Distribution Pole Monitoring Using Magnetic Field Characterization

This paper outlines methodologies for monitoring the supporting structures of distribution power lines by characterizing the rotating magnetic field established by the current carrying conductors. This is achievable since the resultant magnetic field is a function of phase currents and pole geometry. The resultant magnetic field vector (measured using 3-axis magnetic field sensors) rotates with time and forms an ellipse. The formation of an ellipse provides an expedient mechanism for data compression and comparison between pole geometries, which is achieved by wireless communication between two adjacent poles. A detected change in geometric state between poles can be sent to the substation at the end of the line. This data can be used to detect, locate, mitigate, prevent, or repair damage caused by a fallen power line. An experiment was performed to demonstrate the working principal of the single-sensor design methodology. A prototype instrument is under development to be field tested. A simulation was performed to show the effects that nearby metal structures have on the resultant magnetic field. The solution is realizable through the low-cost implementation of existing technologies and practices. A preliminary version of this paper was presented at the South African Universities Power Engineering Conference, SAUPEC 2018.