AC Microgrid Protection Schemes: A Comprehensive Review

The power grid infrastructure has evolved from a centralized to a distributed model utilizing renewable energy sources in the last few years. This trend is likely to continue, given the increasing demand for environmentally conscious energy solutions. Different types of microgrids include sustainable, non-sustainable, and distributed energy sources. As such, microgrids (MGs) are becoming increasingly popular in providing reliable and sustainable energy at a local level. Microgrids can be operated grid-connected and islanded to address the significant increase in electricity demand, storage, and transmission issues. The penetration of renewable energy sources has increased the importance of power electronics in microgrids. The benefits of microgrids are many, but their challenges are also many, especially when it comes to power distribution. This article examines AC microgrid penetration into the distribution network as part of a comprehensive review of protection systems. This review allows us to understand how microgrids will interact with and potentially improve the protection systems found in the distribution network. As a result of the expansion of a microgrid, changes in the distribution network’s direction impact coordination and protection. The literature proposes a variety of solutions for power system protection. In conventional protection systems, relays are timed to transmit backup and primary information at different times. Several protection schemes have been proposed to improve the protection system when microgrids are present. DC/AC systems, communications infrastructures, rotating synchronous machines, and inverter-based distributed generation (IBDG) can all be classified as MGs. An overview of the standards is provided to help developers connect DGs to public distribution networks. Furthermore, a detailed explanation of the requirements is included to ensure successful integration. The overview and description of the standards and conditions should be carefully examined to ensure successful integration. Finally, conventional power systems are discussed with a view to future protection schemes.