A fuzzy logic- (FL-) based control technique for unified power flow controller (UPFC) to resolve the power quality issues in transmission network is presented in this paper. MATLAB/Simulink is used to design the FL-based controllers for shunt and series converters of UPFC, which is validated on 4-bus system. In addition, the performance of the suggested FL-based UPFC is compared with PI (proportional integral), HC (hysteresis controller), MPC (model predictive controller), and FLC (fuzzy logic controller), and the outcomes are compared in terms of settling time and steady-state error. The consequences characterize that the higher enactment of closed loop hybrid power flow controller (HPFC) 4-bus system with FLC UPFC controller’s (FL based) robustness is ensured from the simulation results as it has overcome the power quality issues like reactive power compensation, voltage sag mitigation, and THD reduction of transmission line current below 5% as per IEEE standard. Settling time of CL FBS is abridged from 0.87 to 0.62 sec, and steady-state error of voltage in CL FBS is abridged from 0.9 to 0.1 V using FLC.