Device and method for determining state of battery pack
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsYuki Imade, Tsubasa Migita
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Abstract
A parameter ratio that is a ratio of a parameter of a parallel-cell block to be determined to an average value of parameters of a plurality of parallel-cell blocks is calculated, a moving-average value of the parameter ratio is obtained, and a state of the parallel-cell block to be determined is determined based on an index value that is a difference between the parameter of the parallel-cell block to be determined and the moving-average value.
Claims10
A device that determines a state of a battery pack comprising three or more series-connected parallel-cell blocks each including a plurality of cells connected in parallel, comprising:
- a parameter acquisition unit that obtains a parameter indicating a state of the parallel-cell block;
- a parameter ratio calculation unit that calculates a parameter ratio that is a ratio of a parameter of a parallel-cell block to be determined to an average value of parameters of a plurality of parallel-cell blocks;
- a moving-average calculation unit that calculates a moving-average value of the parameter ratio;
- an index value calculation unit that obtains an index value that is a difference between the parameter ratio of the parallel-cell block to be determined and the moving-average value of the parameter ratio;
- a state determination unit that determines a state of the parallel-cell block to be determined, based on the index value;
- and
- a warning unit that informs warning information indicating that abnormal degradation is caused when the state determination unit determines that the index value exceeds a threshold value;
- wherein
- the parameter acquisition unit obtains the parameter of the parallel-cell block to be determined whenever a predetermined time arrives, and
- the index value calculation unit calculates the index value based on a moving-average value of the parameter ratio calculated using a parameter of the parallel-cell block to be determined obtained when the predetermined time immediately previously arrives and a parameter of the parallel-cell block to be determined obtained when the predetermined time currently arrives.
A method for determining a state of a battery pack comprising three or more series-connected parallel-cell blocks each including a plurality of cells connected in parallel, the method comprising:
- obtaining a parameter indicating a state of the parallel-cell block;
- calculating a parameter ratio that is a ratio of a parameter of a parallel-cell block to be determined to an average value of parameters of a plurality of parallel-cell blocks;
- calculating a moving-average value of the parameter ratio;
- obtaining an index value that is a difference between the parameter ratio of the parallel-cell block to be determined and the moving-average value;
- determining a state of the parallel-cell block to be determined, based on the index value;
- informing warning information indicating that abnormal degradation is caused when the state determining step determines that the index value exceeds a threshold value;
- obtaining the parameter of the parallel-cell block to be determined whenever a predetermined time arrives, and
- calculating the index value based on a moving-average value of the parameter ratio calculated using a parameter of the parallel-cell block to be determined obtained when the predetermined time immediately previously arrives and a parameter of the parallel-cell block to be determined obtained when the predetermined time currently arrives;
- wherein the parameter indicating a state of the parallel-cell block is obtained whenever a predetermined time arrives, and an index value is obtained based on a moving-average value of the parameter ratio calculated using a parameter of the parallel-cell block to be determined obtained when the predetermined time immediately previously arrives and a parameter obtained of the parallel-cell block to be determined when the predetermined time currently arrives.
Dependencies are inferred from the claim text.