Modeling Control and Simulation of a Power-Split Hybrid Wheel Loader

This paper addresses the modeling control and simulation of a power-split hybrid propulsion system for driving a Wheel Loader. The modeling is performed exploiting the Power-Oriented Graphs (POG) graphical modeling technique. The main elements involved in the system are: an ICE (Internal Combustion Engine), two PMSMs (Permanent Magnet Synchronous Motors) controlled using a vectorial control and powered by a DC bus, a planetary gear set, a DC/DC converter, a supercapacitor acting as energy storage device and the transmission system of the vehicle, including all the physical elements from the gearbox to the vehicle wheels. A control strategy aiming at reducing the ICE operating point fluctuations caused by the transmission load and minimizing the ICE specific fuel consumption is proposed. Simulation results with reference to a typical driving cycle for this type of vehicle are finally presented and commented in detail.