A Hierarchy Control Strategy and Management of Interconnected Distributed Generation Systems

In areas where electricity demand is rapidly increasing or already exceeding available supply, distributed energy resources (DERs) can be a quick solution to satisfy needs. As a rapid increase in electricity demand is observed globally, distributed generation (DG) based on renewable energy sources (RESs) is becoming important. These RESs are environment friendly supply sources that assist the main power plants typically located far away from areas with high electrical energy demand. In order to improve power supply systems reliability and quality, DG systems should be connected to each other and also connected to the conventional power systems to back each other up. This paper presents a general control strategy and management of interconnected distributed generation systems. The state variables such as frequency and voltage of the interconnected power systems will be controlled through the interface units (inverters) between DERs and the grids. The obtained results show that the proposed strategy is modular, flexible and reliable. The control strategy can simply be integrated into interconnected grids to form large smart grids.