Development of Low-Wind-Pressure Conductors for Compact Overhead Transmission Line

In order to reduce the wind pressure on overhead power transmission lines, extensive wind tunnel experiments were conducted on conventional conductors. As a result, it seemed feasible to reduce the wind pressure on the conductor by altering the surface roughness of the conductor. Based on this result, another series of extensive wind tunnel experiments was conducted on conductor models with different surface roughness. This resulted in an equation giving the optimum surface shape to minimize the surface drag coefficient for actual conductors. Following this, low- wind-pressure prototype conductors with gauges of 810 mm2 and 410 mm2 were fabricated for field experiments under natural wind conditions. The test results revealed that compared to conventional conductors, the wind pressure could be reduced to about 80% for the 810 mm2 gauge conductor, and to about 95% for the 410 mm2 gauge conductor.