Combining H∞ Control and Communication‐Free Power Allocation for Enhanced Stability in VSC‐MTDC Networks With Offshore Wind Farms

This research explores stability challenges in power systems from integrating offshore wind farms (OWFs) with voltage source converter (VSC)‐based multi‐terminal direct current (MTDC) networks. A novel two‐level integrated control (TLIC) framework is proposed to enhance frequency regulation at grid‐side VSC (GSVSC) stations. The first level features adaptive inertial control (AIC) and adaptive droop control (ADC). By dynamically adjusting AIC and ADC parameters, wind units (WUs) in maximum power point tracking (MPPT) mode effectively mitigate secondary frequency fall (SFF). WUs are clustered by rotor speeds, enabling staged frequency support for improved responsiveness. The second level uses a communication‐independent allocation (CIA) strategy, relying on local frequency measurements in the onshore power system (OPS) to balance power distribution among GSVSC stations. This bolsters OPS frequency stability and minimises SFF during MPPT operations. A robust H∞ controller, designed via loop‐shaping, is applied at the wind farm‐side VSC (WSVSC), employing multi‐criteria decision‐making (MCDM) for voltage optimisation. The MTDC DC voltage employs a Master‐Slave (MS) configuration to suppress variations under disturbances. MATLAB simulations across scenarios validate the strategy's robustness in damping oscillations from uncertainties.