Design and Hardware-in-the-Loop Experiment of Robust Fractional-Order Control for VSC-Based HVDC Transmission Systems

This paper presents a robust fractional-order proportional-integral (FO-PI) control scheme for a voltage-source converter (VSC)-based high-voltage-direct-current (HVD-C) transmission system. Based on the VSC model and fractional calculus theory, robust controllers are designed for the current, active power, reactive power, DC-link voltage loops of rectifier and inverter stations of VSC-HVDC. Experimental studies are undertaken on a hardware-in-the-loop (HIL) testing platform, and the experimental results reveal that the proposed FO-PI scheme has stronger robustness against parameter variations and external disturbances compared with conventional PI control scheme.