at the very top of towers. Surge arresters attempt to divert high-voltage transients safely away from equipment.
Direct line strikes frequently cause severe insulator flashovers and power transformer damage. Transmission engineers install overhead shield wires to intercept direct lightning strikes. Power systems require robust insulation coordination to withstand atmospheric lightning surges. Indirect strokes induce lower voltages on conductors through electromagnetic field coupling. Direct strokes on tower tops are largely intercepted by overhead ground wire protection. Direct strokes on ground wires safely divert surge energy down tower structures to earth.
- Subject
- Engineering
- Category
- Electrical Engineering
- Topic
- —
- Difficulty
- medium
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