An Innovative Fault Detection Approach for Zonal DC Microgrid System

This article introduces an innovative protection technique designed for a zonal DC microgrid to identify low and high resistance faults. The suggested protection scheme accurately identifies such faults by estimating the Cumulative Sum of teager energy in the superimposed current signal and analyzing the sign of the superimposed power available at the cable ends. Under normal conditions, external faults and high resistance faults, the Cumulative Sum of teager energy in the superimposed current wave remains below a predetermined threshold. However, in the event of low resistance internal faults, the Cumulative Sum of teager energy in the superimposed current wave exceeds the threshold value. To identify high resistance fault, the sign of superimposed power is compared at cable both ends. To assess its performance, the suggested protection method is rigorously tested against various internal faults, external faults, and high resistance faults in a simulated 750 V zonal DC microgrid model using MATLAB/SIMULINK. The simulation outcomes prove that the suggested protection method demonstrates resilience and effectiveness across all fault scenarios.