Energization-status identification method of three-core cables based on annular magnetic sensor array

As three-core power cables are increasingly used in power distribution networks, the maintenance and overhaul of cable status have been paid more and more attention to. Because of the high risk of construction operations on energized cables, the energization-status identification of cables not only ensures the reliability of power supply in the power system, but also is a strong guarantee for the safety of repair crew. Recently, research has been carried out on energization-status identification of power cables, but the accuracy of identification results cannot be fully guaranteed. In this paper, we propose an energization-status identification method of three-core cables based on annular magnetic sensor array. According to the parameters of cable, an analytical model of surface magnetic field for three-core cable is constructed, which is used to determine the analytical function of inverse problem about the phase currents and magnetic field around the cable. Combined with the position of measurement points, the measured circumferential magnetic field amplitudes are interpolated. The inverse problem is transformed into a multi-objective optimization problem, and the IMODE algorithm is used to reconstruct the phase currents from the measured values to determine the energization-status of cable. In addition, the proposed method is still effective for the cables with three-core arbitrary distribution. Furthermore, an experiment for the energization-status identification of a three-core cable under low-current was carried out in the laboratory to verify the effectiveness of proposed method.