This paper focuses on power quality improvement in the distribution network using three phase shunt active power filter, where this later is connected to photovoltaic system. In the present work, a new control method has been presented to eliminate harmonic currents that is caused by nonlinear loads, and to compensate reactive power. This control method has a good accuracy and high efficiency, it bases on direct control of power, rather than conventional one (p-q theory) that relies on current harmonic identification and current control loops. This work proposes to combine a photovoltaic generator with the Dc side of the inverter via boost converter, hence this solution allows to inject the maximum of active power produced by photovoltaic system into the grid in addition to power quality enhancement. The proposed system has been verified by using MATLAB/Simulink and power system. Simulation results demonstrate the effectiveness of the system, where the THD of the source current is reduced to 2.2 %.

Keywords: Total harmonic distortion (THD), Direct power control, Shunt active power filter (SAPF), Photovoltaic generator, Power quality, Three phase inverter