Total Harmonic Distortion based Fault Detection in Islanded DC Microgrid

Abstract

DC microgrid is a part of the grid that includes distributed energy resources (DERs), storage equipment, and local loads. In a DC microgrid, protection, and fault analysis is a challenging task, with a rapid increase of current during a fault. Faults can occur in the grid-connected and island modes of the DC microgrid, while in island mode the fault current is reduced by 2–3 times. Thus, in this paper fault detection techniques are developed based on the total harmonic distortion of the voltage and current samples in island mode. For the validation of the proposed method, a pole-ground fault is performed in the six-lines of the DC microgrid, and then the total harmonic distortion for the individual line is assessed. This 6-bus DC microgrid is simulated in PSS®SINCAL software, and the total harmonic distortion is analyzed in Matlab/Simulink. Finally, the effectiveness of the system has been investigated under pole-ground fault in three different line-segments.