Modelling, Simulation and Analysis of Operation Modes in a Series-Parallel Powertrain with Torque-Split Device

As an alternative for conventional fossil fuel powered vehicles, renewable fuel sources such as ethanol represent a proven technology and experienced a continuous growth in the last decade in the Brazilian market [1]. Hybrid vehicles are slowly arriving in Brazil as they still suffer from the increased cost of the hybrid powertrain coupled to high importation taxes.

In this paper, simulations are conducted in order to analyze the operation of a hybrid electric vehicle using a series-parallel topology. A feature of this drivetrain configuration is the use of a planetary gear set as torque-split device between the traction components which can be applicable for an ethanol engine.

The system architecture of the referenced vehicle is first described with a comparison against the main powertrain topologies adopted for hybrid vehicles. The vehicle model is presented and the different modes of operation across the torque split device are analyzed. Test data of component and chassis dynamometer testing available from the literature are used to validate and compare the simulation results. The main focus of this study is the analysis of the hybrid powertrain under the FTP-75 driving cycle, used by the NBR-6601 regulation for emission testing.