Fast goertzel algorithm and RLS-Adaptive filter based reference current extraction for grid-connected system

Abstract

In this paper, a smart hybrid Fast Goertzel Algorithm and RLS-Adaptive Filter based control scheme for harmonic elimination, load balancing is presented. The control algorithm is designed for shunt active power filter (SAPF) connected in parallel with grid under distorted load conditions and non-linear load. The function of the fast Goertzel algorithm is to extract the fundamental frequency component with its magnitude and phase from the load currents. This extracted fundamental frequency component is used for estimating the reference currents based on the Recursive Least Squares (RLS) adaptive filter approach. This hybrid FG-RLS (Fast Goertzel-Recursive Least Square) control algorithm retains its behaviour even under load unbalancing and sudden load shutdown. Such improvement helps the adaptive filter for better convergence rate with less computation burden. The performance of the proposed FG-RLS scheme is simulated on three-phase applications to demonstrate its capability for extracting the fundamental component and further estimating reference currents.