Control Techniques for Microgrids with Renewable Energy Sources - An Overview

Microgrids (MGs) are realised as a means of integrating renewable-based distributed energy resources (DERs); however, their seamless integration remains a challenge owing to their intermittent nature. Control techniques are aimed at efficiently interfacing these energy sources for optimal, reliable, and economic operation of a MG. Typical control topologies include centralised or decentralised systems where modern MG uses an amalgamation of both approaches. This is to minimise the problem of coordination among multiple autonomous controllers in fully decentralised systems and remove computationally complex controllers in fully centralised systems. Contemporary MG control, therefore, consists of three hierarchical layers; a) primary, b) secondary and c) tertiary. This paper presents an overview of this control configuration and analyses several control techniques as examples of basic MG control principles. The aim is to streamline these control methods, which are employed at each layer in a MG control for the benefit of future researchers.