Power cable line and overhead line phase comparison, has the following advantages:

(1) are less vulnerable to the effects of the pollution of the environment and, sending high reliability.

(2) to line insulation distance is small, covers an area of less, no interference waves.

(3) underground laying, don't take up little space, and is safe and reliable, and hardly exposure target. Therefore, in the town the densely populated areas, large factories, power stations, traffic congestion area, power grid cross area for cover an area of an area small, safety and reliability, reduce the power grid to transportation, urban construction, the influence of the more commonly used cable power supply; In the serious pollution area, in order to improve the reliability of the power transfer, use more cable; For large span, unfavorable erection overhead river-crossing, across the river line, or to avoid the overhead line to the ship navigation or radio interference, also use the cable; Some national defense and military engineering, in order to avoid exposure target and use cable, also some for building and beautiful need and use cable.