What is Protective Relay

Electric power should deliver a predicable per condition for the technological, economic, and political development of any countries and it is vital for each individual. Power outage is series problem in Ethiopia at the hole of distribution network. This is due to frequent interruptions and much time service restoration. That is why most customers of Ethiopia have their day-to-day activities highly affected and they are strongly complaining to Ethiopia electric utility daily. But this power outage affected customer cost and the Ethiopian utility. In most developing countries including Ethiopia, distribution systems have received considerably less of the attention to reliability modeling and evaluation than have generating and transmitting systems. Life is directly or indirectly dependent on electric power so a utility should deliver reliable power every day for 24 hours and each year for 8,760 hours to satisfy human needs and to perform their works as much as possible with less economy.