The main purpose of this paper is to enhance the operation of renewable wind energy conversion (WEC) systems connected to power systems. To achieve this, we consider a linear quadratic Gaussian (LQG) control approach for regulating the eects of a WEC system with doubly fed induction generator (DFIG) on the synchronous generator (SG) rotor speed of the interconnected power system. First, we present the mathematical formulation of the interconnected power system comprises a single synchronous generator and a wind turbine with DFIG connected to an infinite bus bar system through a transmission line. We consider that the system is operated under various loading conditions and parameters variation. Second, a frequency damping oscillation observer is designed via Kalman filtering together with an optimal linear quadratic regulator to mitigate the impacts of the WEC system on the SG rotor speed. The performance of the developed interconnected power system is simulated using a MATLAB/SIMULINK environment to verify the eectiveness of the developed controller. In comparison with previously reported results, the proposed approach can stabilize the interconnected power system within 1.28 s compared to 1.3 s without the DFIG.