Adaptive Power Feedforward Control of Grid-Forming VSC-HVDC for Frequency Support Enhancement

The virtual synchronous generator (VSG) control is a key grid-forming strategy in voltage source converter-based high voltage direct current transmission (VSC-HVDC) systems. However, there is an inherent conflict between the steady-state and dynamic performance of the virtual inertia and the damping parameter in VSG control. Most existing studies address this issue using frequency-domain compensation strategies, which rely heavily on the frequency regulation (FR) coefficient, limiting adaptability under complex working conditions. To reduce the reliance on the FR coefficient while retaining the ability to resolve control parameter conflicts, this paper proposes a power feedforward strategy based on the frequency-domain correction. First, the sensitivity of the existing strategy to the FR coefficient is analyzed. Then, a system frequency response model is developed, revealing a dual-path response characteristic consisting of a conventional long-delay path and a fast-response path. Utilizing the fast-response path, a power feed-forward strategy is designed to enhance frequency support capability and reduce the dependence on the FR coefficient. Finally, the proposed strategy is verified with simulations in MATLAB/Simulink.