An improved current control method of shunt active power filter based on state-space variables under asymmetrical and non-sinusoidal conditions

A control method of a shunt active power filter (SAPF) based on state-space is proposed in this paper. The SAPF is a three-phase inverter employed in four-wire grid. This paper presents switching functions extracted by state-space equations based on the averaged model of the SAPF. The proposed improved control method is appropriate under asymmetrically non-sinusoidal source and non-linear loads. The principles of the presented control method are examined for compensation of the reactive current and the harmonic current components. The proposed control method was simulated and the simulation results are provided to validate effectiveness of the proposed control method.