Distributed Optimal Voltage Control in Large-Scale PV Power Stations Considering Q-V Droop Characteristics

For large-scale photovoltaic (PV) power stations, the voltage drop in the internal collecting power lines is significant. The fluctuation in PV power outputs might lead to system-wide voltage violations, necessitating voltage optimal control. Considering that traditional centralized control faces significant communication burdens, a distributed optimal voltage control strategy is proposed. In terms of constructing the optimization model, the influences of Q-V droop characteristics from PV generation units are considered. Accordingly, the segmented linearized Q-V droop curve is formulated as a set of mixed integer linear constraints, embedded into the optimal voltage control model. The alternating direction multiplier method (ADMM) is employed to provide a distributed-solving approach. Particularly, asynchronous updating is taken to enhance the ADMM performances when encountering communication delays. Numerical analysis in case studies is conducted to validate the applicability of the proposed control strategy.