A mathematical model simulating control strategy for three-phase grid-connected photovoltaic systems is presented in this research. This research proposes the perturbation and observation method of maximum power point tracking control for a photovoltaic array. The photovoltaic power converter includes a boost converter and a three-phase voltage source inverter. The boost converter applies the method of constant current control, and the three-phase voltage source inverter utilizes the current control method. The control mechanism maximizes a photovoltaic array power output and stabilizes the DC-link voltage of a three-phase voltage source inverter, then exports three-phase current to a Utility Power Grid. The results of mathematical model developed by this research are examined and validated. Finally, the effectiveness of control strategy related to three-phase grid-connected photovoltaic system is demonstrated by using MATLAB/Simulink.