Design of fuzzy logic controllers for decentralized voltage regulation in grid connected photovoltaic systems

This paper outlines the potential role of Fuzzy Logic Control (FLC) for voltage-rise mitigation in power distribution networks in the presence of grid-connected photovoltaic (PV) systems. In particular, after analyzing the main performances of the traditional techniques currently adopted for voltage rise mitigation by reactive power compensation, a decentralized approach based on local fuzzy controllers is proposed to regulate the reactive power injected into the grid by the distributed PV systems. The proposed solution is based on a closed control loop, where the local voltage at the point of common coupling (PCC) is fed at input to the FLC to decide the amount of reactive power generated by the local PV systems. The results obtained on a realistic case study are presented and discussed in order to assess the benefits deriving by the application of the proposed approach.