Tractive effort modelling and design of hybrid powertrain for a diesel-hydraulic cane haul locomotive

Wilmar owns and operates a mixed fleet of diesel hydraulic locomotives that operate on two foot narrow gauge rail in its Queensland operations. This network serves as an effective transport system, hauling approximately fifteen million tonne of cane annually. An assessment of the practicality of converting Wilmar's diesel locomotives to a hybrid powertrain design provides an opportunity for improving energy efficiency of cane transport and requires the duty cycle performance of the locomotive to be assessed prior to further work. This paper presents a novel method to determine the tractive effort and energy requirements for the duty cycle, using track dependant physical equations of propulsion dynamics, as the conventional methods of dynamometer car measurements and empirical equations are restricted to broad-gauge rail. A simulation model was developed in MATLAB to determine the performance parameters of a modifiable real–time diesel-hydraulic train configuration. Additionally, the performance requirements of the hybrid powertrain in comparison to the diesel-hydraulic powertrain was demonstrated by developing an optimisable real-time model of a series-hybrid locomotive in SIMSCAPE, an interactive tool for physical systems simulation in MATLAB. Testing and validation using field data obtained from on-board sensors, the locomotive's Programmable Logic Controller (PLC) and a track profile extraction method exclusively developed for this research, demonstrated that the model was capable of accurately predicting the performance parameters and energy consumption of the diesel-hydraulic locomotive for a particular duty cycle. The hybrid model developed in SIMSCAPE exhibited superior traction performance and significant improvements in fuel efficiency and emissions compared to the diesel-hydraulic locomotive for the same duty cycle