Microgrid Protection: A Technological, Challenge-Based, and Future-Oriented Review

Microgrids are gaining prominence within modern power systems, fueled by advancements in renewable energy-based distributed generation. However, dynamic network architectures and high bidirectional power flows render traditional protection schemes designed for passive radial distribution networks inadequate. Conventional overcurrent protection faces challenges due to fluctuating fault currents in both grid-connected and islanded modes, further complicated by the unpredictable output impedance of inverter-interfaced distributed generation units during faults. This article aims to comprehensively review current microgrid protection methods, analyzing their benefits and drawbacks while highlighting critical challenges and identifying areas for future research. A hybrid AC-DC microgrid simulation is conducted to validate fault current variations under different operating conditions. The study focuses on intelligent methods and apparatuses that enhance existing protection systems. Ultimately, this thorough investigation seeks to demonstrate the critical role of efficient microgrid protection in ensuring a reliable and sustainable future electricity supply.