ARTIFICIAL NEURAL NETWORK BASED FAULT CURRENT MINIMIZATION IN DISTRIBUTION SYSTEM USING SUPERCONDUCTING FAULT CURRENT LIMITER. (CASE STUDY: HOSANNA SUBSTATION-DISTRIBUTION SYSTEM)

Abstract

High magnitude of short circuit fault current takes place in electric power distribution system. This unexpected high magnitude of short circuit fault current can cause the failure of Hossana substation switchgear equipment’s and even if due to this problem most of industries sharing power from Hossana substation and end users of Hossana substation cannot get power properly. So, fault current minimization in distribution system is a critical issue and to minimize the maximum short circuit fault current in distribution system, superconducting fault current limiter (SFCL) device is applicable in this thesis work. By installing superconducting fault current limiter (SFCL) device to the Hossana substation distribution feeder especially for Gimbichu feeder maximum short circuit fault current to be minimized for different types of short circuit faults like, Line to Ground (L-G) fault, Line to Line (L-L) fault, Double line to Ground (LL-G) fault and balanced three phase faults in distribution feeder. Under this thesis work the case study area focus on Hossana Substation - Distribution system feeders especially from the nine of feeders Gimbichu 15KV feeder. The reason why this feeder is selected is because of this feeder covers long distance approximately 150KM and high system interruption take place frequently. In this thesis work ANN controller is used to control the SFCL device and both ANN controller and SFCL device are modeled in MATLAB/Simulink. After developing SFCL in MATLAB and connect this device to the distribution feeder it is possible check the fault current magnitudes before and after installing SFCL device to the system. Before installing SFCL device to the system the magnitude of short circuit fault current is 20KA to 40KA for L-G fault, L-L fault, LL-G fault and balanced three phase faults in Gimbichu 15 KV feeder. But, after installing SFCL device to the case study area maximum short circuit fault current magnitude become minimized 140A up to 150A for all types of short circuit faults. Finally, the payback period is calculated after installing SFCL device to the 15KV Gimbichu feeder. Therefore, the calculated payback period is 1.14 years i.e., the year of back payment of this thesis work is 1 year,1 month and 21 days