Design Of Power Supply Charging System Based On Modular Lithium Batter

Faced with the severe situation of declining resources,increased environmental pollution and degraded ecosystems,in recent years,China has continuously increased the construction of ecological civilization,encourage the use and construction of new energy electric vehicles.Some mechanical equipment that originally used fuel oil has gradually developed into electromechanic.Lithium batteries are widely used in the market due to their small size,light weight and excellent energy storage characteristics.This paper mainly describes the design of lithium battery charger.The charger is used to charge a single 48V12Ah modular energy storage lithium battery pack.The battery capacity can be expanded by parallel connection of modular lithium battery packs.The charger designed in this subject is suitable for charging modular lithium batteries with a capacity of 48V36Ah.First convert 220V power supply to DC through AC-DC circuit;the UCC28070 chip produced by TI is used for power factor correction;then the half-bridge LLC resonant circuit is used to improve the working efficiency of the charger by soft-switching technology;Finally,set the corresponding charging curve,and charge the lithium battery as quickly as possible while ensuring the safety of the lithium battery.According to the theoretical knowledge,combined with the requirements of the subject,a 2KW lithium battery charger prototype was designed and tested by switching power supply technology,and its performance was tested experimentally.Under the premise of safety certification requirements,the selection and design of components,PCB layout,as much as possible to reduce the size of the charger and improve power density.After the power factor correction of the lithium battery charger,the PF value is close to 1,and the whole machine efficiency is over 92%,and the improved three-stage charging technology is provided.The functionality presented by the final prototype achieved the desired results.