Enhancing the wind farm-based power system stability with coordinated tuned supplementary controller

The effects of the wind farm on the low-frequency oscillations of interconnected power systems have become a significant problem with extensive apprehension. These low-frequency oscillations are undesirable, malfunctioning and resulting in system instability. This paper studies the influence of various factors on stability, with varying wind penetration, a different combination of controllers, wind farm (WF) integration and replacement of synchronous generators. To enhance the stability, it is integrated and analyzed significance of the controller by considering the power oscillation damper for WF, power system stabilizer for synchronous generators and supplementary controller of flexible AC transmission system devices for the system. The rotor speed deviation is considered an objective function with various constraints for particle swarm optimization to provide the controller's optimized value and combination. The small-signal and transient stability problems were examined using eigenvalue analysis and time-domain simulation. The state-space formulation is derived for eigenvalue analysis for small signal stability assessment with system variables. The nonlinear dynamic simulation results for transient stability analysis are obtained using a three-phase fault. From stability analysis, coordinated controllers intensify the capability of SGs and WF under extreme disturbances. The effectiveness and robustness of the proposed approaches have been verified using the IEEE-9 bus test system. All the analysis and simulations are performed using real time digital simulation (RTDS) with interfacing between MATLAB/SIMULINK-2018a software and RT-LAB (an OP5600 RT-LAB).