Design of a system for active balancing of lithium-ion battery cells

U ovome radu dan je teorijski pregled baterija i sustava za upravljanje baterijama te su opisane metode aktivnog balansiranja baterija koje se spominju u literaturi. Doprinos ovoga rada literaturi krije se u objašnjenju nove metode balansiranja baterija znatno različite od postojećih metoda. Ova metoda koristi zavojnice za jednosmjerni prijenos energije između ćelija, a energiju prenosi u suprotnom smjeru pomoću dodatne baterije. Prednosti ove metode u odnosu na konvencionalne metode balansiranja zavojnicama su jednostavnije kontroliranje balansiranja i manji broj MOSFET-a, dok su nedostatci veći gubitci pri balansiranju. Na osnovu nove metode balansiranja izrađen je sustav čiji su rezultati testiranja prikazani u ovome radu.This thesis gives a theoretical overview of batteries and battery management systems, and the description of methods of active battery cell balancing mentioned in the literature. The contribution of this paper to the literature lies in the explanation of the new method of battery cell balancing, significantly different from the existing methods. This method uses inductors for unidirectional energy transfer between cells, and transfers energy in the other direction using external battery. Advantages of this method, in comparison to conventional methods of cell balancing using inductors, are easier balancing control and lower number of used MOSFETs, while disadvantages are bigger energy losses during balancing. Based on the new balancing method, a system was developed, the test results of which are presented in this paper