  The number and intensity of forest fires in the United States have been
steadily increasing and causing massive economic and ecological damage.
Overhead transmission and distribution lines are typically disconnected
preemptively near fires, a practice that causes high social cost. Deployment of
Phasor Measurement Units (PMUs) and their ability for synchronized real-time
measurement of voltage and current inspire the here proposed method for the
just-in-time disconnection of overhead lines at the ignition or approach of
fires. PMUs can detect ambient temperature changes caused by fires through the
change of line resistance. An ambient temperature model at the vicinity of a
fire seat and the dynamic heat exchange model of the IEEE 738 dynamic line
rating standard for bare overhead conductors are used in MATLAB Simulink to
assess the performance of the proposed control method. Extensive testing shows
that, under various conditions, the proposed technique can detect a forest fire
approaching an overhead line, while avoiding, almost completely, any false
alarms.
