A Novel Fractional-Order Damping Control Method for Enhancing Synchronization in Grid-Forming Converters

This paper proposes a novel fractional-order damping control methodology aimed at enhancing synchronization dynamics in grid-forming converters (GFMCs) within converter-dominated power systems. Conventional droop-based control strategies frequently exhibit limitations in accurately and promptly aligning the converter internal estimation frequency with that of the grid during transient disturbances, often resulting in sustained power oscillations and compromised system stability. To address this critical challenge, a fractional-order derivative-based feedforward control loop is introduced as an auxiliary mechanism to the traditional droop controller. The proposed solution leverages the inherent advantages of fractional calculus, namely, its ability to provide tunable dynamic behavior and superior noise attenuation, thereby improving the responsiveness of the internal frequency estimation process during non-steady-state conditions. Importantly, the design ensures that the steady-state performance of the system remains unaffected. The effectiveness of the proposed control strategy is validated through comprehensive time-domain simulations conducted on a representative multi-converter test network. The results demonstrate marked improvements in transient synchronization and damping performance, underscoring the potential of the proposed method as a robust and scalable solution for next-generation power systems characterized by high levels of renewable energy integration.