Morphological Fault Detector for Adaptive Overcurrent Protection in Distribution Networks With Increasing Photovoltaic Penetration

In this paper, a versatile and robust algorithm for overcurrent protection that is adaptive to the feeder PV penetration level as well as changing load condition in the distribution feeder is proposed. The algorithm has built-in dc-offset suppression capability as well as recursive least square error filter for current phasor estimation to provide input to the overcurrent fault detector. The proposed multistage morphological fault detector analyzes sudden change in fault current magnitude and its structure makes it convenient to update the fault threshold dynamically by measuring the current magnitude at regular interval, thus making the algorithm versatile and adaptive. The performance of the proposed algorithm is investigated by simulating different fault distances and fault types for increasing penetration levels of PVs on a simple radial distribution feeder .