This work is devoted to the study of a photovoltaic system connected to the distribution grid. The objective is to propose a new corrector for the control of a three-phase inverter connected to the distribution grid in order to obtain an optimal injection of photovoltaic energy. The system consists of a photovoltaic generator, a DC/DC boost converter and a three-phase inverter connected to the grid via a transformer. In first, a system modeling has established the mathematical models of the different components of the conversion chain. A local method of research maximum power point of the incremental conductance type (InC) is then developed. Furthermore, a control in the synchronous reference frame dq by a modified PID controller is offered to regulate the currents injected by the three-phase inverter compared to conventional PI and PID controllers. Simulation results from the system under the Matlab/Simulink environment prove the efficiency of the MPPT control and show that the currents injected with the modified PID controller have a the best sinusoidal form with a harmonic distortion rate (TDH) of 2.39%.