Parameter Tuning for LV Centralized and Distributed Voltage Control with High PV Production

This paper presents a centralized and a distributed voltage control strategies for a low voltage (LV) grid-connected microgrid with high penetration of photovoltaic (PV) systems. Both strategies are formulated as an optimal power flow (OPF) problem to minimize line losses and PV curtailments. Second-Order Conic Programming (SOCP) relaxation is formulated to "convexify" the OPF problem. Alternating direction method of multipliers (ADMM) is implemented for the distributed voltage control strategy. Moreover, weighting parameters for both controllers are introduced to have more flexibility in the controller operating mode. A sensitivity analysis on those weighting parameters allows to identify different operating regions, with priority given to loss reduction or curtailment minimization. In particular, we identify an infeasible region in cases where the considered SOCP relaxation is not valid, which highlights the need for fine parameter tuning of the controllers. The effectiveness of both voltage control strategies is validated in a LV radial microgrid.