New control approach for four-wire active power filter based on the use of synchronous reference frame

In this paper, three control methods, all based on the instantaneous powers theory introduced by H. Akagi [H. Akagi, Y. Kanazawa, A. Nabae, Generalized theory of the instantaneous reactive power in three-phase circuits, in: Proceedings of International Power Electronics Conference, Tokyo, Japan (1983) 1375-1386.] are compared and advantages and drawbacks of each approach are discussed. Then, the improvements will be presented for these controls so as to obtain better results in case of unbalanced system. The simulation results will show the effectiveness of these improvements. Finally, in order to improve again the performances of APF, a new control is proposed. This approach is based on the use of synchronous reference frame and its effectiveness will be validated through numerical simulations.