Heating method for rechargeable battery, control unit and heating circuit

Patent metadata

Field	Value
Publication number	US-11515588-B2
Application number	US-202016860408-A
Country	US
Kind code	B2
Filing date	Apr 28, 2020
Priority date	May 28, 2019
Publication date	Nov 29, 2022
Grant date	Nov 29, 2022

Abstract

Disclosed are a heating method for a rechargeable battery, a control unit and a heating circuit. The heating method comprises: determining a frequency value of a pulse current for heating the rechargeable battery in response to a heating command of the rechargeable battery; determining a current value of the pulse current according to the frequency value and an acquired state parameter of the rechargeable battery; judging whether the current value satisfies a preset heating demand; if the current value satisfies the heating demand, generating the pulse current under control according to the frequency value; if the current value does not satisfy the heating demand, re-determining the frequency value and the current value of the pulse current. The embodiments of the present disclosure further provide a control unit and a heating circuit.

First claim

What is claimed is:

1. A heating method for a rechargeable battery, comprising:
acquiring, a state parameter of the rechargeable battery, wherein the state parameter comprises a remaining power amount;
selecting, a frequency value from a frequency value interval, according to a preset correspondence between a remaining power amount interval and the frequency value interval, wherein the remaining power amount interval is an interval to which the remaining power amount belongs;
determining, according to the frequency value and the remaining power amount, a current value of a pulse current;
estimating, a theoretical heating rate of the rechargeable battery as heated by the pulse current of the current value; and
generating, the pulse current according to the frequency value, based on a first matching condition, wherein the first matching condition is that a difference between the theoretical heating rate and a target heating rate is less than a preset first difference.

2. The heating method for the rechargeable battery according to claim 1 , wherein, the
state parameter further comprises a battery temperature of the rechargeable battery;
wherein the selecting, a frequency value from a frequency value interval, according to a preset correspondence between a remaining power amount interval and the frequency value interval, comprises:
acquiring, a temperature threshold corresponding to the remaining power amount;
selecting, the frequency value from the frequency value interval, according to the preset correspondence between the remaining power amount interval and the frequency value interval, based on that the battery temperature is lower than the temperature threshold.

3. The heating method for the rechargeable battery according to claim 1 , wherein, the estimating, a theoretical heating rate of the rechargeable battery as heated by the pulse current of the current value, comprises:
calculating, the theoretical heating rate according to the current value, mass of battery cells of the rechargeable battery, specific heat capacity of the battery cells of the rechargeable battery, and thermal conductivity of the battery cells of the rechargeable battery.

4. The heating method for the rechargeable battery according to claim 1 , wherein the method further comprises:
collecting an actual current value of the pulse current;
estimating an actual heating rate of the rechargeable battery as heated by the pulse current of the actual current value; and
wherein the generating, the pulse current according to the frequency value, based on a first matching condition, comprises:
generating, the pulse current according to the frequency value, based on the first matching condition and a second matching condition, wherein the second matching condition is that a difference between the actual heating rate and the target heating rate is less than a preset second difference.

5. The heating method for the rechargeable battery according to claim 4 , wherein the method further comprises:
adjusting, the frequency value according to a preset manner, based on that the difference between the actual heating rate and the target heating rate is larger than the preset second difference, wherein the preset manner comprises addition or deduction of a step value on the frequency value.

6. The heating method for the rechargeable battery according to claim 4 , wherein the preset second difference is less than the preset first difference.

7. The heating method for the rechargeable battery according to claim 1 , wherein, the method further comprises:
estimating, a heating duration of the rechargeable battery according to the current value of the pulse current;
stopping, generating the pulse current after the heating duration.

8. The heating method for the rechargeable battery according to claim 7 , wherein the state parameter further comprises a battery temperature of the rechargeable battery;
wherein the estimating, a heating duration of the rechargeable battery according to the current value of the pulse current, comprises:
calculating, a temperature difference between the battery temperature and a target temperature;
estimating, the heating rate according to the current value of the pulse current; and
calculating, the heating duration according to the heating rate and the temperature difference.

9. The heating method for the rechargeable battery according to claim 1 , wherein the state parameter further comprises a battery temperature of the rechargeable battery; wherein the method further comprises:
stopping, generating the pulse current base on that the battery temperature is not lower than the temperature threshold.

10. A control unit in a heating circuit, wherein the control unit is configured to:
collect a state parameter of a rechargeable battery through a second collecting unit, wherein the state parameter comprises a remaining power amount;
select a frequency value from a frequency value interval, according to a preset correspondence between a remaining power amount interval and the frequency value interval, wherein the remaining power amount interval is an interval to which the remaining power amount belongs;
determine a current value of a pulse current according to the frequency value and the remaining power amount;
estimate a theoretical heating rate of the rechargeable battery as heated by the pulse current of the current value; and
generate the pulse current through controlling ON or OFF of a switch unit according to the frequency value, based on a first matching condition, wherein the first matching condition is that a difference between the theoretical heating rate and a target heating rate is less than a preset first difference.

11. The control unit according to claim 10 , wherein, the control unit is configured to:
collect the state parameter of the rechargeable battery through the second collecting unit,
wherein the state parameter further comprises a battery temperature of the rechargeable battery;
the control unit is further configured to acquire a temperature threshold corresponding to the remaining power amount; and
the control unit is specifically configured to: select the frequency value from the frequency value interval, according to the preset correspondence between the remaining power amount interval and the frequency value interval, when the battery temperature is lower than the temperature threshold, generate the heating command.

12. The control unit according to claim 10 , wherein the control unit is specifically configured to:
calculate the theoretical heating rate according to the current value, mass of battery cells of the rechargeable battery, specific heat capacity of the battery cells of the rechargeable battery, and thermal conductivity of the battery cells of the rechargeable battery.

13. The control unit according to claim 10 , wherein the control unit is further configured to:
collect an actual current value of the pulse current through a first collecting unit;
estimate an actual heating rate of the rechargeable battery as heated by the pulse current of the actual current value; and
the control unit is specifically configured to: generate the pulse current through controlling ON or OFF of the switch unit according to the frequency value, based on the first matching condition and a second matching condition, wherein the second matching condition is that a difference between the actual heating rate and the target heating rate is less than a preset second difference.

14. The control unit according to claim 13 , wherein the control unit is specifically configured to:
generate the pulse current t

Assignees

• Contemporary Amperex Technology Co Ltd

Inventors

• Du Xinxin
• Dan Zhimin
• Luo Fuping
• Wang Shengwei
• Wang Tiancong
• Zuo Xiyang

Classifications

• H02J7/80

  including monitoring or indicating arrangements · CPC title

• H01M10/637 Primary

  characterised by the use of reversible temperature-sensitive devices, e.g. NTC, PTC or bimetal devices; characterised by control of the internal current flowing through the cells, e.g. by switching (means for preventing undesired use or discharge H01M50/572) · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M10/615 Primary

  Heating or keeping warm · CPC title

• H01M10/6571

  Resistive heaters (arrangements for heating the battery by its resistance to the internal current H01M10/637) · CPC title