Abstract: A system for determining the current carrying capability of one or more overhead power transmission lines monitors one or more spans of each line on real-time basis and identifies the span having the lowest current carrying capacity which in turn establishes the maximum capacity of the entire line. The thermal state of each monitored line span is determined by measuring the conductor temperature, line current, solar radiation, ambient temperature, and in some cases wind speed and wind direction. These parameters are monitored by a sensor-transmitter unit that may be removably clamped on the line conductor which may range in size from one to several inches in diameter, and includes a radio transmitter for transmitting sensed data to a receiving substation.

Abstract: A system for monitoring at least one parameter of either an energized electrical power line conductor or at least one parameter adjacent to the power line conductor, on a real-time basis and transmitting signals indicative of the parameter to a remote location where the power line conductor itself is the transmission medium for transmitting the signals to the remote location. The transmitter is powered by either the electric or the electromagnetic field of the energized power line conductor and the transmitter receives induced energy from the conductor via a plurality of turns of wire wound around a mandrel, with the plurality of turns of wire formed as the secondary winding of a transformer, and with the mandrel being at the same electrical potential as the conductor.

Abstract: Apparatus for directly monitoring the conductor temperature or other parameters of an energized electric power line conductor, or of the medium adjacent the conductor, on a real time basis, and transmitting a signal indicative of that parameter to a remote location such as to facilitate data processing by computer. The apparatus is powered by the electric or electromagnetic field of the electric power line conductor.Various embodiments are described for sensing the temperature or other parameter being monitored. Furthermore two techniques are described for transmitting the signal to a remote location. The first such technique is the use of air as the transmission medium and the second technique uses the power line conductor itself as the transmission medium.