A review of voltage and frequency control strategies for islanded microgrid

Nowadays, a large part of the world population lives without access to electricity, principally due to the location, too far from the main grid. Renewable power sources connected in an autonomous local grid are a real opportunity for these communities. These weak electrical grids composed by several microsources, energy storage systems and loads can be considered as islanded microgrids. As it is disconnected from the main grid, the frequency and the voltage of the microgrid have to be controlled. The frequency is generally controlled maintaining the power balance between generation and consumption, using energy storage or dump loads. The voltage regulation is approached in different ways, according with the controller design objectives and the nature of the loads connected to the grid. This paper proposes a review of several voltage and frequency control strategies in islanded microgrids.