Recent control techniques and management of AC microgrids: A critical review on issues, strategies, and future trends

Distributed generation is considered as a key component of the emerging microgrid (MG) concept, enabling the integration of renewable sources in a distributed network. The MG has been accepted globally as a new approach that provides a flexible, reliable, sustainable, and economical solution for green and clean power generation. Microgrid is constituted by distributed energy resources (DERs) and is a combination of parallel connection equipped with suitable control and protection scheme for the operation in both islanded and utility grid-connected mode. Microgrid structure with various hierarchy control techniques is categorized into three layers such as primary control, secondary control, and tertiary control techniques. A comprehensive literature review of these control techniques in AC microgrid is presented. In addition, the technical challenges of existing MGs affect real-time applications around the globe. For the development and execution of various MG topologies, suitable power strategies are adopted to integrate distributed generation (IDG), energy storage system (ESS), and consumer loads for an improved energy management system (EMS). This paper presents a state-of-the-art review of recent control techniques of AC microgrids with DERs having various important aspects; hierarchical control techniques, management strategies, technical challenges, and their future trends in the system. Moreover, a comparative performance analysis of our proposed review with existing surveys of AC control techniques with their individual merits and demerits have been presented. Furthermore, this investigation of different power control techniques applied in MG is compared and classified in terms of various important features, highlighting potential advantages, and different applications.