Adaptive Observer-Based Decentralized Scheme for Robust Nonlinear Power Flow Control Using HPFC

This paper investigates the robust decentralized nonlinear control of power flow in a power system using a new configuration of UPFC. This structure comprises two shunt converters and one series capacitor called as hybrid power flow controller (HPFC). A controller is designed via control Lyapunov function (CLF) and adaptive observer to surmount the problems of stability such as tracking desired references, robustness against uncertainties, rejecting the disturbances, and remote data estimation. The suggested control scheme is decentralized using adaptive observer to estimate the nonlocal varying parameters of the system. Stability of the closed loop system is proved mathematically using Lyapunov stability theorem. Performance of the proposed finitetime controller (FTC) is compared to another suggested exponentially convergent nonlinear controller (ECNC) and a conventional PI controller (PIC). Settling time of the state variables are diminished to a known little time by FTC in comparison with ECNC and PIC. Simulation results are given to validate the proposed controllers. Effects of model uncertainties such as parameter variation in the transmission line and the converters are studied and properly compensated by the proposed controllers. The impact of the control gain and the communication timedelay is shown using the Bode diagram analysis.