Battery pack system, control method thereof and management device

Patent metadata

Field	Value
Publication number	US-10886757-B2
Application number	US-201916243373-A
Country	US
Kind code	B2
Filing date	Jan 9, 2019
Priority date	May 22, 2018
Publication date	Jan 5, 2021
Grant date	Jan 5, 2021

Abstract

A battery pack system, a control method thereof and a management device are provided. A battery pack is connected in series with a discharge circuit unit and a charge circuit unit; a battery management unit is to monitor a temperature of the battery pack, to periodically send, when the temperature of the battery pack is lower than a threshold, a turn-on-instruction to the discharge circuit unit and the charge circuit unit alternately to control the discharge circuit unit and the charge circuit unit to be alternately turned on in heating cycles; the discharge circuit unit is to be turned on according to the turn-on-instruction to enable electricity of the battery pack to flow into the energy storage unit in discharging-phase; and the charge circuit unit is to be turned on according to the turn-on-instruction to enable electricity of the energy storage unit to flow into the battery pack in charging-phase.

First claim

What is claimed is:

1. A battery pack system comprising a battery pack, a battery management unit, a discharge circuit unit, a charge circuit unit and an energy storage unit, wherein:
the battery pack is connected in series with the discharge circuit unit, and the battery pack is connected in series with the charge circuit unit;
the battery management unit is connected to the discharge circuit unit, the charge circuit unit and the battery pack, the battery management unit is configured to monitor a temperature of the battery pack and a state of charge (SOC) of the battery pack, and when the temperature of the battery pack is lower than a first temperature threshold and the SOC of the battery pack is higher than a SOC threshold, periodically send a turn-on instruction to the discharge circuit unit and the charge circuit unit alternately to control the discharge circuit unit and the charge circuit unit to be alternately turned on in each of heating cycles, wherein each of the heating cycles comprises a discharging phase and a charging phase;
the discharge circuit unit is connected to the energy storage unit, and the discharge circuit unit is configured to turn on the discharge circuit unit according to the turn-on instruction to enable electricity of the battery pack to flow into the energy storage unit in the discharging phase;
the charge circuit unit is connected to the energy storage unit, and the charge circuit unit is configured to turn on the charge circuit unit according to the turn-on instruction to enable electricity of the energy storage unit to flow into the battery pack in the charging phase;
the energy storage unit is configured to store and release electricity; and
a total duration of discharging phases of all of the heating cycles is greater than a total duration of charging phases of all of the heating cycles.

2. The battery pack system of claim 1 , wherein in each of the heating cycles, a duration of the discharging phase is greater than a duration of the charging phase.

3. The battery pack system of claim 1 wherein the heating cycle further comprises a dead-time phase during which both of the discharge circuit unit and the charge circuit unit are turned off.

4. The battery pack system of claim 1 , wherein the battery back system further comprises a current detecting unit, the current detecting unit is connected to the battery pack, the battery management unit, the discharge circuit unit and the charge circuit unit, and the current detecting unit is configured to monitor a current of a path of the battery pack system; and
the battery management unit is further configured to send, in the charging phase, a turn-off instruction to the charge circuit unit when the current of the path of the battery pack system reaches a charging current threshold.

5. The battery pack system of claim 1 , wherein the battery pack system further comprises a main switch unit, the main switch unit is connected to the battery pack, and the main switch unit is configured to control whether the electricity of the battery pack flows into the discharge circuit unit or the charge circuit unit.

6. The battery pack system of claim 1 , wherein the battery management unit is further configured to send, when the temperature of the battery pack is higher than a second temperature threshold, a turn-off instruction to the discharge circuit unit and the charge circuit unit so as to disconnect the battery pack from the discharge circuit unit and the charge circuit unit.

7. A method for controlling the battery pack system of claim 1 , comprising:
monitoring a temperature of the battery pack and a state of charge (SOC) of the battery pack; and
periodically sending, when the temperature of the battery pack is lower than a first temperature threshold and the SOC of the battery pack is higher than a SOC threshold, a turn-on instruction to the discharge circuit unit and the charge circuit unit alternately to enable electricity to be transferred between the battery pack and the energy storage unit in heating cycles, wherein each of the heating cycles comprises a discharging phase and a charging phase, and a total duration of discharging phases of all of the heating cycles is greater than a total duration of charging phases of all of the heating cycles.

8. The method of claim 7 , wherein in each of the heating cycles, a duration of the discharging phase is greater than a duration of the charging phase.

9. The method of claim 7 , wherein the heating cycle further comprises a dead-time phase during which both of the discharge circuit unit and the charge circuit unit are turned off.

10. A management device comprising a memory, a processor and a program stored in the memory and executable in the processor, wherein the program, when executed by the processor, causes the processor to perform the method of claim 9 .

11. The method of claim 7 , further comprising:
monitoring a current of a path of the battery pack system; and
sending, in the charging phase, a turn-off instruction to the charge circuit unit when the current of the path of the battery pack system reaches a charging current threshold.

12. A management device comprising a memory, a processor and a program stored in the memory and executable in the processor, wherein the program, when executed by the processor, causes the processor to perform the method of claim 11 .

13. The method of claim 7 , wherein periodically sending, when the temperature of the battery pack is lower than a first temperature threshold and the SOC of the battery pack is higher than a SOC threshold, a turn-on instruction to the discharge circuit unit and the charge circuit unit alternately comprises:
sending, when the temperature of the battery pack is lower than a first temperature threshold and the SOC of the battery pack is higher than the SOC threshold, a turn-on instruction to the main switch unit, to enable electricity of the battery pack to flow into the discharge circuit unit or the charge circuit unit; and
periodically sending the turn-on instruction to the discharge circuit unit and the charge circuit unit alternately.

14. A management device comprising a memory, a processor and a program stored in the memory and executable in the processor, wherein the program, when executed by the processor, causes the processor to perform the method of claim 13 .

15. The method of claim 7 , further comprising:
sending, when the temperature of the battery pack is higher than a second temperature threshold, a turn-off instruction to the discharge circuit unit and the charge circuit unit so as to disconnect the battery pack from the discharge circuit unit and the charge circuit unit.

16. A management device comprising a memory, a processor and a program stored in the memory and executable in the processor, wherein the program, when executed by the processor, causes the processor to perform the method of claim 15 .

17. A management device comprising a memory, a processor and a program stored in the memory and executable in the processor, wherein the program, when executed by the processor, causes the processor to perform the method of claim 7 .

Assignees

• Contemporary Amperex Technology Co Ltd

Inventors

• Zuo Xiyang
• Dan Zhimin
• Zhang Wei
• Hou Yizhen
• Yu Teng
• Lu Wenbin
• Wu Xingyuan
• Zhu Taosheng

Classifications

• H02J7/62

  against overcurrent · CPC title

• H02J7/65

  against overtemperature · CPC title

• H02J7/667

  disconnection of loads if battery is not under charge, e.g. in vehicle if engine is not running · CPC title

• H01M10/482

  for several batteries or cells simultaneously or sequentially · CPC title

• H01M10/486

  for measuring temperature · CPC title