Method and device for estimating charge/discharge electricity amount of secondary cell
First Claim
1. A method for estimating a charge/discharge electricity amount of a secondary battery comprising:
- a step of measuring a pair of data consisting of a current flowing through the secondary battery and a terminal voltage of the secondary battery corresponding to the current, thus obtaining a plurality of pairs of data, a step of, in the case that specific selection conditions are satisfied, calculating a no-load voltage as a voltage intercept at a current of zero in a straight-line approximation obtained by statistical processing with respect to the plurality of pairs of data, a step of, in the case that specific current conditions or voltage conditions continue to be met for a certain amount of time, calculating an open circuit voltage from the terminal voltage of the secondary battery, a step of calculating a change (Δ
Vb) in the no-load voltage or the open circuit voltage over a predetermined period of time, and a step of calculating an estimated charge/discharge electricity amount (Δ
Qe) of the secondary battery based on the change in the no-load voltage or the open circuit voltage.
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Abstract
The present invention provides an apparatus that can estimate the charge/discharge electricity amount without being affected by current measurement error. If specific selection conditions are met, a no-load voltage calculation part (105) takes a plurality of pairs of data consisting of current data I(n) and voltage data V(n) corresponding to the current data and calculates a no-load voltage Vsep as the voltage intercept at a current of zero in a straight-line approximation obtained by statistical processing such as regression analysis using a least squares method with respect to the plurality of pairs of data. In addition, if specific current conditions continue to be met for a certain amount of time, an open circuit voltage calculation part (106) calculates the terminal voltage of the secondary battery as the open circuit voltage Voc. An estimated charge/discharge electricity amount calculation part (114) uses a preset change-in-voltage adjustment constant ΔVbc/adjustment coefficient Kb, change-in-electromotive-force constant Keq and polarization voltage generation constant Kpol to calculate the estimated charge/discharge electricity amount ΔQe as a function of the change ΔVb in the no-load voltage or the open circuit voltage over a predetermined period of time.
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Citations
22 Claims
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1. A method for estimating a charge/discharge electricity amount of a secondary battery comprising:
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a step of measuring a pair of data consisting of a current flowing through the secondary battery and a terminal voltage of the secondary battery corresponding to the current, thus obtaining a plurality of pairs of data, a step of, in the case that specific selection conditions are satisfied, calculating a no-load voltage as a voltage intercept at a current of zero in a straight-line approximation obtained by statistical processing with respect to the plurality of pairs of data, a step of, in the case that specific current conditions or voltage conditions continue to be met for a certain amount of time, calculating an open circuit voltage from the terminal voltage of the secondary battery, a step of calculating a change (Δ
Vb) in the no-load voltage or the open circuit voltage over a predetermined period of time, anda step of calculating an estimated charge/discharge electricity amount (Δ
Qe) of the secondary battery based on the change in the no-load voltage or the open circuit voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. An apparatus for estimating a charge/discharge electricity amount of a secondary battery, comprising:
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a current measurement part that measures current flowing through the secondary battery as current data, a voltage measurement part that measures a terminal voltage of the secondary battery as voltage data, a no-load voltage calculation part that obtains a plurality of pairs of data consisting of current data from the current measurement part and voltage data corresponding to this current data from the voltage measurement part, and that, in the case that specific selection conditions are satisfied, calculates a no-load voltage as a voltage intercept at a current of zero in a straight-line approximation obtained by statistical processing with respect to the plurality of pairs of data, an open circuit voltage calculation part that, in the case that specific current conditions or voltage conditions continue to be met for a certain amount of time, calculates an open circuit voltage from the terminal voltage of the secondary battery, a change-in-measured-voltage calculation part that calculates a change (Δ
Vb) in the no-load voltage or the open circuit voltage over a predetermined period of time, andan estimated charge/discharge electricity amount calculation part that calculates an estimated charge/discharge electricity amount (Δ
Qe) of the secondary battery based on the change in the no-load voltage or the open circuit voltage. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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Specification