Nonintrusive overhead-line current detection using a vertical magnetic-field sensor array

Abstract

With the growing infrastructure for overhead lines, the demand for overhead-line condition-monitoring technologies has become increasingly urgent. Traditional current transformers used to measure three-phase currents are bulky and difficult to install, which further increases the cost of monitoring. In order to meet the current state assessment needs of transmission and distribution networks, this study uses a novel magnetic-field sensor array to realize nonintrusive overhead-line current detection. Based on the magnetic fields measured by magnetic-field sensors placed on the ground under the overhead line, the proposed algorithm can be used to calculate the three-phase current values. The proposed method does not require on-site calibration before the field measurements are conducted. With partially known overhead-line geometry specifications from utilities, the algorithm can optimize the overhead-line geometry and finally achieve accurate current detection. The simulation and experimental results verify that the proposed current-detection technique can accurately calculate the three-phase currents of the overhead line with only three three-axis magnetic-field sensors.