An OPF–based Control Framework for Hybrid AC–MTDC Power Systems under Uncertainty

Abstract

The increasing integration of renewable energy, particularly offshore wind, introduces significant uncertainty into hybrid AC-HVDC systems due to forecast errors and power fluctuations. Conventional control strategies typically rely on fixed setpoints and neglect frequency deviations, which compromise system stability under rapid renewable variations. To address the challenge, this paper presents an optimal power flow (OPF)-based adaptive control framework for hybrid AC-MTDC systems with offshore wind integration. To enable the time-coupled OPF to produce anticipatory setpoints under wind variability, a Random Forest-based wind-speed forecast is integrated as an uncertainty-aware data source, providing the OPF with an informed view of the wind trajectory over the dispatch horizon. The resulting baseline setpoints are further adjusted in real time through an adaptive droop control scheme that simultaneously regulates DC voltage and AC frequency to enhance robustness across a broad class of disturbances. The effectiveness of the proposed framework is validated through hardware-in-the-loop simulations against three benchmark control modes, demonstrating consistent and balanced performance under wind-forecast uncertainty, AC-side load steps, and DC-side faults.