METHOD AND APPARATUS FOR CONTROLLING OSCILLATIONS IN OVERHEAD TRANSMISSION LINES

摘要

A method and apparatus are provided for controlling swinging oscillations in a power line suspended between a first point and a second point. The oscillations are exacerbated by cooling effects when the velocity of the power line is at a maximum, causing a reduced length of the power line. The method comprises countering the cooling effects by relatively increasing the sag of the power line when the velocity is at the maximum. The apparatus includes means for countering the cooling effects by relatively increasing the sag of the power line when the velocity is at a maximum. Typically the velocity is at a maximum at the bottom of the swing. The sag may be adjusted by varying a current passing through the power line. Alternatively the sag may be adjusted by a mechanical device such as a pneumatic cylinder. The effects may also be countered by providing the power line with components having a negative coefficient of expansion to counter the effects of components, including the conductor, which have a positive coefficient of thermal expansion.