Battery pack system including multi-battery
The present invention relates to a battery pack system. In the battery pack system including a multi-battery according to the present invention, replacement may be easily performed in a lower unit of the battery pack system, the battery pack system including a multi-battery may include the battery modules having various forms and performances and capable of being arranged so as to increase space efficiency of the battery pack system, the battery pack system including a multi-battery includes the battery modules having various forms and performances, such that an energy density of the battery pack system may be improved, and the battery pack system including a multi-battery may allow battery modules having various performances and outputs to maintain states of charge (SOCs) (%) in a uniform ratio by estimating the SOCs of the respective battery modules and re-scaling the SOCs according to a capacity criterion of a control unit.
1. A battery pack system including a multi-battery, comprising:
a plurality of battery cells;
a plurality of battery modules including the plurality of battery cells; and
a control unit acquiring information from the plurality of battery modules to balance the plurality of battery modules,
wherein at least any one of capacities, forms, or lifespans of at least any one of the plurality of battery modules are different from each other, and
the control unit:
sets a minimum capacity value of the respective capacity values of the plurality of battery modules as a representative capacity,
estimates a state of charge (SOC) of the any other plurality of battery modules rather than a battery module whose capacity is set to the representative capacity,
re-scales the SOC of each battery module according to a capacity ratio on a basis of the representative capacity, and
calculates the re-scaled SOC.
2. The battery pack system including a multi-battery of claim 1 , wherein the control unit includes a plurality of module control units corresponding to the plurality of battery modules in a one-to-one manner and acquires information from the respective plurality of battery modules to control the respective plurality of battery modules, and a central control unit receives information from the plurality of module control units to control the plurality of module control units.
3. The battery pack system including a multi-battery of claim 2 , wherein the plurality of module control units store capacity information of battery cells applied to the plurality of battery modules corresponding thereto.
4. The battery pack system including a multi-battery of claim 3 , wherein the respective plurality of module control units estimate available outputs of the corresponding plurality of battery modules and transmit the available outputs to the central control unit, and the central control unit sets a minimum value of the transmitted available outputs as a representative output.
5. The battery pack system including a multi-battery of claim 2 , wherein each of the plurality of module control units:
estimates a state of charge (SOC) of a corresponding battery module,
derives a capacity difference between the battery module and the corresponding battery module whose capacity is set to the representative capacity to estimate the capacity ratio, and
re-scales the capacity ratio for the SOC estimated on the basis of the representative capacity and transmits the re-scaled SOC to the central control unit.
6. The battery pack system including a multi-battery of claim 5 , wherein the central control unit balances the respective plurality of battery modules so that the re-scaled SOCs of the respective plurality of battery modules are maintained to be the same as each other.
7. The battery pack system including a multi-battery of claim 1 , wherein the battery pack system including the multi-battery is designed so that a user easily changes an arrangement of the respective plurality of battery modules according to use.