Energy storage system

Abstract

The utility model relates to the technical field of energy storage, and discloses an energy storage system, which comprises a high-voltage box, a power grid side protection circuit, a plurality of battery clusters and a plurality of groups of DC / DC conversion modules, the high-voltage box comprises a box body, a main control module and a plurality of mutually independent electric circuits, the plurality of electric circuits and the main control module are arranged in the box body, the box body is provided with a main control panel, the main control panel is provided with a first wiring terminal and a second wiring terminal, and one end, penetrating out of the box body, of the first wiring terminal is connected with the corresponding battery cluster; and each group of DC / DC conversion module comprises a plurality of bidirectional DC / DC converters which are arranged in parallel, the input sides of the plurality of bidirectional DC / DC converters are jointly connected to a power grid side protection circuit, and the output sides of the plurality of bidirectional DC / DC converters are jointly converged and then connected to one end, penetrating out of the box body, of the second wiring terminal. The high-voltage box can be connected with a plurality of battery clusters, so that the internal installation space can be saved, the installation cost is reduced, and meanwhile, wiring in the energy storage container is facilitated.

Description

Technical Field

[0001] This utility model relates to the field of energy storage technology, and in particular to an energy storage system. Background Technology

[0002] In an energy storage system, a battery pack consists of several cells connected in series. Several battery packs connected in series form a battery cluster, which is then electrically connected to a high-voltage box. The main functions of the battery cluster are energy storage and power supply, while the main function of the high-voltage box is to connect or disconnect the main electrical circuit of the system to ensure the transmission of power to the system, and to monitor insulation faults, open circuits, grounding faults, and high-voltage faults in the entire high-voltage system in real time.

[0003] In existing technologies, such as Chinese invention patent application publication number CN117856306A, a storage system and its control method are disclosed. Specifically, the storage system includes multiple battery cluster circuits connected in parallel to a main circuit, which is then connected to an energy storage converter to power the converter. Through a hierarchical control architecture of cluster controllers and main controllers, the system monitors multi-dimensional characteristic parameters of the battery clusters and system parameters of the battery management system, achieving circuit break protection under abnormal battery cluster conditions. However, the high-voltage control and protection functions of this storage system are mostly integrated into the main circuit or the energy storage transformer. There is no independent high-voltage connection to each battery's high-voltage branch for centralized and modular piping. The high-voltage power circuits of each battery cluster are dispersed, leading to significant difficulties in system installation, commissioning, and subsequent maintenance. Furthermore, it lacks independent pre-charge control and fault isolation capabilities for the high-voltage branch corresponding to each battery cluster. If a single battery cluster circuit fails, it can easily affect the entire high-voltage system of the main circuit. Utility Model Content

[0004] In order to solve the above-mentioned technical problems, or at least partially solve the above-mentioned technical problems, this application provides an energy storage system, which aims to solve the problems of dispersed high-voltage branches of energy storage and lack of independent pre-charging and fault isolation capabilities in the prior art.

[0005] This application provides an energy storage system, including a high-voltage box, a grid-side protection circuit, multiple battery clusters, and multiple sets of DC / DC conversion modules, wherein the multiple battery clusters are configured in a one-to-one correspondence with the multiple sets of DC / DC conversion modules.

[0006] The high-voltage box includes a box body, a main control module, and multiple independent power circuits. The multiple power circuits and the main control module are all located inside the box body. The box body has a main control panel, on which a first terminal and a second terminal are installed. One end of the first terminal protruding outside the box body is connected to the corresponding battery cluster.

[0007] Each set of DC / DC conversion modules includes multiple bidirectional DC / DC converters arranged in parallel. The input sides of the multiple bidirectional DC / DC converters are connected to the grid-side protection circuit, and the output sides converge and are connected to one end of the second terminal that extends out of the enclosure.

[0008] Each of the electrical circuits includes a first circuit breaker, a circuit relay, a pre-charge module, and a protective component connected in series. The first circuit breaker is connected to one end of the second terminal block located inside the housing. The protective component is connected to the corresponding end of the first terminal block located inside the housing. The main control module is electrically connected to the pre-charge module and the circuit relay of each electrical circuit and is used to independently control the on / off state and pre-charge process of each electrical circuit.

[0009] In one possible implementation, the precharge module includes a first precharge relay, a second precharge relay, a first precharge resistor, and a second precharge resistor. One end of the first precharge relay is connected to the circuit relay, and the other end is connected to one end of the first precharge resistor. The other end of the first precharge resistor is connected to one end of the second precharge resistor, and the other end of the second precharge resistor is connected to the protective component. The second precharge relay is connected in parallel across the two ends of the first precharge resistor, and the resistance of the first precharge resistor is much greater than the resistance of the second precharge resistor.

[0010] In one possible implementation, the precharge module further includes a diode, the anode of which is connected to the circuit relay, and the cathode of which is connected to the protective element.

[0011] In one possible implementation, the system further includes a data acquisition module and a temperature sensor. The data acquisition module is located inside the enclosure and is used to acquire the voltage and current of each of the electrical circuits and transmit the acquired information to the main control module. The temperature sensor is fixed to the inner wall of the enclosure and is electrically connected to the main control module.

[0012] In one possible implementation, the circuit breaker opening and closing handle is also included. The circuit breaker opening and closing handle includes a handle portion and a docking portion. The handle portion is rotatably mounted on the main control panel. One end of the docking portion is connected to the handle portion, and the other end is connected to the first circuit breaker.

[0013] In one possible implementation, the main control panel is equipped with communication terminals and power terminals. The communication terminals are used for external devices to communicate with the main control module, and the power terminals are used for external power supplies to electrically connect to the main control module.

[0014] In one possible implementation, the grid-side protection circuit includes a second circuit breaker and a first fuse. One end of the second circuit breaker is connected to the incoming terminal of the grid side, and the other end of the second circuit breaker is connected to one end of the first fuse. The other end of the first fuse is connected to the DC / DC converter module.

[0015] In one possible implementation, the energy storage system further includes a bidirectional power conversion module, which includes at least two power conversion branches connected in parallel. Each power conversion branch includes a bidirectional AC / DC converter, a current transformer, a second fuse, and a conversion relay connected in series. The input terminals of each bidirectional AC / DC converter are connected to the incoming terminal on the grid side, and the output terminals of each conversion relay are connected to one end of the second circuit breaker.

[0016] In one possible implementation, the bidirectional power conversion module further includes a third pre-charge relay and a third pre-charge resistor, the third pre-charge relay and the third pre-charge resistor being connected in series to form a pre-charge circuit, and the pre-charge circuit being connected in parallel with the conversion relay.

[0017] In one possible implementation, the energy storage system further includes a main circuit breaker located between the bidirectional power conversion module and the incoming terminal of the grid side. One end of the main circuit breaker is electrically connected to the incoming terminal of the grid side, and the other end is electrically connected to the common input terminal of each of the bidirectional AC / DC converters.

[0018] The technical solutions provided in this application have the following advantages compared with the prior art:

[0019] First, by setting up multiple independent power circuits, each corresponding to a battery cluster circuit, integrating on / off control, pre-charging, and protection functions, and with the main control module capable of independently controlling the on / off and pre-charging of each power circuit, a fault in a single battery cluster or its corresponding power circuit can be isolated, achieving precise fault isolation and preventing a single-circuit fault from affecting the high-voltage side operation of the entire energy storage system, significantly improving the fault tolerance and stability of the energy storage system. Second, integrating all independent power circuits into a single high-voltage box eliminates the need for a separate high-voltage control box for each battery cluster. This reduces additional box processing and installation costs, simplifies the complexity of on-site wiring for the energy storage system, lowers the probability of faults caused by incorrect wiring, and facilitates centralized inspection and routine maintenance of the entire energy storage unit by operation and maintenance personnel. In addition, multiple battery clusters are set up one-to-one with multiple DC / DC conversion modules, and each DC / DC conversion module contains multiple bidirectional DC / DC converters connected in parallel. The output voltage and power of each battery cluster can be independently and precisely adjusted, which can effectively avoid inter-cluster circulating current and charging and discharging imbalance caused by differences in battery cluster performance and state of charge. This helps to extend the service life of the battery clusters and thus improve the overall charging and discharging efficiency of the energy storage system. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the circuit structure of an embodiment of the energy storage system of this application;

[0021] Figure 2 This is a schematic diagram of the internal circuit structure of the high-voltage box in the energy storage system of this application;

[0022] Figure 3 This is a schematic diagram of the circuit structure of the pre-charge module in the energy storage system of this application;

[0023] Figure 4 This is a schematic diagram of the high-voltage box in the energy storage system of this application;

[0024] Figure 5 This is a structural schematic diagram of the heavy high-voltage box and main control panel of the energy storage system of this application;

[0025] Figure 6 This is a schematic diagram of the circuit breaker opening and closing handle of the energy storage system in this application;

[0026] Figure 7 This is a schematic diagram of the handle structure of the high-voltage box in the energy storage system of this application;

[0027] Figure 8 This is a schematic diagram of the circuit structure of the bidirectional power conversion module in the energy storage system of this application.

[0028] Icon labels:

[0029] 10. Battery cluster; 20. High-voltage box; 21. Box body; 21a. Main control panel; 22. Main control module; 23. Power circuit; 24. Data acquisition module; 25. First terminal block; 26. Second terminal block; 27. Circuit breaker handle; 271. Handle; 272. Connecting part; 28. Communication terminal; 29. ​​Power terminal; 210. Handle; 210a. Groove; 211. Pressure relief valve; 212. Connecting post; 212a. Extension; 212b. Connecting part; 30. DC / DC converter module; 40. Grid side protection circuit; 50. Bidirectional power conversion module. Detailed Implementation

[0030] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by terms such as "front," "rear," "upper," "lower," "left," "right," "longitudinal," "horizontal," "vertical," "horizontal," "top," "bottom," "inner," "outer," "head," and "tail" are based on the orientations or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific orientation. They are only for the convenience of describing this technical solution and do not indicate that the device or component referred to must have a specific orientation; therefore, they should not be construed as limitations on this utility model.

[0031] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "joining," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. When an component is referred to as being "on" or "below" another component, the component can be located "directly" or "indirectly" on the other component, or there may be one or more intermediary components. The terms "first," "second," "third," etc., are only for the convenience of describing this technical solution and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0032] In the following description, specific details such as particular system structures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the present invention. However, those skilled in the art will understand that the present invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

[0033] Figure 1 This is a schematic diagram of the circuit structure of an embodiment of the energy storage system of this application; Figure 2 This is a schematic diagram of the internal circuit structure of the high-voltage box in the energy storage system of this application.

[0034] like Figure 1 As shown, this embodiment provides an energy storage system, which includes a high-voltage box 20, a grid-side protection circuit 40, multiple battery clusters 10, and multiple sets of DC / DC conversion modules 30, with each battery cluster 10 and each set of DC / DC conversion modules 30 corresponding to one another.

[0035] Specifically, such as Figure 2 As shown, the high-voltage box 20 includes a box body 21, a main control module 22, and multiple independent power circuits 23. All power circuits 23 and the main control module 22 are housed within the box body 21. The box body 21 has a main control panel 21a, on which a first terminal block 25 and a second terminal block 26 are mounted. One end of the first terminal block 25 protruding outside the box body 21 is connected to a corresponding battery cluster 10, and the other end of the second terminal block 26 protruding outside the box body 21 is connected to a corresponding DC / DC converter module 30. Each battery cluster 10 includes multiple battery packs, which are connected in series to form a battery cluster 10. In other words, by setting multiple independent power circuits 23 within the box body 21 of the same high-voltage box 20, and by setting the first terminal block 25 and the second terminal block 26 on the main control panel 21a of the box body 21, the first terminal block 25 is connected to a corresponding battery cluster 10, and the second terminal block 26 is connected to a corresponding DC / DC converter module 30. In this way, a single high-voltage box 20 can be used to connect to multiple battery clusters 10. Compared with the existing one-to-one connection mode between the high-voltage box 20 and the battery cluster 10, this can save internal installation space, reduce installation costs, and also reduce the number of connecting cables between the battery cluster 10 and the high-voltage box 20, which is beneficial for the wiring inside the energy storage container.

[0036] For example, the main control module 22 is connected to each power circuit 23. In this way, when a battery cluster 10 or its corresponding DC / DC converter module 30 fails, the main control module 22 can quickly locate the faulty circuit and disconnect that power circuit 23 without affecting the operation of other normal battery clusters 10, greatly improving the reliability and fault tolerance of the entire energy storage system. At the same time, the centralized main control panel 21a makes wiring operations more convenient and standardized. Staff do not need to disassemble the enclosure 21 to check the wiring one by one; they can quickly connect the battery cluster 10, DC / DC converter module 30, and high-voltage box 20 simply through the terminals on the main control panel 21a, significantly reducing the difficulty of on-site installation and subsequent maintenance.

[0037] Furthermore, the corresponding number of DC / DC conversion modules 30 and battery clusters 10 is configured so that when a group of DC / DC conversion modules 30 fails during actual redundant operation, it can be isolated from the system to maintain normal system operation, avoid the entire system from shutting down due to a single module failure, and greatly improve the power supply capability and operational stability of the energy storage system.

[0038] Furthermore, such as Figure 1 As shown, each DC / DC conversion module 30 includes multiple bidirectional DC / DC converters connected in parallel. The input sides of these multiple bidirectional DC / DC converters are connected to the grid-side protection circuit 40, and their output sides converge and connect to the end of the second terminal 26 that extends outside the enclosure 21. Thus, when a single bidirectional DC / DC converter fails, the remaining normal converters can continue to perform the power conversion task, preventing the entire DC / DC conversion module 30 from failing due to a single converter failure. This further refines the fault isolation hierarchy and allows for more precise implementation of the energy storage system's redundancy capability. Simultaneously, the parallel connection of multiple converters allows for flexible adjustment of output power. When the power load fluctuates, the corresponding number of converters can be activated according to actual needs, ensuring that the output power matches the load requirements while reducing unnecessary energy loss and improving the system's operational economy.

[0039] In addition, the grid-side protection circuit 40 provides comprehensive protection for the input circuit of the bidirectional DC / DC converter, preventing excessive current surges from damaging the bidirectional DC / DC converter. Since the input terminals of multiple bidirectional DC / DC converters are connected to the input side of the grid-side protection circuit 40, multiple converters can share a single overcurrent and overvoltage protection mechanism. This simplifies the internal circuit structure of the module and ensures that all converters can trigger protection actions synchronously when abnormal fluctuations occur in the power grid, avoiding cascading failures caused by untimely protection of individual converters.

[0040] In summary, the energy storage system of this application embodiment, firstly, by setting up multiple independent power circuits 23, each power circuit 23 corresponding to a battery cluster 10 circuit, integrates on / off control, pre-charging, and protection functions. Furthermore, the main control module 22 can independently control the on / off and pre-charging of each power circuit 23. Thus, when a single battery cluster 10 or its corresponding power circuit 23 fails, that power circuit 23 can be isolated independently, achieving precise fault isolation and preventing a single-circuit fault from affecting the high-voltage side operation of the entire energy storage system, significantly improving the fault tolerance and stability of the energy storage system. Secondly, by integrating all independent power circuits 23 into the same high-voltage box 20, it is not necessary to configure a separate high-voltage box 20 for each battery cluster 10. This reduces additional box processing and installation costs, simplifies the complexity of on-site wiring for the energy storage system, reduces the probability of faults caused by incorrect wiring, and makes it easier for maintenance personnel to conduct centralized inspection and daily maintenance of the entire energy storage unit. In addition, multiple battery clusters 10 are configured one-to-one with multiple sets of DC / DC conversion modules 30, and each set of DC / DC conversion modules 30 includes multiple bidirectional DC / DC converters connected in parallel, which can independently and precisely adjust the output voltage and power of each battery cluster. This effectively avoids problems such as inter-cluster circulating current and unbalanced charging and discharging caused by differences in battery cluster performance and state of charge, which helps to extend the service life of the battery clusters and thus improve the overall charging and discharging efficiency of the energy storage system.

[0041] In one specific implementation, such as Figure 2 As shown, each electrical circuit 23 includes a first circuit breaker, a circuit relay, a pre-charge module, and a protective component connected in series. The first circuit breaker is connected to one end of the second terminal 26 located inside the housing 21, and the protective component is connected to one end of the corresponding first terminal 25 located inside the housing 21. The main control module 22 is electrically connected to the pre-charge module and circuit relay of each electrical circuit 23 and is used to independently control the on / off state and pre-charge process of each electrical circuit 23.

[0042] During the initial power-up phase, the main control module 22 regulates the pre-charge module, which begins pre-charging the capacitors in the power circuit 23 to prevent excessive current surges during direct power-up and protect the circuit components from damage. Furthermore, during pre-charging, the main control module 22 monitors the pre-charge module's operating status and voltage changes in real time. When the voltage reaches a preset value, the main control module 22 determines that pre-charging is complete. Subsequently, the control circuit relay closes, short-circuiting the pre-charge module, and the power circuit 23 enters normal operation. At this point, the high-voltage box begins to stably supply power to external loads or perform energy storage operations.

[0043] During operation, if an abnormal increase in current occurs, the protective device can quickly disconnect the power circuit to prevent equipment damage or even fire caused by overload or short circuit. Simultaneously, a first circuit breaker is installed on power circuit 23 to automatically trip and disconnect the circuit upon detecting overcurrent, short circuit, or undervoltage faults. After the fault is cleared, the circuit can be manually or automatically re-closed to restore normal operation. This creates a dual protection system where the protective device and the first circuit breaker work together to prevent the circuit from failing to be disconnected in time due to a fault in either one, providing comprehensive circuit protection for the energy storage high-voltage box.

[0044] Figure 3 This is a schematic diagram of the circuit structure of the pre-charge module in the energy storage system of this application.

[0045] Specifically, such as Figure 3 As shown, the precharge module includes a first precharge relay, a second precharge relay, a first precharge resistor, and a second precharge resistor. One end of the first precharge relay is connected to a circuit relay, and the other end is connected to one end of the first precharge resistor. The other end of the first precharge resistor is connected to one end of the second precharge resistor. The other end of the second precharge resistor is connected to a protective component. The second precharge relay is connected in parallel across the two ends of the first precharge resistor, and the resistance of the first precharge resistor is much greater than the resistance of the second precharge resistor.

[0046] When charging battery cluster 10, the pre-charge module starts working. In the initial pre-charge stage, there is a significant difference between the voltage of battery cluster 10 and the output voltage of DC / DC converter module 30. At this time, the first pre-charge relay is closed, while the second pre-charge relay and the circuit relay remain open. Current flows sequentially through the first pre-charge relay, the first pre-charge resistor, and the second pre-charge resistor to battery cluster 10. Because the resistance value of the first pre-charge resistor is much larger than that of the second pre-charge resistor, the current is significantly limited, charging battery cluster 10 with a small current to avoid damage from a large current surge. As charging progresses, the voltage of battery cluster 10 gradually increases, and when it reaches the output voltage of the DC / DC converter... After the voltage difference on the output side of the switching module 30 decreases to a certain extent, the second pre-charge relay closes. At this time, the first pre-charge resistor is short-circuited, and the current no longer flows through the first pre-charge resistor, but flows through the first pre-charge relay, the second pre-charge relay, and the second pre-charge resistor to the battery cluster 10 to continue pre-charging with a moderate current until the voltage on the DC / DC converter module side is basically equal to the battery cluster voltage, thus completing the pre-charge. After the pre-charge is completed, the circuit relay closes, the first pre-charge relay and the second pre-charge relay open, and the energy storage system switches from the pre-charge state to the normal operating state, realizing the normal charging and discharging of the battery cluster 10.

[0047] In other words, under the initial large voltage difference condition of pre-charging, the large resistance of the first pre-charging resistor dominates the current blocking, which can effectively prevent the current peak from exceeding the rated tolerance value of components such as battery cluster 10 and circuit relays, prevent components from burning out or degrading due to overcurrent, and improve the safety and reliability of system operation. Compared with the traditional pre-charging circuit, the pre-charging module of this embodiment switches to a small resistance circuit in the later stage of pre-charging to reduce the circuit impedance. Under the premise of ensuring current safety, it significantly improves the pre-charging speed in the later stage, shortens the overall pre-charging time, and improves the system startup efficiency.

[0048] In one possible implementation, such as Figure 3 As shown, the pre-charge module also includes a diode, with the anode of the diode connected to a circuit relay and the cathode of the diode connected to a protective component. Thus, during the pre-charge phase, when the capacitor voltage of the DC / DC converter module 30 is lower than the battery cluster 10 voltage, the diode conducts in the forward direction, and the battery current charges the capacitor through the diode and the pre-charge resistor, limiting the inrush current. During normal operation or isolation, when the capacitor voltage of the DC / DC converter module 30 is higher than the battery cluster 10 voltage, or when it is necessary to disconnect the battery cluster 10 circuit, the diode is reverse-biased and cut off. In this state, backflow of current from the DC / DC converter module side to the battery cluster 10 is prevented, thereby providing crucial protection against electrical isolation and overcharging.

[0049] In practical applications, fuses are preferred due to their advantages such as simple structure, low cost, and fast response speed. Therefore, in this embodiment, a fuse is preferred as the protective component. This way, when the current abnormally rises to a certain value, the fuse can melt and break the circuit, effectively preventing damage to internal components of the high-voltage box due to overcurrent, and playing a crucial role in circuit protection.

[0050] In practical applications, electrical circuits may exist in multiple different operating states. To ensure timely and accurate monitoring of the operating current and voltage of these circuits, it is crucial to manage and control the energy storage high-voltage box more effectively. For example... Figure 2 As shown, in one possible implementation, it also includes a data acquisition module 24, which is located inside the housing 21. The data acquisition module 24 is used to acquire the voltage and current of each electrical circuit 23 and transmit the acquired information to the main control module 22. After receiving this information, the main control module 22 analyzes and processes it, and can then precisely control each electrical circuit 23 according to different operating conditions to ensure that the energy storage system is always in the best working state.

[0051] Figure 4 This is a schematic diagram of the high-voltage box in the energy storage system of this application; Figure 5 This is a structural schematic diagram of the heavy high-voltage box and main control panel of the energy storage system of this application.

[0052] During operation, excessively high temperatures within the energy storage system's enclosure 21 can affect the performance and lifespan of internal components, and even pose safety hazards. Therefore, in one possible implementation, the high-voltage box also includes a temperature sensor (not shown). The temperature sensor is fixed to the inner wall of the enclosure 21 and electrically connected to the main control module 22. This allows the temperature sensor to monitor temperature changes within the enclosure 21 in real time and feed this information back to the main control module 22. When the temperature exceeds a set safety threshold, the temperature sensor transmits a signal to the main control module 22. Upon receiving the signal, the main control module 22 quickly controls the circuit relay to disconnect, cutting off the power supply circuit 23. This prevents component damage or fires caused by excessive temperature, thus comprehensively ensuring the safety of the energy storage high-voltage box during operation.

[0053] Furthermore, if the internal pressure rises abnormally, it may damage the housing 21, or even cause serious accidents such as an explosion. Therefore, if... Figure 4 and Figure 5 As shown, in one possible implementation, a pressure relief hole is provided on the main control panel 21a, and a pressure relief valve 211 is provided on the pressure relief hole. When the internal pressure reaches the set value of the pressure relief valve 211, the pressure relief valve 211 will automatically open to release the excess pressure, thereby ensuring that the pressure inside the housing 21 is always within a safe range and avoiding danger caused by excessive pressure.

[0054] In one possible implementation, such as Figure 4 As shown, the main control panel 21a is equipped with a communication terminal 28 and a power terminal 29. The communication terminal 28 is used for communication between external devices and the main control module 22, and the power terminal 29 is used for electrical connection between an external power supply and the main control module 22. In this way, external devices can communicate with the main control module 22 via the communication terminal 28, allowing operators to obtain real-time operating data of the high-voltage box 20 and remotely monitor and operate it. The power terminal provides stable power support to the high-voltage box 20, ensuring its continuous and normal operation.

[0055] Figure 6 This is a schematic diagram of the circuit breaker handle of the energy storage system in this application.

[0056] Furthermore, such as Figure 5 and Figure 6As shown, the high-voltage box 20 also includes a circuit breaker opening / closing handle 27, which includes a handle portion 271 and a connecting portion 272. The handle portion 271 is rotatably mounted on the main control panel 21a, and one end of the connecting portion 272 is connected to the handle portion 271, while the other end is connected to the first circuit breaker. Thus, operators can easily control the opening and closing of the first circuit breaker by manually operating the circuit breaker opening / closing handle 27, thereby quickly cutting off the circuit and ensuring the safety of personnel and equipment when the high-voltage box 20 needs inspection, maintenance, or in case of an emergency.

[0057] Figure 7 This is a schematic diagram of the handle structure of the high-voltage box in the energy storage system of this application.

[0058] Furthermore, to facilitate the removal of the high-pressure box, in one possible implementation, such as Figure 4 and Figure 7 As shown, the high-voltage box 20 is also equipped with a handle 210. Specifically, the handle 210 has grooves 210a at both ends, and the groove walls of the grooves 210a have connecting holes. Two connecting posts 212 are installed on the main control panel 21a at intervals. The front end of each connecting post 212 has an extension 212a. The end of the extension 212a that extends into the groove extends to both sides with connecting parts 212b, which are connected to the connecting holes, so that the handle 210 can be folded or unfolded. In this way, when the high-voltage box 20 needs to be moved, the handle 210 can be unfolded for easy gripping and lifting by the operator; when not in use, the handle 210 can be folded up to reduce space occupation and make the storage of the high-voltage box 20 more convenient.

[0059] In one possible implementation, the grid-side protection circuit 40 includes a second circuit breaker and a first fuse. One end of the second circuit breaker is connected to the incoming line of the grid side, and the other end is connected to one end of the first fuse. The other end of the first fuse is connected to the DC / DC converter module 30. Thus, when a common fault such as a small overload current occurs on the grid side, the second circuit breaker will trip first, quickly cutting off the overload current and preventing the fault from escalating further. This also avoids unnecessary blowing of the first fuse, improving the system's economic efficiency. Conversely, when an extreme fault such as a severe short circuit occurs on the grid side, the first fuse will blow quickly, instantly cutting off the fault current and preventing the fault from spreading to the DC / DC converter module 30. In other words, by setting up a second circuit breaker and a first fuse on the grid side, a tiered protection system is formed, further enhancing the protection level of the grid-side circuit. Furthermore, the second circuit breaker can be manually tripped to reliably disconnect the circuit when grid maintenance or repair is needed, or when the first fuse needs to be replaced after blowing, providing a safe working environment for operators.

[0060] In practical applications, to achieve bidirectional power conversion and adapt to the grid connection requirements of energy storage, the energy storage system also includes a bidirectional power conversion module 50. In charging mode, the bidirectional power conversion module 50 converts the AC power from the grid side into DC power, which then charges the corresponding battery cluster 10 after passing through the grid-side protection circuit 40 and the DC / DC conversion module 30. In discharging mode, it converts the DC power stored in the battery cluster 10 into AC power to feed back to the grid, supporting grid peak shaving and frequency regulation, and achieving bidirectional energy flow and efficient utilization.

[0061] Figure 8 This is a schematic diagram of the circuit structure of the bidirectional power conversion module in the energy storage system of this application.

[0062] Among them, such as Figure 1 and Figure 8 As shown, the bidirectional power conversion module 50 includes at least two power conversion branches connected in parallel. Each power conversion branch includes a bidirectional AC / DC converter, a current transformer, a second fuse, and a conversion relay connected in series. The input terminals of each bidirectional AC / DC converter are connected to the incoming line terminal on the grid side, and the output terminals of each conversion relay are connected to one end of the second circuit breaker. In this way, by setting at least two parallel power conversion branches, different numbers of branches can be flexibly deployed according to the actual load demand on the grid side, achieving flexible power allocation and adjustment, and improving the system's adaptability and operating efficiency. For example, when the grid load is small, only one power conversion branch needs to be deployed to meet the demand, avoiding unnecessary energy loss; when the load increases, multiple branches can be deployed simultaneously to provide sufficient power support to the grid. At the same time, the second fuse on each branch can quickly blow in the event of overcurrent, short circuit, or other faults in the corresponding branch, accurately isolating the faulty branch without affecting the operation of other normal branches, ensuring the overall continuous power supply capability of the system. The current transformer can monitor the current changes of each branch in real time. Once an abnormal current is detected in a branch, it can promptly trigger the switching relay to disconnect the branch, further strengthening fault protection at the branch level and forming a double protection with the second fuse. Furthermore, the switching relay can also reliably isolate the branch from the power grid by actively disconnecting during branch inspection and maintenance, creating safe working conditions for operators and comprehensively improving the stability and safety of the bidirectional power conversion module.

[0063] In one possible implementation, the bidirectional power conversion module 50 further includes a third pre-charge relay and a third pre-charge resistor, which are connected in series to form a pre-charge circuit. The pre-charge circuit is connected in parallel with the conversion relay. Thus, when the bidirectional power conversion module 50 starts operating, the third pre-charge relay closes, enabling the pre-charge return current to conduct. The third pre-charge resistor limits the initial current in the circuit, preventing a large current surge caused by the instantaneous charging of the capacitor when the conversion relay is directly closed, effectively protecting the conversion relay, capacitor, and other components from damage. After the branch capacitor has finished charging and the circuit current has stabilized, the conversion relay closes, and the third pre-charge relay opens, causing the pre-charge circuit to stop working, ensuring that the branch is connected to the power grid or energy storage terminal in a stable state.

[0064] In one possible implementation, the energy storage system also includes a main circuit breaker located between the bidirectional power conversion module and the incoming line of the grid. One end of the main circuit breaker is electrically connected to the incoming line of the grid, and the other end is electrically connected to the common input terminal of each bidirectional AC / DC converter. Thus, when the entire bidirectional power conversion module 50 requires overall overhaul or maintenance, or encounters a sudden fault requiring emergency shutdown, operators can quickly disconnect all electrical connections between the bidirectional power conversion module 50 and the grid by disconnecting the main circuit breaker, achieving complete isolation between the module and the grid. This fundamentally avoids safety hazards such as accidental reconnection and backfeeding from the grid during maintenance, providing the most comprehensive safety protection for operators. Meanwhile, during the daily operation of the energy storage system, if extreme faults such as overvoltage, overcurrent, or short circuit are detected on the grid side, the main circuit breaker can automatically disconnect through its own overload protection and short circuit tripping function, immediately limiting the fault range to the grid side and preventing the fault from spreading to the bidirectional power conversion module. This effectively protects the core components such as the AC / DC converter and conversion relays in the module, further improving the fault resistance and operational reliability of the entire module.

[0065] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.

Claims

1. An energy storage system, characterized in that, It includes a high-voltage box, a grid-side protection circuit, multiple battery clusters, and multiple sets of DC / DC conversion modules, with each of the multiple battery clusters and the multiple sets of DC / DC conversion modules being configured in a one-to-one correspondence. The high-voltage box includes a box body, a main control module, and multiple independent power circuits. The multiple power circuits and the main control module are all located inside the box body. The box body has a main control panel, on which a first terminal and a second terminal are installed. One end of the first terminal protruding outside the box body is connected to the corresponding battery cluster. Each set of DC / DC conversion modules includes multiple bidirectional DC / DC converters arranged in parallel. The input sides of the multiple bidirectional DC / DC converters are connected to the grid-side protection circuit, and the output sides converge and are connected to one end of the second terminal that extends out of the enclosure. Each of the electrical circuits includes a first circuit breaker, a circuit relay, a pre-charge module, and a protective component connected in series. The first circuit breaker is connected to one end of the second terminal block located inside the housing. The protective component is connected to the corresponding end of the first terminal block located inside the housing. The main control module is electrically connected to the pre-charge module and the circuit relay of each electrical circuit and is used to independently control the on / off state and pre-charge process of each electrical circuit.

2. The energy storage system according to claim 1, characterized in that, The precharge module includes a first precharge relay, a second precharge relay, a first precharge resistor, and a second precharge resistor. One end of the first precharge relay is connected to the circuit relay, and the other end is connected to one end of the first precharge resistor. The other end of the first precharge resistor is connected to one end of the second precharge resistor. The other end of the second precharge resistor is connected to the protective component. The second precharge relay is connected in parallel across the two ends of the first precharge resistor, and the resistance of the first precharge resistor is much greater than the resistance of the second precharge resistor.

3. The energy storage system according to claim 2, characterized in that, The precharge module also includes a diode, the anode of which is connected to the circuit relay, and the cathode of which is connected to the protective component.

4. The energy storage system according to claim 1, characterized in that, It also includes a data acquisition module and a temperature sensor. The data acquisition module is located inside the enclosure and is used to acquire the voltage and current of each of the electrical circuits and transmit the acquired information to the main control module. The temperature sensor is fixed to the inner wall of the enclosure and is electrically connected to the main control module.

5. The energy storage system according to claim 1, characterized in that, It also includes a circuit breaker opening and closing handle, which includes a handle part and a docking part. The handle part is rotatably mounted on the main control panel, and one end of the docking part is connected to the handle part, while the other end is connected to the circuit breaker.

6. The energy storage system according to claim 1, characterized in that, The main control panel is equipped with communication terminals and power terminals. The communication terminals are used for external devices to communicate with the main control module, and the power terminals are used for external power supplies to electrically connect to the main control module.

7. The energy storage system according to claim 1, characterized in that, The grid-side protection circuit includes a second circuit breaker and a first fuse. One end of the second circuit breaker is connected to the incoming terminal of the grid side, and the other end of the second circuit breaker is connected to one end of the first fuse. The other end of the first fuse is connected to the DC / DC conversion module.

8. The energy storage system according to claim 7, characterized in that, The energy storage system also includes a bidirectional power conversion module, which includes at least two power conversion branches connected in parallel. Each power conversion branch includes a bidirectional AC / DC converter, a current transformer, a second fuse, and a conversion relay connected in series. The input terminals of each bidirectional AC / DC converter are connected to the incoming terminal on the grid side, and the output terminals of each conversion relay are connected to one end of the second circuit breaker.

9. The energy storage system according to claim 8, characterized in that, The bidirectional power conversion module further includes a third pre-charge relay and a third pre-charge resistor. The third pre-charge relay and the third pre-charge resistor are connected in series to form a pre-charge circuit, and the pre-charge circuit is connected in parallel with the conversion relay.

10. The energy storage system according to claim 8, characterized in that, The energy storage system also includes a main circuit breaker, which is located between the bidirectional power conversion module and the incoming terminal of the grid side. One end of the main circuit breaker is electrically connected to the incoming terminal of the grid side, and the other end is electrically connected to the common terminal of the input of each bidirectional AC / DC converter.

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