Modeling and capacitance effect analysis of the cable traction network of an electrified railway

Abstract

This paper models and analyzes the cable traction network (CTN) of a novel AC 110 kV-50 Hz cable traction power supply system (TPSS). First, we propose an equivalent model of the CTN that considers the charging current of the cables, in order to research the capacitance effect of the CTN. Then, three cases based on the novel TPSS are used to validate the proposed model, and to investigate the characteristics of the CTN. Simulation results show that the proposed model is effective in calculating both the charging current and the voltage on the cable system. Calculation results from case 2 show that the capacitance effect is mainly caused by the charging current flowing through the system's reactance, which consists of the reactance of the power system and the reactance of the main transformer. The reactance of the system, compensation coefficient and cable length can each influence the charging current and capacitance effect of the cable. Case 3 illustrates that the novel TPSS is very effective in supplying power and can greatly reduce the number of neutral sections; thus, it is suitable for application in future railway designs.