The recent development of protection coordination schemes based on inverse of AC microgrid: A review

Integration of distributed generation systems and diversity of microgrid operations led to a change in the structure of the power system. Due to this conversion, new challenges have arisen when employing traditional overcurrent protection schemes. As a consequence, non-classical protection schemes have attracted significant attention in the last few years. Engineers and scholars have proposed different non-standard methods to increase the power protection system and ensure the highly selectivity performance. Although the non-standard characteristics and their requirements, in general, have been outlined and analyzed in the available literature, protection coordination based on voltage current-time inverse, as a branch of non-standard optimization methods, has not yet been thoroughly discussed, compared, or debated in detail. To close this gap, this review introduces a broad overview of recent research and developments of the voltage current-time inverse based protection coordination. Focuses on assessing the potential advantages and disadvantages of related studies and provide a classification and analysis of these studies. The future trends and some recommendations have been included in this review for improving fault detection sensitivity and coordination reliability. The traditional OCR faced many protection performance challenges and miss-coordination events due to the high DG penetration. Therefore, the main goal of using the voltage value that the relay discovers is to offer reliable relay coordination under high DG penetration. As the DG contributes to the fault current, the varying fault current indirectly impacts the system bus voltages.image