Multilevel converter control approach of active power filter for harmonics elimination in electric grids

This paper presents a Direct Lyapunov based control technique for active power filtering in electric grids. The proposed technique through the interfacing system is designed with the goal to compensate the harmonic current components and reactive power provoked by the nonlinear grid-connected loads. In the method, based on multilevel converter topologies, active power in fundamental frequency is injected from the main grid, which results in unity PF (power factor) between grid currents and load voltages. The performance of the proposed control technique in a SAPF (Shunt Active Power Filter) model is validated in both dynamic and steady-state operating conditions. The simulation results show that the proposed scheme can effectively compensate the system background harmonics and improve the performance of the line current harmonics. The main benefit of this approach is that it prevents current overshoot as the proposed model connects to the grid.