This thesis present assessment of power quality of mekenisa substation 15KV feeder line which is located in Addis Ababa around lebu area. The assessment investigates the major electrical phenomena that disturb the power quality of feeder line-I. Those are the voltage sag, active power loss, reactive power loss, power factor and short/long interruption or ultimately complete outage of EPDS of power quality phenomena listed by the IEEE Standard 1159-1995 are assessed in this thesis. The necessary data are collected from the record interruption data at mekenisa substation and Addis Ababa region distribution emergency .The collected data are analyzed and the results are then compared with the IEEE standards to identify the type and level of the power quality problems. The modeled systems with and without static var compensator and recloser have been simulated using ETAP software to verify the improvements achieved in terms of power quality. The simulation result of voltage sag from 0.897pu to 0.98pu, power factor from 0.80 to 0.91, active power loss from 2.222MW to 1.678MW, reactive power loss from 1.22Mvar to 0.999Mvar and interruption from 463.3f/yr to 343.6f/yr. Hence, it is recommended the SVC and Recloser that the distribution network feeder line-I of Mekenisa substation customer to be installed in for the betterment and continuity of supply of the Ethiopian Electric Utility (EEU) services.