Energy storage system

Abstract

Provided in the present application is an energy storage system. The energy storage system comprises: at least one power supply branch, a first busbar and a second busbar, wherein one end of the power supply branch is electrically connected to the first busbar, and the other end of the power supply branch is electrically connected to the second busbar; the power supply branch comprises at least one battery pack and a high-voltage box; and when a direct-current time constant of the energy storage system is a first time, the pre-arc Joule integral of a fuse in the battery pack is greater than the fusing Joule integral of a fuse in the high-voltage box.

Description

Energy storage system

[0001] This application claims priority to Chinese Patent Application No. 202410931108.6, filed on July 11, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery technology, specifically to an energy storage system. Background Technology

[0003] When a short circuit occurs in an energy storage system, it can cause significant damage to the lithium batteries and other components within the system. Therefore, the selection of protection devices in the energy storage system is particularly important. Generally, short circuit protection for the energy storage system is achieved by installing protection devices in the battery pack and high-voltage box. Invention Overview

[0004] However, the protection devices in the battery pack and high-voltage box cannot be effectively matched, resulting in the inability to provide effective short-circuit protection for the energy storage system.

[0005] This application provides an energy storage system, comprising: at least one power supply branch, a first busbar, and a second busbar. One end of the power supply branch is electrically connected to the first busbar, and the other end of the power supply branch is electrically connected to the second busbar. The power supply branch includes:

[0006] At least one battery pack, the battery pack including: a first fuse, one end of the first fuse being electrically connected to a first busbar;

[0007] The high-voltage box includes: at least one second fuse, one end of which is electrically connected to the other end of a first fuse, and the other end of which is electrically connected to a second busbar;

[0008] Among them, under the premise that the DC time constant of the energy storage system is a preset first time, the pre-arc Joule integral of the first fuse is greater than the fusing Joule integral of the second fuse. Beneficial effects

[0009] The energy storage system provided in this application includes: at least one power supply branch, a first busbar, and a second busbar. One end of the power supply branch is electrically connected to the first busbar, and the other end of the power supply branch is electrically connected to the second busbar. The power supply branch includes: at least one battery pack and a high-voltage box. The battery pack includes a first fuse, and the high-voltage box includes: at least one second fuse. One end of the first fuse is electrically connected to the first busbar, and the other end of the first fuse is electrically connected to one end of the second fuse. The other end of the second fuse is electrically connected to the second busbar. Under the premise that the DC time constant of the energy storage system is a preset first time, the arc-precursor Joule integral of the first fuse is set to be greater than the melting Joule integral of the second fuse. When both the first and second fuses meet the melting conditions, the second fuse can melt first compared to the first fuse. At the same time, when the first fuse needs to be protected, it can ensure that the first fuse can melt in time, effectively protecting the battery pack and improving the safety of the energy storage system. Attached Figure Description

[0010] Figure 1 is a schematic block diagram of the energy storage system provided in this application.

[0011] Explanation of reference numerals in the attached figures:

[0012] 10. Power supply branch; 110. Battery pack; 120. High voltage box; 20. First busbar; 30. Second busbar; 40. Combiner cabinet; 50. Target equipment; FU1. First fuse; FU2. Second fuse; FU3. Third fuse. Embodiments of the present invention

[0013] In related technologies, to ensure that the fuse in the high-voltage box blows first and the fuse in the battery pack blows later, the selection of fuses for the battery pack and the high-voltage box is usually based on the Joule integral I in the fuse's datasheet. 2 The selection is based on t.

[0014] While the selection method described above allows the fuse in the high-voltage box to blow first, followed by the fuse in the battery pack, this method results in a larger fuse configuration in the battery pack, and suitable products may not be available. Furthermore, when fuses in the battery pack are required for protection, the excessive size of the fuses leads to a longer actual melting time, which is insufficient to effectively protect the battery pack and results in a greater safety risk.

[0015] To address the issue that fuses in battery packs cannot effectively protect the battery pack, this application provides an energy storage system.

[0016] Please refer to Figure 1, which is a schematic block diagram of the energy storage system provided in this application. As shown in Figure 1, this application provides an energy storage system, which includes: at least one power supply branch 10, a first busbar 20, and a second busbar 30. One end of the power supply branch 10 is electrically connected to the first busbar 20, and the other end of the power supply branch 10 is electrically connected to the second busbar 30. The power supply branch 10 includes:

[0017] At least one battery pack 110, the battery pack 110 includes: a first fuse FU1, one end of the first fuse FU1 being electrically connected to a first bus 20;

[0018] High-voltage box 120, high-voltage box 120 includes: at least one second fuse FU2, one end of the second fuse FU2 is electrically connected to the other end of the first fuse FU1, and the other end of the second fuse FU2 is electrically connected to the second busbar 30.

[0019] Among them, under the premise that the DC time constant of the energy storage system is a preset first time, the pre-arc Joule integral of the first fuse FU1 is greater than the fusing Joule integral of the second fuse FU2.

[0020] The Joule integral is the integral of the square of the current over a given time interval. The formula for the Joule integral is: , among which, I 2 t is the Joule integral, t is time, and i is the current.

[0021] Specifically, the pre-arc Joule integral of a fuse refers to the Joule integral during the pre-arc time, while the fusing Joule integral refers to the Joule integral during the actual fusing time. Typically, fuse operation includes four stages: normal conduction, melting / pre-arc time, arcing, and fusing / isolating. Therefore, fuse fusing requires four stages. Thus, in this application, the pre-arc time refers to the period between the normal conduction stage and the melting / pre-arc time, while the actual fusing time refers to the period between the normal conduction stage and the fusing / isolating stage.

[0022] In this embodiment, the pre-arc Joule integral of the first fuse FU1 is greater than the fusing Joule integral of the second fuse FU2, which is based on the premise that the DC time constant of the energy storage system is a preset first time. Specifically, when selecting the first fuse FU1 and the second fuse FU2, this application needs to know the DC time constant of the energy storage system. Based on the DC time constant being a preset first time, the pre-arc Joule integral of the first fuse FU1 and the fusing Joule integral of the second fuse FU2 are tested, ensuring that the pre-arc Joule integral of the first fuse FU1 is greater than the fusing Joule integral of the second fuse FU2. In this case, the configuration of the first fuse FU1 selected is smaller than the configuration selected based on the fuse's specifications. Moreover, the selected first fuse FU1 and second fuse FU2 are more suitable for short-circuit protection of the energy storage system. When the first fuse FU1 and the second fuse FU2 simultaneously reach the fusing condition, the second fuse FU2 can fuse first compared to the first fuse FU1. At the same time, when the first fuse FU1 needs to provide protection, it can ensure that the first fuse FU1 can fuse in a timely manner.

[0023] The energy storage system provided in this application includes: at least one power supply branch 10, a first busbar 20, and a second busbar 30. One end of the power supply branch 10 is electrically connected to the first busbar 20, and the other end of the power supply branch 10 is electrically connected to the second busbar 30. The power supply branch 10 includes: at least one battery pack 110 and a high-voltage box 120. The battery pack 110 includes: a first fuse FU1, and the high-voltage box 120 includes: at least one second fuse FU2. One end of the first fuse FU1 is electrically connected to the first busbar 20, and the other end of the fuse is electrically connected to one end of the second fuse FU2. The other end of the second fuse FU2 is electrically connected to the second busbar 30, and the system is connected to the energy storage... Under the premise that the DC time constant of the energy storage system is a preset first time, the pre-arc Joule integral of the first fuse FU1 is set to be greater than the fusing Joule integral of the second fuse FU2. When the first fuse FU1 and the second fuse FU2 simultaneously meet the fusing conditions, the second fuse FU2 can be fusing first, while the first fuse FU1 can be fusing in a timely manner when protection is required. This effectively protects the battery pack 110, reduces the risk of damage to the battery pack 110, reduces the cost of fuses in the battery pack 110, and improves the safety of the energy storage system.

[0024] In some embodiments, under the premise that the short-circuit current of the power supply branch 10 is a preset first current and the DC time constant is a first time, the pre-arc Joule integral of the first fuse FU1 is greater than the fusing Joule integral of the second fuse FU2.

[0025] Specifically, when screening the first fuse FU1 and the second fuse FU2, this application, based on determining the DC time constant of the energy storage system, also needs to test the first fuse FU1 and the second fuse FU2 under the same current. That is, it needs to ensure that when the short-circuit current of the power supply branch 10 is a preset first current, it needs to ensure that both the first fuse FU1 and the second fuse FU2 can blow. The first current can be 12kA.

[0026] It is understandable that when the first current is used to test the first fuse FU1 and the second fuse FU2, it is necessary to ensure that the DC time constant of the energy storage system is the preset first time, and the first current can be such that the first fuse FU1 can just complete the melting. At this time, the arc-preceding Joule integral of the first fuse FU1 can be measured. At the same time, the first current is used to melt the second fuse FU2, and the melting Joule integral of the second fuse FU2 can be measured. Then, the arc-preceding Joule integral of the first fuse FU1 and the melting Joule integral of the second fuse FU2 are compared. If the arc-preceding Joule integral of the first fuse FU1 is greater than the melting Joule integral of the second fuse FU2, then the two fuses can be regarded as the corresponding fuses in the energy storage system.

[0027] It is understood that the arc-precession Joule integral of the first fuse FU1 and the fusing Joule integral of the second fuse FU2 mentioned in this application are Joule integrals obtained during the testing process, and are not Joule integrals under the standard specifications of the fuses.

[0028] Meanwhile, the arc pre-arc time of the first fuse FU1 is greater than the actual fusing time of the second fuse FU2. Specifically, the arc pre-arc time of the first fuse FU1 refers to the arc pre-arc time of the first fuse FU1 when the short-circuit current of the power supply branch 10 is the first current and the DC time constant of the energy storage system is the first time. The actual fusing time of the second fuse FU2 refers to the actual fusing time of the second fuse FU2 when the short-circuit current of the power supply branch 10 is the first current and the DC time constant of the energy storage system is the first time.

[0029] In some embodiments, as shown in FIG1, the energy storage system further includes: a combiner cabinet 40; wherein the combiner cabinet 40 includes at least one third fuse FU3, one end of the third fuse FU3 is electrically connected to the first end of the combiner cabinet 40, the first end of the combiner cabinet 40 is electrically connected to the first bus 20, the second end of the combiner cabinet 40 is electrically connected to the second bus 30, the third and fourth ends of the combiner cabinet 40 are respectively electrically connected to the target device 50, and the other end of the third fuse FU3 is electrically connected to the third end of the combiner cabinet 40; the product of the arc-front Joule integral of the second fuse FU2 and the square of the number of power supply branches 10 is greater than the fusing Joule integral of the third fuse FU3.

[0030] Specifically, to implement a three-level matching protection mechanism for the energy storage system, this application can install a combiner cabinet 40 in the energy storage system, and install a fuse, namely the third fuse FU3, in the combiner cabinet 40, thereby improving the safety of the energy storage system. When the first fuse FU1, the second fuse FU2, and the third fuse FU3 all meet the blowing conditions, the third fuse FU3 blows before the second fuse FU2, and the second fuse FU2 blows before the first fuse FU1. The target device 50 can be a power conversion system (PCS).

[0031] It should be noted that the number of power supply branches 10 mentioned in this application refers to the number of power supply branches 10 connected in parallel in the energy storage system. If the number of power supply branches 10 connected in parallel in the energy storage system is 1, then the square of the number of branches is 1; if the number of power supply branches 10 connected in parallel in the energy storage system is 2, then the square of the number of branches is 4.

[0032] In some embodiments, provided that the DC time constant is the first time, the product of the pre-arc Joule integral of the second fuse FU2 and the square of the number of power supply branches 10 is greater than the fusing Joule integral of the third fuse FU3.

[0033] Typically, the three-level matching protection mechanism of an energy storage system requires that the third fuse FU3 blows before the second fuse FU2, and the second fuse FU2 blows before the first fuse FU1. Therefore, the configuration required for the third fuse FU3 is minimal. However, when selecting fuses for three-level matching protection of an energy storage system, the selection is usually based on the standard specifications of the fuses, with the third fuse FU3 being selected first. After determining the third fuse FU3, the second fuse FU2 is then selected. The selection criterion at this point is: the product of the pre-arc Joule integral of the second fuse FU2 and the square of the number of power supply branches 10 is greater than the fusing Joule integral of the third fuse FU3. After determining the second fuse FU2, the first fuse FU1 is finally selected. The selection criterion for the first fuse FU1 is: the pre-arc Joule integral of the first fuse FU1 is greater than the fusing Joule integral of the second fuse FU2. Since the first fuse FU1, the second fuse FU2, and the third fuse FU3 were selected based on their own specifications, the configuration of the first fuse FU1 may be too large. There may not be a suitable product under this configuration. At the same time, if a product with this configuration is used as the fuse for the battery pack 110, and a short circuit occurs at the battery pack 110 and the first fuse FU1 is required for protection, the first fuse FU1 may not meet the fusing conditions or the actual fusing time may be too long due to its excessively large configuration, thus resulting in the battery pack 110 not being effectively protected.

[0034] Therefore, when selecting the first fuse FU1, the second fuse FU2, and the third fuse FU3, this application requires, based on the DC time constant, testing the pre-arc Joule integral of the first fuse FU1, the pre-arc Joule integral and the fusing Joule integral of the second fuse FU2, and the fusing Joule integral of the third fuse FU3. It also ensures that the pre-arc Joule integral of the first fuse FU1 is greater than the fusing Joule integral of the second fuse FU2, and that the product of the pre-arc Joule integral of the second fuse FU2 and the square of the number of power supply branches 10 is greater than the product of the third fuse FU3. The Joule integral of the fuse FU3 indicates that the configuration of the first fuse FU1 selected at this time is smaller than that selected according to the fuse specifications. The first fuse FU1 has more options, and the selected first fuse FU1, second fuse FU2 and third fuse FU3 are more suitable for short circuit protection of the energy storage system. Therefore, when the battery pack 110 is short-circuited and the first fuse FU1 needs to be protected, it can be ensured that the first fuse FU1 can melt in time, thereby effectively protecting the battery pack 110.

[0035] In some embodiments, under the premise that the short-circuit current of the combiner cabinet 40 is a preset second current and the DC time constant is a first time, the product of the pre-arc Joule integral of the second fuse FU2 and the square of the number of power supply branches 10 is greater than the fusing Joule integral of the third fuse FU3.

[0036] Specifically, when screening the first fuse FU1, the second fuse FU2, and the third fuse FU3, this application, in addition to determining the DC time constant of the energy storage system, also needs to test the first fuse FU1, the second fuse FU2, and the third fuse FU3 under the same current. That is, it is necessary to ensure that when the short-circuit current of the power supply branch 10 is the preset second current, it is necessary to ensure that the first fuse FU1, the second fuse FU2, and the third fuse FU3 can all blow.

[0037] Meanwhile, the actual fusing time of the third fuse FU3 is less than the pre-arc time of the second fuse FU2. Specifically, the pre-arc time of the second fuse FU2 refers to the pre-arc time of the second fuse FU2 when the short-circuit current of the power supply branch 10 is the second current and the DC time constant of the energy storage system is the first time. The actual fusing time of the third fuse FU3 refers to the actual fusing time of the third fuse FU3 when the short-circuit current of the power supply branch 10 is the second current and the DC time constant of the energy storage system is the first time.

[0038] In some embodiments, as shown in FIG1, the busbar 40 includes two third fuses FU3, namely a main positive busbar fuse and a main negative busbar fuse; wherein, one end of the main positive busbar fuse is electrically connected to the first end of the busbar 40, and the other end of the main positive busbar fuse is electrically connected to the third end of the busbar 40; one end of the main negative busbar fuse is electrically connected to the second end of the busbar 40, and the other end of the main negative busbar fuse is electrically connected to the fourth end of the busbar 40.

[0039] Specifically, in order to improve the safety performance of the energy storage system, this application can install a fuse on one side of the first busbar 20 and on one side of the second busbar 30, that is, install two third fuses FU3 in the combiner cabinet 40, which can be the main positive combiner cabinet fuse and the main negative combiner cabinet fuse, respectively, to improve the reliability of the energy storage system.

[0040] In some embodiments, as shown in FIG1, the power supply branch 10 includes: two second fuses FU2, namely a main positive high voltage box fuse and a main negative high voltage box fuse; wherein, one end of the main positive high voltage box fuse is electrically connected to one end of the first fuse FU1, and the other end of the main positive high voltage box fuse is electrically connected to the first busbar 20; one end of the main negative high voltage box fuse is electrically connected to the other end of the first fuse FU1, and the other end of the main negative high voltage box fuse is electrically connected to the second busbar 30.

[0041] Specifically, in order to improve the safety performance of the energy storage system, this application can install a fuse on the other side of the first busbar 20 and the other side of the second busbar 30. That is, two second fuses FU2 can be installed in the high-voltage box 120, which can be the main positive high-voltage box fuse and the main negative high-voltage box fuse, respectively, to improve the reliability of the energy storage system.

[0042] In some embodiments, the DC time constant is greater than or equal to a preset second time and less than or equal to a preset third time.

[0043] Specifically, the DC time constant of an energy storage system refers to a measure of the voltage or current response change of energy storage elements (such as batteries). When an energy storage system is connected to a load or power source, the time required for its voltage or current to change from its initial state to 63.2% of its steady-state value can be called the DC time constant. The DC time constant of an energy storage system mainly depends on the battery's internal resistance and capacitance effect. The first time can be set between 1ms and 3ms, the second time can be 1ms, and the third time can be 3ms.

[0044] In some embodiments, as shown in FIG1, the energy storage system includes multiple power supply branches 10, one end of each power supply branch 10 is electrically connected to a first busbar 20, and the other end of each power supply branch 10 is electrically connected to a second busbar 30.

[0045] In this embodiment, the energy storage system can be formed by multiple parallel power supply branches 10. Each power supply branch 10 can be equipped with a battery pack 110 and a high-voltage box 120. Each battery pack 110 is equipped with a first fuse FU1. One end of each first fuse FU1 is electrically connected to the first bus 20. Each high-voltage box 120 is equipped with a second fuse FU2. One end of each second fuse FU2 is electrically connected to the other end of the first fuse FU1. The other end of each second fuse FU2 is electrically connected to the second bus 30. Meanwhile, under the premise that the DC time constant of the energy storage system is a preset first time, the pre-arc Joule integral of each first fuse FU1 is greater than the fusing Joule integral of the second fuse FU2.

[0046] In some embodiments, the short-circuit current of each power supply branch 10 is less than or equal to a preset third current.

[0047] Specifically, to ensure the successful selection of each first fuse FU1 and second fuse FU2 in the energy storage system, this application, based on the DC time constant of the energy storage system being a preset first time, needs to ensure that the maximum short-circuit current of each power supply branch 10 is the same. That is, the circuit current of each power supply branch 10 must not be greater than a preset third current. The third current can be the maximum short-circuit current of each power supply branch 10. This ensures that the selected first fuse FU1 and second fuse FU2 are more suitable for providing short-circuit protection for each power supply branch 10 of the energy storage system. Thus, when the first fuse FU1 and the second fuse FU2 in the corresponding power supply branch 10 simultaneously reach the melting condition, the second fuse FU2 can melt first compared to the first fuse FU1. At the same time, when the first fuse FU1 is required for protection, the first fuse FU1 in the corresponding power supply branch 10 can be melted in time.

Claims

1. An energy storage system, comprising: At least one power supply branch (10), a first busbar (20), and a second busbar (30), one end of the power supply branch (10) being electrically connected to the first busbar (20), and the other end of the power supply branch (10) being electrically connected to the second busbar (30), wherein the power supply branch (10) comprises: At least one battery pack (110), the battery pack (110) including a first fuse (FU1), one end of the first fuse (FU1) being electrically connected to the first bus (20); A high-voltage box (120) includes: at least one second fuse (FU2), one end of which is electrically connected to the other end of the first fuse (FU1), and the other end of which is electrically connected to the second busbar (30). Wherein, under the premise that the DC time constant of the energy storage system is a preset first time, the pre-arc Joule integral of the first fuse (FU1) is greater than the fusing Joule integral of the second fuse (FU2).

2. The energy storage system according to claim 1, wherein, Provided that the short-circuit current of the power supply branch (10) is a preset first current and the DC time constant is the first time, the arc-precession Joule integral of the first fuse (FU1) is greater than the melting Joule integral of the second fuse (FU2).

3. The energy storage system according to claim 1, further comprising: Combiner cabinet (40); The combiner cabinet (40) includes at least one third fuse (FU3), one end of which is electrically connected to the first end of the combiner cabinet (40), the first end of which is electrically connected to the first busbar (20), the second end of which is electrically connected to the second busbar (30), the third and fourth ends of which are electrically connected to the target device (50), and the other end of which is electrically connected to the third end of the combiner cabinet (40). The product of the arc-precursor Joule integral of the second fuse (FU2) and the square of the number of power supply branches (10) is greater than the fuse-breaking Joule integral of the third fuse (FU3).

4. The energy storage system according to claim 3, wherein, Under the premise that the DC time constant is the first time, the product of the arc-precursor Joule integral of the second fuse (FU2) and the square of the number of power supply branches (10) is greater than the fuse Joule integral of the third fuse (FU3).

5. The energy storage system according to claim 4, wherein, Under the premise that the short-circuit current of the combiner cabinet (40) is a preset second current and the DC time constant is the first time, the product of the arc-precursor Joule integral of the second fuse (FU2) and the square of the number of power supply branches (10) is greater than the fusing Joule integral of the third fuse (FU3).

6. The energy storage system according to claim 3, wherein, The combiner cabinet (40) includes two third fuses (FU3), namely a main positive combiner cabinet fuse and a main negative combiner cabinet fuse; Wherein, one end of the main positive busbar fuse is electrically connected to the first end of the busbar, and the other end of the main positive busbar fuse is electrically connected to the third end of the busbar; One end of the fuse of the main and negative busbar is electrically connected to the second end of the busbar, and the other end of the fuse of the main and negative busbar is electrically connected to the fourth end of the busbar.

7. The energy storage system according to any one of claims 1-6, wherein, The power supply branch (10) includes: two second fuses (FU2), namely the main positive high voltage box fuse and the main negative high voltage box fuse; Wherein, one end of the main positive high voltage box fuse is electrically connected to one end of the first fuse (FU1), and the other end of the main positive high voltage box fuse is electrically connected to the first busbar (20). One end of the main negative high voltage box fuse is electrically connected to the other end of the first fuse (FU1), and the other end of the main negative high voltage box fuse is electrically connected to the second busbar (30).

8. The energy storage system according to any one of claims 1-7, wherein, The DC time constant is greater than or equal to a preset second time and less than or equal to a preset third time.

9. The energy storage system according to any one of claims 1-7, comprising: Multiple power supply branches (10) as described above; One end of each of the power supply branches (10) is electrically connected to the first busbar (20), and the other end of each of the power supply branches (10) is electrically connected to the second busbar (30).

10. The energy storage system according to claim 9, wherein, The short-circuit current of each of the power supply branches (10) is less than or equal to the preset third current.

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