A seamless control scheme for a microgrid with renewable energy sources

This paper offers a microgrid (MG) system equipped with a classical proportional-integral (PI) control operating in two conditions, i.e., grid-connected and islanding modes. The proposed microgrid mainly consists of hybrid photovoltaic/wind sources, a synchronous generator, a battery storage and a load. The microgrid is able to provide a power factor correction close to unity in the grid-connected mode. Moreover, it can regulate the MG voltage and frequency through the contribution of the photovoltaic and wind sources in the islanding mode. An islanding detection method is used as a trigger for transition between grid-connected and islanding control modes. The effectiveness of the proposed model is investigated via MATLAB simulation. The simulation results highlight the capability of the proposed technique in controlling the voltage and frequency as well as in providing a power factor of unity (PF = 1) regardless the load change.