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

• Published in: IET generation, transmission & distribution transmission & distribution, 2023-04, Vol.17 (7), p.1601-1612
• Main Authors: Chen, Kun‐Long, Wang, Chia‐Lun, Chen, Rui‐Xiang
• Format: Article
• Language: English
• Subjects: current transformers; electric current measurement; harmonics; power overhead lines; power quality
• ISSN: 1751-8687; 1751-8695
• DOI: 10.1049/gtd2.12767

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. In the present study, the new vertical sensor array consists of three three‐axis MF sensors and is placed on the ground plane under the overhead line. According to the ground‐level magnetic fields measured by the sensor array and the partially known overhead‐line geometry information from utilities, the proposed algorithm can be used to accurately calculate the three‐phase currents. Because this new detection method does not require an on‐site calibration procedure, it becomes a more robust and simpler measurement solution.