Energy storage system

Abstract

Disclosed in the present application is an energy storage system, comprising: an alternating current power grid, a main outdoor cabinet and a plurality of slave outdoor cabinets; one side of the main outdoor cabinet is connected to the alternating current power grid; each of the slave outdoor cabinets is separately connected to the other side of the main outdoor cabinet; a first busbar is provided in the main outdoor cabinet, wherein the alternating current power grid is connected to a first side of the first busbar, the main outdoor cabinet is connected to a second side of the first busbar, and each of the slave outdoor cabinets is separately connected to a third side of the first busbar.

Description

An energy storage system

[0001] This application claims priority to Chinese Patent Application No. 202510368643.X, filed with the Chinese Patent Office on March 26, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of energy storage technology, specifically to an energy storage system. Background Technology

[0003] When the power demand is relatively large, traditional lithium battery energy storage outdoor cabinets generally adopt a multi-cabinet parallel solution, as shown in Figure 1. The energy management system (EMS) built into the combiner cabinet is connected to the converter (PCS) and battery management system (BMS) in the outdoor cabinet through communication cables. The EMS controls the outdoor cabinet to connect to the AC power grid through the combiner cabinet, realizing the parallel operation of the outdoor cabinet system. Ultimately, it can use the power of the AC power grid to charge the lithium batteries in the outdoor cabinet system, or discharge the power of the outdoor cabinet system to the AC power grid. Technical issues

[0004] In current energy storage systems, a combiner cabinet is required to enable the outdoor cabinet system to operate in parallel, which increases the cost of the energy storage system. Technical solutions

[0005] This application provides an energy storage system, including an AC power grid, a main outdoor cabinet, and multiple slave outdoor cabinets: one side of the main outdoor cabinet is connected to the AC power grid; each slave outdoor cabinet is connected to the other side of the main outdoor cabinet; wherein, a first busbar is provided inside the main outdoor cabinet, the AC power grid is connected to a first side of the first busbar, the main outdoor cabinet is connected to a second side of the first busbar, and each slave outdoor cabinet is connected to a third side of the first busbar. Beneficial effects

[0006] The beneficial effects of this application are as follows:

[0007] A first busbar is installed inside the main outdoor cabinet, through which the outdoor cabinet can charge and discharge with the AC power grid. Therefore, there is no need to configure a separate combiner cabinet for cable convergence, which can reduce the cost of the energy storage system. Attached Figure Description

[0008] Figure 1 is a schematic diagram of the energy storage system of the relevant technology;

[0009] Figure 2 is a schematic diagram of the energy storage system provided in an embodiment of this application;

[0010] Figure 3 is another structural schematic diagram of the energy storage system provided in an embodiment of this application.

[0011] In the picture:

[0012] 1. Energy storage system; 10. AC power grid; 20. Main outdoor cabinet; 201. First busbar; 202. First converter module; 203. Management module; 2031. System management unit; 2032. First battery management unit; 2033. Switch; 30. Slave outdoor cabinet; 301. Second battery management unit; 302. Second converter module; 303. Second busbar; 40. Communication module.

[0013] Implementation methods of this application

[0014] Please refer to Figure 2, which is a schematic diagram of the structure of the energy storage system provided in an embodiment of this application. In this embodiment, an energy storage system 1 is provided, which includes an AC power grid 10, a main outdoor cabinet 20, and slave outdoor cabinets 30. One side of the main outdoor cabinet 20 is connected to the AC power grid 10, and each slave outdoor cabinet 30 is connected to one side of the main outdoor cabinet 20. The main outdoor cabinet 20 is provided with a first busbar 201. The AC power grid 10 is connected to a first side of the first busbar 201, the main outdoor cabinet 20 is connected to a second side of the first busbar 201, and each slave outdoor cabinet 30 is connected to a third side of the first busbar 201.

[0015] Outdoor cabinets are electrical equipment cabinets or enclosures designed for outdoor environments. They are widely used in power systems, telecommunications, solar photovoltaic systems, energy storage systems, and other fields. Outdoor cabinets typically need to withstand harsh weather conditions and environmental factors, such as rain, dust, high temperatures, and low temperatures. Outdoor cabinets protect sensitive electronic equipment and battery packs from environmental impacts; therefore, they are particularly important in energy storage systems.

[0016] In this embodiment, the main outdoor cabinet 20 refers to an outdoor cabinet integrating multiple key components. It serves as the control center and power management hub of the entire energy storage system. Specifically, the main outdoor cabinet 20 is responsible for distributing electrical energy from the AC power grid 10 to each slave outdoor cabinet 30, or collecting electrical energy from the slave outdoor cabinets 30 and sending it back to the AC power grid 10. The main outdoor cabinet 20 is responsible for monitoring and optimizing the operation of the entire energy storage system, including energy dispatch, optimized operation, and interaction with the power grid. Specifically, in some embodiments of this application, the main outdoor cabinet 20 may include a battery pack configured to provide energy storage capacity and power support.

[0017] In this embodiment, the auxiliary outdoor cabinet 30 refers to an auxiliary energy storage unit connected to the main outdoor cabinet 20. These auxiliary outdoor cabinets can serve as extensions of the energy storage system, providing additional energy storage capacity and power support. The auxiliary outdoor cabinet 30 may also contain battery packs, configured to extend the total capacity of the energy storage system. The auxiliary outdoor cabinet 30 can supply power to the grid during peak demand periods or charge from the grid during low demand periods. The auxiliary outdoor cabinets 30 and the main outdoor cabinet 20 operate in parallel, together forming a coordinated energy storage system. Furthermore, if one auxiliary outdoor cabinet 20 fails, the other auxiliary outdoor cabinets 20 can continue to operate, reducing the impact on the energy storage system.

[0018] Specifically, in some embodiments of this application, the main outdoor cabinet 20 may include a first converter module 202 and a management module 203; wherein, one side of the first converter module 202 is connected to the second side of the first busbar 201, and the management module 203 is connected to the adjacent secondary outdoor cabinet 30 through the other side of the first converter module 202.

[0019] The first converter module 202 is a power conversion system (PCS) configured to convert the direct current (DC) from the battery pack into alternating current (AC) to supply power (discharge) to the AC power grid 10, and also configured to convert the AC power from the AC power grid 10 into DC to charge the battery pack. The first converter module 202 ensures that the output AC power during discharge is synchronized with the frequency and phase of the power grid to guarantee power quality. Simultaneously, the first converter module 202 can receive control signals from the management module 203 to adjust the charging and discharging power or respond to the needs of the power grid.

[0020] The management module 203 refers to a unit integrating multiple control and monitoring functions, which is crucial for ensuring the efficient and safe operation of the energy storage system. Specifically, in some embodiments of this application, the management module 203 may include an Energy Management System (EMS), a Battery Management System (BMS), or other related control and monitoring systems. The management module 203 can monitor and optimize the operation of the entire energy storage system, including energy dispatch, optimized operation, and interaction with the power grid. For example, it can intelligently schedule the charging and discharging process based on grid demand, electricity price information, and battery status. Simultaneously, the management module 203 can also monitor the operating status of the battery pack, including voltage, current, temperature, and SOC (State of Charge). For example, the management module 203 implements battery protection strategies such as overcharge, over-discharge, over-temperature, and short-circuit protection. Furthermore, the management module 203 can collect and process data from multiple parts of the energy storage system, providing data support for system optimization and fault diagnosis.

[0021] The management module 203 is connected to the adjacent outdoor cabinet 30 through the first converter module 202. The management module 203 can send control commands to the first converter module 202, such as adjusting the charging and discharging power and executing protection strategies.

[0022] For example, when the electricity price in the AC grid 10 is low or there is a surplus of renewable energy generation, the electrical energy from the AC grid 10 is transmitted to the first converter module 202 via the first busbar 201. The first converter module 202 converts the AC power into DC power to charge the battery pack. When the grid electricity price is high or the grid needs additional power support, the DC power from the battery pack is converted back to AC power via the first converter module 202. The converted electrical energy is then sent back to the grid via the first busbar 201.

[0023] Specifically, in some embodiments of this application, the management module 203 may include a system management unit 2031, a first battery management unit 2032, and a switch 2033;

[0024] The system management unit 2031 is connected to the adjacent outdoor cabinet 20 via the other side of the first converter module 202, and the other side of the system management unit 2031 is connected to the switch 2033; the first battery management unit 2032 is connected to the switch 2033.

[0025] System Management Unit 2031 is an Energy-Battery Management System (EM-BS). EM-BS is an integrated management system that combines energy management and battery management functions, responsible for monitoring, controlling, and optimizing the entire energy storage system. In energy management, EM-BS can intelligently schedule the charging and discharging process of the energy storage system based on grid demand, electricity price information, load forecasting, and battery status. Simultaneously, it performs grid services such as peak shaving, demand response, and grid frequency regulation. In battery management, EM-BS can monitor the operating status of the battery pack, including voltage, current, temperature, and SOC (State of Charge); implement battery protection strategies such as overcharge, over-discharge, over-temperature, and short-circuit protection; and perform battery balancing to ensure that the voltage or SOC of each cell in the battery pack remains consistent, extending battery life.

[0026] Furthermore, EM-BS can collect and process data from multiple parts of the energy storage system, providing data support for system optimization and fault diagnosis, such as analyzing battery performance and lifespan and predicting battery health status. Additionally, EM-BS can be remotely monitored and controlled via Internet connection, allowing maintenance personnel to remotely access system status and perform maintenance, such as receiving alarm information and handling system maintenance and faults.

[0027] Specifically, the EM-BS connects to the adjacent outdoor cabinet 30 via the first converter module 202, and can send control commands to the first converter module 202, such as adjusting charging and discharging power and executing protection strategies. The EM-BS connects to the switch 2033, and exchanges data and communicates with other components in the energy storage system through the switch.

[0028] The first battery management unit 2032 is the Battery Management System Master Controller (BMS). The BMS is configured to: monitor key parameters of each battery cell in the battery pack in real time, such as voltage, current, and temperature; estimate the remaining battery capacity and provide the system with information on the available energy of the battery; perform battery balancing to ensure that the voltage and SOC of each battery cell in the battery pack are consistent, avoiding overcharging or over-discharging; identify abnormal conditions in the battery pack, such as overheating, overvoltage, and undervoltage, and perform fault diagnosis; when a fault or abnormality is detected, implement protective measures, such as cutting off the current, to protect the battery from damage; and record battery operating data to provide data support for battery health status analysis and life prediction.

[0029] The first battery management unit 2032 communicates with other components in the system through the switch 2033 to achieve data exchange and command transmission.

[0030] It should be noted that the system management unit 2031, as a system-level management unit, is responsible for the energy management, optimization of operation strategies, and interaction with the power grid of the entire energy storage system, ensuring that the system achieves optimal performance in terms of economy and technology. The first battery management unit 2032 focuses on battery pack-level management, including battery monitoring, state estimation, equalization management, and fault protection, to ensure the safe, reliable, and long-life operation of the battery pack.

[0031] Specifically, in some embodiments of this application, the system management unit 2031 is configured to interact with the AC power grid 10 and respond to the needs of the AC power grid 10, adjusting the charging and discharging strategy based on the battery status data reported by the first battery management unit 2032 and the battery status data uploaded from the outdoor cabinet.

[0032] For example, the system management unit 2031 is responsible for real-time interaction with the AC power grid 10 to ensure that the energy storage system can meet the grid's needs, such as frequency regulation, load balancing, and peak shaving. Based on grid demand and electricity price signals, the system management unit 2031 intelligently adjusts the charging and discharging strategy of the energy storage system to optimize economic efficiency and grid support. The system management unit 2031 analyzes and processes the battery status data reported by the first battery management unit 2032 (BMS master controller) and the battery status information collected from each outdoor cabinet. Based on the analysis results, the system management unit 2031 dynamically adjusts the charging and discharging strategy of the energy storage system to ensure that the batteries operate safely and efficiently. The system management unit 2031 can also continuously optimize the overall performance of the energy storage system, improve energy utilization efficiency, extend battery life, and reduce operating costs.

[0033] Specifically, in some embodiments of this application, the first battery management unit 2032 is configured to collect battery status data from the main outdoor cabinet 20 and report the collected battery status data to the system management unit 2031. For example, specifically, the first battery management unit 2032 is responsible for collecting key status data of the battery pack in the main outdoor cabinet 20 in real time, including battery voltage, current, temperature, and state of charge (SOC). Then, the first battery management unit 2032 analyzes the collected data in real time, assesses the health status of the battery, and identifies any abnormalities, such as overheating, overcharging, or over-discharging. Next, the first battery management unit 2032 reports the analyzed battery status data to the system management unit 2031, and the system management unit receives and executes instructions issued by the system management unit 2031, such as adjusting the charge and discharge rate or performing battery balancing.

[0034] Specifically, in some embodiments of this application, the outdoor cabinet 30 includes a second battery management unit 301 and a second converter module 302; wherein, the second battery management unit 301 is connected to the switch 2033, and the second converter module 302 is connected to the first busbar 201.

[0035] The second battery management unit 201 is also the main controller of the BMS. It is configured to monitor the status of the battery pack inside the outdoor cabinet 30 in real time, including voltage, current, temperature, and state of charge (SOC); perform battery balancing operations to ensure that the voltage and SOC of each battery cell in the battery pack are consistent, avoiding overcharging or over-discharging, thereby extending battery life; monitor the battery pack to identify any abnormal conditions, such as overheating, overvoltage, undervoltage, or short circuit, and perform fault diagnosis; send the collected battery status data to the system management unit 2031 or other monitoring systems through the switch 2033; and receive control commands from the system management unit 2031, such as adjusting the charging and discharging strategy, and execute the corresponding operations.

[0036] The second converter module 302 can convert AC power to DC power to charge the battery pack. When the grid electricity price is high or the grid needs additional power support, the DC power from the battery pack in the outdoor cabinet is converted to AC power through the second converter module 302.

[0037] Specifically, in some embodiments of this application, please refer to FIG3, the outdoor cabinet 30 may further include a second busbar 303, and the second converter module 302 is connected to the first busbar 201 through the second busbar 303.

[0038] The second busbar 303 refers to a set of conductive busbars or busbars configured to distribute and transmit electrical energy among different components within the outdoor cabinet. The second busbar 303 functions similarly to the first busbar 201 in the main outdoor cabinet 20, but is specifically designed for power management within the outdoor cabinet 30. Specifically, the second busbar 303 is responsible for distributing the electrical energy generated by the second converter module 302 within the outdoor cabinet 30 to where it is needed, such as battery packs or other system components. Furthermore, the second busbar 303 is also configured to collect electrical energy generated from different sources within the outdoor cabinet 30, such as battery discharge, and then transmit it to the second converter module 302. The second busbar 303 also serves as a standardized connection interface, allowing electrical energy to be transmitted from the second converter module 302 to the first busbar 201, enabling power exchange with the main outdoor cabinet 20. Through the second busbar 303, the outdoor cabinet 30 can work collaboratively with other parts of the energy storage system to meet the needs of the power grid.

[0039] Specifically, in some embodiments of this application, please refer to Figure 2 or Figure 3, the side of the second converter module 302 closest to the main outdoor cabinet 20 is connected to the first converter module 202, the other side of the second converter module 302 closest to the main outdoor cabinet 20 is connected to the adjacent second converter module 302, and the remaining second converter modules 302 are respectively connected to the adjacent second converter modules 302.

[0040] As shown in Figure 3, the main outdoor cabinet 20 contains a first converter module 202, which is responsible for handling the interface with the AC power grid 10. The slave outdoor cabinet 30 (hereinafter referred to as slave cabinet 1), which is closest to the main outdoor cabinet 20, contains a second converter module 302. One side of the slave module 302 is connected to the first converter module 202, and the other side is connected to the second converter module 302 in the adjacent slave outdoor cabinet 30 (hereinafter referred to as slave cabinet 2). One side of the second converter module 302 of cabinet 2 is connected to the first converter module 202, and the other side of cabinet 2 is connected to the second converter module 302 in the adjacent outdoor cabinet 30 (hereinafter referred to as cabinet 3). One side of cabinet 3 is connected to the second converter module 302 of cabinet 2, and the other side of the second converter module 302 of cabinet 3 is connected to the second converter module 302 of the adjacent outdoor cabinet 30 (hereinafter referred to as cabinet 4). One side of the second converter module 302 of cabinet 4 is connected to the second converter module 302 of cabinet 3, and the other side of the second converter module 302 of cabinet 4 is not connected to other components. This configuration allows electrical energy to flow from the AC power grid 10 through the main outdoor cabinet 20, sequentially through cabinet 1, cabinet 2, cabinet 3 and cabinet 4. This design helps to realize flexible distribution and transmission of electrical energy, while ensuring the reliability and maintainability of the system.

[0041] Specifically, in some embodiments of this application, one main outdoor cabinet 20 corresponds to four secondary outdoor cabinets 30.

[0042] It should be noted that in this application, the energy storage system 1 is divided into one main outdoor cabinet 20 and multiple slave outdoor cabinets 30, enabling a modular design. This design makes the energy storage system 1 more flexible, facilitating expansion or reduction as needed. Each slave outdoor cabinet 30 can be considered an independent functional module, allowing for individual installation, maintenance, and replacement. The main outdoor cabinet 20 is responsible for the core control and management functions of the energy storage system 1, while the slave outdoor cabinets 30 provide additional energy storage capacity. If a slave outdoor cabinet 30 fails, the main outdoor cabinet 20 and other slave outdoor cabinets 30 can still continue to operate, improving the reliability and redundancy of the entire energy storage system 1.

[0043] It should also be noted that in some embodiments of this application, the main outdoor cabinet 20 and four slave outdoor cabinets 30 are used as the smallest units of the energy storage system 1. Communication lines have been planned in each smallest unit. Therefore, when multiple smallest units are connected in parallel, they can be connected in parallel simply by connecting the parallel busbars together, without the need for additional communication networking, which greatly simplifies the system networking difficulty. At the same time, each outdoor cabinet's PCS has a built-in AC switch, which can ensure that if an outdoor cabinet (main outdoor cabinet 20 or slave outdoor cabinet 30) fails to work, that outdoor cabinet will be shut down, ensuring the normal operation of the system.

[0044] Compared to the traditional solution that requires a separate combiner cabinet, this solution eliminates the need for a separate combiner cabinet, reducing system costs. Furthermore, eliminating the need for a separate combiner cabinet also saves design time.

[0045] Specifically, in some embodiments of this application, the main outdoor cabinet 20 is also connected to the communication module 40 and transmits information with the communication module 40.

Claims

1. An energy storage system, comprising: AC power grid; The main outdoor cabinet is connected to the AC power grid on one side. Multiple outdoor cabinets, each of which is connected to the other side of the main outdoor cabinet; The main outdoor cabinet is equipped with a first busbar, the AC power grid is connected to the first side of the first busbar, the main outdoor cabinet is connected to the second side of the first busbar, and each of the slave outdoor cabinets is connected to the third side of the first busbar.

2. The energy storage system according to claim 1, wherein, The main outdoor cabinet includes a first power conversion module and a management module; The first converter module is connected to the second side of the first busbar on one side, and the management module is connected to the adjacent outdoor cabinet through the other side of the first converter module.

3. The energy storage system according to claim 2, wherein, The management module includes a system management unit, a first battery management unit, and a switch; The system management unit is connected to an adjacent outdoor cabinet via the other side of the first converter module, and the other side of the system management unit is connected to the switch; the first battery management unit is connected to the switch.

4. The energy storage system according to claim 3, wherein, The system management unit is configured to interact with the AC power grid and respond to the needs of the AC power grid, adjusting the charging and discharging strategy based on the battery status data reported by the first battery management unit and the battery status data uploaded from the outdoor cabinet.

5. The energy storage system according to claim 3, wherein, The first battery management unit is configured to collect battery status data of the main outdoor cabinet and report the collected battery status data to the system management unit.

6. The energy storage system according to claim 3, wherein, The outdoor cabinet includes a second battery management unit and a second converter module; The second battery management unit is connected to the switch, and the second converter module is connected to the first busbar.

7. The energy storage system according to claim 6, wherein, The outdoor cabinet also includes a second busbar, and the second converter module is connected to the first busbar through the second busbar.

8. The energy storage system according to claim 6, wherein, The side of the second converter module closest to the main outdoor cabinet is connected to the first converter module, the other side of the second converter module closest to the main outdoor cabinet is connected to the adjacent second converter module, and the remaining second converter modules are respectively connected to the adjacent second converter modules.

9. The energy storage system according to any one of claims 1 to 8, wherein, One main outdoor cabinet corresponds to four secondary outdoor cabinets.

10. The energy storage system according to any one of claims 1 to 8, wherein the main outdoor cabinet is further connected to a communication module and transmits information with the communication module.

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