Abstarct: In this thesis, a controller for maximum power injection of a photovoltaic (PV) micro-inverter into the grid is presented. The micro-inverter topology is a single-stage boost inverter. Generating an incremental alternating output voltage in a single-stage power conversion, low total harmonic distortion (THD) and increasing the system efficiency are the major advantages of the boost inverter. Nevertheless, the boost inverter has a weak damping, undesirable dynamic behavior and extreme fluctuation response in open-loop mode. Hence, at first, we design an internal feedback controller using the state-feedback method in which in addition to adding virtual resistance to system, it controls and modifies the output voltage amplitude by getting proper feedback from converter voltage and as a result, it improves the stand-alone boost inverter system’s behavior for both resistive and inductive loads. Accordingly, for injecting the maximum power of a photovoltaic source to the grid through the boost inverter, after improving the oscillatory behavior and stabilizing the closed-loop grid-connected boost inverter system using the proposed method, we design the controller of power injection system baxsed on direct power control strategy. The micro-inverter maximum power injection control system consists of two successive stages. The first stage by using a maximum power point tracking (MPPT) algorithm, determines the maximum power reference required for the subsequent stage. Simulation results show the effective performance of proposed control strategy for maximum power injection of the considered photovoltaic micro-inverter into the grid.