This paper presents a formalization of the energy management problem in hybrid electric vehicles and a comparison of three known methods for solving the resulting optimization problem. Dynamic programming (DP), Pontryagin’s minimum principle (PMP), and equivalent consumption minimization strategy (ECMS) are described and analyzed, showing formally their substantial equivalence. Simulation results are also provided to demonstrate the application of the strategies. The theoretical background for each strategy is described in detail using the same formal framework. Of the three strategies, ECMS is the only implementable in real time; the equivalence with PMP and DP justifies its use as an optimal strategy and allows to tune it more effectively.

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This paper proposes a new method for solving the energy management problem for hybrid electric vehicles (HEVs) based on the equivalent consumption minimization strategy (ECMS). After discussing the main features of ECMS, an adaptation law of the equivalence factor used by ECMS is presented, which, using feedback of state of charge, ensures optimality of the strategy proposed. The performance of the A-ECMS is shown in simulation and compared to the optimal solution obtained with dynamic programming.

The paper presents a methodology to account for battery aging in the energy management strategy for a hybrid electric vehicle. An optimal control problem is formulated to minimize fuel consumption as well as battery aging, using recently developed methods for battery lifetime modeling. The approach relies on the concept of severity factor map, a tool used to quantify the aging effects of a battery due to its different on-vehicle operating conditions. The optimal control problem is solved using Pontryagin's Minimum Principle, showing with simulations the effect of the new control approach compared to the standard energy management strategies.

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