Method of detecting battery capacity of secondary battery

Patent metadata

Field	Value
Publication number	US-9566875-B2
Application number	US-201113637946-A
Country	US
Kind code	B2
Filing date	Mar 11, 2011
Priority date	Mar 30, 2010
Publication date	Feb 14, 2017
Grant date	Feb 14, 2017

Abstract

A method detecting a battery capacity of a secondary battery, in which charging mode includes first mode including only ON state, and second mode including ON state and OFF state, the method includes: charging mode selection process of selecting the charging mode; internal resistance calculation process calculating internal resistance of secondary battery when ON state and OFF state are switched; remaining capacity calculation process calculating remaining capacity of secondary battery; remaining capacity variation amount calculation process calculating variation amount of remaining capacity from most recent full charge capacity calculation time; charged electricity amount calculation process of calculating amount of charged electricity in accordance with integrated value of current that flowed from point of time at which most recent full charge capacity is calculated; and full charge capacity detection process of detecting full charge capacity of secondary battery based on variation amount of remaining capacity and amount of charged electricity.

First claim

The invention claimed is:

1. A method of detecting a battery capacity of a secondary battery that is mounted on an electrically driven vehicle that is capable of being charged by an external charger, in which a charging mode when the secondary battery is charged by the external charger includes a first mode including only an ON state in which a power transmission of a charging power is performed, and a second mode including the ON state and an OFF state in which the power transmission is temporarily stopped, the method comprising:
a charging mode selection process of selecting the charging mode while the charging by the external charger is performed;
an internal resistance calculation process of calculating an internal resistance of the secondary battery by using variation amounts of a voltage and a current of the secondary battery when the ON state and the OFF state are switched from each other, in a case where the second mode is selected in the charging mode selection process, and the second mode includes temporarily stopping the power transmission in the OFF state for a plurality of times;
a remaining capacity calculation process of calculating an open voltage of the secondary battery based on the internal resistance and calculating a remaining capacity of the secondary battery from the open voltage that is a result of the calculation;
a remaining capacity variation amount calculation process of calculating a variation amount of the remaining capacity from a most recent full charge capacity calculation time;
a charged electricity amount calculation process of calculating an amount of charged electricity in accordance with an integrated value of the current that flowed from a point of time at which the most recent full charge capacity is calculated; and
a full charge capacity detection process of detecting a full charge capacity of the secondary battery based on the variation amount of the remaining capacity and the amount of the charged electricity;
wherein in the full charge capacity detection process, a value, which is obtained by multiplying a present detection value of the full charge capacity that is detected based on the variation amount of the remaining capacity and the amount of the charged electricity and at least a most recent detection value of the full charge capacity by an arbitrary weighting factor, is newly set to a present detection value of the full charge capacity,
and
an instruction of an execution of the second mode by the charging mode selection process is performed based on the calculated variation amount of an increase of the remaining capacity.

2. The method according to claim 1 , further comprising:
a current sensor error correction process of detecting an error of a current sensor from a detection result of the current, which is output from the current sensor that detects the charging and discharging current of the secondary battery, in the OFF state, and performing correction by using the error, in a case where the second mode is selected in the charging mode selection process.

3. The method according to claim 2 ,
wherein in the current sensor error correction process, the error is detected whenever the ON state transitions to the OFF state, and the correction is performed using a value that is obtained by averaging the errors that are detected within the second mode.

4. The method according to claim 1 ,
wherein in a case where the second mode is selected in the charging mode selection process,
the charging by the external charger is performed by transmission of the charging power having a pulse wave in which duration times of the ON state and the OFF state are different from each other,
in the internal resistance calculation process, the internal resistance is calculated whenever the ON state and the OFF state are switched from each other, and
in the remaining capacity calculation process, the open voltage is calculated using the internal resistance that is calculated in the internal resistance calculation process within the second mode.

5. The method according to claim 1 ,
wherein in the internal resistance calculation process, a value of the internal resistance is calculated using a variation amount of the current when the ON state and the OFF state are switched from each other, and a variation amount of a voltage, which is output from a voltage sensor that detects the voltage of the secondary battery, when the ON state and the OFF state are switched from each other.

6. The method according to claim 1 ,
wherein in the remaining capacity calculation process, in a case where a difference between a voltage computation value, which is computed based on an equivalent circuit model, of the secondary battery and a detection result of a voltage output from a voltage sensor that detects the voltage of the secondary battery is less than or equal to a predetermined threshold value, the remaining capacity is calculated.

7. A method of detecting a battery capacity of a secondary battery that is mounted on an electrically driven vehicle that is capable of being charged by an external charger, in which a charging mode when the secondary battery is charged by the external charger includes a first mode including only an ON state in which a power transmission of a charging power is performed, and a second mode including the ON state and an OFF state in which the power transmission is temporarily stopped, the method comprising:
a charging mode selection process of selecting the charging mode while the charging by the external charger is performed;
a current sensor error correction process, performed by an electronic control unit, of detecting an error of a current sensor from a detection result of the current, which is output from the current sensor that detects the charging and discharging current of the secondary battery, in the OFF state, and performing correction by using the error, in a case where the second mode is selected in the charging mode selection process, and the second mode includes temporarily stopping the power transmission in the OFF state for a plurality of times;
an internal resistance calculation process of calculating an internal resistance of the secondary battery by using variation amounts of a voltage and a current of the secondary battery when the ON state and the OFF state are switched from each other, in a case where the second mode is selected in the charging mode selection process;
a remaining capacity calculation process of calculating an open voltage of the secondary battery based on the internal resistance and calculating a remaining capacity of the secondary battery from the open voltage that is a result of the calculation;
a remaining capacity variation amount calculation process of calculating a variation amount of the remaining capacity from a most recent full charge capacity calculation time;
a charged electricity amount calculation process of calculating an amount of charged electricity in accordance with an integrated value of the current that flowed from a point of time at which the most recent full charge capacity is calculated; and
a full charge capacity detection process of detecting a full charge capacity of the secondary battery based on the variation amount of the remaining capacity and the amount of the charged electricity,
wherein an instruction of an execution of the second mode by the charging mode selection process is performed based on the calculated variation amount of an increase of the remaining capacity.

8. The method according to claim 7 ,
wherein in a case where the second mode is selected in the charging mode selection process,
the charging by the external charger is performed by transmission of the charging power having a pulse wave in which duration times o

Assignees

• Kawakita Koji
• Honda Motor Co Ltd

Inventors

• Kawakita Koji

Classifications

• H02J7/947

  in response to integrated charge or discharge current · CPC title

• B60L2260/44

  by parameter estimation · CPC title

• B60L2240/549

  Current · CPC title

• G01R31/3832

  without measurement of battery voltage · CPC title

• H02J7/044

  Electricity · mapped topic