An Improved Differential Current-Based Fault Detection Scheme for Microgrids

This paper presents a differential current phasor-based relaying scheme for AC microgrids. The differential current is computed from the current signals acquired from both ends of the distribution lines. The magnitude and the angle of the differential current is used to construct a magnitude-phase plane which is utilized for the detection of fault condition in the microgrid. The proposed differential protection technique is extensively tested for all kinds of balanced and unbalanced faults and fault inception at various locations of the lines. This algorithm is also examined for challenging high resistance fault cases. Further, the impact of intermittent penetration of distributed generators (DGs) on the protection methodology has also been examined. MATL.AB/Simulink platform is used to validate the proposed algorithm on a medium voltage AC microgrid.