Averaged modeling and control of a three-phase series active power filter for voltage harmonic compensation

Power electronic loads inject voltage and current harmonics into the utility system. Active power filters, which are classified into shunt and series ones, have been developed in order to reduce these harmonics and to preserve an acceptable power quality at the mains. This paper presents a detailed study of a series active power filter. First, a new low-frequency mathematical model of the series active filter is established. Then, suitable multiple-loops PI controllers are designed on the basis of a small-signal frequency-domain representation of the converter and the use of the linear feedback control. Simulation results are finally shown and discussed in an attempt to validate the proposed mathematical model and the effectiveness of the control approach.