A novel updating method of equivalent factor in ECMS for prolonging the lifetime of battery in fuel cell hybrid electric vehicle

A novel updating method of equivalent factor of the Equivalent Consumption Minimization Strategy (ECMS) is proposed to prolong the lifetime of battery in fuel cell hybrid electric vehicle. ECMS can generate the sub-optimal solution at any instance for current driving condition. Equivalent factor which is dimensionless conversion ratio of electrical power flow into chemical power flow plays an important role in charge-sustaining performance. Well-tuned equivalent factor from iterative search in off-line can only guarantee the charge-sustaining performance, not the lifetime of the battery. Therefore additional updating method of equivalent factor is necessary in order to prolong the lifetime of the battery which only takes the numbers of charge and discharge cycle into account. Backward simulation is used to verify the effectiveness of the updating method.