Abstract: This thesis designs a Fuzzy- based Integral Terminal Sliding Mode (FITSMC) control scheme for the MPPT and VSI of a PV array connected the grid. The proposed approach aims at ensuring that the output voltage is in track with the reference voltage generated by the perturb and observe algorithm. This latter ensures maximum power production for the PV system. The proposed FITSMC eliminates the voltage drag and keeps the output voltage of the MPPT control in track with the reference voltage in a relatively brief time. Its implementation to the VSI control ensures the mitigation of deep voltage sags that arise due to high fluctuations in the load. The performance of the proposed approach is assessed using the SPR-305E-WHT-D PV array structure and further compared to that of a standard SMC. Based on the obtained results, we can assess that the proposed FITSMC ensures finite time convergence of the error to zero and proper mitigation of disturbances and grid faults.