Renewable energy resources such as Solar, wind and hydro are pollution free, easily erectable, and limitless so they represent reliable alternatives to conventional energy sources e.g. oil and natural gas. However, the efficiency and the performance of these systems are still under development. Among them, Photovoltaic systems are mostly used as they are light, clean and easily installable. This systems connection to the grid requires special conditions to obtain a high-quality electric power system. This paper presents interfacing of three-phase grid connected PV system. DC-DC boost converter with maximum power point tracking (MPPT) is used to extract the maximum power obtained from the sun and transfer it to the grid. In any PV based system, the inverter is a critical component responsible for the control of electricity flow between the dc source, and loads or grid so a voltage source inverter (VSI) is used to convert the dc power into AC power before injecting it into the grid. A comprehensive simulation and implementation of a three-phase grid-connected inverter are presented to validate the proposed controller for the grid-connected PV system.