A need for communication-free adaptive protection strategy in microgrids: An integrated survey on impacts, challenges, possible solutions and open research in microgrid protection

The microgrid protection strategy encounters major obstacles because of the varying fault current capacities that result from the diverse modes of microgrid operations. The challenges are heightened with the incorporation of large-scale systems. Protecting microgrids has become a complex task due to various factors. This includes 1) increased fault current contribution during grid-connected operation, 2) insufficient current contribution during islanded operation, 3) sympathetic tripping, 4) blinding, and 5) loss of mains. These factors can render existing protection devices ineffective in clearing faults. To tackle these challenges, researchers are currently focused on the implementation of various adaptive protection schemes that leverage communication technology. In this article both communication and non-communication-based protection schemes of microgrids are systematically reviewed while discussing the pros and cons of these works in literature. The proposed work also addresses the possible 1) impacts, 2) challenges, 3) prospects, and 4) avenues for research in microgrid protection strategy. It also provides a detailed review of 1) conventional methods, 2) intelligent methods, and 3) adaptive protection methods for microgrid protection. Finally, the article concludes by suggesting the need for communication-free adaptive protection methods to ensure reliable and efficient operation of microgrid. The survey compiles a comprehensive list of publications to date in the open literature to represent a complete visual of various developments in this area.