Centralized Control of Distributed Generation Sources in AC Microgrids for Reactive Power Provision

The objective of this paper is to develop a control strategy for Distributed Generation (DG) sources connected to an AC microgrid. The microgrid is assumed to be connected to the main power system through a point of common coupling (PCC) and it is required to provide reactive power to the grid according to a set-point delivered by the Transmission System Operator (TSO). Hence, the objective of the developed centralized control is to set reactive power production of each DG sources in such a way that the total power injected at the grid remains equal to the required set-point. The proposed operation mode is very important since it facilitates the management of reactive production of DG sources on the wide grid basis. In other words, with the developed centralized control, the TSO can consider the whole microgrid as a single entity which is able to deliver the mandatory reactive power services allowing voltage stability control in power systems with a high penetration rate of distributed generation systems. Artificial Bee Colony (ABC) is used to elaborate reactive power reference of each DG source. The design and the performances of the developed centralized control are presented through this paper.