In this paper, an active power line conditioner is conceived for harmonic and reactive power compensation in the single-phase to three-phase systems. The proposed system is divided into two classes: a) parallel active power filter at the single-phase grid side; and b) series active power filter at the three-phase load side. Compared with conventional five-leg single-phase to three-phase converter, the proposed system presents some advantages, like lower dc-link voltages and lower currents of the legs. A suitable control strategy is presented to regulate the load voltages, power factor of the grid close to one, and to minimize the voltage and current harmonics simultaneously. Simulated and experimental results are also presented.