Method for managing charging and discharging of parallel-connected battery pack, electronic device, and electrical system

Patent metadata

Field	Value
Publication number	US-11949273-B2
Application number	US-202117281667-A
Country	US
Kind code	B2
Filing date	Feb 9, 2021
Priority date	Mar 27, 2020
Publication date	Apr 2, 2024
Grant date	Apr 2, 2024

Abstract

A method for managing charging and discharging of a parallel-connected battery pack, including: obtaining a voltage value and a state of charge of a plurality of battery packs; comparing the voltage value and the state of charge of each of the battery packs with a reference voltage value and a reference state of charge; and managing charging and discharging of the plurality of battery packs based on a comparison result. The method can enhance automation of paralleling of battery packs, increase adaptability of a paralleling system, improve paralleling efficiency, further reduce operation and maintenance costs, and improve user experience.

First claim

What is claimed is:

1. A method for managing charging and discharging of a plurality of battery packs connected in parallel, comprising:
obtaining a voltage value and a state of charge of the plurality of battery packs connected in parallel;
comparing the voltage value and the state of charge of each of the plurality of battery packs with a reference voltage value and a reference state of charge; and
managing charging and discharging of the plurality of battery packs based on a comparison result, and managing the plurality of battery packs connecting to a power bus based on the comparison result.

2. The method for managing charging and discharging of a plurality of battery packs connected in parallel according to claim 1 , wherein the reference voltage value is obtained by using a minimum value of voltage values of the plurality of battery packs as the reference voltage value when none of the plurality of battery packs is connected to a power bus.

3. The method for managing charging and discharging of a plurality of battery packs connected in parallel according to claim 1 , wherein the reference state of charge is obtained by using a minimum value of states of charge of the plurality of battery packs as the reference state of charge when none of the plurality of battery packs is connected to a power bus.

4. The method for managing charging and discharging of a plurality of battery packs connected in parallel according to claim 1 , wherein the reference voltage value is obtained by using a minimum value of voltage values of battery packs already connected to a power bus as the reference voltage value when at least one battery pack is already connected to the power bus.

5. The method for managing charging and discharging of a plurality of battery packs connected in parallel according to claim 1 , wherein the reference state of charge is obtained by using a minimum value of states of charge of battery packs already connected to a power bus as the reference state of charge when at least one battery pack is already connected to the power bus.

6. The method for managing charging and discharging of a plurality of battery packs connected in parallel according to claim 1 , further comprising:
obtaining a quantity of battery packs already connected to a power bus; and
determining a charge current limit value I charge and a discharge current limit value I discharge of a power conversion system.

7. The method for managing charging and discharging of a plurality of battery packs connected in parallel according to claim 6 , wherein
I charge =a×k 1 ×P m ,
wherein, I charge is the charge current limit value, a is a 1C current of the battery pack, k 1 is a charge current-limiting coefficient, and P m is the quantity of battery packs already connected to the power bus.

8. The method for managing charging and discharging of a plurality of battery packs connected in parallel according to claim 6 , wherein
I discharge =a×k 2 ×P m ,
wherein, I discharge is the discharge current limit value I discharge , a is a 1C current of the battery pack, k 2 is a discharge current-limiting coefficient, and P m is the quantity of battery packs already connected to the power bus.

9. The method for managing charging and discharging of a plurality of battery packs connected in parallel according to claim 1 , wherein the managing charging and discharging of the plurality of battery packs based on a comparison result comprises:
determining, when none of the plurality of battery packs is connected to a power bus, whether a difference between the voltage value of all the battery packs and the reference voltage value is less than a first threshold, and whether a difference between the state of charge of all the battery packs and the reference state of charge is less than a second threshold; and
controlling the battery packs to sequentially connect to the power bus if the difference between the voltage value of all the battery packs and the reference voltage value is less than the first threshold, and if the difference between the state of charge of all the battery packs and the reference state of charge is less than the second threshold.

10. The method for managing charging and discharging of a plurality of battery packs connected in parallel according to claim 9 , wherein the managing charging and discharging of the plurality of battery packs based on a comparison result further comprises:
determining, when at least one battery pack is already connected to the power bus and the battery pack is in a charging state, whether a difference between the voltage value of battery packs not connected to the power bus and the reference voltage value is within a first range, and whether a difference between the state of charge of the battery packs not connected to the power bus and the reference state of charge is within a second range; and
controlling the battery packs to sequentially connect to the power bus if the difference between the voltage value of all the battery packs not connected to the power bus and the reference voltage value is within the first range, and if the difference between the state of charge of all the battery packs not connected to the power bus and the reference state of charge is within the second range.

11. The method for managing charging and discharging of a plurality of battery packs connected in parallel according to claim 10 , wherein the managing charging and discharging of the plurality of battery packs based on a comparison result further comprises:
determining, when at least one battery pack is already connected to the power bus and the battery packs not connected to the power bus are in a discharging state, whether a difference between the reference voltage value and the voltage value of all the battery packs not connected to the power bus is within a third range, and whether a difference between the reference state of charge and the state of charge of all the battery packs not connected to the power bus is within a fourth range; and
controlling the battery packs to sequentially connect to the power bus if the difference between the reference voltage value and the voltage value of all the battery packs not connected to the power bus is within the third range, and if the difference between the reference state of charge and the state of charge of all the battery packs not connected to the power bus is within the fourth range.

12. The method for managing charging and discharging of a plurality of battery packs connected in parallel according to claim 11 , further comprising:
receiving fault alarm information when a fault alarm occurs on a battery pack; and
controlling all the battery packs to disconnect from the power bus or controlling the faulty battery pack to separately disconnect from the power bus.

13. An electronic device, wherein the electronic device comprises:
a plurality of battery packs; and
a battery management unit, configured to perform the method for managing charging and discharging according to claim 1 .

14. An electrical system, wherein the electrical system comprises a power conversion system and the electronic device according to claim 13 , and the electronic device further comprises a plurality of switches in one-to-one correspondence to a plurality of battery packs, and each switch is connected between the battery packs and the power conversion system.

Assignees

• Dongguan Poweramp Tech Limited

Inventors

• Zhong Di
• Zeng si

Classifications

• H02J7/84

  Control of state of health [SOH] · CPC title

• H02J7/82

  Control of state of charge [SOC] · CPC title

• H02J7/60

  including safety or protection arrangements · CPC title

• H02J7/50

  acting upon multiple batteries simultaneously or sequentially · CPC title

• H02J7/96 Primary

  in response to battery voltage · CPC title