Abstract : Photovoltaic (PV) solar energy is considered one of the highest renewable energy resources worldwide. Hence, PV system installation capacity is increasing, triggering new power quality problems in grid systems. Some examples of these problems include unbalanced voltages, fluctuating power levels and harmonic distortions. To mitigate these problems, a Distribution Flexible Alternating Current Transmission System (D-FACTS) is considered a viable solution that can be integrated into the distribution system. Moreover, to reduce the adverse impacts of PV integration on voltage regulation and harmonic distortion in electrical distribution systems, a Distribution Static Synchronous Compensation (DSTATCOM) is considered a solution. The thesis aims to mitigate power quality concerns related to PV integration by designing an advanced control system for the D-STATCOM. A simulation study is performed by modeling a power system model with an integrated PV system and D-STATCOM. Three control schemes, Proportional Integral (PI), Artificial Neural Network (ANN), and Adaptive Neuro-fuzzy Inference System (ANFIS), were applied within the internal control of D-STATCOM to enhance the power quality of the power system. Two different inverter configurations were adapted, a Sinusoidal Pulse Width Modulation (SPWM) and a Hysteresis Current Controller (HCC). Results are obtained as voltage profiles for all the considered control schemes with different inverter types under different contingency conditions. The performance is also evaluated by control characteristics evaluation for different controllers. Different scenarios were analyzed through graphical methods, Total Harmonic Distortion (THD), and Root Mean Squared Error (RMSE).