Oscillation Frequency Component-Based Protection Scheme for DC Microgrid

A fast and accurate protection scheme for a dc microgrid enhances the service reliability and improves power quality. Thus, the identification of fault should be accurate and speedy. This article proposes a protection scheme for the dc microgrid based on the current components of the oscillation frequencies. Fault at any point in the dc microgrid results in oscillation of current, where oscillation frequency is a function of fault position, type of fault, etc. The proposed method modifies the existing differential protection scheme during high di/dt fault conditions. Furthermore, the maloperation of a relay due to communication delay in the protection method is averted by applying the proposed method. The real-time implementation of the proposed protection method is performed in the National Instruments laboratory virtual instrument engineering workbench (LabVIEW).