Multi-battery-cluster parallel pre-charging energy storage device and cascade energy storage system

Abstract

The utility model discloses a multi-cell cluster parallel pre-charge energy storage device and cascade energy storage system, at least comprising a first energy storage module and a second energy storage module, a second switch member and a first resistor member are connected in series to form a first series branch, and a first switch member and the first series branch are connected in parallel to form at least part of a first buffer parallel branch. The fourth switch piece and the second resistor piece are connected in series to form a second series branch, the third switch piece and the second series branch are connected in parallel to form at least part of a second buffer parallel branch, and the head end of the first buffer parallel branch is used for being connected with a converter device. The tail end of the first buffer parallel branch is connected with the head end of the first battery cluster and the head end of the second buffer parallel branch, the tail end of the second buffer parallel branch is connected with the head end of the second battery cluster, and the tail end of the first battery cluster is connected with the tail end of the second battery cluster; on the basis that original functions are not affected, the structure is optimized, and the arrangement cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of electrical equipment technology, and in particular to a multi-battery cluster parallel pre-charge energy storage device and a cascaded energy storage system. Background Technology

[0002] As the global energy system continues to evolve towards a green and low-carbon direction, emerging long-duration energy storage technologies will become a key condition for the large-scale deployment of renewable energy. To achieve long-duration energy storage, without changing the power output of the energy storage converter 730 (PCS), more battery clusters or stacks need to be connected in parallel. For distributed energy storage and high-voltage cascaded energy storage, the simplest approach is to directly connect multiple battery clusters in parallel, with each cluster managed by an energy storage management component, such as... Figure 1 As shown, when the first battery cluster 710 and the second battery cluster 720 are first connected in parallel to supply power, switches K82, K83, K85 and K86 are all closed, while switches K81 and K84 are open. The current flows through resistors R91 and R92 to supply the converter 730, which can avoid excessive circulating current caused by directly connecting multiple battery clusters in parallel when there is a voltage difference (i.e., avoid the phenomenon of high-voltage battery clusters charging low-voltage battery clusters when connected in parallel). After the output voltage of the first battery cluster 710 and the second battery cluster 720 stabilizes, switches K81 and K84 are closed and switches K82 and K85 are opened.

[0003] In addition, a soft-start device needs to be installed between the converter 730 and the battery pack. When the battery pack supplies power to the converter 730, the switch K92 needs to be closed and the switch K91 needs to be opened first, so that the current can supply power to the converter 730 through the resistor R93. After the output voltage of the battery pack is close to the capacitor voltage of the DC side capacitor of the converter 730, the switch K92 is opened and the switch K91 is closed.

[0004] As a result, the overall structure is quite complex, the cost cannot be reduced, and the higher optimization requirements cannot be met. Utility Model Content

[0005] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a multi-battery cluster parallel pre-charged energy storage device and a cascaded energy storage system, optimizing the structure and reducing the layout cost.

[0006] A multi-battery cluster parallel pre-charge energy storage device according to a first aspect embodiment of the present invention includes at least: a first energy storage module, including a first energy storage management component and a first battery cluster, the first energy storage management component including a first buffer parallel branch, the first buffer parallel branch including a first switch, a second switch, and a first resistor, the second switch and the first resistor being connected in series to form a first series branch, the first switch and the first series branch being connected in parallel to form at least a portion of the first buffer parallel branch; and a second energy storage module, including a second energy storage management component and a second battery cluster, the second energy storage component including a second buffer parallel branch, the second buffer parallel branch including... The circuit includes a third switch, a fourth switch, and a second resistor. The fourth switch and the second resistor are connected in series to form a second series branch. The third switch and the second series branch are connected in parallel to form at least a portion of the second buffered parallel branch. The first end of the first buffered parallel branch serves as a first energy storage output terminal for connection with the converter. The last end of the first buffered parallel branch is connected to the first end of the first battery cluster and the first end of the second buffered parallel branch, respectively. The last end of the second buffered parallel branch is connected to the first end of the second battery cluster. The last ends of the first battery cluster and the second battery cluster are connected and serve as a second energy storage output terminal for connection with the converter.

[0007] A multi-battery cluster parallel pre-charge energy storage device according to an embodiment of the present invention has at least the following beneficial effects:

[0008] This utility model relates to a multi-battery cluster parallel pre-charge energy storage device. When the first and second battery clusters are first connected in parallel to supply power, the second and fourth switches can be closed first. The second resistor can reduce the circulating current formed between the first and second battery clusters due to the voltage difference. At the same time, when supplying power to the converter, the output current of the first and second battery clusters can pre-charge the DC capacitor of the converter through the first resistor. After the voltage of the first and second battery clusters stabilizes and the output voltage of the first and second battery clusters is close to the capacitor voltage of the DC side capacitor of the converter, the first and third switches are closed, while the second and fourth switches are opened. This design optimizes the structure and reduces the layout cost without affecting the original function.

[0009] According to some embodiments of the present invention, the first energy storage management component further includes a fifth switch, and the second energy storage management component further includes a sixth switch. The first end of the sixth switch is connected to the tail end of the second battery cluster, and the tail end of the sixth switch is connected to the tail end of the first battery cluster so that the tail end of the first battery cluster is connected to the tail end of the second battery cluster through the sixth switch. The first end of the fifth switch is connected to the tail end of the first battery cluster and the tail end of the sixth switch, respectively, and the tail end of the fifth switch serves as a second energy storage output terminal.

[0010] According to some embodiments of this utility model, the multi-battery cluster parallel pre-charge energy storage device further includes a third energy storage module. The third energy storage module includes a third energy storage management component and a third battery cluster. The third energy storage management component includes a third buffer parallel branch. The third buffer parallel branch includes a seventh switch, an eighth switch, and a third resistor. The eighth switch and the third resistor are connected in series to form a third series branch. The seventh switch and the third series branch are connected in parallel to form at least a portion of the third buffer parallel branch. The first end of the third buffer parallel branch is connected to the last end of the first buffer parallel branch. The last end of the third buffer parallel branch is connected to the first end of the third battery cluster. The last end of the third battery cluster is connected to the last end of the first battery cluster and the first end of the fifth switch.

[0011] According to some embodiments of the present invention, the third energy storage management component further includes a ninth switch, the first end of which is connected to the tail end of the third battery cluster, and the tail end of which is connected to the tail end of the first battery cluster so that the tail end of the first battery cluster is connected to the tail end of the third battery cluster through the ninth switch.

[0012] According to some embodiments of the present invention, the first energy storage management component further includes a first control module, a first energy storage voltage detection module, and a capacitor voltage detection module. The first energy storage voltage detection module is connected to the first battery cluster to detect the energy storage voltage of the first battery cluster. The capacitor voltage detection module is used to connect to the DC side capacitor of the converter to detect the capacitor voltage. The first control module is connected to the first energy storage voltage detection module, the capacitor voltage detection module, the controlled terminal of the first switch, and the controlled terminal of the second switch to control the on / off state of the first switch and the second switch.

[0013] According to some embodiments of the present invention, the second energy storage management component further includes a second control module and a second energy storage voltage detection module. The second energy storage voltage detection module is connected to the second battery cluster to detect the energy storage voltage of the second battery cluster. The second control module is connected to the second energy storage voltage detection module, the first control module, the third switch and the fourth switch respectively to control the on / off state of the third switch and the fourth switch.

[0014] According to some embodiments of the present invention, the first energy storage management component further includes a first temperature detection module, and the second energy storage management component includes a second temperature detection module. The first temperature detection module is used to detect the battery temperature of the first battery cluster, and the second temperature detection module is used to detect the battery temperature of the second battery cluster. The first control module is connected to the first temperature detection module, and the second control module is connected to the second temperature detection module.

[0015] According to some embodiments of the present invention, the multi-battery cluster parallel pre-charge energy storage device further includes a protective housing, and the first energy storage management component and the second energy storage management component are disposed in the protective housing.

[0016] According to some embodiments of the present invention, the multi-battery cluster parallel pre-charge energy storage device further includes a first housing and a second housing that are independent of each other, the first energy storage management component is disposed in the first housing, and the second energy storage management component is disposed in the second housing.

[0017] The cascaded energy storage system according to a second aspect of the present invention includes a converter and a multi-cell cluster parallel pre-charged energy storage device disclosed in any of the above embodiments.

[0018] The cascaded energy storage system according to the embodiments of this utility model has at least the following beneficial effects:

[0019] This utility model cascaded energy storage system adopts the multi-battery cluster parallel pre-charged energy storage device disclosed in any of the above embodiments, which optimizes the structure and reduces the layout cost.

[0020] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0021] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0022] Figure 1 This is a circuit diagram of a traditional energy storage device;

[0023] Figure 2 This is a circuit diagram of the first embodiment of the multi-battery cluster parallel pre-charge energy storage device of this utility model;

[0024] Figure 3 This is a circuit diagram of the second embodiment of the multi-battery cluster parallel pre-charge energy storage device of this utility model;

[0025] Figure 4 This is a schematic diagram of the first embodiment of the multi-battery cluster parallel pre-charge energy storage device of this utility model.

[0026] Figure label:

[0027] <Prior Art>

[0028] First battery cluster 710; second battery cluster 720; converter 730.

[0029] <This utility model>

[0030] First energy storage module 100; first energy storage management component 110; first buffer parallel branch 120; first switch 121; second switch 122; first resistor 123; fifth switch 124; first battery cluster 130; first control module 140; first energy storage voltage detection module 150; capacitor voltage detection module 160; first temperature detection module 170; second energy storage module 200; second energy storage management component 210; second buffer parallel branch 220; third switch... Switch 221; fourth switch 222; second resistor 223; sixth switch 224; second battery cluster 230; second control module 240; second energy storage voltage detection module 250; second temperature detection module 260; third energy storage module 300; third energy storage management component 310; third buffer parallel branch 320; seventh switch 321; eighth switch 322; third resistor 323; ninth switch 324; third battery cluster 330; converter 400. Detailed Implementation

[0031] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0032] In the description of this utility model, it should be understood that the directional descriptions, such as the terms "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0033] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is used in the description, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0034] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0035] like Figure 2 , 3As shown in Figure 4, a multi-battery cluster parallel pre-charge energy storage device according to a first aspect embodiment of the present invention includes at least a first energy storage module 100 and a second energy storage module 200. The first energy storage module 100 includes a first energy storage management component 110 and a first battery cluster 130. The first energy storage management component 110 includes a first buffer parallel branch 120, which includes a first switch 121, a second switch 122, and a first resistor 123. The second switch 122 and the first resistor 123 are connected in series to form a first series branch. The first switch 121 and the first series branch are connected in parallel to form at least a portion of the first buffer parallel branch 120. The second energy storage module 200 includes a second energy storage management component 210 and a second battery cluster 230. The second energy storage management component 210 includes a second buffer parallel branch 220. The second buffer parallel branch 220 includes a third switch 221, a fourth switch 222, and a second resistor 223. The fourth switch 222 and the second resistor 223 are connected in series to form a second series branch. The third switch 221 and the second series branch are connected in parallel to form at least a portion of the second buffer parallel branch 220. The first end of the first buffer parallel branch 120 serves as a first energy storage output terminal for connection with the converter 400. The tail end of the first buffer parallel branch 120 is connected to the first end of the first battery cluster 130 and the first end of the second buffer parallel branch 220, respectively. The tail end of the second buffer parallel branch 220 is connected to the first end of the second battery cluster 230. The tail ends of the first battery cluster 130 and the tail ends of the second battery cluster 230 are connected and serve as a second energy storage output terminal for connection with the converter 400.

[0036] It should be noted that the DC side of the converter 400 is equipped with a DC capacitor, and the first battery cluster 130, the second battery cluster 230, or even more battery clusters are connected in parallel and can be connected to the DC capacitor for charging.

[0037] Both the first battery cluster 130 and the second battery cluster 230 can be composed of multiple batteries connected in series. Generally speaking, the first energy storage management component 110 is equipped with a first control module 140, and the second energy storage management component 210 is equipped with a second control module 240. Both the first control module 140 and the second control module 240 can be selected from conventional chips with processing capabilities such as MCUs or CPUs and their auxiliary circuits. The first switch 121, the second switch 122, the third switch 221, and the fourth switch 222 can all be selected from semiconductor switching transistors, relay switches, circuit breakers, etc. The first control module 140 and the second control module 240 can communicate with each other. The first control module 140 controls the on / off state of the first switch 121 and the second switch 122, respectively. The second control module 240 controls the on / off state of the third switch 221 and the fourth switch 222, respectively.

[0038] This utility model relates to a multi-battery cluster parallel pre-charge energy storage device. When the first battery cluster 130 and the second battery cluster 230 are first connected in parallel to supply power, the second switch 122 and the fourth switch 222 can be closed first. The second resistor can reduce the circulating current formed between the first battery cluster 130 and the second battery cluster 230 due to the voltage difference. At the same time, when supplying power to the converter 400, the current output by the first battery cluster 130 and the second battery cluster 230 can pre-charge the DC capacitor of the converter 400 through the first resistor. After the voltage of the first battery cluster 130 and the second battery cluster 230 stabilizes and the output voltage of the first battery cluster 130 and the second battery cluster 230 approaches the capacitor voltage of the DC side capacitor of the converter 400, the first switch 121 and the third switch 221 are closed, while the second switch 122 and the fourth switch 222 are opened. This design optimizes the structure and reduces the layout cost without affecting the original function.

[0039] In some embodiments of this utility model, the first energy storage management component 110 further includes a fifth switch 124, and the second energy storage management component 210 further includes a sixth switch 224. The first end of the sixth switch 224 is connected to the tail end of the second battery cluster 230, and the tail end of the sixth switch 224 is connected to the tail end of the first battery cluster 130 so that the tail end of the first battery cluster 130 is connected to the tail end of the second battery cluster 230 through the sixth switch 224. The first end of the fifth switch 124 is connected to the tail end of the first battery cluster 130 and the tail end of the sixth switch 224, respectively. The tail end of the fifth switch 124 serves as a second energy storage output terminal.

[0040] The fifth switch 124 and the sixth switch 224 can also be selected from semiconductor switching transistors, relay switches, circuit breakers, etc. When the first battery cluster 130 and the second battery cluster 230 supply power to the converter 400, the first control module 140 controls the fifth switch 124 to close, and the second control module 240 controls the sixth switch 224 to close.

[0041] In some embodiments of this utility model, such as Figure 3 As shown, the multi-battery cluster parallel pre-charge energy storage device also includes a third energy storage module 300. Specifically, it may also include a fourth energy storage module, a fifth energy storage module, or even more. The third energy storage module 300 includes a third energy storage management component 310 and a third battery cluster 330. The third energy storage management component 310 includes a third buffer parallel branch 320. The third buffer parallel branch 320 includes a seventh switch 321, an eighth switch 322, and a third resistor 323. The eighth switch 322 and the third resistor... The components 323 are connected in series to form a third series branch. The seventh switch 321 and the third series branch are connected in parallel to form at least part of the third buffer parallel branch 320. The first end of the third buffer parallel branch 320 is connected to the last end of the first buffer parallel branch 120, and the last end of the third buffer parallel branch 320 is connected to the first end of the third battery cluster 330. The last end of the third battery cluster 330 is connected to the last end of the first battery cluster 130 and the first end of the fifth switch 124, respectively.

[0042] The third energy storage management component 310 also includes a third control module. The seventh switch 321 and the eighth switch 322 can also be selected from semiconductor switching transistors, relay switches, circuit breakers, etc. The first control module 140, the second control module 240, and the third control module can communicate with each other. Specifically, the first energy storage management component 110 can act as a master, and the second energy storage management component 210 and the third energy storage management component 310 can act as slaves. The third switch 221 in the second energy storage management component 210 and the third energy storage management component 310... The operation of the fourth switch 222, the seventh switch 321 and the eighth switch 322 can control whether the second resistor and the third resistor are connected, thereby reducing the circulating current formed between the first battery cluster 130, the second battery cluster 230 and the third battery cluster 330 due to the voltage difference. After the voltage stabilizes, the second switch 122 in the first energy storage management component 110 closes first and the first switch 121 opens. After the supply voltage of the battery cluster and the capacitor voltage of the converter 400 are close, the second switch 122 opens and the first switch 121 closes.

[0043] In some embodiments of this utility model, the third energy storage management component 310 further includes a ninth switch 324, the first end of which is connected to the tail end of the third battery cluster 330, and the tail end of which is connected to the tail end of the first battery cluster 130 so that the tail end of the first battery cluster 130 is connected to the tail end of the third battery cluster 330 through the ninth switch 324.

[0044] The ninth switch 324 can also be selected from semiconductor switching transistors, relay switches, circuit breakers, etc. When the first battery cluster 130 and the second battery cluster 230 supply power to the converter 400, the third control module controls the ninth switch 324 to close.

[0045] Specifically, the first switch 121 can be switch K11, the second switch 122 can be switch K12, the third switch 221 can be switch K13, the fourth switch 222 can be switch K14, the fifth switch 124 can be switch K15, the sixth switch 224 can be switch K16, the seventh switch 321 can be switch K17, the eighth switch 322 can be switch K18, and the ninth switch 324 can be switch K19. The first resistor can be resistor R1, the second resistor can be resistor R2, and the third resistor can be resistor R3.

[0046] In some embodiments of this utility model, the first energy storage management component 110 further includes a first energy storage voltage detection module 150 and a capacitor voltage detection module 160. The first energy storage voltage detection module 150 is connected to the first battery cluster 130 to detect the energy storage voltage of the first battery cluster 130. The capacitor voltage detection module 160 is used to connect to the DC side capacitor of the converter 400 to detect the capacitor voltage. The first control module 140 is connected to the first energy storage voltage detection module 150, the capacitor voltage detection module 160, the controlled terminal of the first switch 121, and the controlled terminal of the second switch 122 to control the on / off state of the first switch 121 and the second switch 122.

[0047] Both the first energy storage voltage detection module 150 and the capacitor voltage detection module 160 can select a resistor voltage divider sampling circuit to obtain the voltage signal on the first battery cluster 130 and the voltage signal of the DC-side capacitor of the converter 400, respectively, to determine the magnitude of the energy storage voltage on the first battery cluster 130 and the magnitude of the capacitor voltage of the DC-side capacitor.

[0048] The second energy storage management component 210 further includes a second energy storage voltage detection module 250, which is connected to the second battery cluster 230 to detect the energy storage voltage of the second battery cluster 230. The second control module 240 is connected to the second energy storage voltage detection module 250, the first control module 140, the third switch 221, and the fourth switch 222 to control the on / off state of the third switch 221 and the fourth switch 222.

[0049] Similarly, the second energy storage voltage detection module 250 can also select a resistor voltage divider sampling circuit to obtain the voltage signal on the second battery cluster 230 to determine the magnitude of the energy storage voltage of the second battery cluster 230. Since the first control module 140 and the second control module 240 communicate with each other, they can compare the energy storage voltage of the first battery cluster 130 and the energy storage voltage of the second battery cluster 230. After the voltages are close to each other, the second control module 240 controls the third switch 221 to close.

[0050] In some embodiments of this utility model, the first energy storage management component 110 further includes a first temperature detection module 170, and the second energy storage management component 210 includes a second temperature detection module 260. The first temperature detection module 170 is used to detect the battery temperature of the first battery cluster 130, and the second temperature detection module 260 is used to detect the battery temperature of the second battery cluster 230. The first control module 140 is connected to the first temperature detection module 170, and the second control module 240 is connected to the second temperature detection module 260.

[0051] The first temperature detection module 170 and the second temperature detection module 260 can both be selected from conventional thermistors, temperature sensors and other components. The first energy storage management component 110 and the second energy storage management component 210 can know the battery temperature of the first battery cluster 130 and the battery temperature of the second battery cluster 230. When the temperatures of the first battery cluster 130 and the second battery cluster 230 are both within the normal range, the first switch 121, the second switch 122, the third switch 221, the fourth switch 222, the fifth switch 124 and the sixth switch 224 will be closed, so that the first battery cluster 130 and the second battery cluster 230 supply power to the converter 400.

[0052] In some embodiments of this utility model, the multi-battery cluster parallel pre-charge energy storage device also includes a protective housing. The first energy storage management component 110 and the second energy storage management component 210 are disposed in the protective housing. Multiple energy storage management components are disposed in the same protective housing, making the structure more compact and saving installation space.

[0053] In some embodiments of this utility model, the multi-battery cluster parallel pre-charge energy storage device further includes a first box and a second box that are independent of each other. The first energy storage management component 110 is disposed in the first box, and the second energy storage management component 210 is disposed in the second box. It can be understood that the first box and the second box are placed in different areas in space, and the first box and the second box have mutually isolated spaces, thereby separating the first energy storage management component 110 and the second energy storage management component 210 to prevent mutual interference and have better operational reliability and stability.

[0054] The cascaded energy storage system according to a second aspect of the present invention includes a converter 400 and a multi-cell cluster parallel pre-charged energy storage device disclosed in any of the above embodiments.

[0055] It is understandable that the converter 400 in the power grid system typically includes cascaded bridge arms connected by multiple power submodules. Each power submodule can be composed of an H-bridge power circuit consisting of multiple semiconductor switching transistors and DC capacitors.

[0056] This utility model cascaded energy storage system adopts the multi-battery cluster parallel pre-charged energy storage device disclosed in any of the above embodiments, which optimizes the structure and reduces the layout cost.

[0057] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0058] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A multi-cell cluster parallel pre-charged energy storage device, comprising: At least comprising: a first energy storage module comprising a first energy storage management assembly and a first battery cluster, the first energy storage management assembly comprising a first buffer parallel branch, the first buffer parallel branch comprising a first switch element, a second switch element and a first resistance element, the second switch element and the first resistance element being connected in series to form a first series branch, the first switch element and the first series branch being connected in parallel to form at least part of the first buffer parallel branch; a second energy storage module comprising a second energy storage management assembly and a second battery cluster, the second energy storage management assembly comprising a second buffer parallel branch, the second buffer parallel branch comprising a third switch element, a fourth switch element and a second resistance element, the fourth switch element and the second resistance element being connected in series to form a second series branch, the third switch element and the second series branch being connected in parallel to form at least part of the second buffer parallel branch; wherein a head end of the first buffer parallel branch is used as a first energy storage output end for connecting with a power conversion device, a tail end of the first buffer parallel branch is connected with a head end of the first battery cluster and a head end of the second buffer parallel branch respectively, a tail end of the second buffer parallel branch is connected with a head end of the second battery cluster, and a tail end of the first battery cluster and a tail end of the second battery cluster are connected and used as a second energy storage output end for connecting with the power conversion device.

2. A multi-cell cluster parallel pre-charged energy storage device as defined in claim 1, wherein: The first energy storage management assembly further comprises a fifth switch element, the second energy storage management assembly further comprises a sixth switch element, a head end of the sixth switch element is connected with a tail end of the second battery cluster, a tail end of the sixth switch element is connected with a tail end of the first battery cluster so that the tail end of the first battery cluster is connected with the tail end of the second battery cluster through the sixth switch element, and a head end of the fifth switch element is connected with the tail end of the first battery cluster and a tail end of the sixth switch element respectively, and a tail end of the fifth switch element is used as the second energy storage output end.

3. A multi-cell cluster parallel pre-charged energy storage device as claimed in claim 2, wherein, The third energy storage module further comprises a third energy storage management assembly and a third battery cluster, the third energy storage management assembly comprising a third buffer parallel branch, the third buffer parallel branch comprising a seventh switch element, an eighth switch element and a third resistance element, the eighth switch element and the third resistance element being connected in series to form a third series branch, the seventh switch element and the third series branch being connected in parallel to form at least part of the third buffer parallel branch, wherein a head end of the third buffer parallel branch is connected with a tail end of the first buffer parallel branch, a tail end of the third buffer parallel branch is connected with a head end of the third battery cluster, and a tail end of the third battery cluster is connected with the tail end of the first battery cluster and a head end of the fifth switch element respectively.

4. A multi-cell cluster parallel pre-charged energy storage device as claimed in claim 3, wherein, The third energy storage management assembly further comprises a ninth switch element, a head end of the ninth switch element is connected with a tail end of the third battery cluster, and a tail end of the ninth switch element is connected with the tail end of the first battery cluster so that the tail end of the first battery cluster is connected with the tail end of the third battery cluster through the ninth switch element.

5. A multi-cell cluster parallel pre-charged energy storage device as defined in claim 1 wherein, The first energy storage management component further comprises a first control module, a first energy storage voltage detection module and a capacitor voltage detection module, the first energy storage voltage detection module is connected with the first battery cluster to detect the energy storage voltage of the first battery cluster, the capacitor voltage detection module is used to be connected with the DC side capacitor of the current conversion device to detect the capacitor voltage, and the first control module is connected with the first energy storage voltage detection module, the capacitor voltage detection module, the controlled end of the first switch and the controlled end of the second switch respectively to control the on-off of the first switch and the on-off of the second switch.

6. A multi-cell cluster parallel pre-charged energy storage device as defined in claim 5, wherein, The second energy storage management component further comprises a second control module and a second energy storage voltage detection module, the second energy storage voltage detection module is connected with the second battery cluster to detect the energy storage voltage of the second battery cluster, and the second control module is connected with the second energy storage voltage detection module, the first control module, the third switch and the fourth switch respectively to control the on-off of the third switch and the on-off of the fourth switch.

7. A multi-cell cluster parallel pre-charged energy storage device as defined in claim 6 wherein, The first energy storage management component further comprises a first temperature detection module, the second energy storage management component comprises a second temperature detection module, the first temperature detection module is used to detect the battery temperature of the first battery cluster, the second temperature detection module is used to detect the battery temperature of the second battery cluster, the first control module is connected with the first temperature detection module, and the second control module is connected with the second temperature detection module.

8. A multi-cell cluster parallel pre-charged energy storage device as defined in claim 1 wherein, The first energy storage management component and the second energy storage management component are arranged in the protection box.

9. A multi-cell cluster parallel pre-charged energy storage device as defined in claim 1 wherein, The first energy storage management component and the second energy storage management component are arranged in the first box and the second box respectively.

10. A cascaded energy storage system characterized by, The current conversion device and the multi-battery cluster parallel pre-charging energy storage device as claimed in any one of claims 1 to 9 are comprised.

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