Optimal Oscillation Damping Controller Design for Large-Scale Wind Integrated Power Grid

This article presents a reduced-order model-based optimal oscillation damping controller (OODC) design for doubly fed induction generator (DFIG) based wind turbines (WTs). The objective of OODC is to shift the critical interarea modes (IAMs) of the WT integrated power system to the desired location using optimal output feedback. Such a controller provides a supplementary control signal to the DFIG local controller to inject the modulated active and reactive power that provides damping support to the overall power system's local and IAMs of oscillation. In the design, first, a reduced-order model of the WT integrated power system that captures all the relevant system dynamics is designed. Then, a cost function-based optimization is formulated and solved to improve the damping of the critical modes. Simulation studies are conducted on a modified IEEE 68 bus system. The results of eigenvalue analysis show that the dominant and poorly damped IAMs are shifted toward the left half-plane thus enhancing the overall system stability margin. Also, nonlinear time-domain simulation is performed to show the effectiveness of the proposed OODC to effectively improve the damping of the IAMs of the system.