An active filter for unbalanced three-phase system using synchronous detection method

This paper presents an active filter using the synchronous detection method. The equal current synchronous detection method is applied to calculate the reactive and harmonic current compensation components for triggering an active power filter in an unbalanced three-phase power system. The simulation and experimental results show that active filter operation using the synchronous detection method is effective to eliminate line current harmonics and compensate the reactive current component. The merits of the proposed method are its capability to operate under an unbalanced three-phase system by perphase calculation, to avoid conversion error by force waveform calculation, to balance the unbalanced load and to accomplish good performance by very simple implementation