CN-224233336-U - Energy storage system

Abstract

The application provides an energy storage system, which comprises a battery cluster, wherein the battery cluster comprises a plurality of battery packs, a first battery pack protection circuit, a second battery pack protection circuit and a first protection circuit, the battery packs are connected in series between a positive output end and a negative output end of the battery cluster, and the battery packs comprise a first battery pack and a second battery pack which are respectively connected with the positive output end and the negative output end of the battery cluster. The first protection circuit is turned on when a voltage between an output terminal of the battery cluster and the reference ground is greater than a first voltage threshold. The first battery pack protection circuit is conducted under the condition that the voltage between the output end of the first battery pack and the reference ground is larger than a second voltage threshold value, and the first voltage threshold value is larger than the output voltage of the battery cluster and smaller than the second voltage threshold value. The second battery pack protection circuit is turned on when a voltage between an output terminal of the second battery pack and the reference ground is greater than a second voltage threshold. Furthermore, effective lightning protection can be realized when lightning current exists at the output end of the battery cluster.

Inventors

• XIAO HUAFENG
• CHEN BAOGUO
• MENG XIANGTAO
• WANG SHUQIN

Assignees

• 华为技术有限公司

Dates

Publication Date

20260512

Application Date

20250324

Claims (12)

1. 1. An energy storage system, characterized in that, the energy storage system includes the battery cluster, the battery cluster includes a plurality of battery packs, first battery pack protection circuit, second battery pack protection circuit and first protection circuit, the output of battery cluster includes positive output and negative output, wherein: The plurality of battery packs are connected in series between the positive output end and the negative output end of the battery cluster, and each battery pack comprises a first battery pack and a second battery pack which are respectively connected with the positive output end and the negative output end of the battery cluster; The first protection circuit is connected between the output end of the battery cluster and the reference ground and is in a conducting state when the voltage between the output end of the battery cluster and the reference ground is larger than a first voltage threshold, wherein the first voltage threshold is larger than the output voltage of the battery cluster; the first battery pack protection circuit is connected between the output end of the first battery pack and the reference ground and is used for being in a conducting state when the voltage between the output end of the first battery pack and the reference ground is larger than a second voltage threshold value, wherein the second voltage threshold value is larger than the first voltage threshold value; The second battery pack protection circuit is connected between the output end of the second battery pack and the reference ground and is used for being in a conducting state under the condition that the voltage between the output end of the second battery pack and the reference ground is larger than the second voltage threshold value.
2. 2. The energy storage system of claim 1, wherein the first battery pack protection circuit is located within the first battery pack and the second battery pack protection circuit is located within the second battery pack.
3. 3. The energy storage system of claim 1 or 2, wherein the plurality of battery packs comprises an i-th battery pack, the battery cluster comprises an i-th battery pack protection circuit corresponding to the i-th battery pack, 1≤i≤n and n >2, n being the number of battery packs in the battery cluster; The ith battery pack protection circuit is connected between the output end of the ith battery pack and the reference ground and is used for being in a conducting state under the condition that the voltage between the output end of the ith battery pack and the reference ground is larger than the second voltage threshold value.
4. 4. The energy storage system of claim 3, wherein the i-th battery pack protection circuit is located within the i-th battery pack.
5. 5. The energy storage system of any of claims 1-4, wherein the first battery pack protection circuit comprises two first protection units and a second protection unit, the output of the first battery pack comprising a positive output and a negative output, wherein: One end of one first protection unit of the two first protection units is connected with the positive output end of the first battery pack, one end of the other first protection unit is connected with the negative output end of the first battery pack, and the other ends of the two first protection units are connected with the reference ground through the second protection unit after being connected; the first protection unit and the second protection unit are used for being in a conducting state under the condition that the voltage between the positive output end of the first battery pack and the reference ground is larger than the second voltage threshold value; The other first protection unit and the second protection unit are used for being in a conducting state under the condition that the voltage between the negative output end of the first battery pack and the reference ground is larger than the second voltage threshold value.
6. 6. The energy storage system of any of claims 1-4, wherein the first battery pack protection circuit comprises two first protection cells and two second protection cells, the output of the first battery pack comprising a positive output and a negative output, wherein: A first protection unit and a second protection unit in the first battery pack protection circuit are connected in series between the positive output end of the first battery pack and the reference ground, and are used for being in a conducting state when the voltage between the positive output end of the first battery pack and the reference ground is greater than the second voltage threshold; The other first protection unit and the other second protection unit in the first battery pack protection circuit are connected in series between the negative output end of the first battery pack and the reference ground and are used for being in a conducting state under the condition that the voltage between the negative output end of the first battery pack and the reference ground is larger than the second voltage threshold value.
7. 7. The energy storage system according to claim 5 or 6, wherein each of the first and second protection units comprises one protection element, or at least two protection elements in series and/or parallel, wherein the protection elements comprise gas discharge tubes, piezoresistors or transient suppression diodes.
8. 8. The energy storage system of any of claims 1-7, wherein the battery cluster further comprises a cluster control box, the first protection circuit being located within the cluster control box.
9. 9. The energy storage system of any of claims 1-8, wherein the first protection circuit comprises two third and fourth protection units, wherein: One end of one third protection unit of the two third protection units is connected with the positive output end of the battery cluster, one end of the other third protection unit is connected with the negative output end of the battery cluster, and the other ends of the two third protection units are connected with the reference ground through the fourth protection unit after being connected; The third protection unit and the fourth protection unit are used for being in a conducting state under the condition that the voltage between the positive output end of the battery cluster and the reference ground is larger than the first voltage threshold value; the other third protection unit and the fourth protection unit are used for being in a conducting state under the condition that the voltage between the negative output end of the battery cluster and the reference ground is larger than the first voltage threshold value.
10. 10. The energy storage system of any of claims 1-8, wherein the first protection circuit comprises two third protection units and two fourth protection units, wherein: A third protection unit and a fourth protection unit in the first protection circuit are connected in series between the positive output end of the battery cluster and the reference ground, and are used for being in a conducting state under the condition that the voltage between the positive output end of the battery cluster and the reference ground is greater than the first voltage threshold value; The other third protection unit and the other fourth protection unit in the first protection circuit are connected in series between the negative output end of the battery cluster and the reference ground and are used for being in a conducting state under the condition that the voltage between the negative output end of the battery cluster and the reference ground is larger than the first voltage threshold value.
11. 11. Energy storage system according to claim 9 or 10, wherein each of the third and fourth protection units comprises one protection element, or at least two protection elements in series and/or parallel, wherein the protection elements comprise gas discharge tubes, piezoresistors or transient suppression diodes.
12. 12. The energy storage system of any of claims 1-11, further comprising an energy storage converter having a dc terminal connected to an output of the battery cluster; The energy storage converter comprises a second protection circuit, and the second protection circuit is connected between the direct current end of the energy storage converter and the reference ground and is in a conducting state under the condition that the voltage between the direct current end of the energy storage converter and the reference ground is larger than the first voltage threshold value.

Description

Energy storage system Technical Field The application relates to the technical field of power supplies, in particular to an energy storage system. Background Along with the large-scale application of the energy storage system, the direct current side of the energy storage box (comprising a plurality of battery clusters) is connected to the direct current side of the energy storage converter through a cable, the length of the cable is generally at least about 6m, the possibility of being struck by lightning in an outdoor scene is high, and problems such as failure, arc discharge and the like caused by lightning strike can occur, so that the reliability and the safety of the energy storage system are improved. At present, the energy storage system mainly adopts the circuit structure shown in fig. 1 to realize lightning protection of the system. As shown in fig. 1, a lightning protection circuit is arranged inside an energy storage converter in the energy storage system. Under the condition that lightning stroke occurs between the output side of the battery cluster and the direct current side of the energy storage converter, the voltage at two ends of the lightning protection circuit is larger than the conducting voltage threshold value of the lightning protection circuit, and the lightning protection circuit is in a conducting state, so that lightning stroke current is discharged through the lightning protection circuit, and lightning protection to the energy storage converter is realized. Because when a lightning stroke occurs between the output side of the battery cluster and the direct current side of the energy storage converter, a part of lightning stroke current flows to the energy storage converter, and another part of lightning stroke current flows to the battery cluster, and the lightning protection of the energy storage converter can only be realized by the scheme of the built-in lightning protection circuit in the energy storage converter, the energy storage system shown in fig. 1 cannot realize effective lightning protection for the battery cluster under the condition that the lightning stroke occurs between the output side of the battery cluster and the direct current side of the energy storage converter. Disclosure of utility model The application provides an energy storage system, wherein a battery cluster in the energy storage system can realize effective lightning protection when lightning current exists at the output end of the battery cluster, so that the safety and reliability of the energy storage system under the condition of severe lightning weather are improved. In a first aspect, the present application provides an energy storage system comprising a battery cluster comprising a plurality of battery packs, a first battery pack protection circuit, a second battery pack protection circuit, and a first protection circuit, wherein the output of the battery cluster comprises a positive output and a negative output. The battery pack comprises a first battery pack and a second battery pack which are respectively connected with the positive output end and the negative output end of the battery cluster. The first protection circuit is connected between the output end of the battery cluster and the reference ground and is used for being in a conducting state when the voltage between the output end of the battery cluster and the reference ground is larger than a first voltage threshold value, wherein the first voltage threshold value is larger than the output voltage of the battery cluster. The first battery pack protection circuit is connected between the output end of the first battery pack and the reference ground and is used for being in a conducting state under the condition that the voltage between the output end of the first battery pack and the reference ground is larger than a second voltage threshold value, wherein the second voltage threshold value is larger than the first voltage threshold value. The second battery pack protection circuit is connected between the output end of the second battery pack and the reference ground and is used for being in a conducting state under the condition that the voltage between the output end of the second battery pack and the reference ground is larger than a second voltage threshold value. In this embodiment, when the lightning current exists at the output end of the battery cluster, if the voltage between the output end of the battery cluster and the reference ground is greater than the first voltage threshold, the first protection circuit is in a conductive state, so that most of the lightning current at the output end of the battery cluster can be discharged to the reference ground. The small part of lightning current at the output end of the battery cluster flows to the head-tail battery pack (namely the first battery pack and the second battery pack) formed after the plurality of battery packs are connected in series, and two battery pack prot