Black-start control method, energy storage apparatus, and energy storage system

Abstract

Provided in the embodiments of the present application are a black-start control method, an energy storage apparatus, and an energy storage system. The performance of the energy storage system can be effectively improved. The black-start control method is applied to an energy storage system. The energy storage system comprises an energy storage apparatus. The energy storage apparatus comprises a plurality of battery clusters, a first controller, and a black-start switching apparatus, wherein the black-start switching apparatus is disposed between a target battery cluster among the plurality of battery clusters and a first end of the first controller. The method comprises: in response to a black-start requirement of the energy storage system, the first controller performing a black start on the energy storage system on the basis of the target battery cluster, wherein the black-start switching apparatus is in a closed state; and after the black start, the first controller controlling the black-start switching apparatus to switch from the closed state to an open state.

Description

Black start control methods, energy storage devices and energy storage systems Cross-reference to related applications

[0001] This application claims priority to Chinese patent application 202510185538.2, filed on February 19, 2025, entitled “Method for Black Start Control, Energy Storage Device and Energy Storage System”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of energy storage technology, and in particular to a black-start control method, energy storage device, and energy storage system. Background Technology

[0003] With the promotion and application of new energy sources, energy storage technology has also developed. During the operation of an energy storage system, power outages may occur due to various faults. In such cases, power can be restored to the entire energy storage system through black start. Black start refers to a state where the entire energy storage system is in a complete blackout after a power outage due to a fault. In this state, the system does not rely on an external power source but is powered by the electricity generated by the battery devices within the energy storage system.

[0004] Improving the performance of energy storage systems after a black start is an urgent problem to be solved. Summary of the Invention

[0005] This application provides a black-start control method, an energy storage device, and an energy storage system, which can effectively improve the performance of the energy storage system.

[0006] In a first aspect, a black-start control method is provided, applied to an energy storage system. The energy storage system includes an energy storage device, which includes multiple battery clusters, a first controller, and a black-start on / off device. The black-start on / off device is disposed between a target battery cluster among the multiple battery clusters and a first terminal of the first controller. The method includes: responding to a black-start requirement of the energy storage system, the first controller performs a black-start on the energy storage system based on the target battery cluster, wherein during the black-start process, the black-start on / off device is in a closed state; after the black-start, the first controller controls the black-start on / off device to switch from the closed state to the off state.

[0007] In this embodiment, by incorporating a black-start switching device in the energy storage device, the device closes in response to the black-start requirement after a power outage. This allows the first controller to promptly perform a black-start based on the target battery cluster's charge level, reducing the likelihood of loss of critical information and data due to power failure. Furthermore, after the black-start, the switching device switches to the off state, preventing the target battery cluster from supplying power to the first controller. This reduces the charge difference between the target battery cluster and other battery clusters in the energy storage device, and also decreases the possibility of over-utilization of the target battery cluster by the first controller, thereby effectively improving the performance of the energy storage device.

[0008] In some possible implementations, the energy storage device further includes a second target controller, which corresponds to the target battery cluster and is disposed between the target battery cluster and the black-start switching device; the first controller controls the black-start switching device to switch from a closed state to a closed state, including: the first controller sends switching information to the second target controller, the switching information being used to indicate switching the black-start switching device from a closed state to a closed state.

[0009] Since the first controller typically consumes a large amount of power, this technical solution involves the first controller sending switching information to the second target controller, instructing it to switch the state of the black-start switching device to the off state. This allows the second target controller to switch the black-start switching device from the closed state to the off state, thereby reducing the power consumption of the energy storage device. Furthermore, this increases the applicability of the embodiments of this application. For example, the embodiments of this application can be applied to scenarios where the first controller needs to be monitored.

[0010] In some possible implementations, the energy storage device further includes a voltage conversion device, the two ends of which are respectively connected to the second terminal of the first controller and the power supply, for converting the output voltage of the power supply into the voltage required by the first controller; the first controller controls the black-start switching device to switch from a closed state to a closed state, including: the first controller controls the black-start switching device to switch from a closed state to a closed state according to the status information of the voltage conversion device.

[0011] This technical solution, by setting a voltage conversion device between the first controller and the power supply, can convert the voltage output by the power supply to the voltage required by the first controller, reducing the possibility of damage to the first controller due to excessively high voltage output by the power supply and ensuring the normal operation of the energy storage device.

[0012] In some possible implementations, the status information includes the power supply status and fault status of the voltage conversion device. The first controller controls the black-start switching device to switch from a closed state to a closed state based on the status information of the voltage conversion device. This includes: when the voltage conversion device is not faulty and is in a power supply state, the first controller controls the black-start switching device to switch from a closed state to a closed state.

[0013] In this technical solution, the voltage conversion device is not faulty and is in a power supply state, indicating that the power supply can supply power to the first controller through the voltage conversion device. Therefore, the first controller controls the black start switching device to switch from the closed state to the closed state, reducing the possibility that the first controller will not work properly due to the black start switching device being turned off, thereby ensuring the normal operation of the energy storage system.

[0014] In some possible implementations, the voltage conversion device includes a first voltage conversion device and / or a second voltage conversion device. The two ends of the first voltage conversion device are respectively connected to the second end of the first controller and the bus of the energy storage device. The two ends of the second voltage conversion device are respectively connected to the second end of the first controller and a power supply terminal located outside the energy storage device. The step of controlling the black-start switching device to switch from a closed state to a closed state when the voltage conversion device is not faulty and is in a power supply state includes: when the first voltage conversion device is not faulty and is in a power supply state, and / or when the second voltage conversion device is not faulty and is in a power supply state, the first controller controls the black-start switching device to switch from a closed state to a closed state.

[0015] The above technical solution, by configuring the voltage conversion device to include either a first voltage conversion device or a second voltage conversion device, not only reduces the space occupied by the energy storage device but also lowers the cost of the voltage conversion device. Furthermore, configuring the voltage conversion device to include both a first and a second voltage conversion device, with different power supply terminals for the first and second devices, effectively uses multiple power sources to power the first controller. This ensures that if one power source malfunctions, the first controller can still operate normally, improving power supply reliability.

[0016] In some possible implementations, the first voltage conversion device includes a plurality of first voltage conversion devices connected in series, and / or the second voltage conversion device includes a plurality of second voltage conversion devices connected in series; the first controller controlling the black-start switching device to switch from a closed state to a closed state when the first voltage conversion device is not faulty and is in a powered state, and / or when the second voltage conversion device is not faulty and is in a powered state, includes: when each of the plurality of first voltage conversion devices is not faulty and is in a powered state, and / or when each of the plurality of second voltage conversion devices is not faulty and is in a powered state, the first controller controlling the black-start switching device to switch from a closed state to a closed state.

[0017] The above technical solution includes a first voltage conversion device comprising multiple first voltage conversion devices, and / or a second voltage conversion device comprising multiple second voltage conversion devices. In this way, the multiple first voltage conversion devices can convert the high voltage output from the power supply to the low voltage required by the first controller, and / or the multiple second voltage conversion devices can convert the high voltage output from the power supply to the low voltage required by the first controller. This not only reduces the losses of the first voltage conversion devices and / or the second voltage conversion devices, but also facilitates the selection of the first voltage conversion devices and / or the second voltage conversion devices.

[0018] In some possible implementations, where the voltage conversion device includes a second voltage conversion device, the power supply terminal located outside the energy storage device includes the busbars of other energy storage devices in the energy storage system besides the energy storage device.

[0019] Thus, if the energy storage device where the first controller is located fails and cannot supply power to the first controller, the power supply terminal located outside the energy storage device can continue to supply power to the first controller, which is beneficial to the normal operation of the first controller.

[0020] In some possible implementations, the step of the first controller controlling the black-start switching device to switch from a closed state to a closed state when the voltage conversion device is not faulty and is in a power-on state includes: when the voltage conversion device is not faulty and is in a power-on state, and the duration is longer than a preset duration, the first controller controls the black-start switching device to switch from a closed state to a closed state.

[0021] This technical solution considers multiple factors when controlling the black-start switching device to switch from a closed state to a closed state. In addition to the state information of the voltage conversion device, it also considers the duration of the state, which reduces the possibility of misjudgment by the first controller. This reduces the probability that the first controller will fail to work due to the lack of power supply after the black-start switching device is switched to the closed state, thus improving the robustness of the energy storage device.

[0022] In some possible implementations, the first controller performs a black start on the energy storage system based on the target battery cluster, including: the first controller controls the multiple battery clusters to be connected to a high voltage based on the target battery cluster; the method further includes: determining that the first voltage conversion device is in a power supply state when at least one of the multiple battery clusters is online with a high voltage.

[0023] In this technical solution, since multiple battery clusters are connected in parallel, the presence of high voltage in at least one battery cluster indicates that all battery clusters are online at high voltage. With all battery clusters online at high voltage, the busbar of the energy storage device is energized. Since the first voltage conversion device is connected to the busbar of the energy storage device, it is in a power supply state. Therefore, determining whether the first voltage conversion device is in a power supply state based on whether the battery clusters are online at high voltage improves the accuracy of the judgment.

[0024] Secondly, an energy storage device is provided for use in an energy storage system. The energy storage device includes multiple battery clusters, a first controller, and a black-start switching device. The black-start switching device is disposed between a target battery cluster among the multiple battery clusters and a first terminal of the first controller. In response to the black-start requirement of the energy storage system, during the black-start process, the black-start switching device is in a closed state, so that the first controller performs a black start on the energy storage device based on the target battery cluster. After the black start, the black-start switching device is in a closed state.

[0025] In some possible implementations, the energy storage device further includes a second target controller, which corresponds to the target battery cluster and is located between the target battery cluster and the black-start switching device. When the black-start switching device is in the closed state, the target battery cluster supplies power to the second target controller. The first controller is also used to send switching information to the second target controller, which indicates that the black-start switching device should be switched from the closed state to the off state.

[0026] In some possible implementations, the energy storage device further includes a voltage conversion device, the two ends of which are respectively connected to the second terminal of the first controller and the power supply, for converting the output voltage of the power supply into the voltage required by the first controller. After the energy storage device is black-started, the first controller receives power through the voltage conversion device. Specifically, the first controller is used to control the black-start switching device to switch from a closed state to a closed state according to the status information of the voltage conversion device.

[0027] In some possible implementations, the voltage conversion device includes a first voltage conversion device, the two ends of which are respectively connected to the second terminal of the first controller and the bus of the energy storage device; and / or the voltage conversion device includes a second voltage conversion device, the two ends of which are respectively connected to the second terminal of the first controller and a power supply terminal located outside the energy storage device; the first controller is specifically used to control the black-start switching device to switch from a closed state to a closed state when the first voltage conversion device is not faulty and is in a power supply state, and / or when the second voltage conversion device is not faulty and is in a power supply state.

[0028] In some possible implementations, the first voltage conversion device includes a plurality of first voltage conversion devices connected in series; and / or the second voltage conversion device includes a plurality of second voltage conversion devices connected in series; the first controller is specifically configured to: control the black-start switching device to switch from a closed state to a closed state when each of the plurality of first voltage conversion devices is fault-free and in a powered state, and / or, when each of the plurality of second voltage conversion devices is fault-free and in a powered state, control the black-start switching device to switch from a closed state to a closed state.

[0029] In some possible implementations, where the voltage conversion device includes a second voltage conversion device, the power supply terminal located outside the energy storage device includes the busbars of other energy storage devices in the energy storage system besides the energy storage device.

[0030] Thirdly, an energy storage system is provided, comprising a plurality of energy storage devices as described in the second aspect. Attached Figure Description

[0031] Figure 1 shows a schematic diagram of an energy storage device according to an embodiment of this application.

[0032] Figure 2 shows a schematic flowchart of a black start control method according to an embodiment of this application.

[0033] Figure 3 shows a schematic diagram of an energy storage device according to an embodiment of this application.

[0034] Figure 4 shows a schematic diagram of another energy storage device according to an embodiment of this application.

[0035] Figure 5 shows a schematic diagram of an energy storage system according to an embodiment of this application. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0037] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the specification of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, rather than to describe a specific order or hierarchy.

[0038] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of this application. It should also be noted in the description of this application that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0039] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0040] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0041] With the promotion and application of new energy sources, energy storage technology has developed accordingly. An energy storage system is a device or system capable of storing energy and releasing it when needed. In the field of new energy, energy storage systems typically refer to devices that can store electrical energy and release it during peak electricity demand periods. Energy storage systems play multiple roles in the power system, including load balancing, frequency regulation, backup power, peak-valley pricing management, and improving grid stability. With the rapid development of renewable energy, the importance of energy storage systems is increasing daily.

[0042] Electrochemical energy storage, represented by lithium-ion batteries, is the most widely used energy storage technology. An electrochemical energy storage system consists of battery devices, a battery management system (BMS), an energy management system (EMS), a power conversion system (PCS), and auxiliary equipment.

[0043] In an energy storage system, the battery device can be a battery or battery pack, serving as the energy storage medium responsible for storing and releasing electrical energy. The Battery Management System (BMS) monitors and manages the battery device's status, including charging state, voltage, temperature, and current, ensuring it operates within safe operating ranges and preventing overcharging, over-discharging, overheating, and short circuits, thereby extending its lifespan. The Energy Management System (EMS) is the control center, responsible for monitoring the entire system's operation and optimizing energy storage and release strategies to meet grid demands or user-defined goals. The Power Control System (PCS) primarily controls the conversion and flow of electrical energy within the system, converting direct current (DC) to alternating current (AC) to meet grid or load requirements. Simultaneously, the PCS can also convert AC to DC to charge the battery devices within the energy storage system.

[0044] During the operation of an energy storage system, power outages may occur due to various faults. In such cases, a black start can be used to restore power to the entire energy storage system. A black start refers to the process where, after a power outage due to a fault, the energy storage system, without relying on the assistance of other networks, starts up the units with self-starting capabilities within the system, thereby driving the units without self-starting capabilities to gradually expand the recovery scope of the energy storage system and ultimately restore the entire system.

[0045] For example, a black start can be achieved by using the power of the battery devices in the energy storage system. After a black start, if the system continues to be powered by the battery devices, an imbalance may occur between the battery devices and other battery devices in the energy storage system, thereby affecting the performance of the energy storage system.

[0046] In view of this, this application provides a black-start control method applied to an energy storage system. The energy storage system includes an energy storage device comprising multiple battery clusters, a first controller, and a black-start on / off device. The black-start on / off device is disposed between a target battery cluster and a first terminal of the first controller. The method includes: responding to the black-start requirement of the energy storage system, the first controller performs a black-start on the energy storage device based on the target battery cluster, wherein the black-start on / off device is in a closed state during the black-start process. After the black-start, the first controller controls the black-start on / off device to switch from the closed state to the off state. This technical solution, by setting a black-start on / off device in the energy storage device, ensures that after a power outage, the black-start on / off device closes in response to the black-start requirement of the energy storage system. Thus, the first controller can promptly perform a black-start on the energy storage system based on the charge level of the target battery cluster, reducing the possibility of loss of critical information and data in the energy storage system due to power outages. Furthermore, after a black start, the black start on / off device switches to the off state. As a result, the target battery cluster no longer supplies power to the first controller. This not only reduces the power difference between the target battery cluster and other battery clusters in the energy storage device, but also reduces the possibility of the first controller overusing the target battery cluster, thereby effectively improving the performance of the energy storage device.

[0047] The technical solutions of this application embodiment can be applied to energy storage systems, which include energy storage devices. These devices can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. The energy storage device can store electrical energy as needed and output it at appropriate times. For example, the energy storage device can store electrical energy during off-peak hours and provide it to relevant users or electrical equipment during peak hours. The energy storage system provided in this application embodiment can be any power system that requires an energy storage device. The energy storage device can be of various types and sizes. For example, the energy storage device can be the energy storage container shown in Figure 1. The energy storage device can be, for example, a regular cuboid structure, where the six faces of the cuboid are the six outer walls of the energy storage device. Setting the energy storage device as a cuboid structure facilitates its fixed placement and transportation. Of course, the energy storage device can also be of other shapes; for example, at least one wall of the energy storage device may be inclined.

[0048] Figure 2 shows a schematic flowchart of a black start control method 200 according to an embodiment of this application.

[0049] Method 200 can be applied to an energy storage system, which includes an energy storage device. As shown in Figure 3, the energy storage device includes multiple battery clusters, a first controller, and a black-start switching device, which is disposed between a target battery cluster and the first terminal of the first controller.

[0050] Method 200 may include at least some of the following.

[0051] S210: In response to the black start requirement of the energy storage system, the first controller performs a black start on the energy storage system based on the target battery cluster, wherein the black start on / off device is in a closed state during the black start process.

[0052] S220: After a black start, the first controller controls the black start switching device to switch from the closed state to the closed state.

[0053] In this embodiment, by incorporating a black-start switching device in the energy storage device, the device closes in response to the black-start requirement after a power outage. This allows the first controller to promptly perform a black-start based on the target battery cluster's charge level, reducing the likelihood of loss of critical information and data due to power failure. Furthermore, after the black-start, the switching device switches to the off state, preventing the target battery cluster from supplying power to the first controller. This reduces the charge difference between the target battery cluster and other battery clusters in the energy storage device, and also decreases the possibility of over-utilization of the target battery cluster by the first controller, thereby effectively improving the performance of the energy storage device.

[0054] The first controller can be, for example, a master battery management unit (MBMU), or a battery management controller (BMC) or other names. Multiple battery clusters can correspond to one first controller.

[0055] Black-start switching devices can be, for example, relays, fuses, or switches. When the black-start switching device is a relay, the relay can be, for example, a normally closed relay. Normally closed relays have a simple structure and stable operation, thus improving the reliability of the energy storage device. Furthermore, normally closed relays are applicable to various control scenarios, thereby increasing the flexibility of the energy storage device.

[0056] The target battery cluster can be at least one of multiple battery clusters. As shown in Figure 3, the energy storage device includes n battery clusters, namely battery cluster 1, battery cluster 2, ..., battery cluster n, and the target battery cluster is battery cluster n among the n battery clusters.

[0057] The first controller performs a black start on the energy storage system based on the target battery cluster, which may include: the first controller performs a black start on the energy storage system based on the charge of the target battery cluster.

[0058] Specifically, in the event of a power outage in the energy storage system, in response to the system's black start requirement, the black start switching device closes. The target battery cluster then supplies power to the first controller. Once the first controller is energized, it can control multiple battery clusters to apply high voltage. After the multiple battery clusters are energized, the busbar of the energy storage device becomes energized, meaning the energy storage device itself is energized. Since the PCS is connected to the energy storage device, the PCS becomes energized. After the PCS is energized, it can convert DC power to AC power, enabling the entire energy storage system to operate, thus achieving a black start.

[0059] S220 may specifically include: the first controller directly controls the black start switching device to switch from the closed state to the closed state.

[0060] Alternatively, the user can send a command to the first controller via the backend, instructing the black start controller to switch from the closed state to the off state. Upon receiving the command, the first controller can switch the black start on / off device from the closed state to the off state.

[0061] Alternatively, as shown in Figure 4, the energy storage device may also include a second controller, which includes a target controller. The second target controller corresponds to the target battery cluster and is located between the target battery cluster and the black start switching device.

[0062] At this time, the first controller can send a switching message to the second controller, which instructs the black-start switch to be switched from the closed state to the closed state. In response to the switching message, the second controller can switch the black-start switch from the closed state to the closed state.

[0063] Since the first controller typically consumes a large amount of power, this technical solution involves the first controller sending switching information to the second target controller, instructing it to switch the state of the black-start switching device to the off state. This allows the second target controller to switch the black-start switching device from the closed state to the off state, thereby reducing the power consumption of the energy storage device. Furthermore, this increases the applicability of the embodiments of this application. For example, the embodiments of this application can be applied to scenarios where the first controller needs to be monitored.

[0064] The second controller corresponds one-to-one with a battery cluster, meaning one battery cluster corresponds to one second controller. The second controller can be, for example, a slave battery management unit (SBMU). The second target controller is the controller within the second controller that is connected to the target battery cluster.

[0065] The second target controller can, for example, draw power from the inside of the target battery cluster. In the event of a power outage in the energy storage system, the target battery cluster can power the second target controller.

[0066] Alternatively, the second target controller can automatically control the black-start on / off device to switch from the closed state to the off state.

[0067] It should be understood that the first controller can only switch the black start switching device from a closed device to a closed state after other power supplies are available to power the first controller.

[0068] Other power supplies can be directly connected to the first controller to directly power it.

[0069] In some cases, the voltage of other power supplies may be higher, such as several kilovolts, while the voltage required by the first controller is usually lower. If the voltage of other power supplies is directly input to the first controller, it may damage the first controller.

[0070] Therefore, in some embodiments, the energy storage device may further include a voltage conversion device, the two ends of which are respectively connected to the second terminal of the first controller and the power supply, for converting the output voltage of the power supply into the voltage required by the first controller. In this case, the first controller can control the black-start switching device to switch from a closed state to a closed state based on the status information of the voltage conversion device.

[0071] This technical solution, by setting a voltage conversion device between the first controller and the power supply, can convert the voltage output by the power supply to the voltage required by the first controller, reducing the possibility of damage to the first controller due to excessively high voltage output by the power supply and ensuring the normal operation of the energy storage device.

[0072] The power supply can be the busbar of the energy storage device, other energy storage devices in the energy storage system, or other power sources located outside the energy storage system. For example, this other power source could be fire-fighting equipment in the power grid.

[0073] Optionally, the voltage conversion device may include, but is not limited to, a direct current-to-direct current (DC-DC) converter.

[0074] When the power supply is the busbar of the energy storage device, the output voltage may be thousands of volts, such as 1500 volts (V). The required voltage of the first controller may be a few volts or tens of volts, for example, it may be 5V-50V, such as 9V, 15V, 20V, 30V, 36V, 40V, etc.

[0075] In some embodiments, the status information may include the power supply status and fault status of the voltage conversion device. The power supply status indicates whether the voltage conversion device is in a power supply state, and the fault status indicates whether the voltage conversion device has failed.

[0076] When the voltage conversion device is not faulty and is in a power supply state, the first controller can control the black start switching device to switch from the closed state to the closed state.

[0077] In this technical solution, the voltage conversion device is not faulty and is in a power supply state, indicating that the power supply can supply power to the first controller through the voltage conversion device. Therefore, the first controller controls the black start switching device to switch from the closed state to the closed state, reducing the possibility that the first controller will not work properly due to the black start switching device being turned off, thereby ensuring the normal operation of the energy storage system.

[0078] The voltage conversion device may include a first voltage conversion device, the two ends of which are respectively connected to the second terminal of the first controller and the bus of the energy storage device. In this case, if the first voltage conversion device is functioning correctly and is in a power-on state, the first controller can control the black-start switching device to switch from a closed state to a closed state.

[0079] Alternatively, the voltage conversion device may include a second voltage conversion device, the two ends of which are respectively connected to a second terminal of the first controller and a power supply terminal located outside the energy storage device. In this case, if the second voltage conversion device is not faulty and is in a power supply state, the first controller can control the black-start switching device to switch from a closed state to a closed state.

[0080] The above technical solution, by configuring the voltage conversion device to include a first voltage conversion device or a second voltage conversion device, not only reduces the space occupied by the energy storage device for the voltage conversion device, but also reduces the cost of the voltage conversion device.

[0081] The power supply terminal located outside the energy storage device can include, for example, the busbar of another energy storage device in the energy storage system, or other power sources outside the energy storage system. Thus, if the energy storage device containing the first controller fails and cannot supply power to the first controller, the power supply terminal outside the energy storage device can continue to supply power to the first controller, which is beneficial to the normal operation of the first controller.

[0082] Alternatively, the voltage conversion device may include a first voltage conversion device and a second voltage conversion device. In this case, if the first voltage conversion device is not faulty and is in a power supply state, or if the second voltage conversion device is not faulty and is in a power supply state, the first controller may control the black start switching device to switch from a closed state to a closed state.

[0083] The above technical solution configures the voltage conversion device to include a first voltage conversion device and a second voltage conversion device, and the power supply terminals of the first voltage conversion device and the second voltage conversion device are different. That is, multiple power supplies are used to power the first controller, so that if one of the power supplies is abnormal, the first controller can still work normally, thus improving the reliability of power supply.

[0084] Optionally, if the first voltage conversion device is not faulty and is in a power-on state, and the second voltage conversion device is also not faulty and is in a power-on state, the first controller may receive the power output from the first voltage conversion device, or the first controller may receive the power output from the second voltage conversion device, or the first controller may simultaneously receive the power output from both the first and second voltage conversion devices.

[0085] Of course, in addition to the first voltage conversion device and the second voltage conversion device, the voltage conversion device may also include other voltage conversion devices, that is, the embodiments of this application may use more power supplies to power the first controller.

[0086] When one end of the first voltage conversion device is connected to the bus of the energy storage device, the bus of the energy storage device will only become energized after the battery cluster is energized, thus enabling power to the first controller. Therefore, the power supply status of the voltage conversion device can be determined by whether the battery cluster is energized.

[0087] Specifically, the first controller can control multiple battery clusters to be powered by high voltage based on the power of the target battery cluster. When at least one of the multiple battery clusters is powered by high voltage, the first controller can determine that the first voltage conversion device is in a power supply state.

[0088] In this technical solution, since multiple battery clusters are connected in parallel, the presence of high voltage in at least one battery cluster indicates that all battery clusters are online at high voltage. With all battery clusters online at high voltage, the busbar of the energy storage device is energized. Since the first voltage conversion device is connected to the busbar of the energy storage device, it is in a power supply state. Therefore, determining whether the first voltage conversion device is in a power supply state based on whether the battery clusters are online at high voltage improves the accuracy of the judgment.

[0089] The first voltage conversion device may include a first voltage conversion device.

[0090] Alternatively, considering that the bus voltage of energy storage devices is usually high, reaching thousands of volts, while the voltage required by the first controller may be only tens of volts, if the first voltage conversion device includes a first voltage conversion device, then the first voltage conversion device needs to convert thousands of volts to tens of volts. Thus, the requirements for the first voltage conversion device are high.

[0091] Therefore, the first voltage conversion device may include multiple first voltage conversion devices connected in series. In this case, assuming that each of the multiple first voltage conversion devices is functioning correctly and is powered on, the first voltage conversion device can supply power to the first controller.

[0092] For example, the first voltage conversion device includes two first voltage conversion devices. The bus voltage of the energy storage device is 1500V, and the required voltage of the first controller is 24V. The first voltage conversion device connected to the bus of the energy storage device is used to convert 1500V to 220V, and the first voltage conversion device connected to the first controller is used to convert 220V to 24V.

[0093] The second voltage conversion device may include a second voltage conversion device.

[0094] Alternatively, similar to the first voltage conversion device, the second voltage conversion device may include multiple second voltage conversion devices connected in series. In this case, provided that each of the multiple second voltage conversion devices is functioning correctly and is powered on, the second voltage conversion device can supply power to the first controller.

[0095] The above technical solution includes a first voltage conversion device comprising multiple first voltage conversion devices, and / or a second voltage conversion device comprising multiple second voltage conversion devices. In this way, the multiple first voltage conversion devices can convert the high voltage output from the power supply to the low voltage required by the first controller, and / or the multiple second voltage conversion devices can convert the high voltage output from the power supply to the low voltage required by the first controller. This not only reduces the losses of the first voltage conversion devices and / or the second voltage conversion devices, but also facilitates the selection of the first voltage conversion devices and / or the second voltage conversion devices.

[0096] Figure 5 shows a schematic diagram of an energy storage system. As shown in Figure 5, the energy storage system includes energy storage device 1 and energy storage device 2. Energy storage device 1 is the energy storage device of the embodiment of this application, and energy storage device 2 is another energy storage device. The first voltage conversion device includes two first voltage conversion devices, namely first voltage conversion device 1 and first voltage conversion device 2. First voltage conversion device 1 is connected to the bus of the energy storage device and first voltage conversion device 2 respectively. The other end of first voltage conversion device 2 is connected to a first controller. The second voltage conversion device includes two second voltage conversion devices, namely second voltage conversion device 1 and second voltage conversion device 2. Second voltage conversion device 1 is connected to the bus of other energy storage devices and second voltage conversion device 2 respectively. The other end of second voltage conversion device 2 is connected to the first controller.

[0097] Furthermore, in addition to the status information of the voltage conversion device, the first controller can also control the black-start switching device to switch from the closed state to the closed state based on other parameters.

[0098] As an example, in some cases, the voltage conversion device may not be faulty and may be in a powered state, but this may only be a momentary situation. At other times, the voltage conversion device may not be in a powered state or may have malfunctioned. Alternatively, the first controller may make an incorrect judgment, and the voltage conversion device may have malfunctioned or not be in a powered state. In such cases, if the black-start switching device is switched from the closed state to the closed state, the first controller may not have a power supply and may not be able to work.

[0099] Therefore, other parameters may include the duration of the voltage conversion device state. In other words, when the voltage conversion device is not faulty and is in a power-on state, the first controller controlling the black-start switching device to switch from a closed state to a closed state may include: when the voltage conversion device is not faulty and is in a power-on state, and when the duration of this state is longer than a preset duration, the first controller controlling the black-start switching device to switch from a closed state to a closed state.

[0100] This technical solution considers multiple factors when controlling the black-start switching device to switch from a closed state to a closed state. In addition to the state information of the voltage conversion device, it also considers the duration of the state, which reduces the possibility of misjudgment by the first controller. This reduces the probability that the first controller will fail to work due to the lack of power supply after the black-start switching device is switched to the closed state, thus improving the robustness of the energy storage device.

[0101] The preset duration can be, for example, 5 seconds, 10 seconds, 20 seconds, 30 seconds, etc.

[0102] In the embodiments of this application, the order of the above-mentioned process numbers does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0103] Furthermore, without conflict, the various embodiments and / or technical features described in this application can be arbitrarily combined with each other, and the resulting technical solutions should also fall within the protection scope of this application.

[0104] The black-start control method of the embodiments of this application has been described in detail above. The energy storage device of the embodiments of this application will be described below. It should be understood that the black-start control method of the embodiments of this application can be applied to the energy storage device of the embodiments of this application.

[0105] As shown in Figure 3, the energy storage device includes multiple battery clusters, a first controller, and a black-start switching device. The black-start switching device is located between the target battery cluster and the first terminal of the first controller. In response to the black-start requirement of the energy storage system, the black-start switching device is in a closed state during the black-start process, so that the first controller performs a black start on the energy storage device based on the target battery cluster. After the black start, the black-start switching device is in a closed state.

[0106] Optionally, in this embodiment of the application, the energy storage device further includes a second target controller, which corresponds to the target battery cluster and is disposed between the target battery cluster and the black-start switching device. When the black-start switching device is in a closed state, the target battery cluster supplies power to the second target controller. The first controller is also used to send switching information to the second target controller, which is used to indicate that the black-start switching device is switched from a closed state to a closed state.

[0107] Optionally, in this embodiment of the application, the energy storage device further includes a voltage conversion device. The two ends of the voltage conversion device are respectively connected to the second end of the first controller and the power supply, and are used to convert the output voltage of the power supply into the voltage required by the first controller. After the energy storage device is black-started, the first controller receives power through the voltage conversion device. Specifically, the first controller is used to control the black-start switching device to switch from a closed state to a closed state according to the status information of the voltage conversion device.

[0108] Optionally, in this embodiment, the voltage conversion device includes a first voltage conversion device, the two ends of which are respectively connected to the second end of the first controller and the bus of the energy storage device; and / or the voltage conversion device includes a second voltage conversion device, the two ends of which are respectively connected to the second end of the first controller and a power supply end located outside the energy storage device; the first controller is specifically used to control the black-start switching device to switch from a closed state to a closed state when the first voltage conversion device is not faulty and is in a power supply state, and / or when the second voltage conversion device is not faulty and is in a power supply state.

[0109] Optionally, in this embodiment, the first voltage conversion device includes a plurality of first voltage conversion devices connected in series; and / or the second voltage conversion device includes a plurality of second voltage conversion devices connected in series; the first controller is specifically configured to: control the black-start switching device to switch from a closed state to a closed state when each of the plurality of first voltage conversion devices is not faulty and is in a power supply state, and / or, when each of the plurality of second voltage conversion devices is not faulty and is in a power supply state.

[0110] Optionally, in this embodiment of the application, when the voltage conversion device includes a second voltage conversion device, the power supply terminal located outside the energy storage device includes the busbars of other energy storage devices in the energy storage system besides the energy storage device.

[0111] It should be understood that the energy storage device can perform the corresponding operations in the black start control method 200, which will not be elaborated here for the sake of brevity.

[0112] This application also provides an energy storage system. The energy storage system includes multiple energy storage devices. One of the multiple energy storage devices can be, for example, the energy storage device shown in FIG3.

[0113] Among them, two adjacent energy storage devices can be installed close to each other, or two rows of energy storage devices can be spaced a certain distance apart.

[0114] As mentioned above, the energy storage system may also include a power generation system (PCS) for connecting the power generation equipment and the energy storage device. The power generation equipment generates electrical energy, which can be stored in the energy storage device via the PCS. For example, the power generation equipment may specifically be a solar panel, hydroelectric power generation equipment, thermal power generation equipment, wind power generation equipment, etc. This application does not limit the specific type of power generation equipment.

[0115] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for black start control, characterized in that, Applied to an energy storage system, the energy storage system including an energy storage device, the energy storage device including multiple battery clusters, a first controller, and a black-start switching device, the black-start switching device being disposed between a target battery cluster among the multiple battery clusters and a first terminal of the first controller, the method including: In response to the black start requirement of the energy storage system, the first controller performs a black start on the energy storage system based on the target battery cluster, wherein the black start on / off device is in a closed state during the black start process. After a black start, the first controller controls the black start on / off device to switch from a closed state to a closed state.

2. The method according to claim 1, characterized in that, The energy storage device further includes a second target controller, which corresponds to the target battery cluster and is disposed between the target battery cluster and the black start switching device. The first controller controls the black-start switching device to switch from a closed state to a closed state, including: The first controller sends switching information to the second target controller, the switching information being used to instruct the black-start on / off device to be switched from the closed state to the off state.

3. The method according to claim 1 or 2, characterized in that, The energy storage device also includes a voltage conversion device, the two ends of which are respectively connected to the second end of the first controller and the power supply, for converting the output voltage of the power supply into the voltage required by the first controller; The first controller controls the black-start switching device to switch from a closed state to a closed state, including: The first controller controls the black-start switching device to switch from the closed state to the closed state based on the status information of the voltage conversion device.

4. The method according to claim 3, characterized in that, The status information includes the power supply status and fault status of the voltage conversion device. Based on the status information of the voltage conversion device, the first controller controls the black-start switching device to switch from a closed state to a closed state, including: When the voltage conversion device is not malfunctioning and is in a power supply state, the first controller controls the black start switching device to switch from a closed state to a closed state.

5. The method according to claim 4, characterized in that, The voltage conversion device includes a first voltage conversion device and / or a second voltage conversion device. The two ends of the first voltage conversion device are respectively connected to the second end of the first controller and the bus of the energy storage device. The two ends of the second voltage conversion device are respectively connected to the second end of the first controller and a power supply end located outside the energy storage device. When the voltage conversion device is not malfunctioning and is in a power supply state, controlling the black-start switching device to switch from a closed state to a closed state includes: When the first voltage conversion device is not faulty and is in a powered state, and / or when the second voltage conversion device is not faulty and is in a powered state, the first controller controls the black start switching device to switch from a closed state to a closed state.

6. The method according to claim 5, characterized in that, The first voltage conversion device includes a plurality of first voltage conversion devices, which are connected in series with each other, and / or the second voltage conversion device includes a plurality of second voltage conversion devices, which are connected in series with each other; When the first voltage conversion device is not faulty and is in a powered state, and / or when the second voltage conversion device is not faulty and is in a powered state, the first controller controls the black-start switching device to switch from a closed state to a closed state, including: When each of the plurality of first voltage conversion devices is functioning correctly and is in a powered state, and / or when each of the plurality of second voltage conversion devices is functioning correctly and is in a powered state, the first controller controls the black-start switching device to switch from a closed state to a closed state.

7. The method according to claim 5 or 6, characterized in that, In the case where the voltage conversion device includes a second voltage conversion device, the power supply terminal located outside the energy storage device includes the busbars of other energy storage devices in the energy storage system besides the energy storage device.

8. The method according to any one of claims 4 to 7, characterized in that, When the voltage conversion device is not malfunctioning and is in a power supply state, the first controller controls the black-start switching device to switch from a closed state to a closed state, including: If the voltage conversion device is not malfunctioning and is in a power-on state, and the duration of power supply exceeds a preset duration, the first controller controls the black-start switching device to switch from a closed state to a closed state.

9. The method according to any one of claims 5 to 7, characterized in that, The first controller performs a black start on the energy storage system based on the target battery cluster, including: The first controller controls the high voltage applied to the plurality of battery clusters based on the target battery cluster; The method further includes: When at least one of the plurality of battery clusters is online at high voltage, it is determined that the first voltage conversion device is in a power supply state.

10. The method according to any one of claims 3 to 9, characterized in that, The power supply includes the bus of the energy storage device, other energy storage devices in the energy storage system, or other power sources located outside the energy storage system.

11. The method according to any one of claims 1 to 10, characterized in that, The black start switching device is a normally closed relay.

12. An energy storage device, characterized in that, Applied to an energy storage system, the energy storage device includes multiple battery clusters, a first controller, and a black start switching device, wherein the black start switching device is disposed between a target battery cluster in the multiple battery clusters and a first terminal of the first controller; In response to the black start requirement of the energy storage system, the black start on / off device is in a closed state during the black start process, so that the first controller performs a black start on the energy storage device based on the target battery cluster. After a black start, the black start on / off device is in the off state.

13. The energy storage device according to claim 12, characterized in that, The energy storage device further includes a second target controller, which corresponds to the target battery cluster and is located between the target battery cluster and the black start switching device. When the black start switching device is in the closed state, the target battery cluster supplies power to the second target controller. The first controller is also configured to send switching information to the second target controller, the switching information being used to instruct the black-start on / off device to be switched from a closed state to a closed state.

14. The energy storage device according to claim 12 or 13, characterized in that, The energy storage device also includes a voltage conversion device, the two ends of which are respectively connected to the second end of the first controller and the power supply, for converting the output voltage of the power supply into the voltage required by the first controller. After the energy storage device is started up, the first controller receives power through the voltage conversion device. The first controller is specifically used to control the black-start switching device to switch from a closed state to a closed state based on the status information of the voltage conversion device.

15. The energy storage device according to claim 14, characterized in that, The voltage conversion device includes a first voltage conversion device, the two ends of which are respectively connected to the second terminal of the first controller and the bus of the energy storage device; and / or The voltage conversion device includes a second voltage conversion device, the two ends of which are respectively connected to the second end of the first controller and the power supply end located outside the energy storage device; The first controller is specifically used to control the black-start switching device to switch from a closed state to a closed state when the first voltage conversion device is not faulty and is in a power-on state, and / or when the second voltage conversion device is not faulty and is in a power-on state.

16. The energy storage device according to claim 15, characterized in that, The first voltage conversion device includes a plurality of first voltage conversion devices, which are connected in series; and / or The second voltage conversion device includes a plurality of second voltage conversion devices, which are connected in series. The first controller is specifically used for: When each of the plurality of first voltage conversion devices is functioning correctly and is in a powered state, and / or when each of the plurality of second voltage conversion devices is functioning correctly and is in a powered state, the black-start switching device is controlled to switch from a closed state to a closed state.

17. The energy storage device according to claim 15 or 16, characterized in that, In the case where the voltage conversion device includes a second voltage conversion device, the power supply terminal located outside the energy storage device includes the busbars of other energy storage devices in the energy storage system besides the energy storage device.

18. The energy storage device according to any one of claims 14 to 17, characterized in that, The power supply includes the bus of the energy storage device, other energy storage devices in the energy storage system, or other power sources located outside the energy storage system.

19. The energy storage device according to any one of claims 12 to 18, characterized in that, The black start switching device is a normally closed relay.

20. An energy storage system, characterized in that, include: Multiple energy storage devices according to any one of claims 12 to 19.

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