Model Predictive Control Method for VSC Converters in Multi-Terminal HVDC Transmission System with Offshore Wind Farms

With the continuous expansion of offshore wind farms, the voltage source converter based multi-terminal HVDC (VSC-MTDC) has received considerable attentions for offshore wind farms integration due to its flexibility in control and other advantages. However, due to a number of topologies of VSC-MTDC system and various control modes of VSC converter, the existing control strategies for MTDC systems with large amount of offshore wind farms focus on the better steady state indicators, which may neglect the optimal control of transient process. Therefore, in this paper, model predictive control (MPC) method is proposed for the active power control of VSC converters on the offshore wind farm side in MTDC system. First, the state space models for the VSC stations with offshore wind farms are developed. Then, by considering the transient process and analyzing the objectives of optimization, the MPC method is applied for state predicting and online optimization of the transition process. Finally, simulation results will be provided to prove the advantages and effectiveness of the proposed method.