A Decentralized Multiloop Scheme for Robust Control of a Power Flow Controller With Two Shunt Modular Multilevel Converters

摘要

This paper investigates the robust multiloop control for power flow controller in power transmission grids. A hybrid power flow controller (HPFC) is proposed, which comprises two shunt modular-multilevel-converter (MMC) based voltage source converters and one series capacitor. A nonlinear multiloop controller is designed via control Lyapunov function to achieve fast tracking performance, and robustness against system uncertainties and disturbances. Stability of the closed-loop nonlinear HPFC system is proved using Lyapunov stability theorem. The proposed finite-time controller (FTC) is decentralized using adaptive observer to estimate the nonlocal system parameters, in case of communication failure. Simulation and experimental studies are used to validate the proposed FTC with detailed model of MMCs, and the interarea oscillation damping with Phasor model of HPFC. Comparisons of the proposed FTC and the conventional PI controller show that the FTC has fast control response, small transient overshoot, and improved robustness.