Parallel charging and discharging control of lead-acid battery packs based on double hysteresis loop

During the parallel charging and discharging process of lead-acid battery packs, there is a problem of uneven charging and discharging caused by individual performance differences, which in turn affects the overall performance and lifespan of the battery pack. In this regard, research is conducted on a parallel charging and discharging control method for lead-acid battery packs based on double hysteresis loops. Firstly, by analyzing the parallel charging and discharging working status of lead-acid battery packs, an equivalent working model of lead-acid battery packs is established. Then, the identified disturbance factors will be used as input variables for the transfer function, thereby determining the transfer function of the disturbance variables. Finally, based on the principle of double hysteresis technology, the disturbance variables are decomposed for error compensation, achieving balanced control of parallel charging and discharging of lead-acid battery groups. The experimental results show that using the lead-acid battery pack returned from a DC system as the test object, after the application of the designed method, the rated voltage control of a single battery pack during parallel charging and discharging can be achieved, effectively ensuring its stable operation.