Energy storage system and energy storage system control method

Patent metadata

Field	Value
Publication number	US-12562585-B2
Application number	US-202418979531-A
Country	US
Kind code	B2
Filing date	Dec 12, 2024
Priority date	Oct 20, 2022
Publication date	Feb 24, 2026
Grant date	Feb 24, 2026

Abstract

An embodiment of this application provides an energy storage system and an energy storage system control method. The energy storage system includes N battery clusters and N-X first conversion units, where N is a positive integer greater than 1 and X is a positive integer less than N. A first side of each of N-X first conversion units is connected in series to a power transmission circuit of one of N-X first battery clusters among the N battery clusters, so as to combine with a corresponding first battery cluster to form a series branch circuit. The N-X series branch circuits are connected in parallel to X second battery clusters in the N battery clusters.

First claim

What is claimed is:

1 . An energy storage system, wherein the energy storage system comprises N battery clusters and N-X first conversion units, wherein N is a positive integer greater than 1 and X is a positive integer less than N;
a first side of each of N-X first conversion units is connected in series to a power transmission circuit of one of N-X first battery clusters among the N battery clusters, so as to combine with a corresponding first battery cluster to form a series branch circuit of N-X series branch circuits; and the N-X series branch circuits are connected in parallel to X second battery clusters in the N battery clusters, wherein each of the X second battery clusters is not connected in series to a first conversion unit; the energy storage system further comprises a management unit, wherein the management unit is configured to control, based on status of the series branch circuit, the first conversion unit to regulate a voltage of the first battery cluster corresponding to the first conversion unit; the management unit is configured to: control, in a case that a voltage difference between the series branch circuit and the X second battery clusters is less than a first threshold, the series branch circuit to be connected in parallel to the X second battery clusters; the management unit is configured to: control, in a case that a SOC difference between the series branch circuit and the X second battery clusters is greater than a second threshold, the first conversion unit to regulate a current of the corresponding first battery cluster so that a SOC difference between the first battery cluster corresponding to the first conversion unit and the X second battery clusters is less than the second threshold, and control the series branch circuit to be connected in parallel to the X second battery clusters; and a regulation manner of a current I 2 , which is a current value to which the first conversion unit needs to regulate the corresponding first battery cluster, is:

I
2

=

I
+

f
⁡
(

Δ
⁢
SOC

)

in a case that ΔSOC is greater than 0,

f
⁡
(

Δ
⁢
SOC

)

=

k
*

(

(

1
+

Δ
⁢
SOC

)

n

-
1

)

in a case that ΔSOC is less than 0,

f
⁡
(

Δ
⁢
SOC

)

=

-
k

*

(

(

1
+

Δ
⁢
SOC

)

n

-
1

)

wherein ΔSOC is the SOC difference between the first battery cluster corresponding to the first conversion unit and the X second battery clusters, I is an average cluster current of the X second battery clusters, k is a linear coefficient, and n is a power exponent.

2 . The energy storage system according to claim 1 , wherein the management unit is configured to:
controlling, in a case that a voltage difference between the series branch circuit and the X second battery clusters is greater than a first threshold, the first conversion unit to regulate the voltage of the corresponding first battery cluster so that a voltage difference between the first battery cluster corresponding to the first conversion unit and the X second battery clusters is less than the first threshold, and controlling the series branch circuit to be connected in parallel to the X second battery clusters.

3 . The energy storage system according to claim 1 , wherein the management unit is further configured to:
control, in a case that a SOC difference between the series branch circuit and the X second battery clusters is less than or equal to a second threshold, the series branch circuit to be connected in parallel to the X second battery clusters.

4 . The energy storage system according to claim 1 , wherein the energy storage system further comprises a second conversion unit, wherein a first side of the second conversion unit is connected to a power grid, and a second side of the second conversion unit is connected to a second side of the first conversion unit.

5 . The energy storage system according to claim 4 , wherein, in a case that the first conversion unit is a DC-to-DC converter and the second conversion unit is a DC-to-DC converter, the second conversion unit is connected to a direct-current side of the power grid.

6 . The energy storage system according to claim 4 , wherein, in a case that the first conversion unit is a DC-to-DC converter and the second conversion unit is a DC-to-AC converter, the second conversion unit is connected to an alternating-current side of the power grid.

7 . The energy storage system according to claim 4 , wherein, in a case that the first conversion unit is a DC-to-DC converter and the second conversion unit is a direct-current power source, each first conversion unit is equipped with one second conversion unit.

8 . The energy storage system according to claim 4 , wherein, in a case that the first conversion unit is a DC-to-DC converter and the second conversion unit is a direct-current power source, the first conversion units share one second conversion unit.

9 . The energy storage system according to claim 4 , wherein, in a case that the first conversion unit is a DC-to-AC converter and the second conversion unit is an alternating-current power source, each first conversion unit is equipped with one second conversion unit.

10 . The energy storage system according to claim 4 , wherein, in a case that the first conversion unit is a DC-to-AC converter and the second conversion unit is an alternating-current power source

Assignees

• Contemporary Amperex Technology Hong Kong Ltd

Inventors

• Wu Kai
• Chen Xinwei

Classifications

• H02J7/06

  using discharge tubes or semiconductor devices · CPC title

• H01M2010/4271

  Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing · CPC title

• H01M10/425

  Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing (printed circuits H05K1/00) · CPC title

• H02J2207/20

  Charging or discharging characterised by the power electronics converter · CPC title

• H02J7/96

  in response to battery voltage · CPC title