This paper introduces a comparative analysis between three different controllers on a 9.2 kW grid-connected system. This system is designed using the Simulink to test the proposed controllers under the practical operating conditions for a household-sized photovoltaic system. The current study compares between three controllers (PI, Fuzzy and Fuzzy-PI) and attempts to choose the optimal controller for improving the performance of the grid-connected inverter control. The study concludes that the Fuzzy-PI controller outperforms the other ones regarding the performance parameters in terms of total harmonic distortion, dynamic response, settling time, and overshoot. This is attributed to the fact that the Fuzzy-PI changes the values of the gains (KI and KP) based on the variations in temperature and irradiance.