Sensitivity Analysis of Characteristic Parameters of Railway Electric Traction System

Abstract

The modal analysis, which decouples the contact wire and rail track conductors, is used to develop an integrated model of single rail track and contact wire. The characteristic impedance and propagation constant matrices of integrated model have been computed. The authors have studied effects of various parameters of interest on characteristic impedance and propagation constant using sensitivity analysis. The sensitivity functions of series impedance and shunt admittance related to contact wire and catenary have been developed and validated in this paper. Index Terms—railway traction lines, characteristic parameters, sensitivity analysis, parameter sensitivity  I. INTRODUCTION Railway electric traction system is a fast and green transportation system with enhanced load carrying capacity. The analysis and design of power and signaling system of railway electric traction system needs mathematical model of the system. The authors in this paper have used the multi-conductor transmission line theory to develop the mathematical model of the electric traction system and to compute the characteristic impedance and propagation constant of this system. This approach can then be extended to find the voltage and current distribution of the system. The characteristic impedance and propagation constant are the functions of line parameters i.e. self and mutual impedances and admittances of contact wire and rail track. The numerical values of these parameters are not accurately known under practical conditions as they are dependent on varying/uncertain parameters like permeability, supply frequency and shape of the conductor. In order to study the effect of these uncertain parameters on the characteristic parameters of the railway electric traction system, the authors have carried out the sensitivity analysis of characteristic impedance and propagation constant with respect to the above mentioned parameters of interest for the first time in the literature. In a rail track ferromagnetic material, both saturation and hysteresis are