Optimal control of a hybrid powerplant based on a balance of ecological and fuel efficiency factors

In a hybrid electric vehicle (HEV), IC engine can be operated independently (to a certain extent) of vehicle's speed and power demand. Therefore, there is a substantial flexibility in adjusting HEV's fuel consumption and emissions by varying ICE's operating point. Due to high complexity and non-linearity of hybrid powertrain's characteristics it is necessary to use some mathematical tool to derive an optimal combination of ecological and energy consumption properties of HEV. It is generally accepted that dynamic programming (DP) is well suited for such a task. A DP routine based on the HEV's model was developed and implemented in MATLAB/Simulink environment. A number of runs were executed. Results have revealed an apparent trade-off between fuel effectiveness of HEV and NOx emissions. Based on comprehensive analysis of results, certain ways to deal with this trade-off were offered.

hybrid powerplant, optimal control, balance of ecological and fuel efficiency properties