Adaptive Unscented Filtering Based Decoupled Wide-Area Damping Controller for Power Systems

This paper proposes a decoupled wide-area damping controller (WADC) leveraging adaptive unscented Kalman filter (UKF) approach. Initially a modal optimal output feedback (MOOF) technique is employed to extract decoupled single-mode feedback signals, which requires only simple gains to dampen IAOs. The decoupling facilitates the distribution of the control effort through the active power output of power injection sources (PISs). Extracted single-mode feedback signals are estimated in real-time using adaptive UKF and phasor measurement unit (PMU) data. The adaptive UKF dynamically updates the measurement and process noise covariance matrices, ensuring reliable estimation in uncertain scenarios. Finally, an interacting multiple model (IMM) approach is employed to adjust control strategies for operating point uncertainties due to low inertia intermittent renewable energy sources (RESs), changes in loading conditions, and time delay in the feedback signals, etc. The proposed methodology is validated on wind farm-integrated IEEE benchmark 4-machine 11-bus system and 16-machine 68-bus system. The decoupled WADC strategy enables simple and effective control modulation across different PISs, while the proposed adaptive UKF estimates single-mode feedback signals even in the presence of unknown covariance matrices.