Transient-based fault identication algorithm using parametric models for meshed HVDC grids

Abstract : This paper addresses the problem of fault identication in meshed HVDC grids once an abnormal behavior has been detected. A parametric single-ended fault identication algorithm is proposed. The method is able to determine whether the line monitored by a relay is faulty or not using a very short observation window. When a fault is suspected, the proposed algorithm estimates the fault distance and impedance using a parametric model describing the voltage and current evolution just after the fault occurrence. This model combines physical and behavioral parts to represent the fault propagation and to account for ground eects and various losses. The identication of the faulty line is then based on the size of the condence region of the obtained estimate. The performance of the algorithm for a three-node meshed grid is studied using ElectroMagnetic Transient (EMT) simulations. On the considered grid model, the current and voltage need to be observed during less than 0.2ms to get a suciently accurate estimate of the fault characteristics and identify consistently the faulty line.