Short-Circuit Fault Current Modeling of a DC Light Rail System with a Wayside Energy Storage Device

Abstract

This paper proposes a simulation model to calculate short-circuit fault currents in a DC light rail system with a wayside energy storage device. The simulation model was built in MATLAB/Simulink using the electrical information required to define a comprehensive DC traction power rail system. The short-circuit fault current results obtained from the simulation model were compared with hand calculation results obtained using EN 50123-1 guidance. The relative error was 1.02%, which validates the model. A case study was carried out for a 1500 V DC light rail system. In the case study, a method was proposed to assess the DC protection and the withstand and breaking capacity of the DC circuit breakers for maximum current and distant faults. A traction power modeling simulation was conducted for the 1500 V DC light rail system to calculate the maximum load current in the analyzed electrical sections. It is concluded that the proposed simulation model and fault methodology can be used for DC protection settings calculations and DC circuit breaker rating analysis.