Optimal energy management and storage sizing for electric vehicles

Combining storages with different characteristics can improve the performance and lifetime of electric vehicles. For example, a supercapacitor and a battery together can handle large power transfers from acceleration and regenerative braking while protecting the battery from degradation. In this paper, we use approximate dynamic programming to design a policy for power sharing between dual storage devices. We write the dynamic program as a linear program and use basis functions to approximate the optimal value function. Numerical results show that the resulting suboptimal policy can approximate the optimal policy with low error given a sufficient number of basis functions.