Battery-charging model to study transient dynamics of battery at high frequency

This paper initially presents a battery-charging model to describe transient dynamics including inductance characteristic of valve regulated lead acid (VRLA) battery during charging at DC current of high frequency ripple. Next, some formulas are introduced to determine the values of key elements of battery model, which are functions of battery state of charge (SOC). A very simple formula is derived to calculate the value of battery inductance L in the model. Then, the battery-charging model is verified via comparisons between simulation and laboratory measurement of charging transient process. Further simulation study shows that battery inductance characteristic has impact on the working state of high frequency switching mode charger (HFSMC) and parameter selection of the components in output unit of charger power transfer main circuit can be optimized.