A new large-capacity 6.25MWh energy storage system

Abstract

A new type of large capacity 6.25MWh energy storage system relates to the technical field of electrochemical energy storage system equipment. By adopting 587Ah large capacity battery and 26S module structure, 32 modules are integrated in limited space, the system rated energy is up to 6.25MWh, the overall size is constrained in the international standard 20 feet container, the transportation and infrastructure problems caused by non-standard container are solved, and nano microporous heat insulation plate is used in the battery module, which can more effectively inhibit the heat spread in thermal runaway, improve the intrinsic safety level of the system, and the active balancing module is used to effectively balance the inconsistency of the battery module, improve the operation stability of the energy storage system, and prolong the service life of the energy storage system.

Description

Technical Field

[0001] This utility model relates to a novel large-capacity 6.25MWh energy storage system, and relates to the technical field of electrochemical energy storage system equipment. Background Technology

[0002] Currently, the industry mostly uses cells with a rated capacity of around 314Ah to construct megawatt-hour-level energy storage systems. To achieve the predetermined capacity, a large number of cells need to be integrated into 13-string (13S) battery modules through parallel and then series connections, and these modules are then densely arranged in a container. This traditional approach has significant drawbacks: First, the limited number of individual cells results in a large number of cells, complex electrical connections, low system volumetric energy density, and the use of non-standard sized containers to accommodate the equipment, leading to high transportation costs and complex on-site infrastructure; second, aerogel pads are often used for insulation between cells within the module, which have poor mechanical strength, are prone to pulverization, have relatively high thermal conductivity, and limited ability to prevent thermal runaway; third, the system generally uses passive balancing technology with low balancing current, which is difficult to effectively suppress the accumulation of inconsistencies between individual cells in a large-scale battery cluster, leading to accelerated capacity decay.

[0003] Therefore, there is an urgent need for a new energy storage system integration solution that features high energy density, standardized dimensions, excellent thermal safety performance, and the ability to effectively maintain consistency. Utility Model Content

[0004] The purpose of this invention is to address the deficiencies or shortcomings of existing technologies by providing a novel high-capacity 6.25MWh energy storage system. By employing 587Ah high-capacity cells and a 26S module structure, 32 modules are integrated within a limited space, achieving a rated energy of 6.25MWh. The overall size is constrained within a standard 20-foot shipping container, solving the transportation and infrastructure challenges posed by non-standard containers. Furthermore, the use of nanoporous heat insulation panels within the battery modules effectively suppresses heat propagation during thermal runaway, enhancing the system's intrinsic safety. Simultaneously, the adoption of an active balancing module effectively balances inconsistencies among the battery modules, improving the operational stability of the energy storage system and extending its service life.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: It includes a standard container body 1, a battery pack bracket 3 is installed inside the standard container body 1, thirty-two high-capacity battery modules 2 are installed on the battery pack bracket 3, eight of them are connected in series to form a battery cluster, the bottom of each battery cluster is connected to a high-voltage box 8, four battery clusters are connected in parallel to form a battery module cluster, and twenty-six 587Ah high-capacity lithium iron phosphate cells 21 are connected in series inside the battery modules 2, nanoporous heat insulation plates 22 are installed between the cells 21, an integrated combiner cabinet 4 is installed on one side of the battery module cluster, the input end of the integrated combiner cabinet 4 is connected in parallel to the output end of the four battery clusters through a copper busbar, a liquid cooling temperature control system 5 is installed at the bottom of the integrated combiner cabinet 4 and connected to the battery modules 2 through a pipeline, a fire protection system 6 is installed at the rear of the integrated combiner cabinet 4, and a battery management system 9 is also installed in the standard container body 1 and electrically connected to the battery module cluster.

[0006] Furthermore, the battery management system 9 includes a battery management unit 91, a cluster-level management unit 92, and a stack management unit 93. The battery management unit 91, the cluster-level management unit 92, and the stack management unit 93 are interconnected. The battery management unit 91 is integrated into each battery module 2, and a temperature sensor is integrated within the battery management unit 91. The cluster-level management unit 92 is located in the high-voltage box 8 and is interconnected with the battery cluster. The stack management unit 93 is located in the integrated combiner cabinet 4, and a communication interface is provided on the stack management unit 93 for linkage with the EMS energy management unit and the PCS.

[0007] Furthermore, the battery management system 9 also includes an active balancing module 94, which is composed of multiple distributed balancing sub-units 941. Each balancing sub-unit 941 is integrated in the circuit board of the battery management unit 91 and is connected in parallel with all the cells 21 in each battery module 2 through an independent channel. The output terminal of the balancing sub-unit 941 is connected to the parallel DC bus across modules. The balancing sub-unit 941 is a DC / DC converter circuit with bidirectional energy conversion function.

[0008] Furthermore, the integrated combiner cabinet 4 is also equipped with a UPS backup power supply 41 and a high-voltage power distribution unit 42. The high-voltage power distribution unit 42 consists of a contactor, a pre-charging circuit and a circuit breaker, and the logic control terminal of the high-voltage power distribution unit 42 is electrically connected to the control signal output terminal of the battery management system 9.

[0009] Furthermore, the liquid cooling temperature control system 5 includes a liquid cooling host 51, on which an inlet circulation pipe 52 and an outlet circulation pipe 53 are connected. The inlet circulation pipe 52 is vertically provided with an inlet circulation branch pipe 54 corresponding to each row of battery clusters. The inlet circulation branch pipe 54 is horizontally provided with an inlet circulation branch pipe 56 connected to the liquid inlet of each battery module 2. The outlet circulation pipe 53 is vertically provided with an outlet circulation branch pipe 55 corresponding to each row of battery clusters. The outlet circulation branch pipe 55 is arranged in parallel with the inlet circulation branch pipe 54, and the outlet circulation branch pipe 55 is horizontally provided with an outlet circulation branch pipe 57 connected to the upper liquid outlet of each battery module 2.

[0010] Furthermore, the fire protection system 6 includes a fire control panel 61. A fire cylinder 62 is connected to one side of the fire control panel 61. The outlet of the fire cylinder 62 is connected to a first fire pipe 63 and a second fire pipe 64 through a main outlet pipe. The first fire pipe 63 is positioned across the middle of the top of the four battery clusters and has a jet valve at the corresponding position of each battery cluster. The second fire pipe 64 is located on the front side of the top of the four battery clusters and is arranged parallel to the first fire pipe 63. Both the first fire pipe 63 and the second fire pipe 64 are fixed to the top of the standard container body 1 with clamps.

[0011] Furthermore, the front end of the second fire-fighting air pipe 64 is vertically arranged with an air jet branch pipe 65 corresponding to each row of battery clusters, and an air jet valve pipe 66 corresponding to each battery module 2 is arranged horizontally on the air jet branch pipe 65.

[0012] Furthermore, the fire protection system 6 also includes a sprinkler main pipe 67, which is arranged in parallel with the first fire gas pipe 63, and an electrically controlled sprinkler head is provided at the center of each battery cluster. The electrically controlled sprinkler head is electrically connected to the fire control panel 61.

[0013] Furthermore, a set of smoke detectors 68, combustible gas detectors 69, and temperature detectors 610 are installed at the front end of the second fire hydrant 64 at the position adjacent to the first and second battery clusters. Similarly, a set of smoke detectors 68, combustible gas detectors 69, and temperature detectors 610 are installed at the position adjacent to the third and fourth battery clusters on the second fire hydrant 64.

[0014] Furthermore, the integrated combiner cabinet 4 is equipped with a fan system 7 connected to the battery management system 9 on its outer side, and a liquid cooling plate 23 is provided at the bottom of the battery module 2. The liquid cooling plate 23 is connected to the liquid inlet circulation branch pipe 56 and the liquid outlet circulation branch pipe 57.

[0015] The beneficial effects of this utility model after adopting the above technical solution are as follows: By using 587Ah high-capacity cells and a 26S module structure, 32 modules are integrated in a limited space, and the rated energy of the system is as high as 6.25MWh. The overall size is constrained within an international standard 20-foot container, solving the transportation and infrastructure problems caused by non-standard containers. Furthermore, the use of nanoporous heat insulation plates in the battery modules more effectively suppresses the spread of heat during thermal runaway, improving the intrinsic safety level of the system. At the same time, the use of an active balancing module effectively balances the inconsistencies of the battery modules, improves the operational stability of the energy storage system, and extends the service life of the energy storage system. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of this utility model;

[0018] Figure 2 This is a schematic diagram of the internal structure of this utility model;

[0019] Figure 3 This is a schematic diagram of the pipeline layout of the liquid cooling temperature control system 5 in this utility model;

[0020] Figure 4 This is a schematic diagram of the pipeline layout of the fire protection system 6 in this utility model;

[0021] Figure 5 This is a schematic diagram of the internal structure of the battery module 2 in this utility model;

[0022] Figure 6 This is a structural schematic diagram of the integrated combiner cabinet in this utility model;

[0023] Figure 7 This is a schematic diagram showing the connection relationship between the battery management unit 9 and the battery module cluster in this utility model;

[0024] Figure 8 This is a schematic diagram of the rule execution process of the active balancing module in this utility model.

[0025] Explanation of reference numerals in the attached diagram: 1. Standard container body; 2. Battery module; 3. Battery pack bracket; 4. Integrated combiner cabinet; 5. Liquid cooling temperature control system; 6. Fire protection system; 7. Fan system; 8. High-voltage box; 9. Battery management system; 41. UPS backup power supply; 42. High-voltage power distribution unit; 51. Refrigeration unit; 52. Liquid inlet circulation pipe; 53. Liquid outlet circulation pipe; 54. Liquid inlet circulation branch pipe; 55. Liquid inlet circulation branch pipe; 56. Liquid outlet circulation branch pipe; 57. Fire protection main unit; 61. Fire cylinder; 62. First fire protection gas pipe; 63. Second fire protection gas pipe; 64. Jet branch pipe; 65. Jet valve pipe; 66. Sprinkler main pipe; 67. One set of smoke detectors; 68. Combustible gas detector; 69. Temperature detector; 610. Battery management unit; 91. Cluster management unit; 92. Stack management unit; 93. Active balancing module; 94. Balancing subunit; 941. Detailed Implementation

[0026] See Figures 1-8 As shown, the technical solution adopted in this specific embodiment is as follows: It includes a standard container body 1, a battery pack bracket 3 is installed inside the standard container body 1, and thirty-two high-capacity battery modules 2 are installed on the battery pack bracket 3. Eight modules are connected in series in each row to form a battery cluster. The bottom of each battery cluster is connected to a high-voltage box 8. Four battery clusters are connected in parallel to form a battery module cluster. Twenty-six 587Ah high-capacity lithium iron phosphate cells 21 are connected in series in the battery module 2. Traditional energy storage systems generally use lithium iron phosphate cells with a rated capacity of 314Ah for system integration. In order to achieve a system energy level of about 5MWh, the common integration scheme is to form a battery module (usually a 13-string structure, i.e., 13S) by connecting a large number of cells in parallel and then in series. Then, the numerous modules are placed in the container. This scheme has the following significant disadvantages:

[0027] The system suffers from low energy density and poor space utilization: Due to the limited capacity of individual cells, a huge number of cells are required to achieve the predetermined energy target, resulting in complex electrical connection structures within the battery clusters and a cramped layout within the battery compartment. A more significant problem is the severe non-standardization of container sizes designed by different manufacturers to accommodate these devices (e.g., lengths far exceeding 6 meters or heights exceeding standard container height limits). This not only increases the difficulty and cost of on-site infrastructure construction but also fails to meet the transportation requirements of standardized shipping containers (whose external dimensions are typically limited to 6058*2438*2896mm), leading to high transportation costs and complexity. Therefore, in this embodiment, a standard shipping container body with dimensions of 6058*2438*2896mm is used as the compartment. Simultaneously, 587Ah high-capacity lithium iron phosphate cells are employed, with twenty cells connected in series within each battery module. With six battery cells and a total of thirty-two battery modules, the overall battery module size has increased, and the rated capacity has been improved. At the same time, eight cells are connected in series in a row to form a battery cluster, and four battery clusters are connected in parallel to form a battery module cluster, thus forming a 6.25MWh energy storage system. Based on the above-mentioned high-voltage, high-capacity 26S modules, the total number of modules required for system container integration can be reduced. The optimized module structure is more compact, which greatly improves the layout efficiency of the entire battery system. Through precise layout design, the entire 6.25MWh energy storage system is finally integrated into a standard container with external dimensions strictly limited to 6058mm*2438mm*2896mm. This size fully complies with the international standard shipping container specifications, completely solving the problems of high transportation costs and complex infrastructure caused by non-standard containers, and realizing the standardization and convenient deployment of products.

[0028] Traditionally, aerogel pads are used as thermal insulation materials between battery cells. Although aerogel has certain thermal insulation properties, its mechanical strength is low, and it is prone to pulverization and damage under long-term vibration conditions, resulting in insufficient durability. Furthermore, its thermal conductivity (typically >0.02W / m·K) still has room for further optimization. In extreme thermal runaway scenarios, its ability to block the rapid spread of heat needs to be improved, posing a potential risk to system-level thermal safety protection. In this embodiment, a nanoporous thermal insulation plate 22 is provided between the battery cells 21. This nanoplate thermal insulation material has an extremely low thermal conductivity (typically below 0.018W / m·K), and its thermal insulation performance is far superior to that of aerogel. It can more effectively suppress the lateral spread of heat during thermal runaway, providing a longer time window and higher safety redundancy for system-level thermal runaway protection, thereby significantly improving the intrinsic safety level of the system.

[0029] An integrated combiner cabinet 4 is installed on one side of the battery module cluster. The input end of the integrated combiner cabinet 4 is connected in parallel with the output end of the four battery clusters through a copper busbar. A liquid cooling temperature control system 5 is installed at the bottom of the integrated combiner cabinet 4 and is connected to the battery module 2 through a pipeline. A fire protection system 6 is installed at the rear of the integrated combiner cabinet 4. The standard container body 1 is also equipped with a battery management system 9 which is electrically connected to the battery module cluster.

[0030] More specifically, the battery management system 9 includes a battery management unit 91, a cluster-level management unit 92, and a stack management unit 93. The battery management unit 91, cluster-level management unit 92, and stack management unit 93 are interconnected. The battery management unit 91 is integrated into each battery module 2 and includes a temperature sensor. The cluster-level management unit 92 is located in the high-voltage box 8 and is interconnected with the battery clusters. The stack management unit 93 is located in the integrated combiner cabinet 4 and has a communication interface for linkage with the EMS energy management unit and PCS. In this embodiment, the battery management system consists of multiple units, including a battery management unit distributed within the battery module for monitoring and managing the twenty-six cells in a single battery module, a cluster-level management unit for monitoring and managing each row of battery clusters, and a stack management unit for unified management of the above two units. This hierarchical battery management architecture enables more detailed overall and local control of the battery, ensuring effective management of all battery operating states.

[0031] More specifically, the battery management system 9 also includes an active balancing module 94, which consists of multiple distributed balancing sub-units 941. Each balancing sub-unit 941 is integrated into the circuit board of the battery management unit 91 and connected in parallel with all cells 21 in each battery module 2 through an independent channel. The output of the balancing sub-unit 941 is connected to the parallel DC bus across modules. The balancing sub-unit 941 is a DC / DC converter circuit with bidirectional energy conversion function. Energy storage systems are generally composed of hundreds of batteries connected in series to form a cluster. Inconsistency in the batteries can limit the system due to the capacity limitations of some individual batteries, causing a sharp drop in the overall cluster capacity, which in turn leads to a serious reduction in the effective lifespan of the battery system. Long-term operation will also greatly reduce the reliability and safety of the battery system. Therefore, balancing maintenance of the battery system is crucial. This embodiment employs a hierarchical balancing module for proactive balancing management. This proactive balancing strategy achieves battery consistency. The balancing subunit is a DC / DC converter circuit with bidirectional energy conversion capabilities. Combined with a parallel direct bus connected across modules, the drive circuit controlling the channel switches via the balancing controller within the high-voltage box enables bidirectional energy transfer between the primary and secondary windings of the isolation transformer. The DC bus serves as the energy transfer medium, enabling both individual cell balancing within the battery box and inter-cell balancing within the battery cluster. This maximizes battery pack consistency, improves charging and discharging efficiency, and extends battery life. Each balancing subunit is a balancing channel, and each channel supports managing the charging and discharging balancing of the entire module's batteries. Each balancing channel can only activate charging or discharging balancing for one battery cell at a time.

[0032] More specifically, active balancing includes the following steps: battery information acquisition → balancing rule calculation → balancing state output → balancing implementation. The battery management unit acquires battery information, the stack management unit calculates the balancing rules, and the battery management unit and the active balancing module execute the balancing rules, i.e., output the balancing state, and finally achieve balancing.

[0033] More specifically, during the execution phase of the equalization rule, based on the individual cell voltage and SOC, firstly, if the individual cell voltage is higher than the average voltage and exceeds the equalization activation threshold, discharge equalization needs to be activated; if the individual cell voltage is lower than the average voltage and exceeds the equalization activation threshold, charging equalization needs to be activated. Secondly, if the difference between the highest SOC and the average SOC of an individual cell is higher than the difference between the lowest SOC and the average SOC of an individual cell, and exceeds the SOC threshold, discharge equalization is initiated; if the difference between the lowest SOC and the average SOC of an individual cell is higher than the difference between the highest SOC and the average SOC of an individual cell, and exceeds the SOC threshold, charging equalization is initiated.

[0034] During execution, there is also a balancing protection strategy. When the following balancing alarm (i.e., balancing stop condition) is output, balancing will not be performed:

[0035] Abnormal data acquisition wiring;

[0036] Average temperature over-limit protection, with upper and lower alarm limits set (judged by the set values);

[0037] Individual cell voltage alarm (default range: ≤ lower warning value and ≥ upper warning value);

[0038] State equalization charging cannot be activated (enabled by default);

[0039] Discharge state equalization cannot be started (it is enabled by default);

[0040] Balancing timing: After the balancing conditions are met, balancing starts for 60 seconds and stops for 10 seconds (default value).

[0041] More specifically, the integrated combiner cabinet 4 is also equipped with a UPS backup power supply 41 and a high-voltage power distribution unit 42. The UPS backup power supply provides temporary power to the system in case of an accident, preventing system failure caused by sudden power outage. The high-voltage power distribution unit 42 consists of a contactor, a pre-charging circuit and a circuit breaker. The logic control terminal of the high-voltage power distribution unit 42 is electrically connected to the control signal output terminal of the battery management system 9. The high-voltage power distribution unit provides a continuous power supply strategy for the battery management system.

[0042] More specifically, the liquid cooling temperature control system 5 includes a liquid cooling main unit 51, which is connected to an inlet circulation pipe 52 and an outlet circulation pipe 53. The inlet circulation pipe 52 is vertically equipped with an inlet circulation branch pipe 54 corresponding to each row of battery clusters. The inlet circulation branch pipe 54 is horizontally equipped with an inlet circulation branch pipe 56 connected to the liquid inlet of each battery module 2. The outlet circulation pipe 53 is vertically equipped with an outlet circulation branch pipe 55 corresponding to each row of battery clusters. The outlet circulation branch pipe 55 is arranged in parallel with the inlet circulation branch pipe 54, and the outlet circulation branch pipe 55 is horizontally equipped with an outlet circulation branch pipe 57 connected to the upper outlet of each battery module 2. The liquid cooling temperature control system provides liquid cooling temperature control for the energy storage system and realizes individual control of each battery module.

[0043] More specifically, the fire protection system 6 comprises a fire protection main unit 61, one side of the fire protection main unit 61 is connected with a fire gas cylinder 62, the gas outlet end of the fire gas cylinder 62 is connected with a first fire gas pipe 63 and a second fire gas pipe 64 through a main gas outlet pipe, the first fire gas pipe 63 is arranged across the middle position of the tops of four groups of battery clusters, and gas injection valves are arranged at positions corresponding to each group of battery clusters, the second fire gas pipe 64 is located at the front side of the tops of the four groups of battery clusters and arranged in parallel with the first fire gas pipe 63, both the first fire gas pipe 63 and the second fire gas pipe 64 are fixed to the top of the standard container body 1 by clamps, the arrangement of different fire pipelines corresponds to different positions of battery modules, which can realize effective thermal runaway control, the front end of the second fire gas pipe 64 is vertically downward provided with gas injection branch pipes 65 corresponding to each row of battery clusters, the gas injection branch pipes 65 are transversely provided with gas injection valve pipes 66 corresponding to each battery module 2, the fire protection system 6 further comprises a main spray pipe 67, the main spray pipe 67 is arranged in parallel with the first fire gas pipe 63, and an electric control spray head is arranged corresponding to the center position of each row of battery clusters, the electric control spray head is electrically connected with the fire protection main unit 61, a group of smoke detectors 68, combustible gas detectors 69 and temperature detectors 610 are arranged at the adjacent position of the first row of battery clusters and the second row of battery clusters corresponding to the front end of the second fire gas pipe 64, a group of smoke detectors 68, combustible gas detectors 69 and temperature detectors 610 are also arranged at the adjacent position of the third row of battery clusters and the fourth row of battery clusters corresponding to the second fire gas pipe 64, the arrangement of multiple detectors at two positions comprehensively realizes effective monitoring and alarming for various thermal runaway conditions. In this embodiment, a multi-level fire alarm emergency architecture is adopted, which is embodied as water spray and gas fire extinguishing, and has triple detection measures, namely triple detection of smoke, combustible gas and temperature, and meanwhile, combined with temperature sensors in battery modules to implement linked thermal runaway management, a manual fire alarm button is also arranged on the fire protection main unit, and multi-level linked thermal runaway management is realized under the cooperation of multiple detections, so as to ensure the normal operation of the system.

[0044] More specifically, the outer side of the integrated confluence cabinet 4 is provided with a fan system 7 connected with a battery management system 9, when abnormal temperature in the compartment is detected, air circulation inside and outside the compartment is provided by controlling the fan system, which cooperates with liquid cooling temperature control to initially dispose of abnormal temperature, and can also quickly discharge internal smoke when thermal runaway occurs. A liquid cooling plate 23 is arranged at the bottom of the battery module 2, the liquid cooling plate 23 is connected with a liquid inlet circulation branch pipe 56 and a liquid outlet circulation branch pipe 57, and the internal temperature control of the battery module is realized through the circulation of cooling liquid in the liquid cooling plate.

[0045] The working principle of this utility model is as follows: The standard container body 1 has dimensions of 6058*2438*2896mm, which fully conforms to the international standard shipping container specifications. The battery module 2 consists of twenty-six 166.4V / 587Ah high-capacity lithium iron phosphate cells 21 connected in series. Every eight battery modules 2 are connected in series to form a battery cluster, and four battery clusters are connected in parallel to form a battery module cluster, thereby obtaining a large-capacity energy storage system with a rated energy of 6.25MWh. This battery cluster design effectively utilizes the space of the standard container body 1, facilitating product standardization and convenient deployment. By setting nanoporous heat insulation plates 22 between the cells 21, better heat insulation effect can be obtained, which can more effectively suppress thermal runaway. The horizontal spread of energy provides a longer time window and higher safety redundancy for system-level thermal runaway protection, thereby significantly improving the inherent safety level of the system. Furthermore, to improve the economic efficiency throughout the system's lifecycle, an active balancing strategy is adopted. This involves setting up an active balancing module 94 within the battery management system 9, composed of multiple distributed balancing sub-units 941. This enables efficient energy transfer between cells within the cluster and module. The balancing strategy process is as follows: battery information acquisition → balancing rule calculation → balancing state output → balancing implementation. Information acquisition and rule calculation are achieved through the individual management of each battery module 2 by the battery management unit 91. Active balancing is real-time balancing, determined based on individual cell voltage and SOC. First, if the individual cell voltage... If the voltage of a single cell exceeds the average voltage and the equalization activation threshold, discharge equalization needs to be activated. If the voltage of a single cell is lower than the average voltage and the equalization activation threshold, charging equalization needs to be activated. Secondly, if the difference between the highest SOC and the average SOC of a single cell is higher than the difference between the lowest SOC and the average SOC, and exceeds the SOC threshold, discharge equalization is activated. If the difference between the lowest SOC and the average SOC of a single cell is higher than the difference between the highest SOC and the average SOC, and exceeds the SOC threshold, charging equalization is activated. Each equalization channel supports managing the charging and discharging equalization of the entire module's batteries. Each equalization channel can only activate charging or discharging equalization for one battery cell at a time. By adopting an active equalization strategy, the impact of individual battery cells due to manufacturing processes and other factors can be reduced. This prevents overcharging or over-discharging of batteries with smaller capacities and lower performance, thus reducing the overall rate of capacity degradation and extending battery life. For thermal runaway management of the energy storage system, liquid cooling temperature control and multi-level fire monitoring are employed, integrated with the battery management system 9. Each battery module 2 is equipped with a temperature sensor that collects real-time temperature information and feeds it back to the battery management system 9, the liquid cooling temperature control system 5, and the fire suppression system 6. When an anomaly occurs, corresponding control commands are sent based on the abnormal value to accelerate liquid cooling circulation or to extinguish fires using spray or jet fire suppression. Furthermore, during thermal runaway control, the output and input of the corresponding battery module 2 must be cut off to ensure the safety of the energy storage system.

[0046] The above description is only used to illustrate the technical solution of this utility model and is not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solution of this utility model, as long as they do not depart from the spirit and scope of the technical solution of this utility model, should be covered within the scope of the claims of this utility model.

Claims

1. A novel large-capacity 6.25MWh energy storage system, characterized in that: It includes a standard container body (1), inside which a battery pack bracket (3) is installed. Thirty-two high-capacity battery modules (2) are installed on the battery pack bracket (3). Eight modules are connected in series in each row to form a battery cluster. The bottom of each battery cluster is connected to a high-voltage box (8). Four battery clusters are connected in parallel to form a battery module cluster. Twenty-six (587) Ah high-capacity lithium iron phosphate cells (21) are connected in series in the battery module (2). The cells (21) are spaced apart. The battery module cluster is equipped with a nanoporous heat insulation plate (22). An integrated combiner cabinet (4) is installed on one side of the battery module cluster. The input end of the integrated combiner cabinet (4) is connected in parallel with the output end of the four battery clusters through a copper busbar. A liquid cooling temperature control system (5) is installed at the bottom of the integrated combiner cabinet (4) and is connected to the battery module (2) through a pipeline. A fire protection system (6) is installed at the rear of the integrated combiner cabinet (4). The standard container body (1) is also equipped with a battery management system (9) which is electrically connected to the battery module cluster.

2. The novel large-capacity 6.25MWh energy storage system according to claim 1, characterized in that: The battery management system (9) includes a battery management unit (91), a cluster management unit (92), and a stack management unit (93). The battery management unit (91), the cluster management unit (92), and the stack management unit (93) are connected in communication. The battery management unit (91) is integrated into each battery module (2), and a temperature sensor is integrated in the battery management unit (91). The cluster management unit (92) is located in the high-voltage box (8) and is connected in communication with the battery cluster. The stack management unit (93) is located in the integrated combiner cabinet (4), and a communication interface is provided on the stack management unit (93) to link with the EMS energy management unit and the PCS.

3. The novel large-capacity 6.25MWh energy storage system according to claim 1, characterized in that: The battery management system (9) further includes an active balancing module (94), which consists of multiple distributed balancing sub-units (941). Each balancing sub-unit (941) is integrated in the circuit board of the battery management unit (91) and connected in parallel with all the cells (21) in each battery module (2) through an independent channel. The output of the balancing sub-unit (941) is connected to the parallel DC bus across the modules. The balancing sub-unit (941) is a DC / DC converter circuit with bidirectional energy conversion function.

4. The novel large-capacity 6.25MWh energy storage system according to claim 1, characterized in that: The integrated combiner cabinet (4) is also equipped with a UPS backup power supply (41) and a high-voltage power distribution unit (42). The high-voltage power distribution unit (42) consists of a contactor, a pre-charging circuit and a circuit breaker. The logic control terminal of the high-voltage power distribution unit (42) is electrically connected to the control signal output terminal of the battery management system (9).

5. A novel large-capacity 6.25MWh energy storage system according to claim 1, characterized in that: The liquid cooling temperature control system (5) includes a liquid cooling host (51), which is connected to an inlet circulation pipe (52) and an outlet circulation pipe (53). The inlet circulation pipe (52) is vertically provided with an inlet circulation branch pipe (54) corresponding to each row of battery clusters. The inlet circulation branch pipe (54) is horizontally provided with an inlet circulation branch pipe (56) connected to the inlet of each battery module (2). The outlet circulation pipe (53) is vertically provided with an outlet circulation branch pipe (55) corresponding to each row of battery clusters. The outlet circulation branch pipe (55) is arranged in parallel with the inlet circulation branch pipe (54), and the outlet circulation branch pipe (55) is horizontally provided with an outlet circulation branch pipe (57) connected to the upper outlet of each battery module (2).

6. A novel large-capacity 6.25MWh energy storage system according to claim 1, characterized in that: The fire protection system (6) includes a fire control unit (61). A fire cylinder (62) is connected to one side of the fire control unit (61). The outlet of the fire cylinder (62) is connected to a first fire pipe (63) and a second fire pipe (64) through a main outlet pipe. The first fire pipe (63) is set across the middle of the top of the four battery clusters and a jet valve is set at the corresponding position of each battery cluster. The second fire pipe (64) is located on the front side of the top of the four battery clusters and is arranged parallel to the first fire pipe (63). The first fire pipe (63) and the second fire pipe (64) are both fixed to the top of the standard container body (1) by clamps.

7. A novel large-capacity 6.25MWh energy storage system according to claim 6, characterized in that: The second fire hydrant (64) has a vertically downward-facing jet pipe (65) corresponding to each battery cluster, and a jet valve pipe (66) corresponding to each battery module (2) is horizontally arranged on the jet pipe (65).

8. A novel large-capacity 6.25MWh energy storage system according to claim 1, characterized in that: The fire protection system (6) also includes a sprinkler main pipe (67), which is arranged in parallel with the first fire gas pipe (63), and an electrically controlled sprinkler head is provided at the center of each battery cluster. The electrically controlled sprinkler head is electrically connected to the fire control panel (61).

9. A novel large-capacity 6.25MWh energy storage system according to claim 6, characterized in that: A set of smoke detectors (68), combustible gas detectors (69), and temperature detectors (610) is installed at the front end of the second fire hydrant (64) at the position adjacent to the first and second battery clusters. Similarly, a set of smoke detectors (68), combustible gas detectors (69), and temperature detectors (610) is installed at the position adjacent to the third and fourth battery clusters of the second fire hydrant (64).

10. A novel large-capacity 6.25MWh energy storage system according to claim 1, characterized in that: The integrated combiner cabinet (4) is equipped with a fan system (7) connected to the battery management system (9) on the outside. The battery module (2) is equipped with a liquid cooling plate (23) at the bottom, and the liquid cooling plate (23) is connected to the liquid inlet circulation branch pipe (56) and the liquid outlet circulation branch pipe (57).

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