Review of the Current Capacity Reduction Rate

Abstract

In this paper, we evaluate the reduction rate of the current capacity that is used to design the power transmission capacity of the electric power cable constructed in the air and the culvert. In the first, when the distance from the cable, which is adjacent is changed, the behavior in the heat influence receive from the adjacent one is calculated. In the calculation, the radiation and the natural convection generated from the rise of the cable surface temperature are considered. Next, an experiment is done to verify the calculation result with 66kV XLPE Toripurex-type electric power cables, which are constructed in the tent. When the current was made constant in the point where the conductor temperature entered the state of equilibrium at 90° or 105°, the conductor temperature, the surface temperature, and the temperature of the cable of surrounding air are measured with the automatic record meter and evaluated. Finally, it is shown that the reduction rate is nearly 1.00 by the calculation and the experiment.