Control strategies and configurations of hybrid distributed generation systems

Nowadays the use of distributed generating systems, which use a renewable energy source, has experienced a fast development. Moreover their intrinsic intermittent nature can be overcome using hybrid systems which combine more energy sources. This paper discusses the main topologies which can be adopted for a general hybrid generation system and it focuses on a particular hybrid system which combines two different energy sources, evidencing high level and local level power flow control strategies in both stand-alone and grid connected operation. A full experience in the realization of a hybrid plant which uses an internal combustion engine with cogeneration functionalities and solar source, installed in Delebio, Italy is then presented. System design aspects, with particular attention to the possible topologies and power flow control strategies, are analyzed. After the analysis of the design aspects, experimental results of the real plant are reported.