Design And Implementation Of Lithium Battery Equalization Charging Power Supply

With the advent of new materials and the improvement of related technologies,lithium batteries have greatly improved their performance and the range of applications has continued to expand.However,the voltage and capacity of a single-cell lithium battery are often relatively limited,so lithium battery cells are often connected in series in a high-power usage scenario,namely a lithium battery pack.During the long-term use of the individual cell batteries in the lithium battery pack,the difference in material and performance may cause the inconsistency of the lithium battery pack.This will not only reduce the capacity of the battery pack,shorten the cycle life,reduce the charging voltage of the battery pack,and may even directly cause the battery pack to be scrapped.In this paper,a lithium battery pack is taken as the research object,and a balanced charging power supply is designed for the inconsistency problem in the series charging process.The thesis firstly makes a brief analysis of the research status of the charging power supply,and then combines the relevant requirements of the laboratory on the lithium battery maintenance equipment,and designs the relevant indicators of the balanced charging power supply.Then the overall system design scheme and the balanced charging power frame structure are proposed.Among them,the system hardware is mainly composed of power conversion circuit,auxiliary circuit,control circuit,signal conditioning circuit,drive circuit,and communication circuit.The hardware design details the calculation of circuit parameters,MATLAB simulation,device selection,schematic circuit design of each module circuit,and PCB design.The system software section mainly introduces the function and design interface of the host computer,and then analyzes in detail the program design flow and these digital filter algorithms and the advantages and disadvantages of these various digital filter algorithms.Then the PID digital control algorithm is mainly focused on the detailed theoretical calculations and MATLAB simulations,and on the basis of the existing algorithms,some improvements are made,so that the control accuracy and stability are greatly improved.At the same time,the communication protocol between the balanced charging power supply and the host computer is also designed.Finally,the test of the drive signal,output voltage accuracy,output current accuracy,temperature,efficiency and other items verify that the performance and indicators of the charging power supply meet the design requirements.