This thesis introduces a fuzzy-based Distributed Power Flow Controller (DPFC) as a solution for minimizing power losses and improving voltage profiles in transmission networks. The objective is to reduce power losses and improve the voltage profile to meet the standards set by the Institute of Electrical and Electronics Engineers (IEEE) which is 1 ±0.05pu. Targeting Ethiopia's North West 230 kV transmission system, where rapid load growth has led to voltage instability and power losses of up to 21.16 MW, the DPFC system is designed with both a series and a shunt controller, rated at 1 MVA and 100 MVA, respectively. The high rating of the shunt converter enables it to manage significant reactive power demands and maintain stable DC link voltage, which is critical for supporting the series controllers and ensuring system-wide voltage stability in this large-scale network. The selection of the DPFC is motivated by its ability to provide distributed, adaptive control over both real and reactive power flows across critical transmission points. Unlike conventional FACTS devices, the DPFC’s decentralized structure allows it to target specific areas in the network for improved efficiency, reducing transmission line losses and stabilizing voltages. This is further enhanced by a fuzzy logic-based control system, which offers intelligent and responsive decision-making without the need for exact system models. The fuzzy-based control algorithm considers multiple input variables, such as load demand, line currents, and voltage deviations, to determine the appropriate control actions for the DPFC. Fuzzy rules and membership functions are defined to map the inputs to the desired control outputs, ensuring an intelligent and adaptive control strategy. Simulations are conducted on Matlab/Simulink 2021a for NWR-230kV Transmission system to evaluate the performance of the proposed DPFC. The results demonstrate that the fuzzy-based DPFC effectively reduces power losses by 18.54%, 23% and 24.1% with average load, at 25% load increment and at 50% load increment respectively while improving the voltage profile to meet the IEEE standards. Keywords: Distribution Power Flow Controller (DPFC), fuzzy logic controller, power loss minimization, series controller, shunt controller, Voltage profile improvement