Self-Tuning Multiport Resonant DC/DC Converter Based on Actively-Controlled Inductors for Hybrid Storage System Integration

In the field of electric mobility, in particular heavy-duty electric vehicles and long-haul trucks, the energy systems are susceptible to transients with different amplitudes and dynamics due to the high power demand. With the combination of high power and long distances, the available battery technologies become insufficient as a single energy source for such a system. Thus, the integration of hybrid energy storage systems (HESSs) with different energy capabilities, such as fuel cells, battery packs, and supercapacitors, is highly required. In this context, for leveraging HESSs in an efficient way, a resonant multiwinding transformer-based converter is proposed to interconnect these different energy storage systems (ESSs) since the resonant converters are able to operate at a wider range of switching frequencies and, hence, a wider soft-switching range. However, due to the multiple resonant circuits and possible parameter deviations, the control capability might be compromised. Thus, a multiport resonant dc/dc converter embedded with variable inductors is proposed to enhance the power flow management among these different ESSs with reduced conversion stages. Further, the proposed concept can also improve the immunity to parameter deviations on the resonant by compensating for possible variations at the resonant frequencies. Finally, simulations and experimental results of a $\text{20} \;\text{kW}$ four-port resonant dc/dc converter embedded with variable inductors are shown to prove the effectiveness of the proposed concept.