Power Hardware-in-the-loop Simulation of Hybrid Energy Storage System Considering Supercapacitor Voltage Limitation

Hybrid energy storage system (HESS) consisting of battery and supercapacitor (SC) is commonly addressed in studies on electric vehicles (EV). Energy management strategies, which are mandatory for HESS, should be verified in real-time experiments. In many cases, it is of interest to test the system operation on a reduced-scale power hardware-in-the-loop (HIL) simulation before full-scale realization. Due to the power reduction, the energy storage capability of the SC must be scaled by a corresponding ratio. On the other hand, the capacity of the commercially available SC may not fit the desired ratio. As a consequence, the SC voltage limitation should be adapted. This study proposes a method to calculate the SC voltage constraints for the downscale HIL system. The simulation results verify that the proposed SC design properly emulate the full-scale system.