A Power-Assistance System using a Battery and an Electric Double-Layer Capacitor Bank for Light Electric Vehicles

摘要

To improve the performance of light electric vehicles (LEVs), we propose a current sharing control system for series-parallel changeover, whose hybrid energy storage system (HESS) comprises an electric double-layer capacitor (EDLC) bank and a main battery. In the proposed system, the series or parallel connection between the EDLC bank and the main battery is decided depending on the bank voltage for managing the energy stored in the HESS. Moreover, we propose a simple output current control method for the parallel connection of the EDLC bank. This method allows for the ratio of output current in both storage components to be controlled by introducing a share command parameter. Experimental results from field tests demonstrate the parallel operation with adjustable current sharing control. Finally, we discuss the combination of series-parallel operations to provide power assistance for LEVs.