Control and Management for Distributed Generation Inverters in a Microgrid

Abstract

ABSTRACT Microgrid paradigm is the most viable choice to interlink Distributed Energy Resources (DERs) with the main grid. In this thesis a brief overview of microgrid architecture, components, and classification is presented. Despite the great benefits of microgrids, their integration into the main power systems imposes major challenges regarding reliable operation and control. Reliable operation means to be able to manage the microgrid in its two modes of operation; grid-connected and islanded, as well as handling the transition between these two modes. Accordingly, hierarchical control structure has been applied to standardize and organize the operation and control functions of microgrids. In this thesis, decentralized primary and secondary control levels are investigated. Due to its flexibility, reliability, and free laying without the need of communication media, droop-based control method is used for the primary level to coordinate the operation of parallel Distributed Generation (DG) inverters. One DG unit is controlled in Voltage/Frequency (VF) mode to set the voltage and frequency of the microgrid. In contrast, the other DG units of the microgrid control their active and reactive power sharing,