An Algorithm for the Efficient Management of the Power Converters Connected to the DC Bus of a Hybrid Microgrid Operating in Grid-connection Mode

Abstract

In this paper a centralized control strategy for the efficient power management of the power converters conforming a hybrid distributed generation microgrid is explained. The microgrid is based on a DC and an AC bus. The study is focused on the converters connected to the DC bus. The proposed power management algorithm is implemented in a microgrid central processor. This algorithm is based on assigning several operation functions to each of the generators, loads and energy storage systems in the microgrid. A communication system is used to assign the operation functions to each of the microgrid elements. The power flows between the DC and AC buses are studied in several operation scenarios, in which the proposed control can be verified. Experimental and simulation results demonstrate that the algorithm allows to control the power dispatch inside the microgrid properly, by performing the following tasks: (1) the communications among power converters, the grid operator and intelligent loads, (2) the connection and disconnection of loads, (3) the control of the power exchange between the distributed generators and the energy storage system, (4) the compliance of the power dispatch limit set by the grid operator, (5) the synchronization with the grid and (6) the control of the voltage at the DC bus.