Abstarct: In recent years with conventional energy depleting gradually, renewable energy sources is becoming more and more important. Meanwhile, the increasing use of nonlinear devices and unbalanced loads causes serious power quality problems in electrical power systems, such as the harmonic and unbalanced currents. Since grid connected inverters can be used as an active power filter, the technique that combines grid-connected renewable energy sources and active power filter (APF) is proposed. This system’s dual-purpose operation solves both the power generation need, and helps to improve the growing problem of harmonic pollution and reactive power problem of the distribution system. In this study after examining the structures of the four-wire inverter, three-legs four-wires inverter with split capacitors has been selected. the appropriate controller is proposed to achieve the desired control objectives. The simulation results of proposed method in MATLAB show that in addition to active power injection generated by renewable sources connected to the main grid, the harmonics of load current has significantly reduced. The simulation results show that the neutral current reduced significantly and the power factor improved. wavelet baxsed low pass filter has been used to improve the filter performance under transient conditions caused by load changes. The results illustrate that by using the controller baxsed on wavelet transform, the response time of filter improve significantly and filter delay under transient condition reduced about 60%.