Reliability Analysis of Addis Ababa Light Rail Transit Traction Power Supply System

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Addis Ababa University


High reliability of railway power systems is one of the essential criteria to ensure quality and cost-effectiveness of railway services. Reliability analysis of traction power supply system (TPSS) is essential for identifying reliability critical components, which causes most of the disruptions, and providing necessary mitigation techniques. The service quality of Addis Ababa Light Rail Transit Service (AALRTS) has repeatedly been affected by the TPSS component failures that results in part routing, passenger clearing and more severely operation interruption. Thus, analysis and improvement of AALRT TPSS reliability is definitely an important and urgent issue. The main objective of this thesis is conducting the qualitative and quantitative reliability analysis of AALRT TPSS. Fault mode and effect analysis (FMEA) and fault tree analysis (FTA) accompanied by exponential distribution are selected to model the system and evaluate the reliability indices. The reliability evaluation indexes of AALRT TPSS are then calculated via MATLAB code by applying the exponential distribution equations. Accordingly, the reliability analysis showed that AALRT TPSS had poor reliability in the mission time of about three years. Hence, reliability mitigation techniques, such as fostering well trained personnel, applying various maintenance approaches, procuring and localizing high quality components, and introducing standby power systems, to improve the poor reliable traction power supply system operation, are suggested.



traction power supply, failure mode and effect analysis, fault tree analysis, exponential distribution, reliability analysis