Li-Ion battery sizing and dynamic programming for optimal power-split control in a hybrid electric vehicle

Abstract

This study considers the tradeoff between the weight and the storage capacity among different sizes of LiFePO4 battery packs for optimal powertrain design in a parallel hybrid electric vehicle (HEV). Proper power-split strategy between the engine power and the battery power can improve the performance of the designed powertrain. Dynamic programming (DP) approach is adopted to compute the optimal power-split and to evaluate the performance of each battery storage capacity. The fuel economy of HEV with different battery capacities are evaluated against different driving schedules i.e. Japan 10/15 mode, UDDS, HWFET, UN/ECE, and SFTP. Since the solution to the DP is computed offline (within a few minutes for each profile), some rule extractions are illustrated and can be used to improve the powertrain control strategy onboard.

Dynamic programming technique for optimizing fuel cell hybrid vehicles

“…It is the continuous integration of three factors divided by the heat capacity of the battery (H BT ) as shown in equation (10). …”

“…[10], the HEV power sources are the ICE and the battery system. DP is used to test the effect of battery weight and storage capacity on the operational cost.…”