Getachew, Biru (PhD)Asegid, Belay2019-01-022023-11-042019-01-022023-11-042016-06http://etd.aau.edu.et/handle/123456789/15479For more than a decade, the railway has experienced a renaissance in many countries after several years of decay. The main reasons for the renewed interest in the railway are environmental, economical, and safety related. This has quite naturally, in turn, increased the interest in railway associated research. Both passenger and freight transports on railway are increasing. In order to cope with this increase, large railway infrastructure investments are expected. An important part of this infrastructure is the railway power supply system – without it, only the weaker and less energy efficient steam and diesel locomotives could be used. This thesis work presents the design and simulation of traction power supply system for the case of Modjo~Hawassa railway line. For this purpose, all the necessary electrical parameters data are collected through literature survey and the traction power supply system major components such as traction substation transformer, autotransformer, the catenary system and the loads are designed. In connection with this, a model that represents the designed components of the power supply system using an existing blocks in the MATLAB/Simulink library were built and integrated into a system called a traction power supply system, which has a total length of 64 kilometer including 60 kilometer single track and 4 kilometer double track railway line and simulated using MATLAB/Simulink environment. Accordingly, the simulation result of the traction power supply system for the three cascaded train which is found at a distance of 64 kilometers from the traction substation reveals that a train voltage of 19.81 kV and current of 414.63 A, a rail voltage of 87.12 V and autotransformer voltage of 19.82 kV in worst case scenario. In addition, the maximum percentage voltage regulation is found to be 26.45 %. As the result, it was found that the voltages and the currents waveform are according to BS EN 50163:2004, EN 50388:2012 and BS EN 50122-1 (IEC 62128-1) standard limits. This shows the performance of designed traction power supply system is within the industry standard.en-USTraction power supply systemDesignModelMATLAB/SimulinkSimulationCurrentsVoltagesStandardsThesis