Overhead Lines

Sensa’s fiber optic temperature monitoring system has been used to monitor temperatures of overhead line conductors. If a sensing fiber can be integrated into an overhead line phase conductor, real time temperature monitoring is realized thus allowing the heating and cooling effects on the conductor to be analyzed as a result of circuit loading and environmental factors.
 
The effect of wind speed and direction, as well as rain and solar radiation can be seen as direct changes in the conductor temperature along the route.

The data can also be used to support online rating calculations and identification of crucial spans where safety clearances might be breached.
 
Currently over head cable lengths of up to 60 km can be monitored by utilizing two 30km systems form each end of the circuit.  Future systems are expected to provide longer ranges.

Overhead lines with optical ground wire (OPGW) can also be monitored, to provide the ambient temperature along the overhead line route which can provide important information needed for rating and sag calculations. Ambient temperature along the overhead line can vary due to shelter from wind and shade from local features such as trees and hills. Prediction of line icing can also be achieved from a knowledge of the route temperatures.