New distributed architecture and control strategies for DC and AC microgrids

This thesis develops power sharing and control scheme for DC and AC microgrid. The use of microgrid concept to organize renewable and distributed power generation is increasing. Microgrid concept offers an advantage of scalable, flexible, and renewable energy based power system that can act independently or in conjunction with the utility grid. With increasing number of the renewable energy installations, microgrids will find increasing application in both the low and the medium voltage networks around the world. Novel microgrid architecture and related control aspects are explored in this work. Among them three topics are: proportional power sharing based on the downstream current, microgrid stability study with three most common loads types, and novel power line communication method used for the microgrid operational under special conditions. Additional focus is applied on the real life implementation of converter control and topology for the battery based storage system and distributed generators. All the proposed methods are confirmed by the extensive simulations, along with that the most crucial ones have being tested on the experimental AC microgrid. The results show that the proposed power sharing and control architecture allows to greatly simplify the existing control methods, and achieve the desired, stable power sharing between the participants.