Backstepping-Direct Power Control of Three-level Four-Leg Shunt Active Power Filter

Abstract

In this paper, a direct power control associated backstepping control for three-phase three-level four-leg shunt active power filter (SAPF) has been proposed. The SAPF guarantees full compensation for reactive power, harmonic neutral current, harmonic currents, and unbalanced nonlinear load currents. The multiple-loop control scheme consists, first, of inner backstepping regulators that ensures the active and reactive powers controls, and second, an outer backstepping controller to ensure the DC voltage regulation. These backstepping controllers are synthesized using a new model of four-leg SAPF, which based on active and reactive powers derivatives. The DC capacitor voltage control for the three-level four-leg SAPF is performed using three-dimensional space vector modulation (3DSVM). Finally, the proposed control method has been verified and compared with traditional PI controllers through extensive simulations using MATLAB/Simulink.