METHOD AND DEVICE FOR DETERMINING STATE OF BATTERY, AND BATTERY POWER SUPPLY SYSTEM THEREWITH
First Claim
1. A method for determining state of a battery by estimating response voltage when a predetermined discharge current pattern is applied, to determine SOF (State Of Function) or SOH (State Of Health) of a battery, comprising the steps of:
- preparing in advance a prescribed correlative equation, a plurality of coefficients of which are given by functions of the temperature and the SOC (State Of Charge) of the battery, which calculates the response voltage when the predetermined discharge current pattern is applied, by using the measured value of either the internal impedance or the internal resistance of the battery;
determining the values of the coefficients by measuring the temperature and the SOC of the battery;
substituting the measured value of either the internal impedance or the internal resistance in the correlative equation with the values of the coefficients incorporated to calculate the response voltage when the predetermined discharge current pattern is applied; and
determining the SOF and the SOH of the battery based on the response voltage thus calculated.
1 Assignment
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Accused Products
Abstract
Coefficients A and B are calculated from the measured temperature and the measured state of charge. Next, a response voltage Vc is calculated by substituting the measured internal impedance X into a response-voltage correlation equation. Besides, by comparing the response voltage Vc with a predetermined threshold V0, if Vc is bigger than or equal to V0, the battery is determined as normal. By substituting the measured values of internal impedance, temperature, and SOC into the internal impedance calculation formula, a final internal impedance calculation formula is determined by calculating the value of C by an iterating operation. Next, in the case of determining SOH of a battery, by substituting a standard temperature and a standard SOC into the final internal impedance calculation formula, the internal impedance to determine the SOH is calculated. By comparing the internal impedance with SOH determination threshold, the SOH of the battery is determined.
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Citations
20 Claims
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1. A method for determining state of a battery by estimating response voltage when a predetermined discharge current pattern is applied, to determine SOF (State Of Function) or SOH (State Of Health) of a battery, comprising the steps of:
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preparing in advance a prescribed correlative equation, a plurality of coefficients of which are given by functions of the temperature and the SOC (State Of Charge) of the battery, which calculates the response voltage when the predetermined discharge current pattern is applied, by using the measured value of either the internal impedance or the internal resistance of the battery; determining the values of the coefficients by measuring the temperature and the SOC of the battery; substituting the measured value of either the internal impedance or the internal resistance in the correlative equation with the values of the coefficients incorporated to calculate the response voltage when the predetermined discharge current pattern is applied; and determining the SOF and the SOH of the battery based on the response voltage thus calculated. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A device for monitoring state of a battery, the device comprising:
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an internal impedance measurement unit configured to measure either internal impedance or internal resistance of a battery; a temperature sensor configured to measure temperature of the battery; an SOC sensor configured to measure SOC of the battery; and a controller in which a prescribed correlative equation is memorized in advance, a plurality of coefficients of which are given by functions of temperature and SOC (State Of Charge) of the battery, which calculates the response voltage when a predetermined discharge current pattern is applied, by using a measured value of either internal impedance or internal resistance of the battery, the values of the coefficients is determined by measuring the temperature and the SOC of the battery, the measured value of either the internal impedance or the internal resistance is substituted in the correlative equation with the values of the coefficients incorporated to calculate the response voltage when the predetermined discharge current pattern is applied, and the SOF and the SOH of the battery are determined based on the response voltage value thus calculated. - View Dependent Claims (9)
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10. A method for determining a battery state, comprising the steps of:
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preparing in advance a calculation formula to calculate internal resistance or internal impedance of a battery expressed by a predetermined function including at least one of a polynomial function, an exponential function, and a reciprocal function of temperature and SOC, a plurality of coefficients thereof being functions of one specified parameter; obtaining respective measured values by simultaneously measuring one of the internal resistance and the internal resistance, as well as the temperature and the SOC of the battery; calculating the specified parameter value by substituting the respective measured values into the calculation formula; determining the coefficients from the calculated specified parameter value; substituting the predetermined temperature and the predetermined SOC in a complete calculation formula using determined coefficients to estimate either the internal resistance or the internal impedance; and applying either the estimated internal resistance or the estimated internal impedance as an index to determine the SOH of the battery. - View Dependent Claims (11, 12, 13, 14)
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15. A device for determining state of a battery by estimating either internal resistance or internal impedance of a battery at the predetermined temperature and the predetermined SOC, and applying either the estimated internal resistance or the estimated internal impedance as an index to determine the state of a battery, the device comprising:
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an internal impedance measurement unit configured to measure either an internal impedance or an internal resistance of a battery; a temperature sensor configured to measure the temperature of the battery; an SOC sensor configured to measure the SOC of the battery; and a controller configured to prepare in advance and store a calculation formula for calculating either the internal resistance or the internal impedance expressed by a function including at least one of a polynomial function, an exponential function, and a reciprocal function of the temperature and the SOC with a plurality of coefficients thereof expressed by functions of one specified parameter, input respective measured values of either the internal resistance or the internal impedance, as well as the temperature and the SOC which are simultaneously measured by the internal impedance measurement unit, the temperature sensor and the SOC sensor, substitute the measured values of either the internal resistance or the internal impedance, as well as the temperature and the SOC in the calculation formula to calculate the specified parameter, and substitute the predetermined temperature and the predetermined SOC in a complete calculation formula using the coefficients determined from the calculated specified parameter to estimate either the internal resistance or the internal impedance. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification