Enhanced adaptive Hamiltonian control strategy for battery-ultracapacitor hybrid systems in electric vehicle applications

This paper presents an enhanced Hamiltonian control law integrated with differential flatness theory, designed for hybrid vehicle systems utilizing batteries and ultracapacitors (UCs). Compared to conventional methods, the proposed approach improves transient stability, enables dynamic power sharing, and reduces battery stress under rapid load variations, making it particularly effective for commercial electric vehicle (EV) applications. These vehicles operate under dynamic load conditions such as frequent acceleration, breaking, and regenerative events, which demand high-performance power management. The primary objective of the proposed control law is to manage power flow and optimize energy utilization in such hybrid systems. By combining Hamiltonian control with differential flatness techniques, the strategy dynamically regulates energy distribution between the battery and the UC. This is particularly relevant in DC microgrid applications, including vehicle systems, where constant power load (CPL) challenges frequently arise. To evaluate the effectiveness of the proposed strategy, an experimental test bench was developed using a Li-ion battery module (LFeLi-48,100 TB, 48 V, 100 Ah) and a UC module (188.88 F, 51.3 V). Experimental results confirm the superior performance of the proposed control law throughout various load–drive cycles.