Overvoltage suppression device and method for battery energy storage system

Abstract

The invention discloses an overvoltage suppression device and method for a battery energy storage system, the overvoltage suppression device is arranged at a high-voltage port side of the battery energy storage system, and the overvoltage suppression device comprises an insulation body; the multi-gap structure is arranged in the insulating body and comprises a plurality of metal pieces which are arranged at intervals, corresponding arc extinguishing holes are formed in the intervals of the adjacent metal pieces, and each arc extinguishing hole extends to the edge of the insulating body from the interval; the multi-interval structure is used for spraying electric arcs outwards through the arc extinguishing holes to diffuse energy when receiving overvoltage energy. By adopting the multi-gap structure and combining the characteristics of the vacuum environment, the overvoltage suppression efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy safety protection in petrochemical industry, and particularly relates to an overvoltage suppression device and method for a battery energy storage system. Background Art

[0002] The battery energy storage system is an important supporting component of the new energy power generation system and an important means to smooth the fluctuations of new energy power and perform peak shaving and frequency modulation. New energy power generation systems such as wind power and photovoltaic power are mostly built in large open areas with a relatively high lightning strike risk. Lightning strikes on new energy systems will generate strong overvoltages and overcurrents. These high-amplitude overvoltages and overcurrents propagate along the power lines and impact the battery energy storage system. In addition, when a fault such as a short circuit occurs in the power grid connected to the new energy system, the fault current will also invade the battery energy storage system, and in severe cases, it may cause the energy storage battery to burn out.

[0003] Multi-gap lightning arresters are an important means to discharge high-amplitude electrical impulses. Traditional multi-gap lightning arresters are installed on transmission line towers and are mostly used for lightning protection of high-voltage overhead lines. Currently, zinc oxide lightning arresters are mostly used for overvoltage protection at energy storage ports. However, after long-term operation, the zinc oxide resistor chips of zinc oxide lightning arresters are prone to aging, and periodic tests need to be carried out, resulting in relatively high maintenance costs.

[0004] In summary, in view of the problems existing in the current traditional technology for protecting battery energy storage systems, it is urgent to develop a method for a battery energy storage system that can more effectively suppress overvoltages, so as to solve the problems of the installation position of traditional multi-gap lightning arresters and / or the relatively high later maintenance costs caused by the easy aging of zinc oxide lightning arresters, and then improve the efficiency of overvoltage energy release. Summary of the Invention

[0005] The purpose of the present invention is to propose a technical solution for overvoltage suppression in a battery energy storage system to improve the disadvantages of traditional technologies, aiming at the problems in traditional technologies for suppressing overvoltages in battery energy storage systems, such as limited installation positions, relatively high later maintenance costs, and low overvoltage suppression efficiency, so as to solve one or more technical problems in the background art.

[0006] To solve the above technical problems, an embodiment of the present invention provides an overvoltage suppression device for a battery energy storage system. The overvoltage suppression device is arranged on the high-voltage port side of the battery energy storage system. The overvoltage suppression device includes: an insulating body; a multi-gap structure arranged in the insulating body, the multi-gap structure including a plurality of metal parts arranged at intervals, and arc extinguishing holes are formed at intervals between adjacent metal parts. Each arc extinguishing hole extends from the interval to the edge of the insulating body, and the multi-gap structure is used to diffuse energy by spraying arcs outward through each arc extinguishing hole when receiving overvoltage energy.

[0007] Preferably, the overvoltage suppression device determines the arrangement mode of several metal parts in the multi-gap structure according to different voltage levels of the battery energy storage system, wherein the several metal parts are arranged in one of the following ways: linear arrangement mode; disc-shaped annular arrangement mode; planar S-shaped arrangement mode; or spiral arrangement mode.

[0008] Preferably, the overvoltage suppression device further includes: a zinc oxide lightning arrester connected in parallel with the multi-gap structure, which is used to protect the overvoltage suppression device when receiving overvoltage energy; a housing arranged outside the insulating body, and the housing is made of stainless steel or glass or other composite materials.

[0009] Preferably, the overvoltage suppression device further includes: a first connecting piece connected to the first end of the multi-gap structure, wherein the first connecting piece passes through the housing and the insulating body and is grounded; a second connecting piece connected to the second end of the multi-gap structure, wherein the second connecting piece passes through the housing and the insulating body and is connected to the high-voltage bus.

[0010] Preferably, the overvoltage suppression device further includes: a sensor detection group arranged in the housing, wherein the sensor detection group includes but is not limited to: a voltage sensor, the two ends of which are respectively connected to the first connecting piece and the second connecting piece, and is used to measure the voltage of the overvoltage suppression device; a current sensor, which is connected to the first connecting piece or the second connecting piece and is used to measure the current of the overvoltage suppression device.

[0011] Preferably, the overvoltage suppression device, the sensor detection group further includes a pressure sensor, and the pressure sensor is installed at the center of the top inside the housing to measure whether the inside of the housing is in a vacuum environment.

[0012] Preferably, the overvoltage suppression device, the housing, the first connecting piece, the second connecting piece and the sensor detection group are made by a vacuum pumping and integral sealing and forming process.

[0013] Preferably, the overvoltage suppression device, the metal part is configured as a spherical metal electrode, and the spherical metal electrode is made of 304 stainless steel.

[0014] Preferably, the overvoltage suppression device, the depth of the arc extinguishing hole is not less than a first depth, the diameter of the arc extinguishing hole is not less than a first diameter, and the interval is not less than a first distance, wherein the first depth is 5 mm, the first diameter is 4 mm, and the first distance is 0.1 mm.

[0015] On the other hand, the present invention also provides a method for suppressing overvoltage in a battery energy storage system. The overvoltage suppression method is implemented by using the overvoltage suppression device as described above. Wherein, the overvoltage suppression method includes: constructing an insulating body; constructing a multi-gap structure inside the insulating body to utilize the multi-gap structure to spray arcs outward through each arc extinguishing hole when receiving overvoltage energy, so as to dissipate energy. Wherein, the multi-gap structure includes a plurality of metal parts arranged at intervals, and corresponding arc extinguishing holes are constructed at the intervals between adjacent metal parts, and each arc extinguishing hole extends from the interval to the edge of the insulating body.

[0016] Preferably, for the overvoltage suppression method, the overvoltage suppression method further includes: determining the arrangement mode of a plurality of metal parts in the multi-gap structure according to different voltage levels of the battery energy storage system. Wherein, the plurality of metal parts are arranged in one of the following ways: linear arrangement mode, disk-shaped annular arrangement mode, planar S-shaped arrangement mode, and spiral arrangement mode.

[0017] Preferably, for the overvoltage suppression method, the depth of the arc extinguishing hole is not less than a first depth, the diameter of the arc extinguishing hole is not less than a first diameter, and the interval is not less than a first distance. Wherein, the first depth is 5 mm, the first diameter is 4 mm, and the first distance is 0.1 mm.

[0018] Compared with the prior art, one or more embodiments of the above solutions may have the following advantages or beneficial effects:

[0019] The present invention provides an overvoltage suppression device and method for a battery energy storage system. Aiming at the drawback of low efficiency in suppressing overvoltage in the traditional technology, the present invention provides a vacuum multi-gap overvoltage suppression device suitable for a battery energy storage system, which is installed on the energy storage port side and constructed in a form combining a vacuum environment and a multi-gap structure. The vacuum environment shortens the arc extinguishing time of the multi-gap structure and improves the arc extinguishing efficiency. In this way, the vacuum multi-gap overvoltage suppression device proposed by the present invention automatically conducts and breaks down overvoltage, sprays arcs to weaken energy, and automatically restores the insulating state after the energy is reduced, and can achieve maintenance-free after installation.

[0020] Other features and advantages of the present invention will be described in the following specification, and, in part, will become apparent from the specification, or will be understood by implementing the present invention. The objectives and other advantages of the present invention can be realized and obtained by the structures specifically pointed out in the specification, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the present invention, and do not constitute a limitation to the present invention. In the drawings:

[0022] Figure 1 This is a schematic diagram of the overall structure of the overvoltage suppression device for a battery energy storage system according to an embodiment of the present application.

[0023] Figure 2 This is a schematic diagram of the specific structure of the multi-gap structure in the overvoltage suppression device for a battery energy storage system according to an embodiment of the present application.

[0024] Figure 3 This is an overall schematic diagram of a vacuum disc-shaped ring overvoltage suppression device for a battery energy storage system, which is composed of a multi-gap structure arranged in a disc-shaped ring arrangement according to an embodiment of the present application.

[0025] Figure 4 This is a schematic diagram of the structure in which the multi-gap structure in the overvoltage suppression device for a battery energy storage system according to an embodiment of the present application is arranged in a linear arrangement.

[0026] Figure 5 This is a schematic diagram of the structure in which the multi-gap structure in the overvoltage suppression device for a battery energy storage system according to an embodiment of the present application is arranged in a disc-shaped ring arrangement.

[0027] Figure 6 This is a schematic diagram of the structure in which the multi-gap structure in the overvoltage suppression device for a battery energy storage system according to an embodiment of the present application is arranged in a planar S-shaped arrangement.

[0028] Figure 7 This is a schematic diagram of the structure in which the multi-gap structure in the overvoltage suppression device for a battery energy storage system according to an embodiment of the present application is arranged in a spiral arrangement.

[0029] Figure 8 This is a schematic diagram of the steps of the overvoltage suppression method for a battery energy storage system according to an embodiment of the present application. Detailed implementation manners

[0030] The following will combine the drawings and embodiments to detail the implementation manners of the present invention, so as to fully understand how the present invention uses technical means to solve technical problems and achieve the implementation process of technical effects and implement accordingly. It should be noted that as long as there is no conflict, the various embodiments in the present invention and the various features in each embodiment can be combined with each other, and the formed technical solutions are all within the protection scope of the present invention.

[0031] In addition, the steps shown in the flowchart of the drawings can be executed in a computer system such as a set of computer-executable instructions. And although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0032] The terms used herein are merely for describing specific embodiments and are not intended to limit the exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms "a" and "an" used herein are also intended to include the plural. It should also be understood that the terms "comprises" and / or "comprising" specify the presence of the stated features, integers, steps, operations, units, and / or components, and do not preclude the presence or addition of one or more other features, integers, steps, operations, units, components, and / or combinations thereof.

[0033] The battery energy storage system is an important supporting component of the new energy power generation system and is an important means to smooth the fluctuations of new energy power and perform peak shaving and frequency modulation. New energy power generation systems such as wind power and photovoltaic power are mostly built in large open areas with a relatively high lightning strike risk. Lightning strikes on new energy systems will generate strong overvoltages and overcurrents. These high-magnitude overvoltages and overcurrents propagate along the power lines and impact the battery energy storage system. In addition, when a fault such as a short circuit occurs in the power grid connected to the new energy system, the fault current will also invade the battery energy storage system, and in severe cases, it may cause the energy storage battery to burn out.

[0034] The multi-gap arrester is an important means to discharge high-magnitude electrical impulses. Traditional multi-gap arresters are installed on transmission line towers and are mostly used for lightning protection of high-voltage overhead lines. Existing energy storage ports mostly use zinc oxide arresters for overvoltage protection. However, after long-term operation, the zinc oxide resistor chips of zinc oxide arresters are prone to aging, and periodic tests need to be carried out, resulting in relatively high maintenance costs.

[0035] To solve one or more of the above technical problems, the present invention proposes an overvoltage suppression device and method for a battery energy storage system. The device and method combine a vacuum environment and a multi-gap structure. The vacuum environment shortens the arc extinguishing time of the multi-gap structure and improves the arc extinguishing efficiency.

[0036] Example 1

[0037] Figure 1 It is a schematic diagram of the overall structure of the overvoltage suppression device for a battery energy storage system according to an embodiment of the present application. Figure 2 It is a schematic diagram of the specific structure of the multi-gap structure in the overvoltage suppression device for a battery energy storage system according to an embodiment of the present application. The following combines Figure 1 and Figure 2 to illustrate the specific structure of the overvoltage suppression device for a battery energy storage system (hereinafter referred to as "overvoltage suppression device").

[0038] The overvoltage suppression device is arranged on the high-voltage port side of the battery energy storage system. As Figure 1As shown in the figure, the overvoltage suppression device includes an insulating body and a multi-gap structure disposed within the insulating body. The multi-gap structure includes: a plurality of metal parts arranged at intervals. Among them, arc extinguishing holes are formed at the intervals between adjacent metal parts. Each arc extinguishing hole extends from the corresponding interval to the edge of the insulating body. The multi-gap structure is used to diffuse energy by ejecting arcs outward through each arc extinguishing hole when receiving overvoltage energy.

[0039] In this way, the overvoltage suppression device uses the multi-gap structure to eject arcs outward to suppress overvoltage and overcurrent, making the arc extinguishing time shorter, the arc extinguishing efficiency higher, and the overvoltage energy fully released.

[0040] In one embodiment, according to the different voltage levels of the battery energy storage system, the arrangement mode of several metal parts within the multi-gap structure is determined. Among them, the arrangement mode of several metal parts within the multi-gap structure will be arranged in one of the following ways: linear arrangement mode, disc-shaped annular arrangement mode, planar S-shaped arrangement mode, spiral arrangement mode, respectively referring to Figure 4 , Figure 5 , Figure 6 and Figure 7 . In the actual application process, the number of metal parts and the arrangement mode of the metal parts in the overvoltage suppression device are selected according to requirements. Metal parts with different numbers and / or different arrangement modes can suppress different levels of overvoltage, so that the overvoltage suppression device will diffuse different levels of overvoltage energy when the overvoltage breaks through the overvoltage suppression device.

[0041] In one embodiment, the metal part is configured as a spherical metal electrode, and the spherical metal electrode is made of 304 stainless steel. The depth of the arc extinguishing hole is not less than the first depth, the diameter of the arc extinguishing hole is not less than the first diameter, and the interval is not less than the first distance. In one embodiment, the first depth is 5 mm, the first diameter is 4 mm, and the first distance is 0.1 mm. When the circuit where the overvoltage suppression device is located is impacted by overvoltage, the overvoltage will quickly break through the multi-gap structure and diffuse the current outward through the arc extinguishing hole, thereby completing the protection of the battery energy storage system.

[0042] In addition, the overvoltage suppression device further includes: a zinc oxide lightning arrester connected in parallel with the multi-gap structure. As Figure 1 shown, the zinc oxide lightning arrester is used to protect the overvoltage suppression device when receiving overvoltage energy. Specifically, the zinc oxide lightning arrester is connected in parallel with the multi-gap structure and can discharge high-amplitude electrical impulses when the overvoltage suppression device receives overvoltage energy.

[0043] The overvoltage suppression device further includes a housing disposed outside the insulating body. The housing is made of stainless steel, glass, or other composite materials. The housing is installed on the outer side of the multi-gap structure to maintain a vacuum environment inside the overvoltage suppression device. The vacuum multi-gap suppression device has the advantage of fully discharging the overvoltage energy during arc extinguishing, and the multi-gap structure can still return to the non-conductive state after discharging the energy in the vacuum environment, without the need for periodic maintenance.

[0044] The overvoltage suppression device further includes a first connecting member and a second connecting member. The first connecting member is connected to the first end of the multi-gap structure. The second connecting member is connected to the second end of the multi-gap structure. Among them, the first connecting member passes through the housing and the insulating body and is grounded; the second connecting member passes through the housing and the insulating body and is connected to the high-voltage bus.

[0045] In addition, the overvoltage suppression device further includes a sensor detection group disposed inside the housing. Among them, the sensor detection group includes, but is not limited to: a voltage sensor and a current sensor. The two ends of the voltage sensor are respectively connected to the first connecting member and the second connecting member. The voltage sensor is used to measure the voltage of the overvoltage suppression device. The current sensor is connected to the first connecting member or the second connecting member. The current sensor is used to measure the current of the overvoltage suppression device.

[0046] Moreover, the sensor detection group further includes a pressure sensor. The pressure sensor is installed at the center of the top inside the housing. The pressure sensor is used to measure whether the inside of the housing is in a vacuum environment. Specifically, setting a sensor detection group inside the voltage suppression device can directly detect the effect of the overvoltage suppression device in suppressing overvoltage and overcurrent, and directly judge the efficacy of the overvoltage suppression device through data. In this way, it is not only convenient to judge the working state of the overvoltage suppression device, but also the number and arrangement of metal parts in the overvoltage suppression device can be adjusted according to the detected data.

[0047] In one embodiment, the housing, the first connecting member, the second connecting member, and the sensor detection group are made by a vacuum encapsulation and integral molding process. In this way, a vacuum environment will be formed inside the overvoltage suppression device, which can shorten the arc extinguishing time of the multi-gap structure, and the vacuum packaging form enables the overvoltage suppression device to be installed either inside an energy storage power station or inside a container for use.

[0048] Example 2

[0049] Based on the overvoltage suppression device provided in the above-mentioned Embodiment 1, the present invention provides a specific embodiment of a vacuum overvoltage suppression device with a high-voltage side voltage level of 10 kV and applicable to a battery energy storage system.

[0050] The battery energy storage system provided in this embodiment is an electrical energy storage system, generally as a supporting part for new energy power generation. The battery uses lithium-ion batteries, the system capacity is 2 MWh, and the high-voltage side voltage level is 10 kV.

[0051] As Figure 1 shown, the black part in the figure is the insulating material, the insulating material uses silicone rubber, and the middle circular part is the spherical metal electrode, which generally uses 304 stainless steel material.

[0052] The overvoltage suppression device includes an insulating body and a multi-gap structure arranged in the insulating body. The multi-gap structure includes several metal parts arranged at intervals, and arc extinguishing holes are formed at the intervals between adjacent metal parts. Each arc extinguishing hole extends from the interval to the edge of the insulating body. The multi-gap structure is used to diffuse energy by spraying arcs outward through each arc extinguishing hole when receiving overvoltage energy. The several metal parts arranged at intervals in the multi-gap structure are arranged in a linear arrangement. For the specific arrangement method, see Figure 4 。

[0053] Under the surge impact, ground discharge occurs through the multi-gap structure to establish an arc channel, and surge impact energy such as lightning current sprays arcs outward through the arc extinguishing holes of the multi-gap structure to diffuse energy.

[0054] The multi-gap structure includes but is not limited to the following parameters. L1 represents the depth of the arc extinguishing hole, represents the diameter of the arc extinguishing hole, and L2 represents the gap distance. Among them, L1 is 8 mm, is 4 mm, and L2 is 0.1 mm.

[0055] In this embodiment, the system capacity of the battery energy storage system is 2 MWh, and the high-voltage side voltage level is 10 kV. Therefore, the multi-gap structure adopts a linear arrangement. And for a battery energy storage system with a system capacity of 2 MWh and a high-voltage side voltage level of 10 kV, generally speaking, the breakdown field strength in vacuum is 10 - 100 kV / mm, and it can be determined that there are 5 metal parts and 6 arc extinguishing holes in the multi-gap structure.

[0056] In addition, in this embodiment, as Figure 2 shown, zinc oxide arresters of 10 kV are connected in parallel on both sides of the multi-gap structure inside the overvoltage suppression device. This arrester matches the voltage level of the battery energy storage system, and its main purpose is to protect the branch circuit and protect the battery energy storage system from surge impacts.

[0057] The devices arranged inside the housing of the overvoltage suppression device further include a sensor detection group: a current sensor, connected to the first connection member or the second connection member, for measuring the current of the lightning protection device; a voltage sensor, with both ends connected to the first connection member and the second connection member, for measuring the voltage of the overvoltage suppression device; a pressure sensor, installed at the center of the top inside the housing, for measuring whether the inside of the housing is in a vacuum environment.

[0058] Both ends of the overvoltage suppression device are designed with connection members, one end passing through the housing to be grounded and the other end passing through the housing to be connected to the high-voltage bus side.

[0059] The overvoltage suppression device further includes a housing, which can be made of a composite of one or more materials such as stainless steel and glass, and the shape of the housing can be structures such as a cuboid or a sphere.

[0060] The above-mentioned housing, multi-gap structure, connection members, sensors, and cables adopt a vacuum integrated solid-sealing forming process to prevent the device from leaking air and ensure that the structure will not crack after multiple impacts. The purpose of adopting the vacuum multi-gap structure is to enable the multi-gap structure to discharge surge impact arcs more quickly and efficiently.

[0061] Example 3

[0062] Based on the overvoltage suppression device provided in the above-mentioned first embodiment, the present invention provides a specific embodiment of a vacuum overvoltage suppression device applicable to a battery energy storage system with a high-voltage side voltage level of 110 kV.

[0063] The battery energy storage system provided in this embodiment is an electric energy storage system, generally a supporting part for new energy power generation. The battery uses lithium-ion batteries, the system capacity is 1 GWh, and the high-voltage side voltage level is 110 kV.

[0064] Figure 3 This is an overall schematic diagram of a vacuum disk-shaped ring-type overvoltage suppression device for a battery energy storage system, which is composed of a multi-gap structure arranged in a disk-shaped ring arrangement. Several spaced-apart metal parts in the multi-gap structure are arranged in a disk-shaped ring arrangement. For the specific arrangement method, please refer to Figure 5 .

[0065] Under a surge impact, a ground discharge occurs through the multi-gap structure to establish an arc channel, and surge impact energies such as lightning current eject arcs outward through the arc extinguishing holes of the multi-gap structure to dissipate energy.

[0066] The multi-gap structure includes but is not limited to the following parameters. L1 represents the depth of the arc extinguishing hole, represents the diameter of the arc extinguishing hole, and L2 represents the gap distance. Among them, L1 is 8 mm, is 4 mm, and L2 is 0.1 mm.

[0067] In this embodiment, the system capacity of the battery energy storage system is 1 GWh, and the high-voltage side voltage level is 110 kV. Therefore, the multi-gap structure adopts a disc-shaped ring arrangement. With the system capacity of the battery energy storage system being 1 GWh and the high-voltage side voltage level being 110 kV, generally, the breakdown field strength in vacuum is 10 - 100 kV / mm. It can be determined that there are 40 metal parts and 41 arc extinguishing holes in the multi-gap structure.

[0068] In addition, as Figure 3 shown, on both sides of the multi-gap structure inside the overvoltage suppression device, there is a 110 kV zinc oxide arrester connected in parallel. This arrester matches the voltage level of the battery energy storage system, and its main purpose is to protect the branch circuit and protect the battery energy storage system from surge impacts.

[0069] The devices arranged inside the housing of the overvoltage suppression device also include a sensor detection group: a current sensor, connected to the first connector or the second connector, for measuring the current of the lightning protection device; a voltage sensor, with both ends connected to the first connector and the second connector, for measuring the voltage of the overvoltage suppression device; a pressure sensor, installed at the center of the top inside the housing, for measuring whether the inside of the housing is in a vacuum environment.

[0070] Both ends of the overvoltage suppression device are designed with connectors. One end passes through the housing to be grounded, and the other end passes through the housing to be connected to the high-voltage bus side.

[0071] The overvoltage suppression device also includes a housing, which can be made of a composite of one or more materials such as stainless steel and glass. The shape of the housing can adopt structures such as a cuboid and a sphere.

[0072] The above-mentioned housing, multi-gap structure, connectors, sensors, and cables adopt a vacuum integrated solid sealing and forming process to prevent the device from leaking air and ensure that the structure will not crack after multiple impacts. The purpose of adopting the vacuum multi-gap structure is to enable the multi-gap structure to discharge surge impact arcs more quickly and efficiently.

[0073] Example 4

[0074] Based on the overvoltage suppression devices provided in the above-mentioned Embodiment 1 to Embodiment 3, the present invention provides examples of multi-gap structures other than the linear type and the disc-shaped ring type in the overvoltage suppression device applicable to the battery energy storage system.

[0075] The battery energy storage system provided in this embodiment is an electrical energy storage system, generally a supporting part for new energy power generation, and the battery uses lithium-ion batteries. The multi-gap structure includes an insulating material and several spherical metal electrodes. The insulating material uses silicone rubber, and the middle circular part is a spherical metal electrode. The spherical metal electrode generally uses 304 stainless steel. Corresponding arc extinguishing holes are constructed at the intervals between adjacent metal parts. Each arc extinguishing hole extends from the interval to the edge of the insulating body. The multi-gap structure is used to spray arcs outward through each arc extinguishing hole to dissipate energy when receiving overvoltage energy. The overvoltage suppression device uses the multi-gap structure to spray arcs outward to suppress overvoltage and overcurrent, making the arc extinguishing time shorter, the arc extinguishing efficiency higher, and the overvoltage energy fully released.

[0076] According to the different voltage levels of the battery energy storage system, the arrangement mode of several metal parts in the multi-gap structure is determined. In this embodiment, several spaced metal parts in the multi-gap structure are arranged in a planar S-shaped arrangement. For the specific arrangement mode, refer to Figure 6 .

[0077] Under the surge impact, ground discharge occurs through the multi-gap structure to establish an arc channel. Surge impact energy such as lightning current sprays arcs outward through the arc extinguishing holes of the multi-gap structure to dissipate energy.

[0078] The multi-gap structure includes but is not limited to the following parameters. L1 represents the depth of the arc extinguishing hole, represents the diameter of the arc extinguishing hole, and L2 represents the gap distance. Among them, L1 is 8 mm, is 4 mm, and L2 is 0.1 mm.

[0079] In this embodiment, the system capacity of the battery energy storage system is 1 GWh, and the high-voltage side voltage level is 110 kV. Therefore, the multi-gap structure adopts a disk-shaped ring arrangement. And for a battery energy storage system with a system capacity of 1 GWh and a high-voltage side voltage level of 110 kV, generally speaking, the breakdown field strength in vacuum is 10 - 100 kV / mm, and it can be determined that there are 40 metal parts and 41 arc extinguishing holes in the multi-gap structure.

[0080] In addition, as Figure 3 shown, zinc oxide arresters of 110 kV are connected in parallel on both sides of the multi-gap structure inside the overvoltage suppression device. This arrester matches the voltage level of the battery energy storage system, and its main purpose is to protect the branch circuit and protect the battery energy storage system from surge impacts.

[0081] The devices arranged inside the housing of the overvoltage suppression device further include a sensor detection group: a current sensor, connected to the first connecting piece or the second connecting piece, for measuring the current of the lightning protection device; a voltage sensor, with both ends connected to the first connecting piece and the second connecting piece, for measuring the voltage of the overvoltage suppression device; a pressure sensor, installed at the center of the top inside the housing, for measuring whether the inside of the housing is in a vacuum environment.

[0082] Both ends of the overvoltage suppression device are designed with connecting pieces, one end passing through the housing to be grounded, and the other end passing through the housing to be connected to the high-voltage bus side.

[0083] The overvoltage suppression device further includes a housing, which can be made of a composite of one or more materials such as stainless steel and glass, and the shape of the housing can be structures such as a cuboid and a sphere.

[0084] The above-mentioned housing, multi-gap structure, connecting pieces, sensors, and cables adopt a vacuum integrated solid sealing and forming process to prevent air leakage of the device and ensure that the structure will not crack after multiple impacts. The purpose of adopting the vacuum multi-gap structure is to enable the multi-gap structure to discharge surge impact arcs more quickly and efficiently.

[0085] According to different levels of overvoltage in actual situations, the metal parts in the multi-gap structure are arranged in different ways, which can diffuse different levels of overvoltage energy when the overvoltage breaks through the overvoltage suppression device, discharge high-amplitude electrical impulses, and effectively protect the battery energy storage system.

[0086] Example 5

[0087] Based on the overvoltage suppression devices provided in the above-mentioned Embodiment 1 to Embodiment 4, the present invention provides an example of a multi-gap structure in the overvoltage suppression device applicable to a battery energy storage system other than the linear type and the disc-shaped ring type.

[0088] The battery energy storage system provided in this embodiment is an electric energy storage system, generally a supporting part for new energy power generation, and the battery uses a lithium-ion battery. The multi-gap structure includes an insulating material and several spherical metal electrodes. The insulating material uses silicone rubber, and the middle circular part is a spherical metal electrode. The spherical metal electrode generally uses 304 stainless steel material. Corresponding arc extinguishing holes are constructed at the intervals between adjacent metal parts, and each arc extinguishing hole extends from the interval to the edge of the insulating body. The multi-gap structure is used to diffuse energy by spraying arcs outward through each arc extinguishing hole when receiving overvoltage energy. The overvoltage suppression device uses the multi-gap structure to spray arcs outward to suppress overvoltage and overcurrent, so that the arc extinguishing time is shorter, the arc extinguishing efficiency is higher, and the overvoltage energy is fully released.

[0089] According to the different voltage levels of the battery energy storage system, the arrangement of several metal parts in the multi-gap structure is determined. In this embodiment, several metal parts arranged at intervals in the multi-gap structure are arranged in a spiral arrangement. For the specific arrangement, please refer to Figure 7 .

[0090] Under the surge impact, the multi-gap structure discharges to the ground, establishing an arc channel. The surge impact energy such as lightning current jets the arc outward through the arc extinguishing holes of the multi-gap structure to dissipate energy.

[0091] The multi-gap structure includes but is not limited to the following parameters. L1 represents the depth of the arc extinguishing hole, represents the diameter of the arc extinguishing hole, and L2 represents the gap distance. Among them, L1 is 8 mm, is 4 mm, and L2 is 0.1 mm.

[0092] In this embodiment, the system capacity of the battery energy storage system is 1 GWh, and the high-voltage side of the voltage level is 110 kV. Therefore, the multi-gap structure adopts a disc-shaped ring arrangement. For a battery energy storage system with a system capacity of 1 GWh and a high-voltage side voltage level of 110 kV, generally speaking, the breakdown field strength in vacuum is 10 - 100 kV / mm. It can be determined that there are 40 metal parts and 41 arc extinguishing holes in the multi-gap structure.

[0093] In addition, as Figure 3 shown, zinc oxide arresters of 110 kV are connected in parallel on both sides of the multi-gap structure inside the overvoltage suppression device. This arrester is matched with the voltage level of the battery energy storage system, and its main purpose is to protect the branch circuit and protect the battery energy storage system from surge impacts.

[0094] The devices arranged inside the housing of the overvoltage suppression device also include a sensor detection group: a current sensor, connected to the first connector or the second connector, for measuring the current of the lightning protection device; a voltage sensor, with both ends connected to the first connector and the second connector, for measuring the voltage of the overvoltage suppression device; a pressure sensor, installed at the center of the top inside the housing, for measuring whether the inside of the housing is in a vacuum environment.

[0095] The overvoltage suppression device is designed with connectors at both ends. One end passes through the housing to be grounded, and the other end passes through the housing to be connected to the high-voltage bus side.

[0096] The overvoltage suppression device also includes a housing, which can be made of a composite of one or more materials such as stainless steel and glass. The shape of the housing can be structures such as a cuboid and a sphere.

[0097] The housing, multi-gap structure, connectors, sensors, and cables are molded by vacuum integrated sealing process to prevent air leakage and ensure that the structure will not crack after multiple impacts. The purpose of using a vacuum multi-gap structure is to enable the multi-gap structure to discharge surge impact arcs more quickly and efficiently.

[0098] According to the different levels of overvoltage in actual situations, the metal parts in the multi-gap structure are arranged in different ways, which can diffuse different levels of overvoltage energy when the overvoltage strikes through the voltage suppression device, discharge high-amplitude electric shocks, and effectively protect the battery energy storage system.

[0099] Example 6

[0100] Based on the overvoltage suppression device provided in any one of the above-mentioned embodiments 1 to 5, an embodiment of the present invention further provides an overvoltage suppression method for a battery energy storage system (also referred to as an "overvoltage suppression method"). The overvoltage suppression method is applied to protect a battery energy storage system.

[0101] Figure 8 Schematic diagram of the steps of the overvoltage suppression method for a battery energy storage system according to an embodiment of the present application. Figure 8 As shown, the overvoltage suppression method utilizes the overvoltage suppression device provided in any one of Embodiments 1 to 5 to suppress multiple voltages, and is implemented according to the following steps:

[0102] Step S810, constructing an insulating body;

[0103] Step S820, constructing a multi-gap structure inside the insulating body to utilize the multi-gap structure to diffuse the energy by ejecting arcs outward through each arc extinguishing hole when receiving overvoltage energy, wherein the multi-gap structure includes a plurality of metal parts arranged at intervals, and corresponding arc extinguishing holes are constructed at the intervals between adjacent metal parts, and each arc extinguishing hole extends from the interval to the edge of the insulating body.

[0104] In addition, the overvoltage suppression method also includes: determining the arrangement of several metal parts in the multi-gap structure according to different voltage levels of the battery energy storage system. Among them, the several metal parts are arranged in one of the following ways: a linear arrangement, a disc-shaped ring arrangement, a planar S-shaped arrangement, and a spiral arrangement. Different high-amplitude overvoltages are suppressed by different arrangements of metal parts, and different levels of energy are diffused to protect the battery energy storage system from overvoltages of different levels.

[0105] Additionally, in the multi-gap structure, there is an arc quenching hole between two adjacent spherical metal electrodes. Each arc quenching hole extends from the gap to the edge of the insulating body. The depth of the arc quenching hole is not less than the first depth, the diameter of the arc quenching hole is not less than the first diameter, and the gap is not less than the first distance. Among them, the first depth is 5 mm, the first diameter is 4 mm, and the first distance is 0.1 mm. When receiving overvoltage energy, the multi-gap structure diffuses the overvoltage energy by ejecting arcs outward through each arc quenching hole to protect the battery energy storage system.

[0106] Embodiments of the present invention can utilize the above-mentioned overvoltage suppression method for a battery energy storage system to achieve the effect of protecting the battery energy storage system by suppressing overvoltage.

[0107] In summary, the overvoltage suppression device and method for a battery energy storage system proposed by the present invention improve the arc quenching efficiency of multiple gaps in the form of a vacuum multi-gap structure and accelerate the arc quenching speed. Moreover, the vacuum multi-gap structure proposed by the present invention can achieve the effect of long-term operation without maintenance, avoiding the defect of aging caused by the long-term operation of zinc oxide arresters used in existing battery energy storage systems.

[0108] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

[0109] In the description of the present invention, unless otherwise specified, "a plurality of" means two or more; the orientation or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0110] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0111] It should be understood that the embodiments disclosed in the present invention are not limited to the specific structures, processing steps or materials disclosed herein, but should extend to equivalent alternatives of these features understood by those of ordinary skill in the relevant art. It should also be understood that the terms used herein are for the purpose of describing specific embodiments only and do not imply limitation.

[0112] As used herein, the phrase "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrase "one embodiment" or "an embodiment" throughout the specification are not necessarily all referring to the same embodiment.

[0113] The embodiments of the present invention are given for purposes of illustration and description, and are not exhaustive or limiting of the invention to the disclosed form. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are chosen and described in order to better explain the principles of the invention and its practical application, and to enable those of ordinary skill in the art to understand the invention so as to design various embodiments with various modifications suitable for a particular purpose.

[0114] Although the embodiments disclosed in the present invention are as described above, the content described is only an embodiment adopted for the convenience of understanding the present invention and is not intended to limit the present invention. Any person skilled in the art within the technical field to which the present invention pertains may make any modifications and variations in the form and details of the implementation without departing from the spirit and scope disclosed by the present invention. However, the scope of patent protection of the present invention shall still be subject to the scope defined by the appended claims.

Claims

1. An overvoltage suppression device for a battery energy storage system, characterized in that, The overvoltage suppression device is arranged on the high-voltage port side of the battery energy storage system. The overvoltage suppression device includes: An insulating body; A multi-gap structure arranged in the insulating body. The multi-gap structure includes a plurality of metal parts arranged at intervals, and arc extinguishing holes are formed at the intervals between adjacent metal parts. Each arc extinguishing hole extends from the interval to the edge of the insulating body. The multi-gap structure is used to diffuse energy by ejecting arcs outward through each arc extinguishing hole when receiving overvoltage energy.

2. The overvoltage suppression device according to claim 1, characterized in that, Determine the arrangement mode of the plurality of metal parts in the multi-gap structure according to different voltage levels of the battery energy storage system. Among them, the plurality of metal parts are arranged in one of the following ways: Linear arrangement mode; Disk-shaped annular arrangement mode; Planar S-shaped arrangement mode; or Spiral arrangement mode.

3. The overvoltage suppression device according to claim 1 or 2, characterized in that The overvoltage suppression device further includes: A zinc oxide arrester connected in parallel with the multi-gap structure, which is used to protect the overvoltage suppression device when receiving overvoltage energy; A housing arranged outside the insulating body, and the housing is made of stainless steel or glass or other composite materials.

4. The overvoltage suppression device according to claim 3, characterized in that, The overvoltage suppression device further includes: A first connecting piece connected to the first end of the multi-gap structure. Among them, the first connecting piece passes through the housing and the insulating body and is grounded; A second connecting piece connected to the second end of the multi-gap structure. Among them, the second connecting piece passes through the housing and the insulating body and is connected to the high-voltage busbar.

5. The overvoltage suppression device according to claim 4, characterized in that, The overvoltage suppression device further includes: a sensor detection group arranged in the housing. Among them, the sensor detection group includes but is not limited to: A voltage sensor, the two ends of which are respectively connected to the first connecting piece and the second connecting piece, and are used to measure the voltage of the overvoltage suppression device; A current sensor, which is connected to the first connecting piece or the second connecting piece and is used to measure the current of the overvoltage suppression device.

6. The overvoltage suppression device according to claim 5, characterized in that, The sensor detection group further includes a pressure sensor, and the pressure sensor is installed at the center of the top inside the housing to measure whether the inside of the housing is in a vacuum environment.

7. The overvoltage suppression device according to claim 5 or 6, characterized in that The housing, the first connecting piece, the second connecting piece and the sensor detection group are made by a vacuum pumping and integral sealing molding process.

8. The overvoltage suppression device according to any one of claims 1 to 7, characterized in that, The metal part is constructed as a spherical metal electrode, and the spherical metal electrode is made of 304 stainless steel.

9. The overvoltage suppression device according to any one of claims 1 to 8, characterized in that, The depth of the arc extinguishing hole is not less than a first depth, the diameter of the arc extinguishing hole is not less than a first diameter, and the interval is not less than a first distance. Among them, the first depth is 5 mm, the first diameter is 4 mm, and the first distance is 0.1 mm.

10. A method for suppressing overvoltage in a battery energy storage system, characterized in that, The overvoltage suppression method is realized by using the overvoltage suppression device according to any one of claims 1 to 9. Among them, the overvoltage suppression method includes: Construct an insulating body; A multi-gap structure is constructed inside the insulating body to utilize the multi-gap structure to spray the arc outward through each arc extinguishing hole to dissipate energy when receiving overvoltage energy. Among them, the multi-gap structure includes a number of metal parts arranged at intervals, and corresponding arc extinguishing holes are constructed at the intervals between adjacent metal parts, and each arc extinguishing hole extends from the interval to the edge of the insulating body.

11. The overvoltage suppression method according to claim 10, characterized in that, The overvoltage suppression method further includes: Determining the arrangement mode of several metal parts in the multi-gap structure according to different voltage levels of the battery energy storage system. Among them, the several metal parts are arranged in one of the following ways: linear arrangement mode, disc-shaped annular arrangement mode, planar S-shaped arrangement mode, and spiral arrangement mode.

12. The overvoltage suppression method according to claim 10 or 11, characterized in that, The depth of the arc extinguishing hole is not less than the first depth, the diameter of the arc extinguishing hole is not less than the first diameter, and the interval is not less than the first distance. Among them, the first depth is 5 mm, the first diameter is 4 mm, and the first distance is 0.1 mm.

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