Performance Analysis of DC Primary Power Protection in Railway Cars Using a Transient Analysis Tool

This paper presents a detailed simulation model developed in an EMT-type (Electromagnetic Transients-type) tool to study transient short- circuit performance of DC primary power protective devices in railway cars. Detailed models are needed since the fault level depends on the location of the moving train, the primary power architecture, and the vehicle operating conditions. Traditional AC RMS time-current curves (TCCs) and AC peak let-through curves are limited practices for protection analysis of current- limiting devices in DC systems. Theoretical background, modeling techniques and typical case studies are presented to demonstrate the functionality and the advantages of using a transient analysis tool for advanced protection studies.