Adaptive backstepping control of three-phase Three-level neutral point clamped shunt active power filter with LCL output filter

The increasing use of nonlinear loads entails serious electrical energy quality problems in power grids. In this regards, the Three-level shunt active power filter (SAPF) is proposed. The considered SAPF is constituted by an AC/DC Three-level NPC inverter. This latter is connected to the point of common coupling (PCC) through a high order filter instead of conventional filter L. Indeed, a new model for the 3-Level NPC SAPF is developed, this model accounts for the coupling filter LCL. Based on, a non-linear control method is proposed to meet the control objectives: i) Compensation of harmonic and reactive currents referred as power quality improvement. ii) Regulation and balancing DC bus voltage. Moreover, the controller is made adaptive for compensating the switching loss power uncertainty. The proposed adaptive control laws are formally analyzed using tools from the Lyapunov stability and the averaging theory. The performances of the controller are illustrated through several simulations.