In this paper, a novel hierarchical power management strategy is proposed for a plug-in hybrid electric vehicle with multiple energy sources. In the first level, dynamic programming is used to distribute the power between the energy storage system and the engine. Then, the hybrid energy storage system is composed by adding a supercapacitor to the energy storage system. In the second level, the low-pass filtering algorithm is researched to distribute power between the battery and the supercapacitor of the hybrid energy storage system. To control the battery and the supercapacitor working within the energy range, the limit management approach is proposed to redistribute power among the battery, the supercapacitor and the engine. Simulink results show that the final distributed powers of battery, supercapacitor and engine are within the reasonable power and energy ranges.
Keywords Plug-in hybrid electric vehicle; Hybrid energy storage system; Power management strategy; Dynamic programming; Low-pass filtering