A FUZZY BASED PROPULSION SELECTION FOR FUEL EFFICIENCY IN HYBRID ELECTRIC VEHICLE

This article proposes a fuzzy based fuel-efficient propulsion selection logic for a hybrid electric vehicle (HEV) in 'Highway Fuel Economy Test (HWFET)' driving cycle. Optimal utilisation of combustion engine, in HEV, reduces the fossil fuel consumption. This can be realized through an electronic control unit, embedded with effective propulsion selection logic that governs the power split device in series-parallel HEV. A propulsion control logic, based on the road gradeability, velocity, torque demand and vehicle battery state of charge (SOC) is presented in this article. A comparison with conventional propulsion selection logic based system shows that the HEV modelled with proposed fuzzy based one, results in better speed tracking with steep road grades, as it provides better torque supply at desired speed points. The analysis indicates a reduction in consumption of both the fossil fuel as well as the electrical fuel (SOC).