A nonlinear control strategy for three-phase seven-level Shunt Active Power Filter

A nonlinear control for a three-phase seven-level Neutral Point Clamped (NPC) inverter based Shunt Active Power Filter (SAPF) is proposed in this paper. The aim of this system is to mitigate the undesired reactive power and current harmonics created by nonlinear loads. The model of the Multilevel Shunt Active Power Filter (MSAPF) is divided into two subsystems including a Multi-Input Multi-Output (MIMO) subsystem defined by two current dynamics inner loop and a Single-Input Single-Output (SISO) subsystem defined by the DC capacitors voltage dynamic outer loop. The exact feedback linearization approach is applied to decouple the current dynamics. A proportional-integral controller is used to ensure DC bus voltage regulatio. An extensive simulation study using the “Power system Blockset” is tested to prove the viability of the nonlinear control.