Active Balancing Of Lithium-Ion Battery Cells Using Wpt As An Energy Carrier

This study develops a novel equaliser by combining wireless power transmission (WPT) and switch array for series-connected batteries. The physical isolation achieved by WPT can offer unique benefits that traditional equalisers can hardly provide. Parameters of the WPT system are properly designed to achieve an equivalent constant-current output, which can maximise the speed of balance and ensure the health of batteries. This methodology can ensure each battery is connected independently to the inverter through the switch array circuit. Therefore, balancing for either a single battery or multiple batteries can be achieved. In the experiment, the prototype system is built. Experimental results show that the proposed equalisation system can achieve high overall system efficiency (above 87.2%) when balancing four series-connected battery modules.