A novel fuzzy logic controller for active power filter

The conventional PI controller used in active power filters (APF) requires precise linear mathematical models, which are difficult to obtain and may not give satisfactory performance under parameter variations, load disturbances, etc. In order to address this shortcoming, the novel fuzzy logic controller which is composed of PI controller and fuzzy controller is proposed in this paper. The combined controller does not need an accurate mathematical model, can work with imprecise inputs, can handle non-linearity, and are more robust than conventional controllers. Finally, the MATLAB simulation results verify the good dynamic performance, transient stability and strong robustness of the combined controller. Further, compensation of reactive power and harmonics is found to be satisfactory, and the results reflect the effectiveness of the proposed APF to meet the IEEE-519 standard recommendations on harmonic levels.