Fault Levels in Transmission Substations Level 110 KV

Abstract

The analysis of power systems under fault condition represents one of the most important and complex task in Power Engineering. The studies and detection of these faults is necessary to ensure that the reliability and stability of the power system do not suffer a decrement as a result of a critical event such as fault. This dissertation analyzed the behavior of a system under fault conditions for different fault scenarios . A 110-kV level of Khartoum National Electrical Grid is implemented as case study. A short circuit analysis is applied to the system in order to assess and evaluate the short circuit currents. Short circuit currents are required in order to provide information for the selection of circuit breakers and switch of adequate short circuit capacity to maintain continuity of supply. Calculations of short-circuit currents were carried out according to IEC 60909 standard using Electromagnetic Transient Analysis Program (ETAP). All the data used for analysis is real time and collected from Khartoum electric transmission grid. Results of the short-circuit currents were obtained. Maximum fault levels were found in “EID BABIKER” substation, the fault current in 110 KV bus bar was 15.527 KA for three phase faults and 18.771 KA for line to ground faults. The minimum fault levels were found in “ELSHAGARA” substation; the fault current in 110 KV bus bar was 7.395 KA for three phase faults and 9.212KA for line to ground faults.