Electric Vehicles Battery Charging by Estimating SOC using Modified Coulomb Counting
Quick and effective battery charging is critical for battery powered vehicles. This paper describes a multilevel charging technique for Li ion batteries used in electric vehicle applications. Instead of a single constant current level, five constant current levels are used to quickly charge the battery. A DC DC converter is used as a current source in the charging circuit for safe and efficient charging. The precise calculation of state of charge SoC is used as an input to enforce the above optimal battery charging technique. The SoC is calculated using a hybrid method that incorporates both the Open Circuit Voltage OCV and Coulomb integral methods. To estimate battery parameters, the Simulink Design Optimization SDO tool is used. The simulations are performed using MATLAB. The difference between the inbuilt battery SoC estimation method and the updated coulomb counting system in terms of SoC estimation is less than 2 . A 3.7 V, 1.1 Ah Li ion battery was used for all of the tests.
Battery Parameters, Constant Current Constant Voltage CC CV Charging, Fast Battery Charging, Li ion Battery, Modified Coulomb Counting, Multilevel Constant Current Charging, State of Charge SoC
A. Srilatha | A. Pandian