Adaptive Current Control for Shunt Active Power Filters

The paper presents a novel adaptive current control algorithm for three phase shunt active power filters. The observer based current controller guarantees asymptotic current tracking together with the simultaneous harmonic estimation and does not require high gain implementation and information about active resistance of the power filter inductance. As result the asymptotic compensation of the higher order harmonics and reactive component of the line grid current is achieved. A new observer for line voltage vector estimation is designed as well. The nonlinear observer provides fast adaptive estimation of the line voltage vector magnitude, angular frequency and position; reduce influence of line voltage distortions and measurement noise. Simulation and experimental results support the theoretical findings.