An energy storage system
Patent Information
- Application Number
- CN202522075983.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-25
- Publication Date
- 2026-10-16
- Estimated Expiration
- 2035-09-25
AI Technical Summary
[0003]随着储能系统的运行，可能需要新增电池模组以增加储能系统的容量，或者需要将故障损坏的电池模组更换为新的电池模组，而旧的电池模组的容量随着使用会发生衰减，导致新旧电池模组的容量出现不一致，出现较为明显的短板效应(也称木桶小型)，例如，容量较小的电池先充满电，容量较大的电池无法充满电；或者，容量较小的电池先放完电，容量较大的电池无法继续放电
[0006]Using the above scheme, a first battery module and a second battery module are used interchangeably in the battery cluster of the energy storage system. The first battery module can be a newly added battery module for the energy storage system to increase capacity or replace faulty or damaged battery modules. The DC/DC converter circuit included in the first battery module can adjust the discharge power and charging power of the first battery module, allowing the first and second battery modules to have different charging and discharging powers or currents, thereby achieving a balance in the power of the first and second battery modules. Therefore, this scheme can avoid the bottleneck effect and support the mixed use of battery modules with different capacities, improving flexibility and enabling dynamic expansion of system capacity. In addition, the second battery module does not need to include a DC/DC converter circuit, meaning that only some battery modules need to be equipped with a DC/DC converter circuit, which also reduces the hardware cost of the energy storage system.
Smart Images
Figure CN224862818U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of energy storage technology, specifically to an energy storage system. Background Technology
[0002] To achieve standardized production and assembly, energy storage systems typically design batteries as fixed-capacity battery modules, such as a single battery module with a fixed capacity of 10 kWh. Multiple battery modules are connected in series to form battery clusters, and then these clusters are connected in parallel to increase the energy storage capacity.
[0003] As the energy storage system operates, it may be necessary to add new battery modules to increase the system's capacity, or to replace faulty or damaged battery modules with new ones. However, the capacity of the old battery modules will decrease with use, resulting in a mismatch between the old and new battery modules and a significant bottleneck effect (also known as the "smallest barrel" effect). For example, the smaller capacity battery may be fully charged first, while the larger capacity battery may not be fully charged; or the smaller capacity battery may be discharged first, while the larger capacity battery may not be able to continue discharging. Utility Model Content
[0004] In view of this, this application provides an energy storage system that improves the flexibility of adding or replacing battery modules while avoiding the bottleneck effect.
[0005] In a first aspect, this application provides an energy storage system, wherein a battery cluster includes multiple battery modules connected in series, and the multiple battery modules include a first battery module and a second battery module; the first battery module includes a first battery and a DC / DC converter circuit, the first battery is connected to a first DC terminal of the DC / DC converter circuit, the second DC terminal of the DC / DC converter circuit is connected to the output terminal of the first battery module, and the output terminal of the first battery module is connected to the output terminal of the second battery module or to the output terminal of the battery cluster; the second battery module includes a second battery but does not include the DC / DC converter circuit, the second battery is connected to the output terminal of the second battery module, and the output terminal of the second battery module is connected to the output terminal of the first battery module or to the output terminal of the battery cluster; the DC / DC converter circuit is used to adjust the discharge power and charging power of the first battery module.
[0006] Using the above scheme, a first battery module and a second battery module are used interchangeably in the battery cluster of the energy storage system. The first battery module can be a newly added battery module for the energy storage system to increase capacity or replace faulty or damaged battery modules. The DC / DC converter circuit included in the first battery module can adjust the discharge power and charging power of the first battery module, allowing the first and second battery modules to have different charging and discharging powers or currents, thereby achieving a balance in the power of the first and second battery modules. Therefore, this scheme can avoid the bottleneck effect and support the mixed use of battery modules with different capacities, improving flexibility and enabling dynamic expansion of system capacity. In addition, the second battery module does not need to include a DC / DC converter circuit, meaning that only some battery modules need to be equipped with a DC / DC converter circuit, which also reduces the hardware cost of the energy storage system.
[0007] In one possible implementation, when the first battery module is connected to the energy storage system, it differs from the second battery module in at least one of the following parameters: state of charge (SOC), battery capacity, state of health (SOH), battery voltage, and maximum charge / discharge current.
[0008] In one possible implementation, when the energy storage system is discharging and the charge or SOC of the first battery module is higher than that of the second battery module, the DC / DC converter circuit is specifically used to increase the output power of the first battery module; when the energy storage system is discharging and the charge or SOC of the first battery module is lower than that of the second battery module, the DC / DC converter circuit is specifically used to reduce the output power of the first battery module; when the energy storage system is charging and the charge or SOC of the first battery module is higher than that of the second battery module, the DC / DC converter circuit is specifically used to reduce the charging power of the first battery module; when the energy storage system is charging and the charge or SOC of the first battery module is lower than that of the second battery module, the DC / DC converter circuit is specifically used to increase the charging power of the first battery module.
[0009] In one possible implementation, the energy storage system includes a first battery cluster; the first battery cluster includes at least one first battery module and at least one second battery module connected in series.
[0010] In one possible implementation, the energy storage system further includes a second battery cluster; the second battery cluster is connected in parallel with the first battery cluster; the second battery cluster includes at least one first battery module connected in series.
[0011] In one possible implementation, the energy storage system further includes: a third battery cluster; the third battery cluster is connected in parallel with the first battery cluster; the third battery cluster includes at least one first battery module and at least one second battery module connected in series.
[0012] In one possible implementation, the third battery cluster includes a different number of first and / or second battery modules than the first battery cluster.
[0013] In one possible implementation, the energy storage system further includes a fourth battery cluster; the fourth battery cluster is connected in parallel with the first battery cluster; the fourth battery cluster includes at least one second battery module connected in series.
[0014] In one possible implementation, when the energy storage system includes multiple first battery modules, at least two of the first battery modules have different parameters when connected to the energy storage system: state of charge (SOC), battery capacity, state of health (SOH), battery voltage, and maximum charge / discharge current.
[0015] In one possible implementation, the energy storage system also includes a power converter; the first end of the battery cluster is connected to the first end of the power converter, and the second end of the power converter is connected to the power source and / or load equipment; the power source is the power grid or a new energy generation terminal. Attached Figure Description
[0016] Figure 1 A schematic diagram of the phased power supply provided for this application;
[0017] Figure 2 A schematic diagram of an energy storage system provided in an embodiment of this application. Figure 1 ;
[0018] Figure 3 A schematic diagram of an energy storage system provided in an embodiment of this application. Figure 2 ;
[0019] Figure 4 A schematic diagram of an energy storage system provided in an embodiment of this application. Figure 3 ;
[0020] Figure 5 A schematic diagram of an energy storage system provided in an embodiment of this application. Figure 4 ;
[0021] Figure 6 A schematic diagram of an energy storage system provided in an embodiment of this application. Figure 5 ;
[0022] Figure 7 A graph showing the relationship between the output voltage and the state of charge (SOC) of the DC / DC converter circuit provided in the embodiments of this application;
[0023] Figure 8 A schematic diagram of an energy storage system provided in an embodiment of this application. Figure 6 ;
[0024] Figure 9 A schematic diagram of an energy storage system provided in an embodiment of this application. Figure 7 ;
[0025] Figure 10 A schematic diagram of an energy storage system provided in an embodiment of this application. Figure 8 ;
[0026] Figure 11 The graph showing the relationship between the output current and the state of charge (SOC) of the DC / DC converter circuit provided in the embodiments of this application. Detailed Implementation
[0027] To enable those skilled in the art to better understand the technical solution of this application, the application scenarios of the technical solution of this application will be described first below.
[0028] Currently, new energy power generation methods such as photovoltaic and wind power have been widely adopted, but the volatility and intermittency of these new energy sources are becoming increasingly prominent. However, with the development of electrochemical battery technology and the surge in production capacity, the cost of electrochemical batteries has decreased, creating an opportunity for them to participate in energy storage within new energy power generation systems. Furthermore, due to the flexibility, controllable charging and discharging, rapid response capabilities, and high energy density of energy storage systems using electrochemical batteries, their application on the generation, grid, and consumption sides is becoming increasingly widespread.
[0029] Currently, electrochemical batteries (hereinafter referred to as batteries) generally suffer from State of Health (SOH) degradation, meaning that the usable capacity of the battery gradually decreases with increasing years of use. Furthermore, due to inconsistencies in the performance of each battery at the time of manufacture and differences in operating conditions, the SOH degradation varies among different batteries.
[0030] See Figure 1 The figure is a schematic diagram of the phased power replenishment provided in this application.
[0031] To ensure that battery-powered energy storage systems meet capacity requirements during use, a phased charging approach can be adopted to fully allocate capacity. The corresponding curve for this approach is shown in L1. The initial capacity is Q1, and t1, t2, t3, and t4 represent the timing of phased charging. After reaching each corresponding timing, additional batteries need to be added to the energy storage system to increase capacity. However, the state of charge (SOH) of the batteries added through phased charging differs from that of the initially configured old batteries. Therefore, there is a significant bottleneck effect, where batteries with smaller SOH will either fully charge or discharge first, resulting in the inability to fully utilize the capacity of the newly added batteries, thus leading to waste.
[0032] Furthermore, when expanding the capacity of energy storage systems or replacing faulty or damaged battery modules with new ones, there is also a significant bottleneck effect between the old and new battery modules.
[0033] To address the aforementioned technical issues, this application provides an energy storage system that integrates a first battery module and a second battery module. The first battery module can be added to the energy storage system to increase capacity or replace faulty or damaged battery modules. The DC / DC converter circuit included in the first battery module can adjust the discharge and charging power of the first battery module, thereby balancing the charge levels of the first and second battery modules. Therefore, this solution avoids the bottleneck effect and supports the mixed use of battery modules with different capacities, improving flexibility.
[0034] The terms "first" and "second" used in this application description are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.
[0035] In this application, unless otherwise expressly specified and limited, the term "connection" shall be interpreted broadly. For example, "connection" may be a fixed connection, a detachable connection, or an integral part; it may be a direct connection or an indirect connection through an intermediate medium.
[0036] See Figure 2 This figure is a schematic diagram of the energy storage system provided in an embodiment of this application. Figure 1 .
[0037] The energy storage system provided in this application includes a battery cluster 10.
[0038] The battery cluster 10 includes multiple battery modules connected in series, among which are first battery modules 11 and second battery modules 12. It should be understood that an energy storage system may include one or more battery clusters 10, each battery cluster 10 may include one or more first battery modules 11, and one or more second battery modules 12. For ease of explanation, Figure 2 The diagram only illustrates the implementation of the battery cluster 10 when it includes a first battery module 11 and a second battery module 12.
[0039] The first battery module 11 includes a first battery 111 and a DC / DC converter circuit 112. The first battery 111 is connected to the first DC terminal of the DC / DC converter circuit 112, and the second DC terminal of the DC / DC converter circuit 112 is connected to the output terminal of the first battery module 11.
[0040] Specifically, the positive terminal of the first battery 111 is connected to the first port of the first DC terminal of the DC / DC converter circuit 112, and the negative terminal of the first battery 111 is connected to the second port of the first DC terminal of the DC / DC converter circuit 112; the first port of the second DC terminal of the DC / DC converter circuit 112 is connected to the first port OUT1 of the output terminal of the first battery module 11, and the second port of the second DC terminal of the DC / DC converter circuit 112 is connected to the second port OUT2 of the output terminal of the first battery module 11.
[0041] The output terminal of the first battery module 11 can be connected to the output terminal of the battery cluster, or to other battery modules within the same battery cluster. For example... Figure 2 The first port OUT1 of the first battery module 11 is connected to the positive output terminal of the battery cluster 10, and the second port OUT2 of the first battery module 11 is connected to the first port OUT1 of the second battery module.
[0042] The DC / DC converter circuit 112 is used to adjust the discharge power and charging power of the first battery module 11 so as to balance the power of the first battery module 11 and the second battery module 12.
[0043] In one possible implementation, such as Figure 1 In the scenario shown, the first battery module 11 can be a battery module added to the battery cluster 10 during phased power replenishment, or a battery module added during capacity expansion of the energy storage system, or it can be used to replace a faulty or damaged battery module.
[0044] When the first battery module 11 is connected to the battery cluster 10, in order to achieve power balance with the second battery module 12, the output voltage of the output terminal of the first battery module 11 needs to be adjusted through the DC / DC converter circuit 112, thereby changing the discharge power and / or charging power of the first battery module.
[0045] It should be understood that in the embodiments of this application, the DC / DC converter circuit 112 is a bidirectional DC / DC converter circuit, which can adopt a non-isolated topology, such as a boost circuit, a buck circuit, or a buck-boost circuit. Alternatively, it can adopt an isolated topology, such as a dual active bridge (DAB) converter or a CLLC resonant converter circuit.
[0046] In practical applications, when the first battery module 11 is connected to the battery cluster 10, the battery capacity of the first battery module 11 may be greater or less than that of the second battery module 12. Therefore, in order to quickly achieve power balance between the first battery module 11 and the second battery module 12, the DC / DC converter circuit 112 can be selected as a buck-boost circuit, which can realize boost or buck conversion according to the actual situation.
[0047] The second battery module 12 in this embodiment includes a second battery 121. The second battery module 12 does not include a DC / DC converter circuit. The second battery 121 is connected to the output terminal of the second battery module 12. Specifically, the positive terminal of the second battery 121 is connected to the first port OUT1 of the output terminal of the second battery module 12, and the negative terminal of the second battery 121 is connected to the second port OUT2 of the output terminal of the second battery module 12.
[0048] The output terminal of the second battery module 12 can be connected to the output terminal of the battery cluster, or to other battery modules within the same battery cluster. For example... Figure 2 The first port OUT1 of the output terminal of the second battery module 12 in the battery cluster 10 is connected to the second port OUT2 of the output terminal of the first battery module 11 in the battery cluster 10, and the second port OUT2 of the output terminal of the second battery module 12 is connected to the negative output terminal of the battery cluster 10.
[0049] In the embodiment of this application, the second battery module 12 is an existing battery module in the energy storage system. Figure 1 Taking the phased power replenishment scenario shown as an example, the second battery module 12 is the battery module that operates in the energy storage system from time 0 to t1. In the embodiments of this application, each second battery module 12 does not have a DC / DC conversion circuit, which can reduce the hardware cost of the battery cluster and the overall hardware cost of the energy storage system.
[0050] The first battery module 11 can be Figure 1 In the phased power replenishment scenario shown, the battery modules added at replenishment times such as t1, t2, or t3 are either battery modules added by the energy storage system to increase capacity or replace faulty or damaged battery modules. In order to overcome the bottleneck effect between the new battery modules and the old battery modules, a DC / DC conversion circuit 112 is set in the first battery module 11 in this embodiment to achieve power balance. The following is a description in conjunction with specific circumstances.
[0051] When the energy storage system discharges, and the charge or state of charge (SOC) of the first battery module 11 is higher than that of the second battery module 12, the DC / DC converter circuit 112 of the first battery module 11 is specifically used to increase the output power of the first battery module 11. At this time, the DC / DC converter circuit 112 operates in boost mode, increasing the output voltage of the first battery module 11, so that the charge or SOC of the first battery module 11 gradually approaches that of the second battery module. The output power of the first battery module 11 can also be referred to as the discharge power of the first battery module 11.
[0052] When the energy storage system is discharging, and the charge or SOC of the first battery module 11 is lower than that of the second battery module 12, the DC / DC converter circuit 112 of the first battery module 11 is specifically used to reduce the output power of the first battery module 11. At this time, the DC / DC converter circuit 112 operates in a step-down state, reducing the output voltage of the first battery module 11, so that the charge or SOC of the first battery module 11 gradually approaches that of the second battery module.
[0053] When the energy storage system is charging, and the charge or SOC of the first battery module 11 is higher than that of the second battery module 12, the DC / DC converter circuit of the first battery module 11 is specifically used to reduce the charging power of the first battery module. At this time, the second DC side of the DC / DC converter circuit 112 is the power input side, and the first DC side of the DC / DC converter circuit 112 is the power output side. The DC / DC converter circuit 112 operates in a step-down state to reduce the charging power of the DC / DC converter circuit 112, so that the charge or SOC of the first battery module 11 gradually approaches that of the second battery module 12.
[0054] When the energy storage system is charging, and the charge or SOC of the first battery module is lower than that of the second battery module, the DC / DC converter circuit of the first battery module 11 is specifically used to increase the charging power of the first battery module. At this time, the second DC side of the DC / DC converter circuit 112 is the power input side, the first DC side of the DC / DC converter circuit 112 is the power output side, and the DC / DC converter circuit 112 operates in boost mode to increase the charging power of the DC / DC converter circuit 112, so that the charge or SOC of the first battery module 11 gradually approaches that of the second battery module 12.
[0055] Based on the above description, the first battery module 11 can achieve power balance with the second battery module 12 through its own DC / DC conversion circuit 112 during the charging or discharging process, thus overcoming the bottleneck effect.
[0056] Furthermore, it simplifies the operation of adding the first battery module 11. Traditional solutions often require pre-charging / pre-discharging the new or old battery module to make their SOCs close, for example, both at 50%, before expanding / replacing them, which is time-consuming. However, the first battery module 11 in this application can be directly connected, and the SOC of the first battery module 11 when connected can be any value, without the need for pre-charging / pre-discharging, thus shortening the installation time.
[0057] Furthermore, the power balancing function of the DC / DC converter circuit 112 also facilitates the selection of battery modules. Traditional solutions generally require that new and old battery modules have the same parameters, for example, both are 100Ah and 5.12kWh battery modules. This forces battery module manufacturers to continuously produce battery modules with the same parameters throughout the energy storage system's lifespan (e.g., 5 to 15 years), making upgrades difficult and resulting in significant costs. However, with the solution proposed in this application, the DC / DC converter circuit 112 adjusts the output characteristics of the battery module, broadening the selection range of the first battery module 11. For example, the capacity of the first battery module 11 can be 100Ah, or it can be other capacities, such as a smaller 50Ah battery module or a larger 314Ah battery module, allowing selection based on the battery module manufacturer's technological upgrade path, without limitation. Similarly, the capacity of the first battery module 11 can be 5.12kWh, or it can be other capacities.
[0058] In summary, the energy storage system in this embodiment uses a combination of first and second battery modules in its battery cluster. The first battery module can be a newly added battery module for increasing capacity or replacing faulty or damaged battery modules. The DC / DC converter circuit included in the first battery module can adjust the discharge and charging power of the first battery module, thus balancing the charge levels of the first and second battery modules. Therefore, this solution avoids the bottleneck effect and supports the mixed use of battery modules with different capacities, improving flexibility and enabling dynamic expansion of system capacity. Furthermore, the second battery module does not need to include a DC / DC converter circuit, meaning only some battery modules require a DC / DC converter circuit, which also reduces the hardware cost of the energy storage system.
[0059] The following section will explain the specific implementation method.
[0060] See Figure 3 This figure is a schematic diagram of the energy storage system provided in an embodiment of this application. Figure 2 .
[0061] Figure 3 The energy storage system shown includes a first battery cluster 10A and a second battery cluster 10B connected in parallel, and also includes a power converter 20.
[0062] When the first battery cluster 10A and the second battery cluster 10B are connected in parallel, the positive output terminals V+ of the first battery cluster 10A and the second battery cluster 10B are connected, and the negative output terminals V- of the first battery cluster 10A and the second battery cluster 10B are connected.
[0063] The first battery cluster 10A includes at least one first battery module 11 and at least one second battery module 12 connected in series. For details on the specific implementation and working principle of the first battery module 11 and the second battery module 12, please refer to the description in the above embodiments, which will not be repeated here.
[0064] The second battery cluster 10B includes at least one first battery module 11 connected in series. For ease of explanation... Figure 3 The second battery cluster 10B, which includes two first battery modules 11 connected in series, will be used as an example for illustration.
[0065] The first battery module 11 in the first battery cluster 10A corresponds to the scenario of phased power replenishment, energy storage system expansion, or replacement of faulty or damaged battery modules.
[0066] When the first battery module 11 in the first battery cluster 10A is first connected to the energy storage system, it may have one or more different parameters from the second battery module 12, such as SOC, battery capacity, state of health (SOH), battery voltage, and maximum charge / discharge current. The first battery module 11 can achieve power balance between the first battery module 11 and the second battery module 12 by utilizing the output power regulation capability and charging power regulation capability of the DC / DC converter circuit 112.
[0067] The second battery cluster 10B can correspond to scenarios of phased power replenishment or energy storage system expansion, meaning the second battery cluster 10B can be a newly added battery cluster. In this case, when the multiple first battery modules 11 connected in series in the second battery cluster 10B are connected to the energy storage system, one or more parameters such as SOC, battery capacity, SOH, battery voltage, and maximum charge / discharge current can differ. Each first battery module 11 can achieve power balance with other first battery modules 11 by utilizing the output power regulation capability and charging power regulation capability of its own DC / DC converter circuit 112.
[0068] The power converter 20 is used to discharge and charge the individual battery clusters. In one possible implementation, the power converter 20 is a power conversion system (PCS). The DC side of the power conversion system is connected to the individual battery clusters, and the AC side of the power conversion system can be connected to the power grid or a new energy power generation terminal, etc. The AC side of the power conversion system can also be used for electrical equipment.
[0069] In this implementation, the first battery cluster uses a combination of first and second battery modules. The DC / DC converter circuit included in the first battery module can adjust the discharge and charging power of the first battery module, thus balancing the power of the first and second battery modules. Furthermore, it eliminates the need for the original second battery modules in the first battery cluster to have their own DC / DC converter circuits, reducing the hardware cost of the energy storage system. The various second battery modules in the second battery cluster can use battery modules with the same or different parameters, facilitating selection and allowing battery manufacturers to upgrade and replace battery modules throughout the energy storage system's lifecycle. This solution avoids the bottleneck effect and supports the mixed use of battery modules with different capacities, improving flexibility and enabling dynamic expansion of system capacity.
[0070] See Figure 4 This figure is a schematic diagram of the energy storage system provided in an embodiment of this application. Figure 3 .
[0071] Figure 4 The energy storage system shown includes a first battery cluster 10A and a third battery cluster 10C connected in parallel, and also includes a power converter 20.
[0072] When the first battery cluster 10A and the third battery cluster 10C are connected in parallel, the positive output terminals V+ of the first battery cluster 10A and the third battery cluster 10C are connected, and the negative output terminals V- of the first battery cluster 10A and the third battery cluster 10C are connected.
[0073] The first battery cluster 10A includes at least one first battery module 11 and at least one second battery module 12 connected in series. For details on the specific implementation and working principle of the first battery module 11 and the second battery module 12, please refer to the description in the above embodiments, which will not be repeated here.
[0074] The second battery cluster 10B also includes at least one first battery module 11 and at least one second battery module 12 connected in series. For ease of explanation, Figure 3 The following description uses the second battery cluster 10B, which includes a first battery module 11 and a second battery module 12, as an example. It should be understood that the number of first battery modules in the second battery cluster 10B may be the same as or different from the number of first battery modules in the first battery cluster 10A; the number of second battery modules in the second battery cluster 10B may be the same as or different from the number of second battery modules in the first battery cluster 10A.
[0075] The first battery module 11 in the first battery cluster 10A corresponds to the scenario of phased power replenishment, energy storage system expansion, or replacement of faulty or damaged battery modules.
[0076] The second battery cluster 10B can be used for scenarios such as phased power replenishment, energy storage system expansion, or replacement of faulty or damaged battery modules.
[0077] When the first battery modules 11 in the first battery cluster 10A and the second battery cluster 10B are first connected to the energy storage system, one or more parameters such as SOC, battery capacity, SOH, battery voltage, and maximum charge / discharge current may differ from those of the second battery modules 12 in the same battery cluster. The first battery modules 11 utilize the output power regulation and charging power regulation capabilities of the DC / DC converter circuit 112 to achieve power balance between the first battery modules 11 and the second battery modules 12 in the same battery cluster.
[0078] The power converter 20 is used to discharge and charge the individual battery clusters. In one possible implementation, the power converter 20 is a PCS, with the DC side of the PCS connected to the individual battery clusters and the AC side of the PCS connected to the power grid or a new energy generation source. The AC side of the energy storage converter can also be used for electrical equipment.
[0079] It should be understood that energy storage systems can also include a greater number of battery clusters. Furthermore, the second battery modules in the first battery cluster 10A and the second battery cluster 10B can use battery modules with the same or different parameters, which facilitates selection and allows battery manufacturers to upgrade and replace battery modules throughout the life cycle of the energy storage system.
[0080] In this implementation, the first and second battery clusters utilize a hybrid approach, combining first and second battery modules. The DC / DC converter circuitry within the first battery module adjusts its discharge and charging power, ensuring a balance in the charge levels of both modules. Furthermore, the original second battery module does not require its own DC / DC converter circuitry, reducing the hardware cost of the energy storage system. This approach avoids the bottleneck effect and supports the mixed use of battery modules with different capacities, enhancing flexibility and enabling dynamic expansion of system capacity.
[0081] See Figure 5 This figure is a schematic diagram of the energy storage system provided in an embodiment of this application. Figure 4 .
[0082] Figure 5 The energy storage system shown includes a first battery cluster 10A and a fourth battery cluster 10D connected in parallel, and also includes a power converter 20.
[0083] When the first battery cluster 10A and the fourth battery cluster 10D are connected in parallel, the positive output terminal V+ of the first battery cluster 10A and the positive output terminal V+ of the fourth battery cluster 10D are connected, and the negative output terminals V- of the first battery cluster 10A and the fourth battery cluster 10D are connected.
[0084] The first battery cluster 10A includes at least one first battery module 11 and at least one second battery module 12 connected in series. For details on the specific implementation and working principle of the first battery module 11 and the second battery module 12, please refer to the description in the above embodiments, which will not be repeated here.
[0085] The fourth battery cluster 10D includes at least one second battery module 12 connected in series. For ease of explanation, Figure 5 The following explanation uses the fourth battery cluster 10D, which includes two second battery modules 12, as an example. It should be understood that the number of second battery modules in the fourth battery cluster 10D may be the same as or different from the number of second battery modules in the first battery cluster 10A.
[0086] The first battery module 11 in the first battery cluster 10A corresponds to the scenario of phased power replenishment, energy storage system expansion, or replacement of faulty or damaged battery modules.
[0087] When the first battery module 11 in the first battery cluster 10A is first connected to the energy storage system, one or more parameters such as SOC, battery capacity, SOH, battery voltage, and maximum charge / discharge current may differ from those of the second battery module 12 in the first battery cluster 10A. The first battery module 11 utilizes the output power regulation and charging power regulation capabilities of the DC / DC converter circuit 112 to achieve power balance between the first battery module 11 and the second battery module 12 in the first battery cluster 10A.
[0088] The power converter 20 is used to discharge and charge the individual battery clusters. In one possible implementation, the power converter 20 is a PCS, with the DC side of the PCS connected to the individual battery clusters and the AC side of the PCS connected to the power grid or a new energy generation source. The AC side of the energy storage converter can also be used for electrical equipment.
[0089] It should be understood that energy storage systems can also include a greater number of battery clusters. Furthermore, the first and second battery modules in the first battery cluster 10A can use battery modules with the same or different parameters, which facilitates selection and allows battery manufacturers to upgrade and replace battery modules throughout the life cycle of the energy storage system.
[0090] In this implementation, first and second battery modules can be mixed in some battery clusters of the energy storage system. The DC / DC conversion circuit included in the first battery module can adjust the discharge and charging power of the first battery module, thus balancing the power of the first and second battery modules. Furthermore, the original second battery module does not require its own DC / DC conversion circuit, reducing the hardware cost of the energy storage system. This solution avoids the bottleneck effect and supports the mixed use of battery modules with different capacities, improving flexibility and enabling dynamic expansion of system capacity.
[0091] See Figure 6 This figure is a schematic diagram of the energy storage system provided in an embodiment of this application. Figure 5 .
[0092] Figure 6 The energy storage system shown includes the first battery cluster 10A, the second battery cluster 10B, the third battery cluster 10C, and the fourth battery cluster 10D described above. The first battery module 11 can be connected to the energy storage system throughout its lifecycle, depending on specific scenario requirements, offering high flexibility. It should be understood that the energy storage system may also include only portions of the aforementioned battery clusters, which will not be elaborated upon here.
[0093] See Figure 7 The figure shows the relationship between the voltage at the output terminal of the DC / DC converter circuit provided in the embodiment of this application and the SOC.
[0094] like Figure 7 As shown, when the first battery module 11 is charging or discharging, the voltage at the output terminal of the DC / DC converter circuit has a linear relationship with the SOC of the first battery module 11. Specifically, when the first battery module 11 is discharging, the output terminal of the DC / DC converter circuit is the second DC terminal; when the first battery module 11 is charging, the output terminal of the DC / DC converter circuit is the first DC terminal.
[0095] Preferably, the linear relationship can be a monotonic linear function. It should be understood that in practical applications, the voltage at the second DC terminal of the DC / DC converter circuit and the SOC of the first battery module 11 can also adopt a piecewise linear relationship, or other monotonic functional relationships, which will not be elaborated here.
[0096] The control method of the DC / DC converter circuit in the first battery module is explained below.
[0097] See Figure 8 This figure is a schematic diagram of the energy storage system provided in an embodiment of this application. Figure 6 .
[0098] The energy storage system provided in this application embodiment is... Figure 2The difference is that the first battery module 11 also includes a controller 113.
[0099] The controller 113 can be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), a digital signal processor (DSP), or a combination thereof. The PLD can be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof; this application embodiment does not impose specific limitations.
[0100] The controller 113 is used to acquire the power information or SOC information of the first battery 111 in the first battery module 11 and the power information or SOC information of the second battery 121 in the second battery module 12, and control the discharge power and charging power of the DC / DC converter circuit based on the acquired information so as to balance the power of the first battery module 11 and the second battery module 12.
[0101] At this time, the controller 113 can be integrated into the first battery module 11, and the controller 113 can be the battery module unit (BMU) of the first battery module 11.
[0102] See Figure 9 This figure is a schematic diagram of the energy storage system provided in an embodiment of this application. Figure 7 .
[0103] The energy storage system provided in this application embodiment is... Figure 2 The difference is that the battery cluster 10 also includes a controller 13.
[0104] The controller 13 can be the battery cluster unit (BCU) of the battery cluster 10, responsible for the management of the battery cluster. The controller 13 is used to obtain the power information or SOC information of the first battery 111 in the first battery module 11, and the power information or SOC information of the second battery 121 in the second battery module 12, and control the discharge power and charging power of the DC / DC converter circuit based on the obtained information, so as to balance the power of the first battery module 11 and the second battery module 12.
[0105] The above embodiments illustrate the implementation method when the first battery module and the second battery module are connected in series. The following describes the implementation method when the first battery module and the second battery module are connected in parallel.
[0106] See Figure 10 This figure is a schematic diagram of the energy storage system provided in an embodiment of this application. Figure 8 .
[0107] The battery cluster 10 of the energy storage system provided in this application embodiment includes multiple battery modules connected in parallel, among which are first battery modules 11 and second battery modules 12. It should be understood that the energy storage system may include one or more battery clusters 10, and each battery cluster 10 may include one or more first battery modules 11 and one or more second battery modules 12. For ease of explanation, Figure 10 The diagram only illustrates the implementation of the battery cluster 10 when it includes a first battery module 11 and a second battery module 12.
[0108] The first battery module 11 includes a first battery 111 and a DC / DC converter circuit 112. The first battery 111 is connected to the first DC terminal of the DC / DC converter circuit 112, and the second DC terminal of the DC / DC converter circuit 112 is connected to the output terminal of the first battery module 11.
[0109] Specifically, the positive terminal of the first battery 111 is connected to the first port of the first DC terminal of the DC / DC converter circuit 112, and the negative terminal of the first battery 111 is connected to the second port of the first DC terminal of the DC / DC converter circuit 112; the first port of the second DC terminal of the DC / DC converter circuit 112 is connected to the first port OUT1 of the output terminal of the first battery module 11, and the second port of the second DC terminal of the DC / DC converter circuit 112 is connected to the second port OUT2 of the output terminal of the first battery module 11.
[0110] The output terminal of the first battery module 11 is connected to the output terminal of the battery cluster and the output terminals of other battery modules within the same battery cluster. For example... Figure 10 The first port OUT1 of the first battery module 11 is connected to the positive output terminal of the battery cluster 10 and the first port OUT1 of the output terminal of the second battery module 12. The second port OUT2 of the first battery module 11 is connected to the negative output terminal of the battery cluster 10 and the second port OUT2 of the output terminal of the second battery module 12.
[0111] The second battery module 12 includes a second battery 121 but does not include a DC / DC converter circuit. The second battery 121 is connected to the output terminal of the second battery module. Specifically, the positive terminal of the second battery 121 is connected to the first port OUT1 of the output terminal of the second battery module 12, and the negative terminal of the second battery 121 is connected to the second port OUT2 of the output terminal of the second battery module 12.
[0112] In the embodiments of this application, the second battery module 12 can be an existing battery module in the energy storage system, to Figure 1 Taking the phased power replenishment scenario shown as an example, the second battery module 12 is the battery module that operates in the energy storage system from time 0 to t1. In the embodiments of this application, each second battery module 12 does not have a DC / DC conversion circuit, which can reduce the hardware cost of the battery cluster and the overall hardware cost of the energy storage system.
[0113] The first battery module 11 can be Figure 1 In the phased power replenishment scenario shown, the battery modules added at replenishment times t1, t2, or t3 are either battery modules added by the energy storage system to increase capacity or replace faulty or damaged battery modules. The DC / DC converter circuit 112 of the first battery module 11 is used to adjust the discharge power and charging power of the first battery module 11 to balance the power of the first battery module 11 and the second battery module 12. This will be explained in detail below.
[0114] When the energy storage system is discharging, and the charge or SOC of the first battery module 11 is higher than that of the second battery module 12, the DC / DC converter circuit 112 of the first battery module 11 is specifically used to increase the output power of the first battery module 11. At this time, the DC / DC converter circuit 112 operates in boost mode.
[0115] When the energy storage system is discharging and the charge or SOC of the first battery module 11 is lower than that of the second battery module 12, the DC / DC converter circuit 112 of the first battery module 11 is specifically used to reduce the output power of the first battery module 11. At this time, the DC / DC converter circuit 112 operates in a step-down state.
[0116] When the energy storage system is charging, and the charge or SOC of the first battery module 11 is higher than that of the second battery module 12, the DC / DC converter circuit of the first battery module 11 is specifically used to reduce the charging power of the first battery module. At this time, the second DC side of the DC / DC converter circuit 112 is the power input side, the first DC side of the DC / DC converter circuit 112 is the power output side, and the DC / DC converter circuit 112 operates in a step-down state to reduce the charging power of the DC / DC converter circuit 112.
[0117] When the energy storage system is charging, and the charge or SOC of the first battery module is lower than that of the second battery module, the DC / DC converter circuit of the first battery module 11 is specifically used to increase the charging power of the first battery module. At this time, the second DC side of the DC / DC converter circuit 112 is the power input side, the first DC side of the DC / DC converter circuit 112 is the power output side, and the DC / DC converter circuit 112 operates in boost mode to increase the charging power of the DC / DC converter circuit 112.
[0118] Based on the above description, the first battery module 11 can achieve power balance with the second battery module 12 through its own DC / DC conversion circuit 112 during the charging or discharging process, thus overcoming the bottleneck effect.
[0119] Similarly, when the first battery module 11 is connected in parallel, it can be directly connected. The SOC of the first battery module 11 upon connection can be any value, eliminating the need for pre-charging / pre-discharging operations and shortening installation time. One or more of the following parameters of the first battery module 11—SOC, battery capacity, SOH, battery voltage, and maximum charge / discharge current—can differ from those of the second battery module 12, thus providing greater flexibility in the selection of the first battery module 11.
[0120] See Figure 11 The figure shows the relationship between the current at the output terminal of the DC / DC converter circuit provided in the embodiment of this application and the SOC.
[0121] like Figure 11 As shown, when the first battery module 11 is charging or discharging, the current at the second DC terminal of the DC / DC converter circuit has a linear relationship with the SOC of the first battery module 11. Specifically, when the first battery module 11 is discharging, the output terminal of the DC / DC converter circuit is the second DC terminal; when the first battery module 11 is charging, the output terminal of the DC / DC converter circuit is the first DC terminal.
[0122] Preferably, the linear relationship can be a monotonic linear function. It should be understood that in practical applications, the voltage at the second DC terminal of the DC / DC converter circuit and the SOC of the first battery module 11 can also adopt a piecewise linear relationship, or other monotonic functional relationships, which will not be elaborated here.
[0123] for Figure 10 The implementation shown is used to control the controller of the DC / DC converter circuit 112. It can also be a BCU or BMU, which will not be described in detail in this embodiment.
[0124] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.
[0125] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. An energy storage system, characterized in that, include: Battery clusters; The battery cluster includes multiple battery modules connected in series, among which a first battery module and a second battery module are included; The first battery module includes a first battery and a DC / DC converter circuit. The first battery is connected to the first DC terminal of the DC / DC converter circuit, and the second DC terminal of the DC / DC converter circuit is connected to the output terminal of the first battery module. The output terminal of the first battery module is connected to the output terminal of the second battery module or to the output terminal of the battery cluster. The second battery module includes a second battery but does not include a DC / DC converter circuit. The second battery is connected to the output terminal of the second battery module, and the output terminal of the second battery module is connected to the output terminal of the first battery module or to the output terminal of the battery cluster. The DC / DC converter circuit is used to adjust the discharge power and charging power of the first battery module.
2. The energy storage system according to claim 1, characterized in that, When the first battery module is connected to the energy storage system, it differs from the second battery module in at least one of the following parameters: State of charge (SOC), battery capacity, state of health (SOH), battery voltage, and maximum charge / discharge current of the battery.
3. The energy storage system according to claim 1 or 2, characterized in that, When the energy storage system is discharging, and the charge or SOC of the first battery module is higher than that of the second battery module, the DC / DC converter circuit is specifically used to increase the output power of the first battery module. When the energy storage system discharges and the charge or SOC of the first battery module is lower than that of the second battery module, the DC / DC converter circuit is specifically used to reduce the output power of the first battery module. When the energy storage system is charging and the charge or SOC of the first battery module is higher than that of the second battery module, the DC / DC converter circuit is specifically used to reduce the charging power of the first battery module. When the energy storage system is charging, and the charge or SOC of the first battery module is lower than that of the second battery module, the DC / DC converter circuit is specifically used to increase the charging power of the first battery module.
4. The energy storage system according to claim 1, characterized in that, The energy storage system includes a first battery cluster; The first battery cluster includes at least one first battery module and at least one second battery module connected in series.
5. The energy storage system according to claim 4, characterized in that, The energy storage system also includes a second battery cluster; The second battery cluster is connected in parallel with the first battery cluster; The second battery cluster includes at least one first battery module connected in series.
6. The energy storage system according to claim 4 or 5, characterized in that, The energy storage system further includes: a third battery cluster; the third battery cluster is connected in parallel with the first battery cluster; The third battery cluster includes at least one of the first battery modules and at least one of the second battery modules connected in series.
7. The energy storage system according to claim 6, characterized in that, The number of the first battery modules and / or the second battery modules included in the third battery cluster is different from that in the first battery cluster.
8. The energy storage system according to claim 4 or 5, characterized in that, The energy storage system further includes a fourth battery cluster; the fourth battery cluster is connected in parallel with the first battery cluster. The fourth battery cluster includes at least one second battery module connected in series.
9. The energy storage system according to claim 1, characterized in that, In the case where the energy storage system includes multiple first battery modules, at least two of the first battery modules differ in at least one of the following parameters when connected to the energy storage system: State of charge (SOC), battery capacity, state of health (SOH), battery voltage, and maximum charge / discharge current of the battery.
10. The energy storage system according to claim 1, characterized in that, The energy storage system also includes a power converter; The first end of the battery cluster is connected to the first end of the power converter, and the second end of the power converter is connected to the power supply and / or load device; The power source is either the power grid or a new energy power generation terminal.