NOVEL FORMULATION OF COMPLEX KALMAN FILTER FOR TRACKING AND MITIGATING THE UNBALANCED VOLTAGE SAGS/SWELLS

Nabeel Alawadhi,∗ Amr Elnady,∗ and Saif Sinan∗

Keywords

Power quality, voltage sag/swell, complex Kalman filter, symmetrical components, UPQC, negative sequence

Abstract

This article explores an innovative formulation of symmetrical components of grid voltage. Many techniques have been used to extract the symmetrical components, but they have drawbacks of inaccuracy and delay in response time or high computation cost. The proposed formulation models unbalanced three-phase voltages using innovative exponential state-space equations. Then, the complex Kalman filter is employed to accurately estimate and seamlessly track the positive, the negative and the zero-sequence components with minimum transient time and without a need of any further transformation. The proposed formulation enhances the efficiency of the extraction process by reducing its computation cost as it is able to replace the conventional extraction steps by a single processing step without losing its accuracy. The extracted symmetrical components are then used to operate the unified power quality conditioner, which restores the voltage at the load terminal to its nominal value. Simulation results of the suggested method along with other extraction techniques are presented to confirm its validity and its advantageous performance compared to other techniques.

Important Links:



Go Back