Influence of Parameters of Electric Locomotive on its Critical Speed

Abstract

A high speed is one of the most important todays requirements for the rail transport. However, increasing the maximum speed brings also the problem of vehicle stability. The parameters of the vehicle suspension should be tuned in order to achieve vehicle stability in the entire speed range. The article presents the results of theoretical study of the impact of the suspension parameters of the mainline electric locomotive type DS3 on the magnitude of its critical speed. The stability and critical speed are assessed by eigenvalues calculation of the linear model of the vehicle. The study compares 9 variants of vehicle parameters. The sensitivity of the critical speed on the individual parameters is shown and discussed. At the same time, it is shown that by tuning vehicle parameters in order to achieve high critical speed, some other vehicle characteristics may deteriorate. As the result, the optimal range of the stiffness values of the connection of axle-boxes and bogie-frame is recommended.