Study on optimization control for hybrid electric bus

The new control strategy for hybrid electric bus is studied based on instantaneous optimization, with enhancing fuel economy as objective. A concept of equivalent fuel consumption of battery is introduced, by which the electric energy consumption or replenishment of the battery is converted to the fuel consumption of the engine, and thus the instantaneous fuel consumption function of the system is established. A charge-sustaining function for the battery is proposed to ensure the battery working at the optimum region. A simulation is performed and the result show that the control for hybrid electric bus based on instantaneous optimization can improve fuel economy while the SOC of the battery is maintained at reasonable range.