Current Sharing Control for Series-Parallel Changeover using Battery and Electric Double-Layer Capacitor Bank

We previously proposed a series-parallel changeover system for connecting an electric double-layer capacitor (EDLC) bank to the main battery, aiming to improve the performance of electric vehicles. In this paper, we propose a control method for output current sharing by connecting the EDLC bank in parallel to the battery. The proposed method can control the ratio of output current in both components to perform the sharing operation. Therefore, the stored energy in the EDLC bank can be used when required by controlling its output current. Experimental results verify the parallel operation with suitable current sharing and suggest the applicability of the method to providing power assistance for light electric vehicles.