Implementation of a control strategy for harmonic suppression and dynamic voltage compensation in series active power filter

This paper presents a control strategy of series APF for harmonic suppression and dynamic voltage compensation. The harmonic current through the primary winding of transformer and the voltage swell or sag of power supply voltage are extracted. After these two signals are controlled and combined as a reference signal, VSI connected in parallel with the secondary side of transformer would present a controllable voltage characteristic. And the control parameter of harmonic currents can make the transformer show a large controllable impedance to harmonics so as to isolate harmonics. Besides, VSI can compensate the system voltage deviation by detecting voltage drop. Finally, the simulation model was established to prove that the series APF based on the control strategy can isolate harmonics, and effectively compensate the voltage deviation.