High-voltage box and energy storage system

Abstract

The utility model relates to the technical field of battery system energy storage, particularly provides a high-voltage box and an energy storage system, and aims to solve the technical problems of large occupied space and low energy density of the energy storage system when one high-voltage box is used for managing one battery cluster. In order to achieve the purpose, the high-voltage box comprises a control unit and protection units in one-to-one correspondence with a plurality of battery clusters, the nth protection unit comprises a first branch circuit and a second branch circuit, the first end of the first branch circuit is connected with the first end of the nth battery cluster, the second end of the first branch circuit is connected to a first node, and the first node is connected with the nth battery cluster. The first end of the second branch is connected with the second end of the nth battery cluster, the second end of the second branch is connected to the second node, the control unit is used for communicating with the multiple battery clusters, n is larger than or equal to 1 and smaller than or equal to N, and N represents the total number of the battery clusters. The high-voltage box provided by the utility model solves the problems of large occupied space and low energy density of an energy storage system caused by one-to-one correspondence of traditional high-voltage boxes and battery clusters.

Description

Technical Field

[0001] The present application relates to the technical field of battery system energy storage, and particularly relates to a high-voltage box and an energy storage system. Background Art

[0002] In the prior art, usually one battery cluster corresponds to one high-voltage box, that is, each high-voltage box is only used to manage one battery cluster. This design not only increases the floor area of the energy storage system, but also increases the construction and maintenance costs, and limits the energy density of the energy storage system. In addition, since each high-voltage box needs to be equipped with a set of communication modules, the complexity and failure rate of the system are increased.

[0003] Correspondingly, there is a need in the art for a new high-voltage box and an energy storage system to solve the above problems. Utility Model Content

[0004] In order to overcome the above defects, the present application is proposed to solve or at least partially solve the technical problems of large occupied space and low energy density of the energy storage system when using one high-voltage box to manage one battery cluster.

[0005] In a first aspect, a high-voltage box is provided, including a control unit and protection units corresponding to a plurality of battery clusters one by one. Among them, the nth protection unit includes a first branch and a second branch. The first end of the first branch is connected to the first end of the nth battery cluster, the second end of the first branch is connected to a first node, the first end of the second branch is connected to the second end of the nth battery cluster, and the second end of the second branch is connected to a second node. The control unit is used to communicate with a plurality of battery clusters, where 1≤n≤N, and N represents the total number of battery clusters.

[0006] In one embodiment, the first branch of the nth protection unit includes a first relay, and the second branch of the nth protection unit includes a second relay.

[0007] In one embodiment, the first branch of the nth protection unit includes a first fuse connected in series with the first relay; and / or the second branch of the nth protection unit includes a second fuse connected in series with the second relay.

[0008] In one embodiment, the first branch of the nth protection unit includes a first Hall current sensor connected in series with the first relay; and / or the second branch of the nth protection unit includes a second Hall current sensor connected in series with the second relay.

[0009] In one embodiment, the first branch of the nth protection unit includes a first Hall current sensor connected in series with the first relay and the first fuse; and / or the second branch of the nth protection unit includes a second Hall current sensor connected in series with the second relay and the second fuse.

[0010] In one embodiment, it further includes: a circulating current branch, which is connected in parallel with the first relay or the second relay in the ith protection unit, where 1 ≤ i ≤ N.

[0011] In one embodiment, the circulating current branch includes a circulating current resistor and a circulating current relay connected in series.

[0012] In one embodiment, it further includes: a bipolar disconnector and a first output terminal and a second output terminal, where the first node and the second node are respectively connected to the first output terminal and the second output terminal through the bipolar disconnector.

[0013] In one embodiment, it further includes a handle switch, which is used to control the closing or opening of the bipolar disconnector during operation.

[0014] In a second aspect, there is provided an energy storage system, including a plurality of battery clusters; and a high-voltage box in the first aspect or any corresponding embodiment thereof.

[0015] This application has at least one or more of the following beneficial effects:

[0016] In the embodiments of this application, multiple protection units are designed for a high-voltage box to protect and control multiple battery clusters, and one control unit is used to communicate with N battery clusters, achieving the purpose of reducing the volume occupied by the energy storage system, improving the energy density of the energy storage system, and reducing the construction and maintenance costs.

[0017] In the embodiments of this application, by using the first relay in the first branch and the second relay in the second branch of the n protection units, the purpose of respectively controlling and protecting multiple battery clusters is achieved.

[0018] In the embodiments of this application, by connecting the circulating current branch in parallel with the first relay or the second relay at both ends of the ith protection unit, compared with connecting a circulating current branch in parallel for each battery cluster, the purpose of further simplifying the protection circuit of the high-voltage box is achieved, and the effect of balancing the voltages of multiple battery clusters is achieved.

[0019] In the embodiments of this application, by applying the above high-voltage box in the energy storage system, the purpose of improving the energy density of the energy storage system, reducing the system failure rate, simplifying the communication wire harness, and reducing the construction and maintenance costs is achieved. Description of the Drawings

[0020] With reference to the accompanying drawings, the disclosure of the present application will become more readily understandable. It is readily understood by those skilled in the art that these drawings are merely for illustrative purposes and are not intended to limit the scope of protection of the present application. Among them:

[0021] Figure 1 is a schematic diagram of the main structure of a high-voltage box according to an embodiment of the present application;

[0022] Figure 2 is a schematic diagram of the main structure of a high-voltage box including a circuit breaker according to an embodiment of the present application;

[0023] Figure 3 is a schematic diagram of the main structure of a high-voltage box including a fuse according to an embodiment of the present application;

[0024] Figure 4 is a schematic diagram of the main structure of a high-voltage box including a circuit breaker and a fuse according to an embodiment of the present application;

[0025] Figure 5 is a schematic diagram of the main structure of a high-voltage box including a circuit breaker, a fuse and a Hall current sensor according to an embodiment of the present application;

[0026] Figure 6 is a schematic diagram of the main structure of a high-voltage box including a circulating current branch according to an embodiment of the present application;

[0027] Figure 7 is a schematic diagram of the main structure of a high-voltage box according to another embodiment of the present application;

[0028] Figure 8 is a schematic diagram of the main structure of a high-voltage box according to yet another embodiment of the present application;

[0029] Figure 9 is a partial schematic diagram of a energy storage system according to an embodiment of the present application;

[0030] Figure 10 is a partial schematic diagram of a energy storage system according to another embodiment of the present application.

[0031] Reference numerals:

[0032] 1: The first protection unit; 11: The first branch of the first protection unit; 12: The second branch of the first protection unit; 2: The second protection unit; 21: The first branch of the second protection unit; 22: The second branch of the second protection unit; 3: The third protection unit; 31: The first branch of the third protection unit; 32: The second branch of the third protection unit; 4: The control unit; K1: The first circuit breaker; K2: The second circuit breaker; FU1: The first fuse; FU2: The second fuse; R: The circulating current resistance; K: The circulating current relay; J1: The first node; J2: The second node; QS: The bipolar disconnecting switch; P+: The first output terminal; P-: The second output terminal. Detailed implementation manners

[0033] Some implementation manners of the present application will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these implementation manners are only used to explain the technical principle of the present application and are not intended to limit the protection scope of the present application.

[0034] In the description of the present application, the terms "first", "second", etc. are used to distinguish similar objects and do not have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances so that the embodiments of the present application described here can be implemented in an order other than those illustrated or described here. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices. The terms "install", "connect", and "couple" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can also be the communication inside two elements. It can be a wireless connection or a wired connection.

[0035] The orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present application.

[0036] In addition, if the meaning of "and / or" appears in this application, it includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application. The terms "at least one of A or B" or "at least one of A and B" have a meaning similar to "A and / or B", and can include only A, only B, or A and B. The singular terms "a" and "this" can also include the plural form.

[0037] In the field of electrical equipment for energy storage systems, the high-voltage box is an important device, mainly used for managing the stored high-voltage electricity. In the field of control equipment for energy storage systems, the high-voltage box is an important part of the energy storage electrical system, responsible for controlling and regulating the output of high-voltage electricity to ensure the stable operation of the energy storage system. In the field of energy storage device integration technology, it is an important research direction to design a high-voltage box to improve the integration and efficiency of energy storage devices. Currently, usually one battery cluster corresponds to one high-voltage box, that is, each high-voltage box only serves one battery cluster. This design can meet the storage and management needs of battery clusters to a certain extent, but there are also some problems: First, the traditional high-voltage box design makes the energy storage system occupy a large volume of space, not only increasing the floor area of the energy storage system, but also increasing the construction and maintenance costs. Second, since each high-voltage box needs to be equipped with a set of communication modules, the number of communication modules in the energy storage system is relatively large, increasing the complexity and failure rate of the system. Finally, since each high-voltage box can only serve one battery cluster, it greatly limits the energy density of the energy storage system, that is, the energy storage capacity per unit volume.

[0038] To solve the above problems, this application provides a high-voltage box. Refer to the attached Figure 1 , Figure 1 is the main structural schematic diagram of the high-voltage box according to an embodiment of this application. As Figure 1 shown, the high-voltage box in the embodiment of this application mainly includes N protection units (N represents the total number of battery clusters, that is, the total number of protection units, N > 1, N = 3 in the figure), which are respectively represented by reference numerals 1 - 3, and a control unit 4. The 3 protection units respectively correspond to 3 battery clusters, namely battery cluster 1 to battery cluster 3. The nth (1 ≤ n ≤ 3) protection unit includes a first branch and a second branch. The first end of the first branch is connected to the first end (positive end or negative end) of the nth battery cluster, and the second end of the first branch is connected to the first node J1. The first end of the second branch is connected to the second end (negative end or positive end) of the nth battery cluster, and the second end of the second branch is connected to the second node J2.

[0039] Specifically, asFigure 1 As shown, the first protection unit 1 includes a first branch 11 and a second branch 12. The first end of the first branch 11 is connected to the first end of the battery cluster 1, the second end of the first branch 11 is connected to the first node J1, the first end of the second branch 12 is connected to the second end of the battery cluster 1, and the second end of the second branch 12 is connected to the second node J2; the second protection unit 2 includes a first branch 21 and a second branch 22. The first end of the first branch 21 is connected to the first end of the battery cluster 2, the second end of the first branch 21 is connected to the first node J1, the first end of the second branch 22 is connected to the second end of the battery cluster 2, and the second end of the second branch 22 is connected to the second node J2; the third protection unit 3 includes a first branch 31 and a second branch 32. The first end of the first branch 31 is connected to the first end of the battery cluster 3, the second end of the first branch 31 is connected to the first node J1, the first end of the second branch 32 is connected to the second end of the battery cluster 3, and the second end of the second branch 32 is connected to the second node J2.

[0040] In one embodiment, the control unit communicates with N battery clusters, and N groups of (battery cluster) communication lines can be used to connect the N battery clusters and the control unit to achieve communication.

[0041] In one embodiment, any battery cluster is composed of multiple battery packs, and any battery pack and the control unit include network cards. The control unit can also perform wireless communication with the N battery clusters by using the network cards. As an example, after connecting the wireless group network card in the battery pack to the wireless main card in the control unit, the control unit and the N battery clusters can communicate using WiFi.

[0042] In one embodiment, the battery cluster includes multiple battery packs, and each battery pack includes a controller for counting battery parameters such as the voltage of the battery cells. The control unit can obtain the battery parameters by using N groups of communication lines and calculate the voltage, state of charge (SOC), state of power (SOP), etc. of the battery packs in the N battery clusters.

[0043] In one embodiment, the first branch and / or the second branch of the protection unit may include current protection devices, sensors, etc.

[0044] In an alternative embodiment, as Figure 2 shown, the first branch of the nth protection unit includes a first relay K1, and the second branch includes a second relay K2. K1 and K2 play roles such as automatic regulation, safety protection, and circuit conversion in the protection unit.

[0045] In one embodiment, the first relay K1 and / or the second relay K2 may be contactor relays, which are closed or opened according to the control signals sent by the control unit.

[0046] In one embodiment, the first relay K1 and the second relay K2 of the nth protection unit are used to cut off the power supply of the first end and the second end (positive end and negative end) of the nth battery cluster, ensuring electrical safety.

[0047] In an alternative embodiment, as Figure 3 shown, the first branch of the nth protection unit includes a first fuse FU1, and the second branch of the nth protection unit includes a second fuse FU2, which play a short-circuit protection role for the battery cluster.

[0048] In one embodiment, the first branch of the nth protection unit includes a first fuse connected in series with the first relay, and the second branch of the nth protection unit includes a second fuse connected in series with the second relay. Specifically, as Figure 4 shown, the first end of the nth battery cluster is sequentially connected to the first node J1 through the first fuse FU1 and the first circuit breaker K1 of the nth protection unit, and the second end of the nth battery cluster is sequentially connected to the second node J2 through the second fuse FU2 and the second circuit breaker K2 of the nth protection unit.

[0049] In an alternative embodiment, the first branch of the nth protection unit includes a first Hall current sensor connected in series with the first relay; and / or the second branch of the nth protection unit includes a second Hall current sensor connected in series with the second relay.

[0050] In this embodiment, the Hall current sensor is used to measure the current direction and magnitude of the battery cluster. Based on the above current measurement values, the state (charging / discharging) of the battery cluster can be judged, the battery cluster can be protected according to a preset threshold, and the SOC (State of Charge) can be calculated by the current integration method, etc.

[0051] In one embodiment, the Hall current sensor can also be other current measurement devices, such as a shunt.

[0052] In one embodiment, as Figure 5 shown, the first branch of the nth protection unit includes a Hall current sensor. The first end of the nth battery cluster is sequentially connected to the first node J1 through the first fuse FU1, the first Hall current sensor, and the first circuit breaker K1 of the nth protection unit, and the second end of the nth battery cluster is sequentially connected to the second node J2 through the second fuse FU2 and the second circuit breaker K2 of the nth protection unit.

[0053] In an alternative embodiment, the high-voltage box further includes a circulating current branch, and the circulating current branch is connected in parallel with the first relay K1 or the second relay K2 in the ith (1≤i≤N) protection unit. Among them, the circulating current branch includes a series-connected circulating current resistor R and a circulating current relay K.

[0054] As an example, as Figure 6 shown, the series-connected circulating current resistor R and the circulating current relay K form a circulating current branch, and this circulating current branch is connected in parallel across the two ends of the second relay K2 of the first protection unit.

[0055] In one embodiment, the circulating current resistor R can be used to limit the circulating current, and the circulating current relay K can be used to adjust (balance) the voltage difference of multiple battery clusters. Exemplarily, referring to the appendix Figure 6 , assuming that the voltage of battery cluster 1 is relatively high and the voltage of battery cluster 2 is relatively low. At this time, the circulating current relay and the first relay K1 of the first protection unit 1 can be closed, and at the same time, the first relay K1 and the second relay K2 of the second protection unit 2 can be closed, so that battery cluster 1 charges battery cluster 2 with a small current until the voltages of the two battery clusters are equal.

[0056] It should be noted that by adjusting the resistance value of the circulating current resistor, the magnitude of the passing current can be changed. Generally, the current on the circulating current resistor can be between 2A and 10A. In addition, in order to avoid the occurrence of circulating current, the N battery clusters should be used as synchronously as possible.

[0057] In one embodiment, in order to avoid excessive current at the moment of battery cluster charging, the first relay K1 of the first protection unit 1 and the circulating current relay K can be closed first, and after the current is normal, the second relay K2 of the first protection unit 1 can be closed, and the circulating current relay K can be disconnected.

[0058] In an alternative embodiment, as Figure 7 shown, the high-voltage box further includes a handle switch, a bipolar disconnecting switch QS, a first output terminal P+ and a second output terminal P-. The first node J1 and the second node J2 are respectively connected to the first output terminal P+ and the second output terminal P- through the bipolar disconnecting switch QS. P+ and P- are used as the total output terminals (output positive electrode and output negative electrode) of 3 battery clusters, and the handle switch is used to control the closing or opening of the bipolar disconnecting switch during operation.

[0059] In one embodiment, the disconnecting switch QS is the main power switch for closing and cutting off the total power supply of N battery clusters. Through the disconnecting switch QS, operations such as maintenance and safe power-on and power-off can be realized.

[0060] In an alternative embodiment, the high-voltage box further includes N groups of connection terminals for electrically connecting N battery clusters to N protection units.

[0061] In this embodiment, the nth group of connection terminals includes the first connection terminal Bn+ of the nth battery cluster, the second connection terminal Bn−, and the third connection terminal COMn, which are respectively used for electrically connecting the first end of the nth battery cluster to the first branch of the nth protection unit, the second end of the nth battery cluster to the second branch of the nth protection unit, and the communication end of the nth battery cluster to the control unit.

[0062] Refer to the appendix Figure 8 , the positive electrode of battery cluster 1 is connected to the first branch 101 of protection unit 10 through the first connection terminal B1+, the negative electrode of battery cluster 1 is connected to the second branch 102 of protection unit 10 through the second connection terminal B1−, the communication end of battery cluster 1 is connected to the control unit through the third connection terminal COM1, and the connection of battery cluster 2 and battery cluster 3 is similar. In this embodiment, 3 groups of connection terminals are used to connect the battery clusters and the high-voltage box, achieving the effect of facilitating the disassembly and replacement of the battery clusters and the high-voltage box.

[0063] This application also provides a high-voltage energy storage system, including a plurality of battery clusters and the high-voltage box in any of the above embodiments. Refer to the appendix Figure 9 , 3 battery clusters (battery cluster 1 to battery cluster 3) are connected to 3 protection units of the high-voltage box, and the 3 battery clusters are protected and controlled by the 3 protection units.

[0064] The energy storage system using the above high-voltage box achieves the purpose of improving the system energy density, simplifying the communication wire harness, reducing the system failure rate, and reducing the construction and maintenance costs.

[0065] In one embodiment, Figure 10 is a partial structural schematic diagram of an energy storage system according to another embodiment of the present application. As Figure 10 shown, any battery cluster includes a plurality of serially connected battery packs, and each battery pack further includes a battery group and a fuse. The positive / negative electrode after the series connection of the plurality of battery packs is the positive / negative electrode of the battery cluster. The positive and negative electrodes of the nth battery cluster are connected to the first branch and the second branch of the nth protection unit through the first connection terminal Bn+ and the second connection terminal Bn− of the high-voltage box 1. The nth battery cluster (a plurality of battery packs) is connected to the central coordination controller (control unit) through the communication wire via the third connection terminal COMn. The central coordination controller obtains battery parameters through the communication wire, thereby controlling the first relay K1, the second relay K2, and the circulating current relay K of each protection unit.

[0066] The positive electrodes of N battery clusters after parallel connection are all connected to the first node J1, and the negative electrodes of N battery clusters after parallel connection are all connected to the second node J2. The first node J1 and the second node J2 are respectively connected to the moving contact of the bipolar disconnector QS, and the static contacts of the bipolar disconnector QS are connected to the first output terminal P+ and the second output terminal P-. The handle switch is mechanically connected to the bipolar disconnector QS and is used to control the closing or opening of the bipolar disconnector during operation.

[0067] In one embodiment, the energy storage system may further include a Battery Management System (BMS), an Energy Management System (EMS), a Power Conversion System (PCS), etc.

[0068] In one embodiment, N battery clusters are connected to the PCS via a high-voltage box, and the PCS controls N battery clusters to perform operations such as charging, discharging, and AC-DC conversion.

[0069] In the embodiments of the present application, a design of one high-voltage box corresponding to N battery clusters is adopted. Compared with the traditional one-to-one design, the number of high-voltage boxes is greatly reduced, thereby reducing the volume occupied by the energy storage system, saving land resources, and also reducing the construction and maintenance costs. In addition, the number of control units is reduced, the system structure is simplified, and the purposes of reducing system complexity and failure rate and improving system stability and reliability are achieved. By increasing the energy storage capacity per unit volume of the energy storage system, the purpose of improving the efficiency and performance of the energy storage system is finally achieved. Generally speaking, compared with the prior art, the present application has the advantages of saving space, simplifying the system, and increasing the energy density.

[0070] So far, the technical solutions of the present application have been described in conjunction with one embodiment shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific embodiments. Without departing from the principle of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present application.

Claims

1. A high-voltage box, characterized in that, Comprising: A control unit and protection units corresponding one by one to a plurality of battery clusters, wherein, the nth protection unit includes a first branch and a second branch. The first end of the first branch is connected to the first end of the nth battery cluster, the second end of the first branch is connected to a first node, the first end of the second branch is connected to the second end of the nth battery cluster, and the second end of the second branch is connected to a second node. The control unit is used to communicate with a plurality of battery clusters, where 1 ≤ n ≤ N, and N represents the total number of battery clusters.

2. The high-voltage box according to claim 1, wherein the first branch of the nth protection unit includes a first relay, and the second branch of the nth protection unit includes a second relay.

3. The high-voltage box according to claim 2, wherein the first branch of the nth protection unit includes a first fuse connected in series with the first relay; and / or the second branch of the nth protection unit includes a second fuse connected in series with the second relay.

4. The high-voltage box according to claim 2, wherein the first branch of the nth protection unit includes a first Hall current sensor connected in series with the first relay; and / or the second branch of the nth protection unit includes a second Hall current sensor connected in series with the second relay.

5. The high-voltage box according to claim 3, wherein the first branch of the nth protection unit includes a first Hall current sensor connected in series with the first relay and the first fuse; and / or the second branch of the nth protection unit includes a second Hall current sensor connected in series with the second relay and the second fuse.

6. The high-voltage box according to claim 2, characterized in that, Further comprising: A circulating current branch, which is connected in parallel with the first relay or the second relay in the ith protection unit, where 1 ≤ i ≤ N.

7. The high-voltage box according to claim 6, wherein the circulating current branch includes a circulating current resistor and a circulating current relay connected in series.

8. The high-voltage box according to claim 1, characterized in that, Further comprising: A bipolar disconnector and a first output terminal and a second output terminal, wherein the first node and the second node are respectively connected to the first output terminal and the second output terminal through the bipolar disconnector.

9. The high-voltage box according to claim 8, characterized in that, Further comprising: A handle switch, which is used to control the closing or opening of the bipolar disconnector during operation.

10. An energy storage system, characterized in that, Comprising: A plurality of battery clusters; and The high-voltage box according to any one of claims 1 to 9.

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