Constrained Optimization of Energy Management for a Mild-Hybrid Vehicle

G Rousseau (1, 2) , D. Sinoquet (1) , P. Rouchon (2)

1 IFPEN - IFP Energies nouvelles
2 Mines Paris - PSL (École nationale supérieure des mines de Paris)

Hybrid-electric vehicles appear to be one of the most promising technologies for reducing fuel consumption and pollutant emissions. The presented work focuses on a power train architecture for mild hybrid vehicles where the kinematic energy in the breaking phases is stored in a battery to be re-used later via the electric motor. This additional traction power allows to downsize the engine and still fulfill the power requirements. Moreover, the engine can be turned off in idle phases. The complete mild-hybrid vehicle is modelled in AMESim environment and the fuel consumption for given driving cycles is estimated. The control strategies for the energy management between the two power sources are optimized with respect to fuel consumption with a classical dynamic programming (DP) method. We propose an other method based on Pontryagin Minimum Principle which furnishes results very close to the DP results for a significantly reduced calculation time. These optimization results furnish the optimal control laws from which could be derived the control laws to be implemented on the vehicle. To illustrate the potential of optimization for component design, mild hybrid vehicles with varying battery and electric motor sizes, with different types of engine (gasoline / natural gas), are evaluated in terms of consumption gain with the presented methodology.

Keywords: Hybrid vehicle; Modelling; Optimal control; Optimization

Domains: Earth Sciences

G Rousseau, D. Sinoquet, P. Rouchon. Constrained Optimization of Energy Management for a Mild-Hybrid Vehicle. E-COSM - Rencontres Scientifiques de l'IFP, Oct 2006, RUEIL MALMAISON, France. pp.1 - 3. ⟨hal-02284267⟩