Hybrid Lithium Capacitor Voltage Balancing with Planar Power Inductor for Electric Vehicles and Other Applications

This paper presents an evaluation for hybrid lithium-ion capacitor (LiC) balancing topology with low-profile planar power inductor design. The inverting buck-boost topology can be used to transfer charges through the inductor in both directions between LiC cells connected in series to equalize their voltage values. In this paper, the balancing topology, its principle of operation, and planar power inductor design are discussed. A set of experimental results obtained from a laboratory prototype is presented and used to evaluate the topology operation.