Uncertainty assessment and validation of current remote measurement on high voltage overhead conductors

Abstract

This paper analyzes the uncertainty in the measurement of 50-Hz current on high voltage overhead conductors by means of low-cost magnetic field sensors (inductive coils) located at the electric clearance from the conductors. It is assumed that no external magnetic field sources exist in the vicinity. Expanded uncertainty associated with the measurement of current under a single-phase system is evaluated. The results are validated in a lab setup. A single sensor is considered first, followed by the case of 3 sensors. In this last case, due to the redundancy the least squares method is applied to reduce the uncertainty of the measurement.