Protection circuit for energy storage system

Abstract

A protection circuit for an energy storage system, comprising an energy storage side module (210), a power conversion side module (220), and a protection module (230). The energy storage side module (210) is connected to the power conversion side module (220) through the protection module (230). The energy storage side module (210) is used for outputting a direct current. The power conversion side module (220) is used for providing a direct current for a standby power system in the energy storage side module (210). The protection module (230) is used for disconnecting a power supply circuit between the energy storage side module (210) and the power conversion side module (220) in the event of a short circuit.

Description

Protection circuit of energy storage system

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on December 11, 2023, with application number 202323372946.4 and invention name “Protection Circuit for Energy Storage System”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of energy storage technology, and in particular to a protection circuit for an energy storage system. Background Art

[0003] Current energy storage systems pursue high integration. The positive and negative wires of energy storage units are directly connected to power conversion units (PCSs) via cables, for example, in a power storage converter (PCS), ensuring that one PCS corresponds to one power conversion unit. However, when the energy storage system is supplying internal auxiliary power, positive and negative cables must be pulled from any power conversion unit as auxiliary power input. Even power conversion units not receiving power still require positive and negative cables to be pulled and equipped with fuses, making maintenance difficult.

[0004] Summary of the Invention

[0005] The present application provides a protection circuit for an energy storage system, which is used to set an external protection module on the power supply circuit of an auxiliary power system, and promptly disconnect the power supply circuit when the energy storage system is short-circuited, thereby reducing the number of fuses required for the energy storage system and reducing maintenance difficulty.

[0006] A first aspect of the present application provides an auxiliary power supply protection circuit for an energy storage system, comprising: an energy storage side module, a power conversion side module, and a protection module, wherein the energy storage side module is connected to the power conversion side module after passing through the protection module; the energy storage side module is used to output direct current (DC) power; the power conversion side module is used to provide DC power to an auxiliary power supply system in the energy storage side module; and the protection module is used to disconnect the power supply circuit between the energy storage side module and the power conversion side module in the event of a short circuit.

[0007] In a feasible implementation manner, the protection module includes: two power supply circuits, each of which is provided with a fuse protection device; the fuse protection device is used to disconnect when a short circuit occurs.

[0008] In a feasible embodiment, each power supply circuit also includes a first terminal and a second terminal; the two ends of the fuse protection device are respectively connected to the first terminal and the second terminal; the first terminal is used to connect the auxiliary power supply output interface in the power conversion side module; the second terminal is used to connect the input interface of the auxiliary power supply system in the energy storage side module.

[0009] In a feasible embodiment, the protection module includes a first fuse protection device located on the first power supply circuit and a second fuse protection device located on the second power supply circuit; the first input end of the auxiliary power supply system is connected to the positive pole of the target energy storage unit through the first fuse protection device; the second input end of the auxiliary power supply system is connected to the negative pole of the target energy storage unit through the second fuse protection device.

[0010] In a feasible implementation manner, the first fuse protection device is loaded with a first fuse, and the second fuse protection device is loaded with a second fuse.

[0011] In a feasible implementation manner, the protection module is provided on the housing of the power conversion side module.

[0012] In a feasible implementation manner, the protection module is provided on the housing of the auxiliary power supply system.

[0013] In a feasible embodiment, the energy storage side module includes at least one energy storage unit and an auxiliary power supply system; the auxiliary power supply system is used to transmit the direct current output by any energy storage unit to the internal load of the energy storage system.

[0014] In a feasible embodiment, the power conversion side module includes at least one power conversion module, and the power conversion module includes a power change unit, a third fuse and a fourth fuse; the power change unit is connected to the positive pole of the corresponding energy storage unit through the third fuse, and the power change unit is connected to the negative pole of the corresponding energy storage unit through the fourth fuse.

[0015] In a feasible implementation manner, the power conversion side module is further used to convert the direct current output by the energy storage side module into alternating current, or to adjust the voltage or current of the direct current output by the energy storage side module.

[0016] In the technical solution provided by the present application, there is an energy storage side module, a power conversion side module and a protection module. The energy storage side module is connected to the power conversion side module after passing through the protection module; the energy storage side module is used to output direct current; the power conversion side module is used to provide direct current to the auxiliary power supply system in the energy storage side module; and the protection module is used to disconnect the power supply circuit between the energy storage side module and the power conversion side module in the event of a short circuit. In the present application, an external protection module is provided on the power supply circuit of the auxiliary power supply system to disconnect the power supply circuit in time when the energy storage system is short-circuited, thereby reducing the number of fuses in the power conversion side module and reducing the difficulty of maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG1 is a schematic structural diagram of a protection circuit of an energy storage system according to an embodiment of the present application;

[0018] FIG2 is another structural diagram of a protection circuit of an energy storage system according to an embodiment of the present application;

[0019] FIG3 is another structural diagram of a protection circuit of an energy storage system according to an embodiment of the present application;

[0020] FIG4 is a schematic diagram of a fuse protection device according to an embodiment of the present application;

[0021] FIG5 is another structural diagram of the protection circuit of the energy storage system in an embodiment of the present application. DETAILED DESCRIPTION

[0022] The present application provides a protection circuit for an energy storage system, which is used to set an external protection module on the power supply circuit of an auxiliary power system, and promptly disconnect the power supply circuit when the energy storage system is short-circuited, thereby reducing the number of fuses required for the energy storage system and reducing maintenance difficulty.

[0023] The terms "first," "second," "third," "fourth," etc. (if any) in the specification and claims of the present application and in the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential sequence. It should be understood that the numbers used in this way are interchangeable where appropriate, so that the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having," and any variations thereof, are intended to cover non-exclusive inclusions, for example, a process, method, system, product, or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products, or apparatus.

[0024] In existing solutions, the energy storage system includes an energy storage side module and a power conversion side module. As shown in Figure 1, the DC source required for the auxiliary power system (standby power system, SPS) within the energy storage system to draw power must be pulled from any power conversion module in the power conversion side module, with two positive and negative cables as the input of the auxiliary power system. Each power conversion module contains a power conversion unit and four fuses, of which the third fuse FU3 and the fourth fuse FU4 are located in the control loop between the energy storage unit and the power conversion unit, the first fuse FU1 and the second fuse FU2 are set on the auxiliary power supply circuit of the power conversion module, and the power supply terminal of the auxiliary power supply circuit is set between the third fuse / fourth fuse and the energy storage unit. However, during the actual power supply process, the auxiliary power system in the energy storage side module will only draw power from one power conversion module, and the first fuse FU1 and the second fuse FU2 in the other parallel power conversion modules will be idle, resulting in redundancy and increasing hardware costs.

[0025] To solve the above problems, an embodiment of the present application provides a protection circuit for an energy storage system, as shown in FIG2 , specifically comprising:

[0026] An energy storage side module 210, a power conversion side module 220 and a protection module 230, wherein the energy storage side module 210 is connected to the power conversion side module 220 after passing through the protection module 230;

[0027] The energy storage side module 210 is used to output direct current;

[0028] The power conversion side module 220 is used to provide DC power to the auxiliary power system in the energy storage side module 210;

[0029] The protection module 230 is used to disconnect the power supply circuit between the energy storage side module 210 and the power conversion side module 220 in the event of a short circuit.

[0030] In this application, an external protection module is set on the power supply circuit of the auxiliary power supply system, and the external power supply circuit between the auxiliary power supply system and the power conversion side module is promptly disconnected when a short circuit occurs in the energy storage system, thereby reducing the number of fuses required for the energy storage system and reducing the difficulty of maintenance.

[0031] In a feasible implementation, as shown in FIG3 , the protection module 230 includes:

[0032] Two power supply circuits, each of which is provided with a fuse protection device 231;

[0033] The fuse protection device 231 is used to disconnect when a short circuit occurs.

[0034] It should be noted that, as long as a short circuit occurs in the circuit where the fuse protection device is located, the fuse loaded in the fuse protection device will melt, that is, the circuit will be disconnected.

[0035] In a feasible embodiment, as shown in FIG3 , each power supply circuit further includes a first wiring terminal 232 and a second wiring terminal 233 ;

[0036] The two ends of the fuse protection device 231 are connected to the first wiring terminal 232 and the second wiring terminal 233 respectively;

[0037] The first terminal 232 is used to connect to the auxiliary power output interface of the power conversion side module 220;

[0038] The second connection terminal 233 is used to connect to the input interface of the auxiliary power system in the energy storage side module 210.

[0039] It should be noted that the setting of the first terminal 232 and the second terminal 233 needs to follow the fuse protection device. For example, when the fuse protection device is set on the housing of the power conversion module 221, the first terminal 232 and the second terminal 233 are both on the housing of the power conversion module 221; when the fuse protection device is set on the housing of the auxiliary power supply system, the first terminal 232 and the second terminal 233 are both on the housing of the auxiliary power supply system.

[0040] In a feasible implementation manner, the protection module 230 includes a first fuse protection device 231 located on the first power supply circuit and a second fuse protection device 231 located on the second power supply circuit;

[0041] The first input end of the auxiliary power supply system is connected to the positive electrode of the target energy storage unit through the first fuse protection device 231;

[0042] The second input end of the auxiliary power supply system is connected to the negative electrode of the target energy storage unit through the second fuse protection device 231 .

[0043] For example, as shown in Figure 3, the protection module 230 includes a first fuse protection device FU1 located on the first power supply circuit and a second fuse protection device FU2 located on the second power supply circuit; the first input end of the auxiliary power supply system is connected to the positive pole of the energy storage unit 1 through the first fuse protection device FU1; the second input end of the auxiliary power supply system is connected to the negative pole of the energy storage unit 1 through the second fuse protection device FU2.

[0044] It is understandable that the first fuse protection device and the second fuse protection device in the control circuit are only used to distinguish the power supply circuits in which they are located, and do not constitute a limitation on the structure of the fuse protection device.

[0045] In a feasible implementation manner, as shown in FIG4 , the first fuse protection device 231 is loaded with a first fuse 234 , and the second fuse protection device 231 is loaded with a second fuse 234 .

[0046] It should be noted that the fuse protection device involved in this application adopts an IP68 shell protection level and is installed on the outside of the power conversion unit (such as an energy storage inverter or a DC converter) for easy maintenance. Therefore, it is necessary to increase the waterproof and dustproof level. This application adopts the highest level of waterproof and dustproof level to increase the protection of the fuse and avoid interfering with the normal operation of the fuse.

[0047] In a feasible implementation manner, the protection module 230 is disposed on the housing of the power conversion side module 220 .

[0048] It should be noted that the protection module is separately provided outside the power conversion module 221 , for example, it can be provided on the housing for easy maintenance.

[0049] As shown in Figure 3, the fuses on the positive and negative poles of the auxiliary power supply inside the n power conversion modules 221 are removed, and the fuse protection device shown in Figure 4 is added to the power supply circuit between the DC side of the auxiliary power supply system SPS and the DC side of the power conversion unit 1 in the energy storage side module, and is set on the side of the power supply circuit close to the power conversion module 221. The protection circuit structure of the energy storage system can achieve protection for the DC side of the SPS in the energy storage side module connected to any power conversion unit (for example, the energy storage converter PCS), and achieve optimal cost without safety risks.

[0050] It is understood that the protection module can be adaptively adjusted based on the housing structure of the power conversion module 221, placing the protection module in a position that is easily maintained and does not increase the risk of external damage due to the installation location. For example, assuming that the protection module is installed outside the PCS, then the lack of the protection of the PCS housing increases the risk of water ingress to the protection module. Therefore, it is necessary to install a structure for installing the protection module in an area of ​​the PCS housing that is not prone to water accumulation, and the protection module itself also needs to have a dustproof and waterproof protective structure such as an external protective cover. Similarly, if it is installed on the housing of the SPS, it is also necessary to consider dustproof and waterproof conditions, and to ensure that the protection device is not easily damaged, so as to set a reasonable installation location, which is not limited here.

[0051] In a feasible implementation manner, the protection module is provided on the housing of the auxiliary power supply system.

[0052] It should be noted that the protection module 230 is separately provided outside the auxiliary power system, for example, can be provided on the housing, for easy maintenance.

[0053] As shown in FIG3 , the fuses on the positive and negative poles of the auxiliary power supply inside the n power conversion modules 221 are removed, and a fuse protection device as shown in FIG4 is added to the power supply circuit between the DC side of the auxiliary power supply system SPS and the DC side of the power conversion unit 1 in the energy storage side module, and is set on the side of the power supply circuit close to the SPS. The protection circuit structure of the energy storage system can achieve protection for the DC side of the SPS in the energy storage side module connected to any power conversion unit (for example, the energy storage converter PCS), and achieve optimal cost without safety risks.

[0054] In a feasible embodiment, as shown in FIG5 , the energy storage side module 210 includes at least one energy storage unit 211 and an auxiliary power system 212 ;

[0055] The auxiliary power supply system is used to transmit the direct current output by any energy storage unit to the internal load of the energy storage system.

[0056] It should be noted that the internal load may be: DC switching power supply, DC fan, DC switching power supply, lighting, heating resistor wire (for anti-icing and defrosting functions in cold areas), fire alarm, etc., and is not limited here.

[0057] It is understandable that the number of energy storage units is consistent with the number of power conversion models (ie, power conversion units), and one-to-one control is performed, that is, one energy storage unit is controlled by one corresponding power conversion unit.

[0058] In a feasible implementation manner, the power conversion side module 220 includes at least one power conversion module 221 , and the power conversion module 221 includes a power changing unit 2211 , a third fuse 2212 , and a fourth fuse 2213 ;

[0059] The power changing unit 2211 is connected to the positive electrode of the corresponding energy storage unit through the third fuse 2212 , and the power changing unit 2211 is connected to the negative electrode of the corresponding energy storage unit through the fourth fuse 2213 .

[0060] For example, as shown in FIG5 , the power conversion side module 1 includes a power changing unit 1 , a third fuse ( FU3 ) and a fourth fuse ( FU4 );

[0061] The power changing unit 1 is connected to the positive electrode of the corresponding energy storage unit 1 through the third fuse FU3 , and the power changing unit 1 is connected to the negative electrode of the corresponding energy storage unit 1 through the fourth fuse FU4 .

[0062] It should be noted that the power conversion side module 220 may include at least one power conversion module 221. The power conversion module 221 may be an energy storage converter or a DC converter, and each power conversion module includes a power conversion unit and two fuses.

[0063] In a feasible implementation manner, the power conversion side module 220 is further configured to convert the direct current output by the energy storage side module into alternating current, or to adjust the voltage or current of the direct current output by the energy storage side module.

[0064] It should be noted that the power conversion side module may include a DC converter and an energy storage inverter. When the power conversion side module 220 includes a DC converter, the DC converter can adjust the voltage or current of the DC power output by the corresponding energy storage unit in the energy storage side module; when the power conversion side module 220 includes an energy storage inverter, the energy storage inverter can convert the DC power output by the corresponding energy storage unit in the energy storage side module into AC power.

[0065] It is understandable that when all modules on the power conversion side are DC converters, the protection circuit of the energy storage system can be applied to DC-DC products. By setting a pair of external fuse protection devices on the input circuit of the SPS to replace the fuse on the auxiliary power interface of each connected DC converter, the purpose of reducing the number of fuses in the DC converter can also be achieved. While meeting the original needs, the hardware cost is reduced without affecting reliability. The external fuse protection device is more convenient to maintain.

[0066] When all modules on the power conversion side are energy storage converters, the protection circuit of the energy storage system can be applied to inverter circuit products. By setting a pair of external fuse protection devices on the input circuit of the SPS to replace the fuse on the auxiliary power interface of each connected energy storage converter, the number of fuses in the energy storage converter can also be reduced. While meeting the original requirements, the hardware cost is reduced without affecting reliability. The external fuse protection device is more convenient to maintain.

[0067] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0068] In addition, in the description of the embodiments of this application, unless otherwise specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0069] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0070] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0071] Finally, it should be noted that the above embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The scope of protection of the present application is not limited thereto. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that any person skilled in the art who is familiar with the technical field can still modify the technical solutions described in the above embodiments within the technical scope disclosed in the present application, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not deviate from the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A protection circuit for an energy storage system, characterized in that: include: An energy storage side module, a power conversion side module and a protection module, wherein the energy storage side module is connected to the power conversion side module after passing through the protection module; The energy storage side module is used to output direct current; The power conversion side module is used to provide direct current to the auxiliary power supply system in the energy storage side module; The protection module is used to disconnect the power supply circuit between the energy storage side module and the power conversion side module in case of short circuit.

2. The protection circuit of the energy storage system according to claim 1, characterized in that: The protection module comprises: Two power supply circuits, each of which is provided with a fuse protection device; The fuse protection device is used to disconnect when a short circuit occurs.

3. The protection circuit of the energy storage system according to claim 2, characterized in that: Each power supply circuit also includes a first wiring terminal and a second wiring terminal; Two ends of the fuse protection device are connected to the first wiring terminal and the second wiring terminal respectively; The first wiring terminal is used to connect the auxiliary power output interface in the power conversion side module; The second wiring terminal is used to connect to the input interface of the auxiliary power system in the energy storage side module.

4. The protection circuit of the energy storage system according to claim 2, characterized in that: The protection module includes a first fuse protection device located on the first power supply circuit and a second fuse protection device located on the second power supply circuit; The first input end of the auxiliary power supply system is connected to the positive electrode of the target energy storage unit through the first fuse protection device; The second input end of the auxiliary power system is connected to the target through the second fuse protection device. Negative connection for the energy storage unit.

5. The protection circuit of the energy storage system according to claim 4, characterized in that: The first fuse protection device is loaded with a first fuse, and the second fuse protection device is loaded with a second fuse.

6. The protection circuit of the energy storage system according to claim 1, characterized in that: The protection module is arranged on the housing of the power conversion side module.

7. The protection circuit of the energy storage system according to claim 1, characterized in that: The protection module is arranged on the housing of the auxiliary power supply system.

8. The protection circuit of the energy storage system according to claim 1, characterized in that: The energy storage side module includes at least one energy storage unit and an auxiliary power supply system; The auxiliary power supply system is used to transmit the direct current output by any energy storage unit to the internal load of the energy storage system.

9. The protection circuit of the energy storage system according to claim 8, characterized in that: The power conversion side module includes at least one power conversion module, and the power conversion module includes a power change unit, a third fuse and a fourth fuse; The power changing unit is connected to the positive electrode of the corresponding energy storage unit through the third fuse, and the power changing unit is connected to the negative electrode of the corresponding energy storage unit through the fourth fuse.

10. The protection circuit of the energy storage system according to claim 9, characterized in that: The power conversion side module is also used to convert the direct current output by the energy storage side module into alternating current, or to adjust the voltage or current of the direct current output by the energy storage side module.

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