Novel Differential Protection Strategy for Zonal DC Microgrid

Fault detection in zonal dc microgrids involves several challenges, such as rapid fault identification, sensitivity to low and high-resistance faults, and selectivity issues. These challenges emphasize the importance of employing intelligent and specialized fault detection algorithms. Therefore, this article describes a unit protection strategy for identifying high impedance and simultaneous faults in zonal dc microgrid systems. The suggested approach estimates the superimposed impedances utilizing the voltage and current data presented at the line segment’s ends. By utilizing the sign of the superimposed impedance and the difference in the superimposed impedance obtained from both ends of a line segment, the fault in the zonal dc microgrid is identified. The suggested technique feasibility is evaluated by simulating an eight-bus zonal dc microgrid with MATLAB SIMULINK. To evaluate its effectiveness, numerous fault and nonfault conditions, as well as various types of distributed generation operations, are simulated. Furthermore, the suggested approach is tested on a lab-implemented dc microgrid hardware test bed and dSPACE-1104 controller. The results of simulation and hardware demonstrate that the suggested approach accurately identifies the fault in a zonal dc microgrid.