Energy storage system

Abstract

The utility model discloses an energy storage system which comprises a box body, and a battery cluster, an energy storage high-voltage control box, a DC / DC device and an inversion device are arranged in the box body. The number of the battery clusters is multiple, the number of the energy storage high-voltage control boxes is the same as that of the battery clusters, and the input ends of the energy storage high-voltage control boxes are connected with the battery clusters in a one-to-one correspondence mode. The number of the DC / DC devices is multiple, each DC / DC device comprises a DC voltage stabilization channel, the DC voltage stabilization channels included in the multiple DC / DC devices are mutually independent, the number of the DC voltage stabilization channels is the same as that of the energy storage high-voltage control boxes, and the input ends of the DC voltage stabilization channels are connected with the output ends of the energy storage high-voltage control boxes in a one-to-one correspondence mode. The output end of the direct current voltage stabilization channel is electrically connected with the input end of the inversion device. By the adoption of the scheme, the problem of how to reduce circulating current and risks caused by direct-current confluence type design is solved.

Description

Technical Field

[0001] This utility model relates to the technical field of energy storage, and in particular to an energy storage system. Background Technology

[0002] Existing energy storage systems typically employ a DC-DC converter design, which combines the DC power from multiple solar panels into a single battery pack, and then converts the current into AC power through an inverter to supply electrical equipment.

[0003] Existing energy storage systems typically involve adding a DC combiner cabinet between the battery and the inverter, and an AC combiner cabinet on the inverter output side to combine the outputs of multiple devices for unified output. This design results in a large combiner cabinet size, which can lead to circulating current on the battery side, affecting the system's detection accuracy. Furthermore, due to the compact internal design, short circuits and arcing are prone to occur between the copper busbars. Utility Model Content

[0004] This invention provides an energy storage system to reduce circulating currents and risks caused by DC busbar design.

[0005] According to one aspect of the present invention, an energy storage system is provided, the energy storage system including a housing, wherein the housing is provided with a battery cluster, an energy storage high-voltage control box, a DC / DC device and an inverter device;

[0006] The number of battery clusters is multiple, and the number of energy storage high-voltage control boxes is the same as the number of battery clusters. The input terminals of the multiple energy storage high-voltage control boxes are connected to the multiple battery clusters one by one.

[0007] The number of DC / DC devices is multiple, and each DC / DC device includes a DC voltage regulation channel. The DC voltage regulation channels included in the multiple DC / DC devices are independent of each other and the number is the same as the number of energy storage high-voltage control boxes. The input terminal of each DC voltage regulation channel is connected to the output terminal of each energy storage high-voltage control box in a one-to-one correspondence. The output terminal of each DC voltage regulation channel is electrically connected to the input terminal of the inverter device.

[0008] In an optional embodiment of this utility model, the DC / DC device includes a plurality of independent DC / DC circuits, and each DC / DC circuit includes one DC regulated channel.

[0009] In an optional embodiment of this utility model, the energy storage high-voltage control box includes a switch module, which is connected in series between the DC / DC device and the battery cluster;

[0010] The switch module is used to disconnect the electrical connection between the battery pack and the DC / DC device when it is turned on, and to connect the battery pack and the DC / DC device when it is turned off.

[0011] In an optional embodiment of this utility model, the switching module includes a first circuit breaker.

[0012] In an optional embodiment of this utility model, the energy storage high-voltage control box further includes a main relay, which is connected in series between the DC / DC device and the battery cluster.

[0013] In an optional embodiment of this utility model, the energy storage high-voltage control box further includes a power-on slow-start module, which includes a pre-charge resistor and a pre-charge relay. The pre-charge resistor and the pre-charge relay are connected in series and then connected in parallel with the main relay.

[0014] In an optional embodiment of this utility model, the energy storage high-voltage control box further includes a fuse, which is connected in series between the DC / DC device and the battery cluster.

[0015] In an optional embodiment of this utility model, the inverter device includes a string inverter.

[0016] In an optional embodiment of this utility model, a second circuit breaker is connected to the output terminal of the inverter device.

[0017] In an optional embodiment of this utility model, the box is provided with a first partition and a second partition. There are multiple first partitions, and the multiple first partitions are spaced apart in the box along a first direction to divide the interior of the box into multiple storage areas. The length direction of the first partition is a second direction, the length direction of the second partition is the first direction, and the second direction is perpendicular to the first direction.

[0018] The second partition divides one of the multiple storage areas into a first sub-area and a second sub-area. The inverter device is located in the first sub-area, the DC / DC device is located in the second sub-area, and the battery cluster and the energy storage high-voltage control box are located in the remaining storage areas.

[0019] The technical solution of this utility model embodiment includes battery clusters, energy storage high-voltage control boxes, DC / DC devices, and inverter devices. There are multiple battery clusters, and the number of energy storage high-voltage control boxes is the same as the number of battery clusters. The input terminals of the multiple energy storage high-voltage control boxes are connected one-to-one with the multiple battery clusters. There are also multiple DC / DC devices, each including a DC voltage regulating channel. These DC voltage regulating channels are independent of each other and their number is the same as the number of energy storage high-voltage control boxes. The input terminals of the DC voltage regulating channels are connected one-to-one with the output terminals of the energy storage high-voltage control boxes, and the output terminals of the DC voltage regulating channels are electrically connected to the input terminals of the inverter devices. Therefore, it achieves one-cluster-one-management on the DC side, directly separating different battery clusters. Different battery clusters are controlled and regulated by different energy storage high-voltage control boxes and DC voltage regulating channels, avoiding inter-cluster circulating currents and short-circuit risks caused by DC busbars, and also avoiding system failures due to excessive inter-cluster voltage differences. This solves the problem of how to reduce circulating currents and risks caused by DC busbar design.

[0020] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A schematic diagram of the structure of an energy storage system provided in an embodiment of this utility model;

[0023] Figure 2 A circuit diagram of an energy storage system provided for an embodiment of this utility model.

[0024] The components are as follows: 1. Cabinet; 11. First partition; 12. Second partition; 13. Storage area; 131. First sub-area; 132. Second sub-area; 2. Battery cluster; 3. Energy storage high-voltage control box; 31. Switch module; 311. First circuit breaker; 32. Main relay; 33. Power-on soft start module; 331. Pre-charge resistor; 332. Pre-charge relay; 34. Fuse; 4. DC / DC equipment; 41. DC / DC circuit; 5. Inverter equipment; 51. String inverter; 6. Second circuit breaker. Detailed Implementation

[0025] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0026] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0027] Figure 1 This is a schematic diagram of the structure of an energy storage system provided in an embodiment of the present invention. Figure 2 A circuit diagram of an energy storage system provided for an embodiment of this utility model is shown below. Figure 1 and Figure 2 As shown, the energy storage system includes a housing 1, which houses a battery cluster 2, an energy storage high-voltage control box 3, a DC / DC converter 4, and an inverter 5. The battery cluster 2 is a battery assembly composed of individual battery cells connected in series, parallel, or series-parallel configurations. It operates independently after being connected to an energy storage converter and auxiliary facilities, thus providing direct current (DC). The energy storage high-voltage control box 3 is a high-voltage circuit management module connecting the battery cluster 2 and the DC / DC converter 4, and it has functions such as voltage / current acquisition, contactor control, and protection for the battery cluster 2. The DC / DC converter 4 is a device that converts electrical energy from one voltage value to another in a DC circuit; therefore, it converts the voltage of the battery cluster 2 to the voltage required by the load. The inverter 5 converts DC power to AC power; therefore, it converts the DC power output from the DC / DC converter 4 into AC power to supply AC loads.

[0028] There are multiple battery clusters 2, and the number of energy storage high-voltage control boxes 3 is the same as the number of battery clusters 2. The input terminals of the multiple energy storage high-voltage control boxes 3 are connected one-to-one with the multiple battery clusters 2. That is, each battery cluster 2 is electrically connected to a corresponding energy storage high-voltage control box 3. For example, when there are four battery clusters 2, there are also four energy storage high-voltage control boxes 3. Each battery cluster 2 is connected to one energy storage high-voltage control box 3, so the energy storage high-voltage control boxes 3 connected to the four battery clusters 2 are all different.

[0029] There are multiple DC / DC devices 4, each including a DC voltage regulator channel. These DC voltage regulator channels are independent of each other and their number is the same as the number of energy storage high-voltage control boxes 3. The input terminals of each DC voltage regulator channel are connected one-to-one with the output terminals of the energy storage high-voltage control boxes 3, and their output terminals are electrically connected to the input terminals of the inverter device 5. A DC voltage regulator channel is a channel that can stabilize the input voltage at a specific value before outputting it. The multiple independent DC voltage regulator channels mean that they are not electrically connected; that is, the input terminal of each DC voltage regulator channel is connected to a different energy storage high-voltage control box 3. Therefore, the DC power output from each battery cluster 2 is output to its corresponding DC voltage regulator channel through the connected energy storage high-voltage control box 3. The DC power output from different battery clusters 2 is regulated by different DC voltage regulator channels before being output to the inverter device 5. This allows for individual management of each battery cluster on the DC side, with different battery clusters 2 controlled and stabilized by different energy storage high-voltage control boxes 3 and DC voltage regulation channels, completely avoiding the problems that occur in traditional DC bus operation.

[0030] The above scheme includes multiple battery clusters 2, energy storage high-voltage control boxes 3, DC / DC devices 4, and inverter devices 5. The number of battery clusters 2 is the same as the number of energy storage high-voltage control boxes 3, with each box's input terminal connected to a corresponding battery cluster 2. Multiple DC / DC devices 4 are also included, each containing a DC voltage regulator channel. These channels are independent and their number matches the number of energy storage high-voltage control boxes 3. The input terminals of these DC voltage regulator channels are connected to the output terminals of the energy storage high-voltage control boxes 3, and their output terminals are electrically connected to the input terminals of the inverter devices 5. This achieves one-cluster-one-management on the DC side, directly separating different battery clusters 2. Each battery cluster 2 is controlled and regulated by a different energy storage high-voltage control box 3 and DC voltage regulator channel, avoiding inter-cluster circulating currents and short-circuit risks caused by DC confluence, and also preventing system failures due to excessive inter-cluster voltage differences. This solved the problem of how to reduce circulating current and risks caused by DC bus design.

[0031] In an optional embodiment of this utility model, such as Figure 2As shown, the DC / DC device 4 includes multiple independent DC / DC circuits 41, each of which includes a DC voltage regulation channel. The DC voltage regulation channel is the circuit between the input and output terminals of the DC / DC circuit 41. The DC / DC circuit 41 converts DC to DC, thus enabling the conversion of the voltage output from the battery cluster 2 to a specific voltage, i.e., achieving DC voltage regulation. By including multiple independent DC / DC circuits 41 in the DC / DC device 4, different battery clusters 2 can be directly separated, with different DC / DC circuits 41 converting the voltage output from different battery clusters 2. In this embodiment, there are two DC / DC devices 4, each including two independent DC / DC circuits 41. There are four battery clusters 2 and four energy storage high-voltage control boxes 3, allowing each battery cluster 2 to be connected to its corresponding energy storage high-voltage control box 3 and DC / DC circuit 41, forming four different branches.

[0032] In an optional embodiment of this utility model, such as Figure 1 and Figure 2 As shown, the box body 1 is provided with a first partition 11 and a second partition 12. There are multiple first partitions 11, which are spaced apart along a first direction within the box body 1 to divide the interior of the box body 1 into multiple storage areas 13. The length direction of the first partition 11 is a second direction, and the length direction of the second partition 12 is the first direction, which is perpendicular to the first direction. In a specific embodiment, the first direction is the length direction of the box body 1, and the second direction is the width direction of the box body 1.

[0033] The second partition 12 divides one of the multiple storage areas 13 into a first sub-area 131 and a second sub-area 132. The first sub-area 131 is equipped with an inverter device 5, the second sub-area 132 is equipped with a DC / DC device 4, and the remaining storage areas 13 are equipped with a battery cluster 2 and an energy storage high-voltage control box 3.

[0034] The second partition 12 can be located in the upper middle part of the storage area 13. Since the inverter 5 and DC / DC device 4 are smaller than the battery cluster 2, and the battery cluster 2 needs to be directly connected to the energy storage high voltage control box 3, the box 1 is first divided into multiple storage areas 13 by the first partition 11, and then one of the storage areas 13 is divided into a smaller first sub-area 131 and a second sub-area 132 by the second partition 12. The inverter 5 and DC / DC device 4 are respectively placed in the smaller first sub-area 131 and the second sub-area 132, which realizes the rational use of the space of the box 1 and makes the energy storage system smaller.

[0035] In an optional embodiment of this utility model, such as Figure 1 and Figure 2 As shown, the energy storage high-voltage control box 3 includes a switch module 31, which is connected in series between the DC / DC device 4 and the battery cluster 2. The switch module 31 is used to disconnect the electrical connection between the battery cluster 2 and the DC / DC device 4 when it is open, and to connect the battery cluster 2 and the DC / DC device 4 when it is closed.

[0036] Since the number of energy storage high-voltage control boxes 3 is the same as that of battery clusters 2, each energy storage high-voltage control box 3 includes a switch module 31 for controlling the connection and disconnection of the corresponding battery cluster 2 with the DC / DC device 4. Therefore, different switch modules 31 can manage different battery clusters 2. When a single battery cluster 2 fails, the electrical connection between the battery cluster 2 and the DC / DC device 4 can be cut off through the switch module 31 of that branch, and the battery cluster 2 can be isolated from the energy storage system for maintenance without affecting the continued operation of other battery clusters 2. Compared with the conventional DC bus design, which requires the entire system to be shut down for maintenance when a single battery cluster 2 fails, this solution avoids the power outage of the energy storage system caused by maintenance, reducing the loss of user revenue.

[0037] Based on the above embodiments, the switch module 31 includes a first circuit breaker 311. The first circuit breaker 311 is a switching device capable of closing, carrying, and interrupting current under normal circuit conditions and capable of closing, carrying, and interrupting current under abnormal circuit conditions within a specified time. The first circuit breaker 311 is connected in series between the DC / DC device 4 and the battery pack 2, thus facilitating the control of the connection and disconnection of the battery pack 2 and the DC / DC device 4.

[0038] In an optional embodiment of this invention, the energy storage high-voltage control box 3 further includes a main relay 32, which is connected in series between the DC / DC device 4 and the battery cluster 2. The main relay 32 is an electrical control device that causes a predetermined step change in the controlled quantity in the electrical output circuit when the change in the input quantity (excitation quantity) reaches a specified requirement. By connecting the main relay 32 in series between the DC / DC device 4 and the battery cluster 2, the circuit can be protected.

[0039] In an optional embodiment of this utility model, the energy storage high-voltage control box 3 further includes a power-on slow-start module 33. The power-on slow-start module 33 includes a pre-charge resistor 331 and a pre-charge relay 332, which are connected in series and then in parallel with the main relay 32. When the battery cluster 2 first starts outputting power, the voltage of the DC / DC device 4 is zero. If the pre-charge resistor 331 is not used, the current of the DC / DC device 4 will be very large. Therefore, the pre-charge resistor 331 is needed as a component to limit the current of the DC / DC device 4 and reduce the current surge. The main function of the pre-charge relay 332 is to prevent damage to components when the voltage of the DC / DC device 4 rises. By setting the pre-charge resistor 331 and the pre-charge relay 332, the DC / DC device 4 can be protected, preventing excessive current at the moment of power-on.

[0040] In an optional embodiment of this utility model, the energy storage high-voltage control box 3 further includes a fuse 34, which is connected in series between the DC / DC device 4 and the battery cluster 2. A fuse 34 is an electrical device that breaks the circuit by melting its own fusible element when the current exceeds a specified value. By connecting the fuse 34 in series between the DC / DC device 4 and the battery cluster 2, the circuit can be protected by promptly cutting off the circuit when the current is too high.

[0041] In an optional embodiment of this utility model, such as Figure 1 and Figure 2 As shown, the inverter device 5 includes a string inverter 51. The string inverter 51 directly converts the DC power generated by the modules into AC power, which is then combined, thus completely avoiding the problems that occur in traditional DC combiner operation. Using a string inverter 51 also facilitates maintenance, simplifies equipment maintenance procedures, and enables standby maintenance of the system. The number of string inverters 51 is set according to requirements, such as the power of the string inverters 51 used and the required voltage of the load. Therefore, the number of string inverters 51 can be single or multiple; no specific limit is made here. In this embodiment, the number of string inverters 51 is specifically three.

[0042] In an optional embodiment of this invention, the output terminal of the inverter device 5 is connected to a second circuit breaker 6. The second circuit breaker 6 is a switching device capable of closing, carrying, and interrupting current under normal circuit conditions and capable of closing, carrying, and interrupting current under abnormal circuit conditions within a specified time. Therefore, when the load connected to the energy storage system malfunctions, the second circuit breaker 6 can disconnect the energy storage system from the load, preventing damage to the energy storage system.

[0043] Preferably, there are multiple string inverters 51, and the number of second circuit breakers 6 is the same as the number of string inverters 51, and they are connected one-to-one. Therefore, the energy storage system can supply power to multiple loads. When a single load fails, the connection between the energy storage system and the load can be cut off by the corresponding second circuit breaker 6, while the energy storage system can still supply power to the remaining loads normally, reducing the loss of user revenue caused by the downtime of the energy storage system.

[0044] It should be understood that the various forms of the process shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this utility model can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this utility model can be achieved, and this is not limited herein.

[0045] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. An energy storage system, characterized by, The enclosure includes a battery pack, an energy storage high-voltage control box, a DC / DC converter, and an inverter. The number of battery clusters is multiple, and the number of energy storage high-voltage control boxes is the same as the number of battery clusters. The input terminals of the multiple energy storage high-voltage control boxes are connected to the multiple battery clusters one by one. The number of DC / DC devices is multiple, and each DC / DC device includes a DC voltage regulation channel. The DC voltage regulation channels included in the multiple DC / DC devices are independent of each other and the number is the same as the number of energy storage high-voltage control boxes. The input terminal of each DC voltage regulation channel is connected to the output terminal of the energy storage high-voltage control box in a one-to-one correspondence, and the output terminal of each DC voltage regulation channel is electrically connected to the input terminal of the inverter device.

2. The energy storage system of claim 1, wherein, The DC / DC device includes multiple independent DC / DC circuits, and each DC / DC circuit includes one DC regulated channel.

3. The energy storage system of claim 1, wherein, The energy storage high-voltage control box includes a switch module, which is connected in series between the DC / DC device and the battery cluster. The switch module is used to disconnect the electrical connection between the battery pack and the DC / DC device when it is turned on, and to connect the battery pack and the DC / DC device when it is turned off.

4. The energy storage system of claim 3, wherein, The switching module includes a first circuit breaker.

5. The energy storage system of any one of claims 1-4, wherein, The energy storage high-voltage control box also includes a main relay, which is connected in series between the DC / DC device and the battery cluster.

6. The energy storage system of claim 5, wherein, The energy storage high-voltage control box also includes a power-on slow-start module, which includes a pre-charge resistor and a pre-charge relay. The pre-charge resistor and the pre-charge relay are connected in series and then connected in parallel with the main relay.

7. The energy storage system according to any one of claims 1 to 4, characterized in that, The energy storage high-voltage control box also includes a fuse, which is connected in series between the DC / DC device and the battery cluster.

8. The energy storage system of any one of claims 1-4, wherein, The inverter equipment includes a string inverter.

9. The energy storage system of any one of claims 1-4, wherein, The output terminal of the inverter is connected to a second circuit breaker.

10. The energy storage system of any one of claims 1-4, wherein, The box is provided with a first partition and a second partition. There are multiple first partitions. The multiple first partitions are spaced apart in the box along a first direction to divide the interior of the box into multiple storage areas. The length direction of the first partition is the second direction, the length direction of the second partition is the first direction, and the second direction is perpendicular to the first direction. The second partition divides one of the multiple storage areas into a first sub-area and a second sub-area. The inverter device is located in the first sub-area, the DC / DC device is located in the second sub-area, and the battery cluster and the energy storage high-voltage control box are located in the remaining storage areas.

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