Patent ID: 7504819

Claim:
An apparatus for determining the maximum conductor current loading of an overhead transmission line or conductor that comprises a spanning transmission line catenary spanning two transmission line towers, comprising: a sensing device adapted to be clamped to said overhead transmission line or conductor near one of the two said transmission line towers to acquire real-time information and including a transmitter for transmitting said acquired real-time information to a remote information processing center, said acquired real-time information including at least parameters of an angle of inclination from a horizontal line of said transmission line or conductor and a surface temperature of said transmission line or conductor; and means for performing a two step iterative process using said angle of inclination to determine the present sag of said transmission line or conductor; wherein said performing means performs a first step that operates in accordance with the algorithm wherein a value for said conductor's unit weight w and a value for horizontal tension in the conductor F h is assumed and a horizontal distance X 1 from the lowest point of said spanning transmission line catenary to said transmission line tower closest to said sensor is first assumed to be equal to a horizontal distance X 2 from said lowest point to the other said transmission line tower, wherein X 1 +X 2 =X 0 , the horizontal distance between said two transmission line towers, and Y 1 and Y 2 are sags relative to said respective transmission line towers determined in accordance with the following Equation (1): Sag = Y = F h w ⁡ [ Cosh ⁡ ( w F h ⁢ X ) - 1 ] ( 1 ) and X 1 is reduced by an incremental amount and X 2 is increased by said incremental amount if Y 2 −Y 1 <H, where H is the difference in height between said transmission line towers and said Equation (1) is repeated successively until Y 2 −Y 1 ≧H, at which time X 1 is increased by said incremental amount and X 2 is reduced by said incremental amount, said incremental amount is decreased by dividing it by a fixed factor, said decreased incremental amount is subtracted from X 1 and added to X 2 and said sags Y 1 and Y 2 are computed in accordance with Equation (1), said difference Y 2 −Y 1 is compared to said H, and said iterative process is repeated successively until Y 2 −Y 1 is substantially equal to said H, thereby determining the position of said lowest point of said catenary consistent with said assumed horizontal tension F h .