Energy storage system

Abstract

The present application provides an energy storage system. The energy storage system comprises at least one energy storage device, at least one power conversion system, and an energy management system. The energy management system is communicatively connected to the at least one energy storage device, and the energy management system is communicatively connected to the at least one power conversion system. Each energy storage device comprises at least one battery cluster and at least one battery control unit, each battery control unit is communicatively connected to the at least one power conversion system, and each battery control unit is communicatively connected to a corresponding battery cluster in a one-to-one correspondence manner, and is used for monitoring operation information of the battery cluster, sending the operation information of the battery cluster to the energy management system, and sending the operation information of the battery cluster to the at least one power conversion system. The energy management system is used for issuing a control instruction to the at least one power conversion system and the at least one energy storage device, and the at least one power conversion system is used for performing charging and discharging control on the at least one energy storage device. By using the present application, the response speed of the energy storage system and that of the energy storage device can be increased, the application range of the energy storage system and that of the energy storage device are expanded, the manual operation and maintenance costs are reduced, and the requirement for rapid charging and discharging of the battery cluster is satisfied.

Description

An energy storage system

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on December 29, 2023, with application number 202311863067.3 and application name “A Energy Storage System”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of power electronics, and in particular to an energy storage system. Background Art

[0003] With increasing attention to global environmental issues, the new energy industry has experienced rapid growth in recent years, with its application in various sectors of the national economy becoming increasingly widespread and in-depth. However, most new energy sources are characterized by uneven distribution in time and space. Energy storage devices have both charging and discharging capabilities, allowing them to store the electricity converted from renewable energy when it is abundant and release it to the grid and users when it is scarce. These characteristics have led to an increasing variety of application scenarios and power levels for energy storage systems. An energy storage system often includes multiple battery clusters. Meeting the requirements for rapid charging and discharging of battery clusters, improving the response speed of energy storage systems and devices, expanding their application scope, reducing the cost of manual operation and maintenance, and ensuring the stability and reliability of energy storage system operations have become key areas of focus for researchers in this field.

[0004] Summary of the Invention

[0005] The present application provides an energy storage system and energy storage equipment, which can improve the system response speed and the flexibility of application scenarios, reduce manual operation and maintenance costs, and meet the requirements of rapid charging and discharging of battery clusters.

[0006] In a first aspect, the present application provides an energy storage system, which includes: at least one energy storage device, at least one energy storage converter and an energy management system, wherein the energy management system is communicatively connected to the at least one energy storage device, and the energy management system is communicatively connected to the at least one energy storage converter; each of the energy storage devices includes at least one battery cluster and at least one battery control unit, each of the battery control units is communicatively connected to at least one of the energy storage converters, and the battery control units are communicatively connected to the battery clusters one-to-one, the battery control unit is used to monitor the operating information of the battery cluster, send the operating information of the battery cluster to the energy management system, and send the operating information of the battery cluster to the energy storage converter; the energy storage converter is used to send the operating information of the battery cluster to the energy management system; the energy management system is used to issue control instructions to the at least one energy storage converter and the at least one energy storage device; and the at least one energy storage converter is used to control the charging and discharging of the at least one energy storage device.

[0007] In this implementation, communication connections exist between the energy storage device, the energy management system, and the energy storage converter. This allows the energy storage device to directly transmit some operating parameters to the energy storage converter, allowing the converter to promptly control the charging and discharging process of the energy storage device without going through the energy management system. This results in a fast response speed for the entire energy storage system. Furthermore, even if communication between any two of the three fails, communication can still be maintained through the remaining one, ensuring the normal operation of the energy storage system. The energy storage device adopts a distributed battery cluster control architecture, where each battery cluster is controlled by a battery control unit. If a battery control unit or battery cluster fails, the remaining battery control units or battery clusters can still operate normally, resulting in high reliability. Furthermore, the battery control unit is communicatively connected to the energy storage converter and the energy management system, achieving decoupling of battery monitoring and control, and accelerating the response speed of the battery cluster's charging and discharging process. The battery control unit is connected to the battery cluster in communication, and the battery control unit is also connected to the energy storage inverter. Therefore, the connection relationship between the energy storage inverter and the battery cluster can also be automatically identified. The energy storage inverter can send the automatically identified energy storage system topology relationship to the energy management system. In this way, the energy management system can automatically identify the topology relationship in the energy storage system, reducing the cost of manual identification of the energy storage system topology relationship.

[0008] In conjunction with the first aspect, in one implementation, each of the energy storage devices includes a centralized management unit, which is communicatively connected to the energy management system, and the at least one battery control unit is configured to transmit operating information of the battery cluster to the energy management system via the centralized management unit. The energy storage device utilizes a distributed architecture, with multiple battery control units controlled by a centralized management unit. This allows for precise monitoring and control of the battery control units, and ensures that failure of a single battery control unit does not affect the normal operation of the remaining battery control units.

[0009] In conjunction with the first aspect, in one implementation, the at least one battery control unit in each of the energy storage devices is sequentially communicatively connected, and the first and last of the sequentially communicatively connected battery control units are respectively communicatively connected to a centralized management unit in the energy storage device. The "hand-in-hand" communication connection method for the battery control units in this implementation can reduce the number of communication ports required for communication between the centralized management unit and multiple battery control units. Even if one of the two communication ports of the centralized management unit or the battery control unit fails, the energy storage device can still operate normally.

[0010] In conjunction with the first aspect, in one implementation, each battery control unit in each of the energy storage devices is separately communicatively connected to a centralized management unit in the energy storage device. In this implementation, each battery control unit is separately communicatively connected to the centralized management unit, ensuring that the remaining battery control units can continue to communicate normally with the centralized management unit even if one or more of the multiple battery control units fail.

[0011] In conjunction with the first aspect, in one implementation, at least one energy storage converter is sequentially communicatively connected, with the first and last of the sequentially communicatively connected energy storage converters each being communicatively connected to the energy management system. This "hand-in-hand" communication connection method of the energy storage converters in this implementation can reduce the number of communication ports required for communication between the energy management system and the energy storage converter, ensuring that if some energy storage converters fail, the remaining energy storage converters can still function normally.

[0012] In conjunction with the first aspect, in one implementation, each of the at least one energy storage converter is separately communicatively connected to the energy management system. In this implementation, each energy storage converter is separately communicatively connected to the energy management system, which ensures that if some energy storage converters fail, the other energy storage converters can still operate normally.

[0013] In conjunction with the first aspect, in one implementation, each energy storage converter includes a monitoring unit and a control unit. A first communication line and a second communication line are provided between the monitoring unit and the control unit. The baud rate of the first communication line is different from the baud rate of the second communication line. In this implementation, the energy storage converter utilizes dual-channel communication to decouple its operation and maintenance information from its operational information, ensuring that the transmission of the two types of information does not interfere with each other, thereby improving the reliability of the converter's operation.

[0014] In conjunction with the first aspect, in one implementation, each battery cluster is power-connected to at least two energy storage converters. In this implementation, the energy storage converters increase the charge and discharge power of the energy storage device by parallel operation, and the solution is easily scalable, flexible, and reliable.

[0015] In conjunction with the first aspect, in one implementation, each battery control unit is communicatively connected to at least two energy storage converters. In this implementation, the energy storage converters adopt a parallel operation technical solution, and a group of parallel energy storage converters are still communicatively connected to a corresponding battery control unit.

[0016] In conjunction with the first aspect, in one implementation, at least one energy storage inverter is configured to receive connection relationship information between the at least one energy storage inverter and the at least one battery control unit, and the connection relationship information is configured to be transmitted to the energy management system. In this implementation, the energy storage inverter is communicatively connected to the battery control unit, so the connection relationship information between the energy storage inverter and the battery control unit / battery cluster can be automatically identified by a machine without manual effort, greatly improving identification efficiency. This is particularly suitable for high-power application scenarios, as the energy management system can automatically identify the topological relationship of the energy storage system.

[0017] In combination with the first aspect, in one implementation, the communication connection method includes CAN communication or FE communication.

[0018] In conjunction with the first aspect, in one implementation, each energy storage device includes an environmental device, which is communicatively connected to the centralized management unit. The environmental device includes fire protection equipment, temperature control equipment, anti-theft equipment, or auxiliary power supply equipment. In this implementation, the environmental device is communicatively connected to the centralized management unit, and the energy management system can monitor or control environmental parameters of the energy storage device, such as fire protection, temperature control, flooding, door magnetic contact, temperature, and humidity, to ensure that the energy storage device is always in an environment suitable for its operation.

[0019] In a second aspect, the present application provides an energy storage device, which includes a battery cluster, a battery control unit and a centralized management unit, wherein the battery cluster is communicatively connected to the battery control unit, the battery cluster is used to be power-connected to an energy storage inverter, the battery control unit is used to communicate with the energy storage inverter, the centralized management unit is used to communicate with an energy management system, the battery cluster is used to store electrical energy, the battery control unit is used to send battery information of the battery cluster to the centralized management unit, the centralized management unit is used to send the battery information to the energy management system, the energy storage inverter is used to convert between direct current and alternating current, and the energy management system is used to monitor and control the energy storage device and the energy storage inverter.

[0020] In combination with the second aspect, in one implementation, the energy storage device includes a plurality of the battery control units, and the plurality of the battery control units are communicatively connected in sequence, and the first of the plurality of the battery control units and the last of the plurality of the battery control units are respectively communicatively connected to the centralized management unit.

[0021] In combination with the second aspect, in one implementation, the energy storage device includes a plurality of the battery control units, and each of the plurality of battery control units is communicatively connected to the centralized management unit.

[0022] In combination with the second aspect, in one implementation, the energy storage device includes a plurality of the battery clusters, and each of the plurality of the battery clusters is respectively used to be power-connected to at least two of the plurality of the energy storage converters.

[0023] In combination with the second aspect, in one implementation, the energy storage device includes a plurality of the battery control units, and each of the plurality of the battery control units is respectively used to communicate with at least two of the plurality of the energy storage converters.

[0024] In combination with the second aspect, in one implementation, the energy storage device includes an environmental device, the energy storage device is communicatively connected to the environmental device, and the environmental device includes a fire-fighting device, a temperature control device, an anti-theft device, and an auxiliary power supply device.

[0025] In a third aspect, the present application provides an energy storage inverter, which is used to communicate with an energy management system and to control the charging and discharging of an energy storage device; the energy storage inverter is used to communicate with a battery control unit in the energy storage device and to receive operating information of a battery cluster sent by the battery control unit; the energy storage inverter is used to send the operating information of the battery cluster to the energy management system; and to receive control instructions issued by the energy management system.

[0026] In combination with the third aspect, in one implementation, the energy storage converter includes a monitoring unit and a control unit, and a first communication line and a second communication line are provided between the monitoring unit and the control unit, and the baud rate of the first communication line is different from the baud rate of the second communication line.

[0027] In combination with the third aspect, in one implementation, the energy storage converter is configured to receive connection relationship information between the energy storage converter and the battery control unit, and send the connection relationship information to the energy management system.

[0028] In conjunction with the third aspect, in one implementation, the communication connection method includes CAN communication or FE communication.

[0029] The beneficial effects achieved by the technical solutions disclosed in the second and third aspects can be referred to the first aspect and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG1 is a schematic diagram of an energy storage system application scenario provided by an embodiment of the present application;

[0031] FIG2 is a schematic diagram of an energy storage system architecture provided by an embodiment of the present application;

[0032] FIG3 is a schematic diagram of a communication architecture of an energy storage system provided in an embodiment of the present application;

[0033] FIG4 is a schematic diagram of another energy storage system communication architecture provided by an embodiment of the present application;

[0034] FIG5 is a schematic diagram of another energy storage system communication architecture provided in an embodiment of the present application. DETAILED DESCRIPTION

[0035] The technical solution in this application will be described below with reference to the accompanying drawings.

[0036] References to "some embodiments" and the like in this specification mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in some embodiments" and the like that appear in different places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0037] For ease of understanding, the relevant technical terms and English abbreviations involved in the embodiments of this application are explained and described below.

[0038] Photovoltaic inverter: An inverter is a converter that converts direct current into constant frequency and constant voltage or frequency and voltage adjustable alternating current. A photovoltaic inverter is an inverter that converts the variable direct current voltage generated by solar panels (also known as photovoltaic panels) into mains frequency alternating current.

[0039] Energy storage converter: PCS, Power Conversion System. Energy storage converters can convert AC and DC power and can directly power AC loads in the absence of a power grid.

[0040] Energy Management System (EMS): The highest-level control unit of the entire energy storage system, responsible for monitoring and controlling the operating status of the entire energy storage system.

[0041] Central management unit (CMU): As the master control unit of the energy storage device, it connects not only to the battery control unit but also to the environmental devices in the energy storage device, such as firefighting equipment, temperature control equipment, anti-theft equipment, and auxiliary power supply equipment.

[0042] Battery control unit: BCU. Controls, manages, detects, or calculates electrical and thermal parameters of the battery system.

[0043] State of charge (SOC): The percentage of available battery capacity that can be released under specified discharge conditions.

[0044] State of health: SOH, state of health. Battery health status is a comprehensive indicator that describes battery quality.

[0045] Microprocessor: MCU, micro control unit.

[0046] Controller Area Network: CAN. CAN is a serial communication bus that effectively supports distributed real-time control with a high level of security.

[0047] Fast Ethernet: FE, fast Ethernet. Any network that supports the 100Mbit / s Ethernet specification.

[0048] In particular, in this application, communication connection refers to a connection method that forms communication between connected devices through signal transmission interaction, and power connection refers to a connection method that forms a high-voltage line between connected devices through the transmission of power energy.

[0049] The embodiments of the present application provide an energy storage system and an energy storage device.

[0050] The energy storage system includes an energy storage device, an energy storage converter and an energy management system. The energy storage device is connected to a power grid or a load through the energy storage converter. The energy storage device is communicatively connected to the energy management system. The energy management system is communicatively connected to the energy storage converter. The energy storage converter is communicatively connected and power-connected to the energy storage device. The energy storage converter is used for converting between direct current and alternating current. The energy management system is used for monitoring and controlling the energy storage device and the energy storage converter.

[0051] The energy storage device includes a battery cluster, a battery control unit and a centralized management unit. The battery cluster is communicatively connected to the battery control unit, the battery cluster is power-connected to the energy storage converter, the battery control unit is communicatively connected to the energy storage converter, and the centralized management unit is communicatively connected to the energy management system. The battery cluster is used to store electrical energy, the battery control unit is used to send battery information of the battery cluster to the centralized management unit, and the centralized management unit is used to send the battery information to the energy management system.

[0052] The energy storage system provided by the embodiment of the present application has communication connections between the energy storage device, the energy management system, and the energy storage converter, which improves the communication response speed of the entire system, realizes the decoupling of battery power control and battery operation information monitoring, and ensures the reliability of system operation. The energy storage converter is communicated with the battery control unit, and the battery control unit is communicated with the battery cluster. The energy storage converter can send the connection relationship between the battery cluster and the energy storage converter in the energy storage system to the northbound energy management system, thereby realizing automatic identification of the topological relationship of the energy storage system. In addition, the energy storage converter adopts two-way communication internally, which can decouple the operation and maintenance of the energy storage device and ensure the reliability of the operation of the energy storage device.

[0053] The energy storage device provided in the embodiments of the present application can be applied to various application scenarios requiring energy storage devices, such as pure storage, solar storage, and wind storage.

[0054] Please refer to Figure 1, which is a schematic diagram of an energy storage system application scenario provided by one embodiment of the present application. In one embodiment, the application scenario includes: photovoltaic power generation equipment 01, energy storage system 30, energy storage converter 40, load 50, and power grid 60. Optionally, photovoltaic power generation equipment 01 may also include: photovoltaic modules 10 and photovoltaic inverter 20.

[0055] Specifically, in this application scenario, the energy storage system 30 is connected to the load 50 and the power grid 60 through the energy storage converter 40. The energy flow between the energy storage system 30 and the energy storage converter 40 is bidirectional, the energy flow between the energy storage converter 40 and the power grid 60 is bidirectional, and the energy flow of the load 50 is unidirectional. The load 50 can obtain energy from the power system for use by the load 50. When the power grid 60 has sufficient power, the AC power of the grid 60 passes through the energy storage converter 40, is rectified and converted into DC power, and then stored in the energy storage system 30. When the power grid 60 is insufficient, the energy storage system 30 transmits energy to the energy storage converter 40 via DC power, and the energy storage converter 40 converts the DC power into AC power for use by the load 50 through inversion. In particular, in some scenarios involving intelligent power management systems, the charging and discharging process of the energy storage system 30 can be controlled by setting a specific strategy. For example, the specific strategy is an electricity cost saving strategy. When the electricity price of the power grid 60 is low, the energy storage system 30 is controlled to start charging. When the electricity price of the power grid 60 is high, the energy storage system 30 is controlled to discharge to supply the load 50 for startup.

[0056] The energy storage system provided in this application can also be used in conjunction with a photovoltaic power generation device 01. The photovoltaic power generation device 01 includes a photovoltaic module 10 and a photovoltaic inverter 20. The photovoltaic module 10 can convert solar energy into direct current (DC) electricity, and the photovoltaic inverter then converts DC into alternating current (AC). When used with the photovoltaic power generation device 01, the energy storage system has a richer energy source for application scenarios. The AC electricity generated by the photovoltaic power generation device can be supplied to the load 50 and the grid 60, or it can be converted and stored in the energy storage system 30 through the energy storage converter 40. The energy storage system also has a richer range of specific strategies for application scenarios. For example, the specific strategy is a photovoltaic power generation self-sufficiency strategy. During the day, the photovoltaic power generation device 01 generates electricity, and the generated electricity is preferentially supplied to the load 50 for use, and then stored in the energy storage system 30. When there is sufficient sunlight, the excess electricity can also be supplied to the grid 60. At night, the energy storage system 30 is preferentially selected to supply power to the load 50. When the load 50 has a large power demand, the grid 60 supplements part of the power required by the load 50.

[0057] Energy storage systems typically include a battery cluster, a PCS, and an EMS. In actual operation, the EMS collects real-time operating status parameters from the battery cluster and PCS, including battery cluster charge and voltage, and the PCS's real-time power. Based on these operating status parameters and user instructions, the EMS issues control instructions to the battery cluster and PCS to control their operating status. When the EMS collects operating status parameters and issues control instructions, its communication relies on the communication channel (or communication connection) between the battery cluster, PCS, and EMS.

[0058] Currently, the energy storage industry is developing toward increasing battery capacity in energy storage systems and increasing the power of electrical equipment. This has led to a gradual increase in the number of battery clusters and PCSs in energy storage systems, making it increasingly difficult for PCSs and battery clusters to compete for communication channels. This has prevented the energy storage system from quickly responding to control commands from the EMS. Furthermore, existing technologies require installers to manually determine the connection status of battery clusters and PCSs on-site. As the number of battery clusters and PCSs increases, the difficulty and cost of operating and maintaining the energy storage system rapidly increase. This is particularly true in industrial and commercial power plants and large ground-based power plants. Manually determining the connection status of hundreds or thousands of battery clusters is extremely error-prone and costly. Furthermore, as the number of battery clusters increases, the impact of inconsistent factory specifications on the energy storage system becomes more significant.

[0059] In the technical solution provided in the present application, each battery cluster is controlled individually by a BCU, the inconsistency between battery clusters can be reduced or even eliminated, and there is a communication connection between the EMS, BCU and PCS. The control instructions issued by the EMS can be responded to quickly, and the EMS can also collect the operating status parameters of the battery cluster and PCS in a timely manner. Moreover, the EMS can automatically identify the topological connection mode between the battery cluster and PCS in the energy storage system without manual identification.

[0060] The energy storage system architecture and specific connection methods of the energy storage system provided in the embodiments of the present application will be described in detail below. It should be understood that the embodiments of the present application provide an energy storage system for a pure energy storage scenario. However, the energy storage system can also be applied to a photovoltaic storage application scenario coupled with photovoltaic power generation, a wind storage application scenario coupled with wind power generation, a water storage application scenario coupled with hydropower generation, a photovoltaic and wind storage application scenario coupled with photovoltaic power generation and wind power generation, and so on. The present application does not limit the application scenarios of the energy storage system.

[0061] Please refer to FIG2 , which is a schematic diagram of the energy storage system architecture provided by an embodiment of the present application. In the figure, the dotted lines represent communication connections, and the solid lines represent power connections.

[0062] In one embodiment, the energy storage system includes an energy storage device, a PCS, and an EMS, wherein the PCS is used to connect to a power grid or a load. The energy storage device has a communication connection with the EMS, the energy storage device has a communication connection and a power connection with the PCS, the EMS has a communication connection with the PCS, and the PCS has a power connection with the power grid or the load. The main component of the energy storage device is a battery, which is used to store electrical energy. The energy storage device is connected to the power grid or the load through the PCS. When the energy storage device is charging, the PCS converts the AC power from the power grid or the load into DC power and supplies it to the energy storage device. When the energy storage device is discharging, the PCS converts the DC power released by the energy storage device into AC power and supplies it to the power grid / load. The EMS is communicatively connected to the energy storage device and the PCS respectively. In this way, the energy storage device and the PCS can report the monitored device information and operating parameters to the EMS respectively through two communication paths, and the EMS can also send control signals to the energy storage device and the PCS respectively through two communication paths. Communication between the EMS and the energy storage device is relatively independent of communication between the EMS and the PCS. This improves the signal response speed of the EMS, energy storage device, and PCS, thereby ensuring the rapid response of the entire energy storage system. The PCS and energy storage device are connected in communication. The energy storage device can directly transmit some operating parameters or monitoring information to the PCS, allowing the PCS to promptly control the charging and discharging process of the energy storage device, thus achieving charge and discharge current limiting for individual battery clusters. Compared to solutions without a communication connection between the PCS and energy storage device, this solution eliminates the need for communication between the EMS and the energy storage device, speeding up communication between the two. Furthermore, it also enables automatic identification of the energy storage system topology, a feature described in detail below. Specifically, the EMS, energy storage device, and PCS maintain a communication connection between each of the three. Even if a communication failure occurs between any two of the three, normal communication can still be maintained through the remaining one. For example, if a communication failure occurs between the energy storage device and the PCS, the energy storage device can still communicate with the PCS through the EMS, ensuring the normal operation of the energy storage system.

[0063] The energy storage device includes a battery cluster, a CMU, and a BCU. Among them, the battery cluster is the main component of the energy storage device. The battery cluster determines the power capacity of the energy storage device. The battery cluster is connected to the PCS power, and the PCS directly controls the charging or discharging process of the battery cluster. For example, the PCS can control whether the battery cluster discharges, and the PCS can control the power or current during the charging and discharging process of the battery cluster. As the upper-level control unit of the battery cluster, the BCU has communication connections with the battery cluster and the PCS, and can monitor the operating parameters and status of the battery cluster in real time. For example, the BCU monitors the SOC value, SOH value, and temperature of the battery cluster in real time during operation. Then, based on the operating parameters and status of the battery cluster, the BCU sends control instructions to the PCS to drive the PCS to adjust the charging and discharging process of the battery cluster. Compared with the technical solution in which there is no communication connection between the BCU and the PCS, the BCU of this application does not need to go through the CMU or EMS, etc., and can directly send control instructions to the PCS, and the response process of the PCS controlling the charging and discharging of the battery cluster is faster. As the master control unit of the energy storage device, the CMU has communication connections with the BCU to the south and the EMS to the north. It is also connected to the fire protection equipment, temperature control equipment, and anti-theft equipment in the energy storage device. On the one hand, one CMU can usually be used to monitor and control multiple BCUs, realizing the function of centralized management of multiple CMUs. The CMU can report the battery cluster parameters monitored by the BCU to the EMS. The EMS presents the battery operation status of the energy storage system to the user based on these battery cluster parameters, adjusts the operation strategy, and issues control instructions to the CMU and PCS. On the other hand, the CMU can control the environmental equipment such as the temperature control device in the energy storage device to maintain the internal temperature of the energy storage device within a reasonable range, ensuring the normal operation of the battery cluster and other equipment.

[0064] In commercial and industrial energy storage and power plant energy storage scenarios, energy storage equipment typically takes the form of a "box" or "cabinet" structure, with battery clusters housed within the box or cabinet, thus isolating them from the external environment. This means that after the energy storage system is fully installed, the PCS is located outside the energy storage device. Without opening the energy storage device, it's impossible to determine the connection between the PCS and the battery clusters, and therefore the topology of the energy storage system. However, during operation, battery clusters may need to be repaired or replaced. Accurately locating the battery clusters that require repair or replacement requires a clear understanding of the energy storage system's topology. In commercial and industrial energy storage scenarios, for example, a single energy storage device might include one battery cluster and two PCSs. In power plant energy storage scenarios, for example, a single energy storage device might include six battery clusters and 12 PCSs. As the number of battery clusters, PCSs, and energy storage devices increases, manual energy storage system topology identification becomes costly and prone to false positives. In this application, the PCS has a communication connection with the BCU, and the connection relationship between the PCS and the BCU can be automatically identified. Since the BCU is communicated with the battery cluster, the connection relationship between the PCS and the battery cluster can also be automatically identified. Each PCS sends the above connection relationship to the energy management system. In this way, the energy management system summarizes the connection relationship between all BCUs and PCSs in the energy storage system and automatically identifies the topological relationship in the energy storage system. Without manual work, the energy management system can show the user the connection status of each device in the monitored energy storage system, thereby accurately locating the battery cluster that needs to be repaired or replaced.

[0065] When the energy storage device is in the form of an energy storage box, the CMU can serve as the master control unit of the entire box. The CMU can also be called a "Container Monitor Unit."

[0066] The following describes this solution in conjunction with specific communication methods.

[0067] Please refer to Figure 3, which is a schematic diagram of the communication architecture of the energy storage system provided by an embodiment of the present application. In the figure, the thick solid line represents the power connection, the dotted line represents the FE communication connection, and the dashed line represents the CAN communication connection.

[0068] In one embodiment, the energy storage system includes an energy storage device, multiple PCSs, and an EMS, and the PCS is used to connect to the power grid or load. The energy storage device includes multiple battery clusters and multiple BCUs, and each battery cluster in the multiple battery clusters is connected to each BCU in the multiple BCUs in a one-to-one correspondence, and there is a communication connection between each battery cluster and each BCU (not shown in Figure 3). A battery cluster is managed separately by a BCU. When a BCU or battery cluster fails, the remaining BCUs or battery clusters can still ensure normal operation, with high reliability. The multiple BCUs are connected to the CMU for FE communication through a "hand-in-hand" connection, that is, the multiple BCUs are connected in sequence, and the two BCUs at the head and tail of the connection are connected to the CMU, and the multiple BCUs and the CMU form a ring network. The multiple BCUs send the battery information of the corresponding multiple battery clusters, such as SOC or SOH information, to the CMU through a communication method, and the CMU then sends it to the northbound EMS. Using a "hand-in-hand" connection approach can reduce the number of communication ports required for the multiple BCUs in the CMU to communicate with each other. In this embodiment, only two communication ports are required. Furthermore, even if one of the two communication ports on the CMU fails, the remaining port can still ensure normal communication between the multiple BCUs and the CMU. Similarly, even if one of the two communication ports on each BCU fails, the remaining port can still ensure normal communication between each BCU and the CMU. In this embodiment, the CMU can also communicate with CMUs in other energy storage devices via FE communication lines, enabling information exchange between multiple energy storage devices.

[0069] The energy storage system also includes environmental equipment, including fire protection equipment, temperature control equipment, anti-theft equipment, and auxiliary power supply equipment. This environmental equipment also has a communication connection with the CMU. The CMU can send its own fire protection information, safety information, and environmental parameters to the northbound EMS. Users can monitor these parameters of the energy storage system in real time and control environmental parameters such as fire protection, temperature control, flooding, door sensor, temperature, and humidity within the box to ensure that the energy storage system is always in an environment suitable for its operation.

[0070] Each of the multiple PCSs has a one-to-one power connection with each of the multiple battery clusters. The multiple PCSs function as power conversion devices and are also connected to the grid or load power to control the charging and discharging of the multiple battery clusters. Each of the multiple PCSs has a one-to-one communication connection with each of the multiple BCUs. The communication connection between each PCS and each BCU is CAN communication. The multiple PCSs are connected to the EMS through a "hand-in-hand" FE communication connection. That is, the multiple PCSs are connected sequentially, with the two PCSs at the beginning and end of the connection connected to the EMS. The multiple PCSs and the EMS form a ring network. A BCU and a PCS have corresponding communication connections. On the one hand, this can realize automatic identification of the power architecture topology of the energy storage system. The multiple PCSs send the connection relationship between themselves and the multiple BCUs to the EMS. Even if the number of the multiple PCSs or the multiple battery clusters is huge, there is no need for manual intervention. The energy storage system can quickly complete the identification of the power architecture topology of the energy storage system. On the other hand, it can realize rapid exchange of information between the multiple PCSs and the multiple BCUs. Due to the direct communication connection between the multiple PCSs and the multiple BCUs, the response speed is fast and the battery safety is high. The multiple PCSs are communicatively connected to the EMS via a "hand-in-hand" connection method, which has high reliability. The EMS can issue control instructions to the multiple PCSs based on the topological relationship between the multiple PCSs and the multiple BCUs and in combination with the information of the multiple battery clusters. The multiple PCSs can also send the operating information of the battery clusters or their own operating information to the EMS. In this embodiment, the CMU and the multiple PCSs are respectively connected to the EMS via independent FE communication connection lines. The operating log of the battery cluster and the battery information monitoring instructions issued by the EMS are transmitted through the CMU, while the power control instructions issued by the EMS are directly issued to the PCS, so as to achieve decoupling of the multiple battery clusters and the energy storage equipment, thereby improving the reliability of the energy storage equipment. In addition, the multiple PCSs can directly receive control instructions from the EMS with a fast response speed.

[0071] Each PCS includes a control MCU and a monitoring MCU, connected via two CAN communication lines. When the energy management system sends information to each PCS, the monitoring MCU serves as the communication port between the PCS and the energy management system, first processing the information and then sending the processed information to the control MCU. Similarly, when each PCS sends information to the energy management system, it transmits the required information to the energy management system via the monitoring MCU. In this embodiment, two CAN communication lines are used for data exchange between the control MCU and the monitoring MCU. Operational instructions requiring a quick response, such as control instructions sent by the EMS to control the charge and discharge power of the energy storage system, are transmitted using one CAN communication line. Operational instructions that do not require a quick response, such as management information, log information, or upgrade information for the energy storage device, are transmitted using another CAN communication line. The baud rates of these two CAN communication lines are different. This decoupling of the operation and maintenance of the energy storage converter can be achieved, ensuring that the two types of information do not interfere with each other, thereby improving the reliability of the energy storage converter.

[0072] Please refer to FIG4 , which is a schematic diagram of another energy storage system communication architecture provided by an embodiment of the present application. In the figure, the thick solid line represents the power connection, the dotted line represents the FE communication connection, and the dashed line represents the CAN communication connection.

[0073] In one embodiment, unlike the energy storage system shown in FIG3 of the present application, the connection method between the CMU and the multiple BCUs is different, and the connection method between the EMS and the multiple PCSs is also different. In this embodiment, each of the multiple BCUs is separately connected to the CMU via FE communication. With this connection method, when one or part of the multiple BCUs fails, the communication between the other BCUs and the CMU is guaranteed to be normal, thereby improving the reliability of the operation of the energy storage device. Each of the multiple PCSs is separately connected to the EMS via FE communication. Similarly, when one or part of the multiple PCSs fails, the communication between the other PCSs and the EMS is guaranteed to be normal, thereby improving the reliability of the operation of the energy storage device.

[0074] It should be understood that the connection method between the multiple BCUs and the CMU and the connection method between the multiple PCSs and the EMS can also include: 1. The multiple BCUs are communicated with the CMU through a "hand-in-hand" connection method, and the multiple PCSs are communicated with the EMS respectively; 2. The multiple BCUs are communicated with the CMU respectively, and the multiple PCSs are communicated with the EMS through a "hand-in-hand" connection method.

[0075] It should be understood that the technical solutions of the above two embodiments can be used to easily change the architecture of the existing energy storage system. On the basis of the existing architecture, adding or reducing PCSs, or adding or reducing battery clusters can be completed quickly, and the entire energy storage system has good flexibility.

[0076] Please refer to FIG5 , which is a schematic diagram of another energy storage system communication architecture provided by an embodiment of the present application. In the figure, the thick solid line represents the power connection, the dotted line represents the FE communication connection, and the dashed line represents the CAN communication connection.

[0077] In one embodiment, the energy storage system includes an energy storage device, multiple PCSs, and an EMS. The PCS is used to connect to the power grid or load, and the energy storage device includes multiple battery clusters and multiple BCUs. Different from the energy storage system shown in Figure 3 of this application, two PCSs in the multiple PCSs control the charge and discharge of the same battery cluster in parallel, that is, each BCU in the multiple BCUs has a CAN communication connection with the two PCSs, and each battery cluster in the multiple battery clusters has a power connection with the two PCSs. The multiple PCSs and EMSs are still connected by FE communication in a "hand-in-hand" connection. The technical solution of adopting this PCS parallel connection improves the charge and discharge power of the energy storage device, making the energy storage system more widely applicable.

[0078] It should be understood that in this embodiment, the number of PCSs connected in parallel is not limited to 2. In actual applications, 3, 4 or other numbers of PCSs can be selected for parallel connection depending on the application scenario. This application does not impose any restrictions on this.

[0079] It should be understood that in the above embodiment, CAN communication and FE communication are only one solution of the embodiment, and the communication mode is not limited to CAN communication and FE communication, and this application does not impose any limitation on this.

[0080] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. An energy storage system, characterized in that, Comprising: At least one energy storage device, at least one energy storage converter, and an energy management system, where the energy management system is communicatively connected to the at least one energy storage device, and the energy management system is communicatively connected to the at least one energy storage converter; Each of the energy storage devices includes at least one battery cluster and at least one battery control unit. Each of the battery control units is communicatively connected to at least one of the energy storage converters, and the battery control unit is communicatively connected to the battery cluster in a one-to-one correspondence. The battery control unit is configured to monitor the operating information of the battery cluster, send the operating information of the battery cluster to the energy management system, and send the operating information of the battery cluster to the energy storage converter; The energy storage converter is configured to send the operating information of the battery cluster to the energy management system; The energy management system is configured to send control commands to the at least one energy storage converter and the at least one energy storage device; The at least one energy storage converter is configured to perform charge and discharge control on the at least one energy storage device.

2. The energy storage system according to claim 1, wherein Each of the energy storage devices includes a centralized management unit, the centralized management unit is communicatively connected to the energy management system, and the at least one battery control unit is configured to send the operating information of the battery cluster to the energy management system through the centralized management unit.

3. The energy storage system according to claim 2, wherein The at least one battery control unit in each of the energy storage devices is communicatively connected in sequence, and the first and the last of the sequentially communicatively connected battery control units are respectively communicatively connected to the centralized management unit in the energy storage device.

4. The energy storage system according to claim 2, wherein Each battery control unit in each of the energy storage devices is respectively communicatively connected to the centralized management unit in the energy storage device.

5. The energy storage system according to claim 3 or 4, characterized in that, The at least one energy storage converter is communicatively connected in sequence, and the first and the last of the sequentially communicatively connected energy storage converters are respectively communicatively connected to the energy management system.

6. The energy storage system according to claim 3 or 4, characterized in that Each of the at least one energy storage converters is respectively communicatively connected to the energy management system.

7. The energy storage system according to claim 1, characterized in that Each of the energy storage converters includes a monitoring unit and a control unit, and there are a first communication line and a second communication line between the monitoring unit and the control unit, and the baud rate of the first communication line is different from the baud rate of the second communication line.

8. The energy storage system according to claim 1, wherein Each of the battery clusters is power-connected to at least two of the energy storage converters.

9. The energy storage system according to claim 1, characterized in that Each of the battery control units is communicatively connected to at least two of the energy storage converters.

10. The energy storage system according to claim 1, wherein The at least one energy storage converter is configured to receive the connection relationship information between the at least one energy storage converter and the at least one battery control unit, and the at least one energy storage converter is further configured to send the connection relationship information to the energy management system.

11. The energy storage system according to claim 1, wherein The communication connection method includes CAN communication or FE communication.

12. The energy storage system according to claim 2, wherein, Each of the energy storage devices includes environmental equipment, the environmental equipment is communicatively connected to the centralized management unit, and the environmental equipment includes fire-fighting equipment, temperature control equipment, anti-theft equipment, or auxiliary power supply equipment.

13. A energy storage converter, characterized in that, The energy storage converter is configured to be communicatively connected to the energy management system and to perform charge and discharge control on the energy storage device; The energy storage converter is used to communicate with the battery control unit in the energy storage device and receive the operation information of the battery cluster sent by the battery control unit; The energy storage converter is used to send the operation information of the battery cluster to the energy management system; And it is used to receive the control instructions issued by the energy management system.

14. The energy storage converter according to claim 13, wherein, The energy storage converter includes a monitoring unit and a control unit. There are a first communication line and a second communication line between the monitoring unit and the control unit, and the baud rate of the first communication line is different from that of the second communication line.

15. The energy storage converter according to claim 13, characterized in that, The energy storage converter is used to receive the connection relationship information between the energy storage converter and the battery control unit and send the connection relationship information to the energy management system.

16. The energy storage converter according to claim 13, wherein The communication connection method includes CAN communication or FE communication.

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