Battery management apparatus
First Claim
1. A battery management apparatus for grasping a change in impedance of a battery to reflect the battery management, the apparatus comprising:
- impedance calculating means for calculating the impedance of the battery using the terminal voltage of the battery, the open circuit voltage thereof, and the current thereof as parameters when a variation in current of the battery and the temperature thereof are respectively within predetermined ranges; and
impedance correction value calculating means for comparing the impedance obtained by the impedance calculating means with an initial impedance previously obtained from the initial state of the battery to calculate an impedance correction value depending on the degree of deterioration of the battery.
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Abstract
When impedance calculating conditions are satisfied after a system is started, the impedance of a battery is calculated using the current of the battery, a time variation in open circuit voltage thereof, a time variation in terminal voltage thereof, a time variation in current thereof, and a time variation in impedance thereof. The ratio of the calculated impedance to the initial impedance is calculated. The impedance ratio is subjected to weighting and averaging, thus obtaining a weighted average. When the system is terminated, an impedance-correction-coefficient learned value is updated using the weighted average. Thus, a change in impedance of the battery can be accurately grasped. Advantageously, parameters indicating the state of the battery, e.g., the remaining capacity thereof, reflect the change in impedance, resulting in accurate battery management.
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Citations
11 Claims
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1. A battery management apparatus for grasping a change in impedance of a battery to reflect the battery management, the apparatus comprising:
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impedance calculating means for calculating the impedance of the battery using the terminal voltage of the battery, the open circuit voltage thereof, and the current thereof as parameters when a variation in current of the battery and the temperature thereof are respectively within predetermined ranges; and
impedance correction value calculating means for comparing the impedance obtained by the impedance calculating means with an initial impedance previously obtained from the initial state of the battery to calculate an impedance correction value depending on the degree of deterioration of the battery. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification