An Advanced Instantaneous Detection Method for Active Power Filter

Active power filter is an effective device to clear harmonics. Accurate detection of compensated components decides its compensation effect directly. This paper proposes an advanced instantaneous detection method for distorted three-phase system voltage by detecting fundamental positive sequence voltage and current respectively using d-q transformation. Thus fundamental positive-sequence active current and the compensated current components can be obtained exactly by phasor projection. The detection of voltage and current are simultaneous. Simulation results illustrate efficiency and accuracy of the improved method.