Downstream ground defect directional detection method for three phase medium voltage electrical distribution network, involves signaling downstream ground defect based on signals representing phase currents

摘要

The method involves signaling a downstream ground defect based on signals representing phase currents. The defect is signaled by calculating a residual current and comparing shape of the current with that of the phase currents and determining whether the defect is situated downstream or not of a defect detection apparatus. The defect is determined to be situated downstream, if the shape of the residual current resembles that of one of the phase currents. The defect is determined as not situated downstream, if the residual current`s shape is not same as that of the phase current. An independent claim is also included for a downstream directional detection device implementing of a downstream ground defect directional detection method.