HVDC Ground Fault Detection Method Based on the Shield Leakage Current Measurement for Long Cable Energization

摘要

HVDC transmission lines have been taking more and more importance among electric technologies. The importance of these lines mainly becomes from their asynchronous behavior and loss reductions. However, when a fault occurs, the grid stability can be affected and it could cause serious damages, especially in power electronics. For this reason, a new method to detect and differentiate ground faults from a normal energization during HVDC long cables connections with high inrush currents is here presented. The method considers the grounding of the extremes of the conductor's shield and the current measurement in these connections. If a fault exists in the cable, the current measured during the energization presents certain characteristics that can be used to distinguish a ground faulty energization from a normal one, and also to detect if the fault has occurred in the first half of the conductor or the last of it. To corroborate this method, numerous simulations have been carried out obtaining positive results.