Abstract—This paper presents Unified Power Flow Controller (UPFC) with a new control strategy to improve the transmission capacity in power system network. With the growing demand of electricity, it is not possible to erect new lines to face the situation. Therefore UPFC is optimally utilizes to enhance the existing transmission network. A detail explanation of the controllers for both shunt and series converters of UPFC and DC link capacitor rating are presented in this study. To justify the performance of the UPFC model, 230kV transmission system in Upper Myanmar National Grid is considered as case study. The proposed control system performance is checked by applying different faults across a transmission line to which UPFC is connected. This is necessary because of the chance for occurance of fault is larger for this case study network. And, loading condition is changed to study the control system response. The simulation results show the effectiveness and suitable performance of the control strategy at improving transmission capacity. Transmission network model and all simulations have been done using MATLAB/Simulink software.