Voltage equalization of lithium iron phosphate batteries cooperating with supercapacitors

This paper is aimed to develop a voltage equalization circuit for lithium iron phosphate batteries cooperating with supercapacitors. In this proposed equalizer, a bi-directional dc-dc converter circuit is utilized to deliver the redundant energy to supercapacitors such that the unequal battery voltage problem can be solved, while the energy loss can be minimized simultaneously. The study begins with the charging and discharging of batteries of interest. Then, the cell balancing circuit is constructed with the designated control procedure. This prototype has been extensively validated in the laboratory. Experimental results confirm the feasibility of the proposed approach for battery voltage balancing applications.