Locomotive traction and rail wear control

In recent decades, advanced power-electronics-based control techniques have been widely used to upgrade direct current (DC) drives for the traction of locomotives. However the dynamic response of such upgraded DC locomotives under transient conditions due to external perturbations has not been fully investigated. In this work, an integrated dynamic model for a typical DC Co-Co locomotive/track system is developed to provide predictive simulations of the motion and forces transmitted throughout the DC locomotive dynamic system. The model integrates a 2D longitudinal-vertical locomotive structural vibration model, wheel/rail contact mechanics using Polach’s creep force model, a generic DC dynamic traction model and a traditional creep controller to simulate the transient response to a change in friction conditions. It is found that although the largest creep is constrained below 10% there are large transient creep and traction fluctuations related to identified modes of vibration of the locomotive.