Energy usage optimisation of heavy haul freight trains

Abstract

The aim of this paper is to outline a preliminary investigation into an energy optimisation model with the aim of eventually being incorporated into a real-time driver assist program. A significant portion of the South African economy is sustained by a large and extensive mining industry. Integral to sustaining the mining economy is the transport of mined raw material via freight rail over large distances, typically from the mines to central distribution or processing centres. Due to the heavy tonnage and long distances an enormous amount of energy is required. Using classical mechanics, an energy usage model for typical freight trains based on available tractive power and typical rolling stock resistances (curvature, friction, gravity etc) is considered. The aim is to find the optimal velocity profile over the full distance of the intended track for which the total locomotive energy usage is reduced. We will illustrate the robustness of the proposed model to predict optimal operational velocity profiles for a number of interesting scenarios, many supported by similarly related analytical studies.