Charging control device and charging unit

Patent metadata

Field	Value
Publication number	US-11283279-B2
Application number	US-201916600750-A
Country	US
Kind code	B2
Filing date	Oct 14, 2019
Priority date	Apr 14, 2017
Publication date	Mar 22, 2022
Grant date	Mar 22, 2022

Abstract

Provided is a charging control device including a current detector, an abnormal current determination circuit, and a charging stop circuit. The current detector is configured to detect a charging current, the abnormal current determination circuit is configured to determine whether the charging current is attenuated and/or increased in a constant voltage charging region, and to determine whether a value of the charging current per unit time is increased, and the charging stop circuit is configured to stop a constant voltage charging when the value of the charging current per unit time is increased.

First claim

The invention claimed is:

1. A charging control device comprising a current detector, an abnormal current determination circuit, and a charging stop circuit,
wherein the current detector is configured to detect a difference (d log(In)/dt−d log(I(n−1))/dt) between d log(In)/dt and d log(I(n−1))/dt, which are log values per unit time of at least two consecutive charging currents at a specified time interval,
wherein the abnormal current determination circuit is configured to determine that the difference (d log(In)/dt−d log(I(n−1))/dt) changes from a negative value to a positive value and
wherein the charging stop circuit is configured to stop a constant voltage charging when the difference (d log(In)/dt−d log(I(n−1))/dt) changes from a negative value to a positive value.

2. The charging control device according to claim 1 , further comprising
a battery temperature detector and an abnormal temperature determination circuit,
wherein the battery temperature detector is configured to detect a battery temperature,
wherein the abnormal temperature determination circuit is configured to determine whether the battery temperature in a constant voltage region is 45° C. or higher, and
wherein the charging stop circuit is configured to stop the constant voltage charging when the battery temperature is 45° C. or higher.

3. The charging control device according to claim 1 , further comprising
a battery temperature detector and an abnormal temperature determination circuit,
wherein the battery temperature detector is configured to detect a battery temperature,
wherein the abnormal temperature determination circuit is configured to determine whether the battery temperature in the constant voltage region is higher than the battery temperature at a start of the constant voltage charging and to determine whether a rate of increase in the battery temperature in the constant voltage region is greater than a maximum value of a rate of increase in the battery temperature in the constant current charging region, and
wherein the charging stop circuit is configured to stop the constant voltage charging when the battery temperature in the constant voltage region is higher than the battery temperature at a start of the constant voltage charging, and the rate of increase in the battery temperature in the constant voltage region is greater than the maximum value of the rate of increase in the battery temperature in the constant current charging region.

4. The charging control device according to claim 1 , further comprising
a battery temperature detector, an outside air temperature detector, and an abnormal temperature determination circuit, wherein
the battery temperature detector is configured to detect a battery temperature, wherein
the outside air temperature detector is configured to detect an outside air temperature, wherein
the abnormal temperature determination circuit is configured to determine whether a rate of increase in the battery temperature in the constant voltage region is greater than a rate of increase in an outside air temperature, and wherein
the charging stop circuit is configured to stop the constant voltage charging when the rate of increase in the battery temperature in the constant voltage region is greater than the rate of increase in the outside air temperature.

5. The charging control device according to claim 1 , wherein
the current detector is configured to detect a difference (I n −I (n-1) ) between I n and I (n-1) , which are at least two consecutive charging current values at a specified time interval, and wherein
the abnormal current determination circuit is configured to determine that the difference (I n −I (n-1) ) changes from a negative value to a positive value.

6. The charging control device according to claim 1 , wherein
the current detector is configured to detect a difference (Ima n −Ima (n-1) ) between Ima n obtained by applying a moving average to at least two consecutive charging current values at a specified time interval, and Ima (n-1) obtained by applying a moving average to at least two further consecutive charging current values at a specified time interval, and wherein
the abnormal current determination circuit is configured to determine that the difference (Ima n −Ima (n-1) ) changes from a negative value to a positive value.

7. The charging control device according to claim 1 , wherein
the current detector is configured to detect a first difference (Ia n −Ia (n-1) ) between Ia n and Ia (n-1) , which are at least two consecutive charging current values at a specified time interval, and to detect a second difference (Ib n −Ib (n-1) ) between Ib n and Ib (n-1) , which are at least two consecutive charging current values at a specified time interval, and to detect a third difference (ma(ΔI n )) obtained by applying a moving average to at least the first difference (Ia n −Ia (n-1) ) and the second difference (Ib n −Ib (n-1) ), and wherein
the abnormal current determination circuit is configured to determine that the third difference (ma(ΔI n )) obtained by applying the moving average changes from a negative value to a positive value.

8. The charging control device according to claim 1 , wherein
the current detector is configured to detect a ratio (I n /I (n-1) ) between I n and I (n-1) , which are at least two consecutive charging current values at a specified time interval, and wherein
the abnormal current determination circuit is configured to determine that the ratio (I n /I (n-1) ) changes from a value of 1 or less to a value of more than 1.

9. The charging control device according to claim 1 , wherein
the current detector to detect a ratio (Ima n /Ima (n-1) ) between Ima n obtained by applying a moving average to at least two consecutive charging current values at a specified time interval, and Ima (n-1) obtained by applying a moving average to at least two further consecutive charging current values at a specified time interval, and wherein
the abnormal current determination circuit is configured to determine that the ratio (Ima n /Ima (n-1) ) changes from a value of 1 or less to a value of more than 1.

10. The charging control device according to claim 1 , wherein
the current detector is configured to detect a first ratio (Ia n /Ia (n-1) ) between Ia n and Ia (n-1) , which are at least two consecutive charging current values at a specified time interval, and to detect a second ratio (Ib n /Ib (n-1) ) between Ib n and Ib (n-1) , which are at least two consecutive charging current values at a specified time interval, and to detect a third ratio (ma(r)) obtained by applying a moving average to at least the first ratio (Ia n /Ia (n-1) ) and the second ratio (Ib n /Ib (n-1) ), and wherein
the abnormal current determination circuit is configured to determine that the third ratio (ma(r)) obtained by applying the moving average changes from a value of 1 or less to a value of more than 1.

11. The charging control device according to claim 1 , wherein
the current detector is configured to detect a difference (ma(d log(I n )/dt))−ma(d log(I (n-1) )/dt)) between ma(d log(I n )/dt) obtained by applying a moving average to log values per unit time of at least two consecutive charging currents at a specified time interval, and ma(d log(I (n-1) )/dt) obtained by applying a moving average to values of at least two further consecutive charging currents at a specified time interval, and wherein
the abnormal current determination circuit is configured to determine that the difference (ma(d log(I n )/dt))−ma(d log(I (n-1) )/dt)) changes from a negative value to a positive value.

12. The charging control device according to

Assignees

• Murata Manufacturing Co

Inventors

• Katase Natsuko
• Shimura Jusuke

Classifications

• H02J2101/30

  Fuel cells · CPC title

• H02J2101/24

  Photovoltaics · CPC title

• H02J7/62

  against overcurrent · CPC title

• H02J7/975

  in response to temperature · CPC title

• H02J7/953

  in response to charge current gradient · CPC title