A dynamic overvoltage limiting technique for low-voltage microgrids

Low-voltage grids are characterized by mainly resistive interconnection impedances, which cause grid voltage profiles to be influenced by active power flows, and, in particular, to be susceptible to overvoltage conditions at active nodes during periods of peak production. This paper describes an overvoltage control technique for low-voltage microgrids that aims to regulate the power injection from distributed renewable resources in the case of an overvoltage condition. The effect of its application is a bounded voltage profile along the distribution grid and a limited impact on the total produced energy. The devised control technique is currently being integrated into a master/slave laboratory-scale microgrid architecture, aiming at achieving both the participation of the distributed energy resources to the global energy needs of the microgrid and the fulfilling of local voltage constraints. Based on that set-up, the experimental verification of the proposed technique performance in a significant application case is provided.