Estimation and Mitigation of Voltage Flicker Using Extended Complex Kalman Filter

This paper presents an efficient utilization of Kalman filter for estimating the disturbance signal of the voltage flicker. The proposed method is able to extract the instantaneous flicker disturbance using a single extended Kalman filter. In this paper, the disturbance signal is modeled in a complex form to facilitate the performance of the estimation and tacking for the Instantaneous Flicker Level (IFL) of the voltage flicker compared to the conventional models that require two versions of the Kalman filter to do the same extraction process. The estimated disturbance is employed for mitigating the cyclic voltage flicker using the Unified Power Quality Conditioner (UPQC), which restores the voltage level at the load terminal to its nominal accepted value. Simulation results using MATLAB/Simulink are provided to prove the validity of the proposed method.