Traction performance simulations for locomotives in heavy haul trains

This paper introduced wheel-rail contact based traction control into conventional Longitudinal Train Dynamics (LTD) simulations via co-simulation and parallel computing techniques. A LTD simulation package was connected with a multibody vehicle system dynamics simulation package called GENSYS using the TCP/IP protocol. The LTD simulations replicated the dynamic environment (in-train forces) of train operations while the vehicle system dynamics simulations integrated wheel-rail contact models and mechatronic traction control models for locomotives. In-train forces and a traction reference were sent to GENSYS to determine traction effort values which were then sent back to LTD. A distributed-power train with the configuration of 1 locomotive + 61 wagons + 1 locomotive + 61 wagons was modelled. Two computer cores were used to simulate the two locomotives in parallel. Co-simulations with and without the consideration of curve lubrication were conducted and compared with conventional LTD simulations. The results show that the maximum traction forces simulated in co-simulations are about 11% lower than those in conventional LTD simulations. With the consideration of curve lubrication, traction forces on curved tracks were about 23 % lower than on tangent tracks. Without the consideration of curve lubrication, traction forces on curved tracks were about 3% lower than on tangent tracks.