A Scalable Multi-input Hybrid Converter for Energy Management Control in Hybrid Energy Systems Empowering Electric Mobility

The energy system with a fuel cell (FC) and energy storage systems (ESS), including batteries and supercapacitors, has been considered to extend operation time and ensure long life cycles of ESSs in various electric mobility applications, such as unmanned aerial vehicles and electric vehicles. To enable the utilization of multiple inputs with a simple structure, a hybrid converter is promising, and its energy management control should be developed cooperatively to achieve optimal performance. However, if the desired system specification or configuration is changed, the hybrid converter and its energy management control must be modified, which requires significant effort and leads to considerable delays in overall system redesign. To address this challenge, this paper proposes a scalable multi-input hybrid converter and a flexible control scheme capable of rapid adaptation to modified designs, especially those involving a different number of ESS, while realizing three crucial functions: 1) output voltage regulation, 2) energy flow optimization, and 3) protections for all energy sources. The proposed converter has been validated by the experiment using 14.8 V and 400 W output and three input sources, 450 W FC, one 12-stack Lithium Polymer battery, and a 160 V rating supercapacitor for small unmanned aerial vehicles.