Control Strategy for Multifunctional PV Converter

This paper proposes a multifunctional converter applied to distributed generation with an energy storage system. The main functionalities include the possibility to have programmable power dispatch to the utility grid and trade of energy between the Battery Energy System (BESS) and utility grid, accordingly to the specific interest of an Energy Management System (EMS). In order to allow these functionalities, modifications are proposed in the bidirectional buck-boost converter that is responsible for the BESS power processing. With that, it is also proposed the sharing of the DC bus voltage controller between the bidirectional DC-DC converter and the DC-AC converter. To validate the proposed system, real-time hardware-in-the-loop (HIL) simulations are presented. In the simulations, real data of solar irradiance is considered. Moreover, a model of a lithium- ion battery bank is also incorporated. The proposed system guarantees programmable dispatch with low power errors. In addition, the system is able to operate with and without BESS at the same time it ensures smooth transitions between the operation modes.