Distribution Of Conductive Path In Pre-stranded Wire During Lightning Strike
When lightning strikes a transmission line, the transient high current generates a massive thermal shock. armor rods transmission line is tightly wound around the surface of the conductor, and its spiral metal structure establishes a multi-point contact model. This physical contact reduces contact resistance, allowing the lightning current to rapidly diffuse from the main conductor to the helical wire.
armour rod can shunt the lightning current. The shunt ratio depends on the cross-sectional area and conductivity of the wire. When a lightning surge occurs, armour rod in transmission line participates in conduction as a parallel branch. During grounding, energy is evenly distributed to each wire. This energy distribution slows down heat accumulation in the main conductor.
Thermodynamic Performance under Lightning Current
Large currents passing through conductors generate Joule heating, and the resulting temperature rise can cause the conductor strands to melt. armor rods conductor addresses the thermal effect through the following methods:
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Physical Capacitance: Increasing the total conductive cross-sectional area at the point of lightning strike on the transmission line.
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Impedance Regulation: Utilizing low impedance characteristics to reduce the rate of local temperature rise.
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Heat Dissipation: The helical void structure accelerates heat exchange with the air.
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Mechanical support: Maintains the physical strength of the heated conductor and mitigates thermal damage.
The pre-stranded wire is typically made of aluminum alloy or aluminum-clad steel, whose electrochemical properties are highly compatible with the conductor. Under lightning current surges, the clamping force between the metal layers maintains the continuity of the electrical connection. A shunt protection mechanism reduces the current density of individual conductors. This redistribution of the current path protects the core load-bearing structure.
