Combined Centralized and Local Voltage correction in Active Distribution Network

This paper presents a two-level real-time voltage control scheme to address the voltage violations in distribution grids hosting a significant number of Dispersed Generation Units (DGUs). The proposed scheme consists of a centralized and a local reactive power control. The local control provides fast response after a disturbance, reducing its impact and enhancing voltage quality. The centralized control relies on Model Predictive Control (MPC). It uses measurements collected throughout the network to bring the voltages inside desired limits. To do so, it adjusts in a coordinated way the reactive power set-points of the DGUs taking into account the local controls. The control method effectiveness has been evaluated on a 75-bus 11-kV test system hosting 22 DGUs.