APPLICATION OF FUZZY LOGIC TECHNIQUE IN POWER LOSS REDUCTION IN THE NIGERIAN 330KV SYSTEM

To improve the overall efficiency of the power system, the performance of transmission system must be improved. Some of the vital ways of achieving this objective is by reducing power losses in the system and also improving voltage profile. An important method of controlling bus voltage is by shunt capacitor banks in the transmission substations. The capacitor absorbs reactive power flow in the system, thus improving power factor. When this is done, active power is also improved. In this work, a 10-bus transmission system is taken as model. Newton-Raphson’s power flow program is executed using MATLAB toolbox to obtain p. u nodal voltage ranging from 0.8890 to 1.0564, total real power line losses (0.09438 p.u), and total reactive power line losses (0.36970 p. u). By using power loss reduction, power loss index is evaluated and normalized in the range [0, 1]. These indices, together with the p. u nodal voltage magnitude,is fed as inputs to the Fuzzy Inference System to obtain Capacitor Suitability Index (CSI). The CSIs obtained, ranges from 0.244 to 0.897. The values ofthe CSIs determine nodes most suitable for capacitor installation. Experimentally, highest values of CSIs are chosen for capacitor installation. As a result, 3 buses (3, 8, and 10) with CSI values of 0.680, 0.750, and 0.897 respectively, are chosen. Capacitor sizes of 50MVar, 85MVar, and 60MVar (obtained from Index Based Method) are installed on the buses. Voltage profile improves by 3.74%, 3.27%, and 3.33% respectively, while total real power loss in the system reduces by 17.55% and total reactive power injection to the network reduces by 8.70% respectively. Overall, system stability and efficiency, hence, reliability, are improved by installation of capacitors at suitable locations in a transmission system.