Study and analysis of control techniques for power converters in a hybrid AC/DC microgrid with energy storage system and photovoltaic generating unit

Abstract

The present proposal aims at the study, modeling and analysis of control techniques for power converters in a hybrid AC/DC microgrid that includes a battery-based energy storage unit and a solar photovoltaic generating unit. Hybrid AC/DC microgrids have been the focus of research in the last decade due to the fact that they can connect distributed energy resources in AC and DC with AC and DC microgrids, respectively, which in turn are interconnected through an interlinking unit, thus cost of installation and power losses are reduced. Power converters are designed in a generic manner, i.e. independent of hardware implementation, so they can operate as storage, generating or demand units in both AC or DC microgrids. Besides that, approximate models and control techniques are analyzed for battery-based storage converter and photovoltaic-based generating converter, as well as control strategies for power and energy management. The studied control techniques and strategies are based on classical methods, thus the responses of these methods are compared with the intention of verifying the advantages and disadvantages of the methods when they are used in hybrid AC/DC microgrids. Operation of each power converter is verified through experimentation, and the complete operation of the hybrid AC/DC microgrid is validated through simulations.