Modeling and simulation of traction of power supply system case study: Modjo-Hawassa Railway Line in Ethiopia

Abstract

This paper presents the modeling and simulation of traction power supply system case study of Modjo-Hawassa railway line in Ethiopia. In this particular case a 2 × 25 kV autotransformer fed traction power supply system model is developed. The traction performance of a railway system depends on the variation of the voltage along the overhead lines. In this study, the voltage profile along the traction line has been evaluated. The system has been investigated by applying different headway distances on the trains and by increasing the number of train along the feeding section. The load flow simulation results using Matlab software show that the voltage profile in the feeding circuit differs substantially depending upon the train positions, train current, numbers of trains in the same power-feeding section and track impedance. The minimum calculated pantograph voltage and maximum percentage voltage regulation are 22.93 kV and 8.28% respectively with a maximum rail line potential of 66.2 V. These computed values are within the tolerable voltage range of the industry standard. Hence, the simulation result verified the validity of the system being adopted.

Keywords: Modeling Autotransformer, Traction power supply, Voltage profile, Simulation