A novel digital protection scheme for microgrid

During islanded mode operation of a microgrid (MG), the rating of fault current is very low, which cannot be properly detected by existing protection systems. Even conventional protection schemes suffer from issues of variable current ratings when working with AUTO microgrids. Literature surveys indicate that AUTO microgrids lack proper protection strategies. Therefore, designing appropriate protection for islanded mode is crucial. In this paper, a digital protection scheme is designed based on the system voltage and current levels. This proposed relay is specifically designed for island mode microgrids. Case studies have been conducted in the MATLAB/Simulink environment to validate the designed protection model. The proposed protection system successfully detects various types of faults in island mode microgrids, including different fault locations and resistances. Additionally, this proposed relay efficiently detects fault zones, isolating only the faulty section from the microgrid system without disturbing other healthy sections. All solid faults and overvoltage issues are considered in analyzing the performance of the proposed protection model in the MATLAB/Simulink platform.