Energy storage sub-module and energy storage system

Abstract

The utility model relates to an energy storage sub-module and an energy storage system. The energy storage sub-module comprises a power module, and the power module is provided with a first direct current end and a second direct current end; and the plurality of battery clusters connected in parallel are connected to the second direct current end in parallel, and at least one battery cluster is connected to the second direct current end in parallel through a direct current converter. According to the invention, the current among a plurality of battery clusters can be balanced, the risk of overcurrent is reduced, and the charge-discharge depth and availability of the battery clusters are improved.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to an energy storage submodule and an energy storage system. Background Art

[0002] With the development of new energy technologies, energy storage systems have been widely used in grid dispatching, power stability and energy management.

[0003] At present, many energy storage systems have battery clusters in parallel. Due to battery consistency issues, there may be uneven current between multiple battery clusters, which can easily lead to overcurrent, as well as low charge and discharge depth and low availability of the battery clusters. Utility Model Content

[0004] Based on the above problems, the present application provides an energy storage submodule and an energy storage system, which can balance the current between multiple battery clusters, reduce the risk of overcurrent, and improve the charge and discharge depth and availability of the battery cluster.

[0005] In a first aspect, the present application provides an energy storage submodule, which includes a power module, the power module having a first DC terminal and a second DC terminal; a plurality of battery clusters connected in parallel, connected in parallel to the second DC terminal, at least one battery cluster being connected in parallel to the second DC terminal via a DC converter.

[0006] In the technical solution of the embodiment of the present application, the current of at least one battery cluster can be adjusted by a DC converter, so as to balance the current among multiple battery clusters, reduce the risk of overcurrent, and improve the charge and discharge depth and availability of the battery cluster.

[0007] In some embodiments, the energy storage submodule includes multiple DC converters; each battery cluster is connected in parallel to the second DC terminal through a corresponding DC converter. In the technical solution of the embodiment of the present application, each battery cluster can have a correspondingly connected DC converter for current regulation, so that the current of each battery cluster can be more accurately controlled, so that the current between multiple battery clusters is more balanced, thereby greatly reducing the risk of overcurrent and improving the charge and discharge depth and availability of the battery cluster.

[0008] In some embodiments, the first positive port of each DC converter is connected to the positive electrode of the corresponding battery cluster, and the first negative port of the DC converter is connected to the negative electrode of the corresponding battery cluster; the second positive port of each DC converter is connected to the positive port of the second DC terminal of the power module, and the second negative port of the DC converter is connected to the negative port of the second DC terminal of the power module, and the first DC terminal of the power module is used to connect to the DC bus. In the technical solution of the embodiment of the present application, the DC converter can realize bidirectional energy transmission, and can realize current regulation in both the charging and discharging processes of the battery cluster, thereby balancing the charging current and discharging current of multiple battery clusters.

[0009] In some embodiments, the energy storage submodule includes multiple battery cluster controllers; each battery cluster controller is connected to a corresponding battery cluster and a DC converter. In the technical solution of the embodiment of the present application, the battery cluster controller can realize the functions of collecting data and controlling the battery cluster and the DC converter, so that the current regulation can be more timely and rapid, thereby reducing various risks caused by current imbalance.

[0010] In some embodiments, the battery cluster includes a plurality of battery packs connected in series, each battery pack includes a battery pack controller; the battery cluster controller is connected to the battery pack controllers in each battery pack. In the technical solution of the embodiment of the present application, the battery pack controller can collect data and accurately control the battery packs in the battery cluster, which can improve the reliability and safety of the battery cluster, and further improve the reliability and safety of the energy storage submodule.

[0011] In some embodiments, the battery pack includes a switch circuit and a battery cell; the switch circuit is connected to the battery pack controller and the battery cell respectively. In the technical solution of the embodiment of the present application, the battery cell can be connected to the battery cluster and the battery cell can be cut out from the battery cluster through the switch circuit. When the battery pack fails, the battery pack can be cut out separately, thereby reducing the impact on the entire battery cluster and improving the availability of the battery cluster.

[0012] In some embodiments, the switch circuit includes a first switch and a second switch; the first end of the first switch is connected to a node, and the second end of the first switch is connected to the positive electrode of the battery cell; the first end of the second switch is connected to the node, and the second end of the second switch is connected to the negative electrode of the battery cell; wherein the node is the first positive port of the DC converter or the second end of the second switch in the previous battery pack. In the technical solution of the embodiment of the present application, the battery cell can be connected to the battery cluster and the battery cell can be cut out of the battery cluster through the first switch and the second switch. When the battery pack fails, the battery pack can be cut out separately, thereby reducing the impact on the entire battery cluster and improving the availability of the battery cluster.

[0013] In some embodiments, the energy storage submodule further includes a submodule controller, which is connected to the power module and each battery cluster controller respectively. In the technical solution of the embodiment of the present application, the submodule controller can accurately control the entire energy storage submodule, thereby improving the safety and reliability of the energy storage system.

[0014] In some embodiments, the power module includes a plurality of power devices; the submodule controller is connected to each power device respectively. In the technical solution of the embodiment of the present application, the control of the power module can realize the energy storage submodule being connected to the energy storage system or being cut out from the energy storage system, which can not only adjust the voltage, current and charge state of the energy storage system, but also cut out the faulty energy storage submodule from the energy storage system to avoid the faulty energy storage submodule affecting the energy storage system, thereby improving the safety and reliability of the energy storage system.

[0015] In a second aspect, the present application also provides an energy storage system, which includes a system controller and multiple energy storage sub-modules as described in any one of the first aspects, wherein the multiple energy storage sub-modules are connected in series and connected to a DC bus; the system controller is connected to the sub-module controllers of each energy storage sub-module.

[0016] In the technical solution of the embodiment of the present application, a DC converter is provided in the energy storage submodule of the energy storage system, which can balance the current between multiple battery clusters in the energy storage submodule, reduce the risk of overcurrent, increase the charge and discharge depth and availability of the battery cluster, and thus improve the system performance of the energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the optional embodiments below. The accompanying drawings are only used for the purpose of illustrating the optional embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0018] Figure 1 This is a schematic diagram of the structure of an energy storage submodule according to an embodiment of the present application;

[0019] Figure 2 is a structural schematic diagram of an energy storage submodule according to an embodiment of the present application;

[0020] Figure 3 is a schematic diagram of the connection relationship of a DC converter according to an embodiment of the present application;

[0021] Figure 4 It is a partial structural schematic diagram of an energy storage submodule according to an embodiment of the present application;

[0022] Figure 5 is a schematic structural diagram of a battery cluster according to an embodiment of the present application;

[0023] Figure 6 is a schematic structural diagram of a battery pack according to an embodiment of the present application;

[0024] Figure 7 is a schematic structural diagram of a battery cluster according to an embodiment of the present application;

[0025] Figure 8 is a schematic structural diagram of a power module according to an embodiment of the present application;

[0026] Fig. 9 is a schematic structural diagram of a power module according to an embodiment of the present application;

[0027] Fig.10 is a structural schematic diagram of an energy storage system according to an embodiment of the present application;

[0028] Fig.11 is a structural schematic diagram of an energy storage system according to an embodiment of the present application;

[0029] Description of reference numerals:

[0030] Power module 10, battery cluster 20, DC converter 30, battery cluster controller 40;

[0031] Battery pack 21, battery pack controller 211, switch circuit 212, battery cell 213;

[0032] A first switch S1, a second switch S2, a first switch tube M1, and a second switch tube M2;

[0033] A first diode D1, a second diode D2, a third switch tube M3, and a fourth switch tube M4;

[0034] A fifth switch tube M5, a sixth switch tube M6, a third diode D3, and a fourth diode D4;

[0035] A fifth diode D5, a sixth diode D6, a capacitor C, a module resistor Rc, and a bypass switch K1;

[0036] System controller, isolating switch K2, starting resistor R, pre-charge switch K3, reactor L. DETAILED DESCRIPTION

[0037] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0039] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0040] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0041] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0042] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0043] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0044] With the development of new energy technologies, energy storage systems are widely used in grid dispatching, power stability and energy management. At present, many energy storage systems have battery clusters in parallel. Due to battery consistency issues, there may be current imbalances between multiple battery clusters, which can easily lead to overcurrent, low charge and discharge depth of the battery cluster, and low availability.

[0045] In view of the above problems, an embodiment of the present application provides an energy storage submodule, which includes a power module, the power module having a first DC terminal and a second DC terminal; a plurality of battery clusters connected in parallel, connected in parallel to the second DC terminal, and at least one battery cluster connected in parallel to the second DC terminal through a DC converter. In the technical solution of the embodiment of the present application, the current of at least one battery cluster can be adjusted by a DC converter, so that the current between the multiple battery clusters is balanced, the risk of overcurrent is reduced, and the charge and discharge depth and availability of the battery cluster are improved.

[0046] According to some embodiments of the present application, referring to Figure 1 , provides an energy storage submodule. The energy storage submodule includes a power module 10, the power module 10 has a first DC terminal and a second DC terminal; a plurality of battery clusters 20 connected in parallel, connected in parallel to the second DC terminal, at least one battery cluster 20 is connected in parallel to the second DC terminal through a DC converter 30.

[0047] In the embodiment of the present application, the energy storage submodule may include a power module 10, a plurality of battery clusters 20, and a DC converter 30. The power module 10 has a first DC terminal and a second DC terminal, the first DC terminal is used to be connected to the DC bus, and the second DC terminal is used to be connected in parallel with the battery cluster 20. Among the plurality of battery clusters 20, at least one battery cluster 20 is connected in parallel to the second DC terminal of the power module 10 through the DC converter 30. The DC converter 30 may convert the DC current output by the power module 10 and input it to the battery cluster 20 during the charging process of the battery cluster 20; the DC converter 30 may also convert the DC current output by the battery cluster 20 and input it to the power module 10 during the discharge process of the battery cluster 20, so as to output the DC current to the DC bus through the power module 10.

[0048] It is understandable that there may be current imbalance between multiple battery clusters 20, which may easily lead to overcurrent, low charge and discharge depth, and low availability of the battery cluster 20. The battery cluster 20 is connected in parallel with the power module 10 using a DC converter 30. The DC converter 30 can adjust the current of the corresponding connected battery cluster 20, thereby balancing the current between the multiple battery clusters 20, reducing the risk of overcurrent, and improving the charge and discharge depth and availability of the battery cluster 20.

[0049] In the above embodiment, the energy storage submodule includes a power module, the power module has a first DC terminal and a second DC terminal; a plurality of battery clusters connected in parallel are connected in parallel to the second DC terminal, and at least one battery cluster is connected in parallel to the second DC terminal through a DC converter. In the technical solution of the embodiment of the present application, the current of at least one battery cluster can be adjusted by a DC converter, so that the current between the multiple battery clusters is balanced, the risk of overcurrent is reduced, and the charge and discharge depth and availability of the battery cluster are improved.

[0050] According to some embodiments of the present application, referring to Figure 2 The energy storage submodule includes a plurality of DC converters 30 ; each battery cluster 20 is connected in parallel to the second DC terminal through the corresponding DC converter 30 .

[0051] In an embodiment of the present application, the energy storage submodule may include multiple battery clusters 20 and multiple DC converters 30, the battery clusters 20 are connected to the DC converters 30 in a one-to-one correspondence, and each battery cluster 20 is connected in parallel to the second DC terminal of the power module 10 through the corresponding DC converter 30.

[0052] In the above embodiment, the energy storage submodule includes a plurality of DC converters, and each battery cluster is connected in parallel to the second DC terminal through a corresponding DC converter. In the technical solution of the embodiment of the present application, each battery cluster can have a correspondingly connected DC converter for current regulation, so that the current of each battery cluster can be more accurately controlled, so that the current between multiple battery clusters is more balanced, thereby greatly reducing the risk of overcurrent and improving the charge and discharge depth and availability of the battery cluster.

[0053] According to some embodiments of the present application, referring to Figure 3 The first positive port of each DC converter 30 is connected to the positive electrode of the corresponding battery cluster 20, and the first negative port of the DC converter 30 is connected to the negative electrode of the corresponding battery cluster 20; the second positive port of each DC converter 30 is connected to the positive port of the second DC end of the power module 10, and the second negative port of the DC converter 30 is connected to the negative port of the second DC end of the power module 10. The first DC end of the power module 10 is used to connect to the DC bus.

[0054] In the embodiment of the present application, the DC converter 30 is provided with a first positive port and a first negative port for connecting to the battery cluster 20 , and a second positive port and a second negative port for connecting to the power module 10 .

[0055] The first positive port of the DC converter 30 is connected to the positive electrode of the battery cluster 20, and the first negative port of the DC converter 30 is connected to the negative electrode of the battery cluster 20. The second positive port of the DC converter 30 is connected to the positive port of the second DC terminal of the power module 10, and the second negative port of the DC converter 30 is connected to the negative port of the second DC terminal of the power module 10.

[0056] The DC converter 30 can realize bidirectional energy transmission. When the battery cluster 20 is charged, the DC converter 30 can receive the DC current output by the power module 10 through the second positive port and the second negative port, perform current conversion on the DC current, and input the converted DC current to the battery cluster 20 through the first positive port and the first negative port. When the battery cluster 20 is discharged, the DC converter 30 can also receive the DC current output by the battery cluster 20 through the first positive port and the first negative port, perform current conversion on the DC current, and input the converted DC current to the power module 10 through the second positive port and the second negative port.

[0057] In the above embodiment, the first positive port of each DC converter is connected to the positive electrode of the corresponding battery cluster, and the first negative port of the DC converter is connected to the negative electrode of the corresponding battery cluster; the second positive port of each DC converter is connected to the positive port of the second DC terminal of the power module, and the second negative port of the DC converter is connected to the negative port of the second DC terminal of the power module, and the first DC terminal of the power module is used to connect to the DC bus. In the technical solution of the embodiment of the present application, the DC converter can realize bidirectional energy transmission, and can realize current regulation in both the charging and discharging processes of the battery cluster, thereby balancing the charging current and discharging current of multiple battery clusters.

[0058] According to some embodiments of the present application, the energy storage submodule includes a plurality of battery cluster controllers 40; Figure 4 Each battery cluster controller 40 is connected to the corresponding battery cluster 20 and the DC converter 30 respectively.

[0059] In the embodiment of the present application, the energy storage submodule includes multiple battery cluster controllers 40 , which correspond to the battery clusters 20 one by one. Each battery cluster controller 40 is connected to the corresponding battery cluster 20 and to the DC converter 30 corresponding to the battery cluster 20 .

[0060] The battery cluster controller 40 can obtain the status information of the battery cluster 20 and control the charging or discharging of the battery cluster 20. The status information of the battery cluster 20 includes the cluster voltage, cluster current, and cluster charge state of the battery cluster 20.

[0061] It should be noted that the status information of the battery cluster 20 is not limited to the above examples, and in practical applications, may also include other information.

[0062] The battery cluster controller 40 can control the on / off and current regulation of the DC converter 30. For example, the battery cluster controller 40 generates a regulation instruction according to the cluster current of the battery cluster 20 and sends the regulation instruction to the DC converter 30; the DC converter 30 regulates the cluster current of the battery cluster 20 according to the regulation instruction.

[0063] It should be noted that the functions of the battery cluster controller 40 are not limited to the above examples and can be set according to actual conditions.

[0064] In the above embodiment, the energy storage submodule includes multiple battery cluster controllers, and each battery cluster controller is connected to the corresponding battery cluster and DC converter. In the technical solution of the embodiment of the present application, the battery cluster controller can realize the functions of collecting data and controlling the battery cluster and DC converter, so that the current regulation can be more timely and rapid, thereby reducing various risks caused by current imbalance.

[0065] According to some embodiments of the present application, referring to Figure 5 The battery cluster 20 includes a plurality of battery packs 21 connected in series, each battery pack 21 includes a battery pack controller 211 ; the battery cluster controller 40 is connected to the battery pack controller 211 in each battery pack 21 .

[0066] In the embodiment of the present application, each battery cluster 20 is composed of a plurality of battery packs 21 connected in series. Each battery pack 21 includes a battery pack controller 211 , and the battery pack controller 211 in each battery pack 21 is connected to the battery cluster controller 40 .

[0067] The battery pack controller 211 can obtain the status information of the battery pack 21 and control the battery pack 21 to charge or discharge. The status information of the battery pack 21 includes the voltage, current, state of charge and temperature of the battery pack 21. The battery pack controller 211 can transmit the status information of the battery pack 21 to the battery cluster controller 40, so that the battery cluster controller 40 can determine the status information of the battery cluster 20 according to the status information of the battery pack 21.

[0068] It should be noted that the status information of the battery pack is not limited to the above examples, and in practical applications, it may also include other information.

[0069] In the above embodiment, the battery cluster includes a plurality of battery packs connected in series, each battery pack includes a battery pack controller; the battery cluster controller is connected to the battery pack controller in each battery pack. In the technical solution of the embodiment of the present application, the battery pack controller can collect data and accurately control the battery packs in the battery cluster, which can improve the reliability and safety of the battery cluster, and further improve the reliability and safety of the energy storage submodule.

[0070] According to some embodiments of the present application, referring to Figure 6 The battery pack 21 includes a switch circuit 212 and a battery cell 213; the switch circuit 212 is connected to the battery pack controller 211 and the battery cell 213 respectively.

[0071] In the embodiment of the present application, the battery pack 21 further includes a switch circuit 212 and a battery cell 213, and the switch circuit 212 is respectively connected to the battery pack controller 211 and the battery cell 213. The battery pack controller 211 can control the switch circuit 212 to connect the battery cell 213 to the battery cluster 20 or disconnect it from the battery cluster 20.

[0072] For example, when the battery cell 213 is normal, the battery pack controller 211 controls the switch circuit 212 to connect the battery cell 213 to the battery cluster 20 ; when the battery cell 213 fails, the battery pack controller 211 controls the switch circuit 212 to disconnect the battery cell 213 from the battery cluster 20 .

[0073] In one embodiment, the switch circuit 212 may include a single-pole double-throw switch, the moving end of the single-pole double-throw switch is connected to the DC converter 30 or the switch circuit 212 in the previous battery pack 21, the first fixed end of the single-pole double-throw switch is connected to the battery cell 213, and the second fixed end is connected to the switch circuit 212 of the next battery pack 21. The battery pack controller 211 can control the moving end to be connected to the first fixed end or the second fixed end. When the moving end is connected to the first fixed end, the battery cell 213 is connected to the battery cluster 20, and the battery cell 213 can be charged or discharged; when the moving end is connected to the second fixed end, the battery cell 213 is cut out of the battery cluster 20.

[0074] In the above embodiment, the battery pack includes a switch circuit and a battery cell; the switch circuit is connected to the battery pack controller and the battery cell respectively. In the technical solution of the embodiment of the present application, the battery cell can be connected to the battery cluster and the battery cell can be cut out from the battery cluster through the switch circuit. When the battery pack fails, the battery pack can be cut out separately, thereby reducing the impact on the entire battery cluster and improving the availability of the battery cluster.

[0075] According to some embodiments of the present application, referring to Figure 7 The switch circuit 212 includes a first switch S1 and a second switch S2; the first end of the first switch S1 is connected to a node, and the second end of the first switch S1 is connected to the positive electrode of the battery cell 213; the first end of the second switch S2 is connected to the node, and the second end of the second switch S2 is connected to the negative electrode of the battery cell 213; wherein the node is the first positive port of the DC converter 30 or the second end of the second switch S2 in the previous battery pack 21.

[0076] In the embodiment of the present application, the switch circuit 212 includes a first switch S1 and a second switch S2. For the battery pack 21 at the positive electrode of the battery cluster 20, the first end of the first switch S1 is connected to the first positive port of the DC converter 30, and the second end of the first switch S1 is connected to the positive electrode of the battery cell 213; the first end of the second switch S2 is connected to the first positive port of the DC converter 30, and the second end of the second switch S2 is connected to the negative electrode of the battery cell 213.

[0077] For the battery pack 21 at the negative electrode of the battery cluster 20, the first end of the first switch S1 is connected to the second end of the second switch S2 in the previous battery pack 21, and the second end of the first switch S1 is connected to the positive electrode of the battery cell 213; the first end of the second switch S2 is also connected to the second end of the second switch S2 in the previous battery pack 21, and the second end of the second switch S2 is connected to the negative electrode of the battery cell 213, and the second end of the second switch S2 is also connected to the first negative port of the DC converter 30.

[0078] For the battery pack 21 in the middle of the battery cluster 20, the first end of the first switch S1 is connected to the second end of the second switch S2 in the previous battery pack 21, and the second end of the first switch S1 is connected to the positive electrode of the battery cell 213; the first end of the second switch S2 is also connected to the second end of the second switch S2 in the previous battery pack 21, and the second end of the second switch S2 is connected to the negative electrode of the battery cell 213 and the first end of the first switch S1 and the first end of the second switch S2 in the next battery pack 21.

[0079] In the above embodiment, the switch circuit includes a first switch and a second switch; the first end of the first switch is connected to a node, and the second end of the first switch is connected to the positive electrode of the battery cell; the first end of the second switch is connected to the node, and the second end of the second switch is connected to the negative electrode of the battery cell; wherein the node is the first positive port of the DC converter 30 or the second end of the second switch in the previous battery pack. In the technical solution of the embodiment of the present application, the battery cell can be connected to the battery cluster and cut out from the battery cluster through the first switch and the second switch. When the battery pack fails, the battery pack can be cut out separately, thereby reducing the impact on the entire battery cluster and improving the availability of the battery cluster.

[0080] According to some embodiments of the present application, the energy storage submodule further includes a submodule controller, and the submodule controller is respectively connected to the power module 10 and the controllers of each battery cluster 20 .

[0081] In the embodiment of the present application, the energy storage submodule also includes a submodule controller, which is connected to the power module 10 and can control the power module 10 to connect the battery cluster 20 to the DC bus, or control the power module 10 to disconnect the battery cluster 20 from the DC bus.

[0082] The submodule controller is also connected to each battery cluster controller 40. Each battery cluster controller 40 can transmit the status information of the battery cluster 20 and the status information of each battery pack 21 to the submodule controller, and the submodule controller can determine the status information of the energy storage submodule according to the status information of the battery cluster 20 and the status information of the battery pack 21, and control the energy storage submodule to charge or discharge according to the status information of the energy storage submodule, and connect the energy storage submodule to the energy storage system or cut it out from the energy storage system.

[0083] It should be noted that the functions of the sub-module controller are not limited to the above examples and can be set according to actual conditions.

[0084] In the above embodiment, the energy storage submodule further includes a submodule controller, which is connected to the power module and each battery cluster controller respectively. In the technical solution of the embodiment of the present application, the submodule controller can accurately control the entire energy storage submodule, thereby improving the safety and reliability of the energy storage system.

[0085] According to some embodiments of the present application, the power module 10 includes a plurality of power devices; and the submodule controllers are respectively connected to each power device.

[0086] In the embodiment of the present application, the power module 10 includes a plurality of power devices, and the submodule controller is connected to each power device respectively. The submodule controller can control the on and off of each power device, thereby connecting the energy storage submodule to the energy storage system or disconnecting it from the energy storage system through the on and off of the plurality of power devices.

[0087] Reference Figure 8 The power device includes a first switch tube M1 and a second switch tube M2; the control electrode of the first switch tube M1 is connected to the sub-module controller, the first electrode of the first switch tube M1 is connected to the second positive port of the DC converter 30, and the second electrode of the first switch tube M1 is connected to the first electrode of the second switch tube M2; the control electrode of the second switch tube M2 is connected to the sub-module controller, and the second electrode of the second switch tube M2 is connected to the second negative port of the DC converter 30; the second electrode of the first switch tube M1 and the second electrode of the second switch tube M2 are used to connect to the DC bus.

[0088] The power module 10 further includes a first diode D1 and a second diode D2; two ends of the first diode D1 are respectively connected to the first pole and the second pole of the first switch tube M1; two ends of the second diode D2 are respectively connected to the first pole and the second pole of the second switch tube M2.

[0089] In some embodiments, reference Fig. 9The power device includes a third switch tube M3, a fourth switch tube M4, a fifth switch tube M5 and a sixth switch tube M6; the control electrode of the third switch tube M3 is connected to the sub-module controller, the first electrode of the third switch tube M3 is connected to the second positive port of the DC converter 30, and the second electrode of the third switch tube M3 is connected to the first electrode of the fourth switch tube M4; the control electrode of the fourth switch tube M4 is connected to the sub-module controller, and the second electrode of the fourth switch tube M4 is connected to the second negative port of the DC converter 30; the control electrode of the fifth switch tube M5 is connected to the sub-module controller, the first electrode of the fifth switch tube M5 is connected to the second positive port of the DC converter 30, and the second electrode of the fifth switch tube M5 is connected to the first electrode of the sixth switch tube M6; the control electrode of the sixth switch tube M6 is connected to the sub-module controller, and the second electrode of the sixth switch tube M6 is connected to the second negative port of the DC converter 30; the second electrode of the third switch tube M3 and the second electrode of the fifth switch tube M5 are used to connect the DC bus.

[0090] The power module 10 also includes a third diode D3, a fourth diode D4, a fifth diode D5 and a sixth diode D6; the two ends of the third diode D3 are respectively connected to the first pole and the second pole of the third switch tube M3; the two ends of the fourth diode D4 are respectively connected to the first pole and the second pole of the fourth switch tube M4; the two ends of the fifth diode D5 are respectively connected to the first pole and the second pole of the fifth switch tube M5; the two ends of the sixth diode D6 are respectively connected to the first pole and the second pole of the sixth switch tube M6.

[0091] The power module 10 may further include a capacitor C, a module resistor Rc and a bypass switch K1. The bypass switch K1 may be connected to a submodule controller, which controls the on and off of the bypass switch K1. When the bypass switch K1 is on, the power module 10 and the battery cluster 20 are cut out of the energy storage system.

[0092] The energy storage submodule may further include fuses, one fuse connected between the positive port of the second DC end of the power module 10 and the second positive port of the DC converter 30 , and another fuse connected between the negative port of the second DC end of the power module 10 and the second negative port of the DC converter 30 .

[0093] In the above embodiment, the power module includes a plurality of power devices; the submodule controller is connected to each power device respectively. In the technical solution of the embodiment of the present application, the control of the power module can realize the energy storage submodule being connected to the energy storage system or being cut out from the energy storage system, which can not only adjust the voltage, current and charge state of the energy storage system, but also cut out the faulty energy storage submodule from the energy storage system to avoid the faulty energy storage submodule affecting the energy storage system, thereby improving the safety and reliability of the energy storage system.

[0094] According to some embodiments of the present application, referring to Fig.10, an energy storage system is provided. The energy storage system includes a system controller 50 and a plurality of energy storage submodules SM as in the above embodiment, wherein the plurality of energy storage submodules SM are connected in series and connected to a DC bus; the system controller 50 is connected to a submodule controller of each energy storage submodule SM.

[0095] In the embodiment of the present application, the energy storage system includes a system controller 50 and multiple energy storage submodules SM as in the above embodiment. The multiple energy storage submodules SM are connected in series, and one end is connected to the positive DC bus and the other end is connected to the negative DC bus.

[0096] The system controller 50 is connected to the submodule controllers of each energy storage submodule. Each submodule controller can transmit the status information of the energy storage submodule to the system controller 50, and the system controller 50 can control the energy storage submodule SM to charge or discharge, and connect the energy storage submodule SM to the energy storage system or disconnect it from the energy storage system according to the status information of each energy storage submodule SM.

[0097] In some embodiments, reference Fig.11 The energy storage system further includes an isolating switch K2, a starting resistor R and a pre-charging switch K3 connected in parallel, and a reactor L. The first end of the isolating switch K2 is connected to the positive DC bus, and the second end of the isolating switch K2 is connected to the first end of the starting resistor R and the first end of the pre-charging switch K3. The second end of the starting resistor R is connected to the first end of the reactor L, and the second end of the pre-charging switch K3 is connected to the first end of the reactor L. The second end of the reactor L is connected to the energy storage submodule SM.

[0098] When multiple energy storage submodules SM need to be connected to the DC bus, the isolation switch K2 can be controlled to be turned on; when multiple energy storage submodules SM need to stop working, the isolation switch K2 can be controlled to be turned off, and the multiple energy storage submodules SM are directly cut out. The system controller 50 can be connected to the isolation switch K2 to control the on and off of the isolation switch K2.

[0099] In actual application, after the isolation switch K2 is turned on, the DC current is transmitted to the starting resistor R through the isolation switch K2 and then to the reactor L. After a preset time, the pre-charge switch K3 is controlled to be turned on, and the DC current is transmitted to the pre-charge switch K3 and then to the reactor L through the isolation switch K2.

[0100] It can be understood that the starting resistor is used in conjunction with the pre-charge switch to avoid excessive current in the path, and the starting resistor can play a role in protecting the energy storage system.

[0101] Reactors can filter and reduce noise to assist the normal operation of the energy storage system.

[0102] In the above embodiment, the energy storage system includes a system controller and a plurality of energy storage submodules SM, the plurality of energy storage submodules are connected in series and connected to a DC bus; the system controller is connected to the submodule controller of each energy storage submodule. In the technical solution of the embodiment of the present application, a DC converter is provided in the energy storage submodule of the energy storage system, which can balance the current between the plurality of battery clusters in the energy storage submodule, reduce the risk of overcurrent, improve the charge and discharge depth and availability of the battery cluster, and thus improve the system performance of the energy storage system.

[0103] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0104] The above-described embodiments only express several implementation methods of the present application, which is convenient for understanding the technical solution of the present application in detail, but it cannot be understood as limiting the scope of protection of the utility model patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the scope of protection of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided in the present application are all within the scope of protection of the attached claims described in the present application. Therefore, the scope of protection of the patent of this application shall be based on the content of the attached claims, and the description and drawings can be used to explain the content of the claims.

Claims

1. An energy storage submodule, characterized in that: The energy storage submodule includes a power module, and the power module has a first DC terminal and a second DC terminal; A plurality of battery clusters connected in parallel are connected in parallel at the second DC terminal, and at least one of the battery clusters is connected in parallel to the second DC terminal via a DC converter.

2. The energy storage submodule according to claim 1, characterized in that: The energy storage submodule includes a plurality of the DC converters; each of the battery clusters is connected in parallel to the second DC terminal via a corresponding DC converter.

3. The energy storage submodule according to claim 2, characterized in that: The first positive port of each DC converter is connected to the positive electrode of the corresponding battery cluster, and the first negative port of the DC converter is connected to the negative electrode of the corresponding battery cluster; The second positive port of each DC converter is connected to the positive port of the second DC end of the power module, the second negative port of the DC converter is connected to the negative port of the second DC end of the power module, and the first DC end of the power module is used to connect to the DC bus.

4. The energy storage submodule according to claim 2, characterized in that: The energy storage submodule includes a plurality of battery cluster controllers; each of the battery cluster controllers is respectively connected to a corresponding battery cluster and a DC converter.

5. The energy storage submodule according to claim 4, characterized in that: The battery cluster includes a plurality of battery packs connected in series, each of the battery packs including a battery pack controller; The battery cluster controller is connected to the battery pack controllers in each of the battery packs.

6. The energy storage submodule according to claim 5, characterized in that: The battery pack includes a switch circuit and a battery cell; The switch circuit is connected to the battery pack controller and the battery cell respectively.

7. The energy storage submodule according to claim 6, characterized in that: The switch circuit includes a first switch and a second switch; The first end of the first switch is connected to a node, and the second end of the first switch is connected to the positive electrode of the battery cell; A first end of the second switch is connected to the node, and a second end of the second switch is connected to the negative electrode of the battery cell; The node is the first positive port of the DC converter or the second end of the second switch in the previous-stage battery pack.

8. The energy storage submodule according to claim 4, characterized in that: The energy storage submodule further includes a submodule controller, and the submodule controller is respectively connected to the power module and each of the battery cluster controllers.

9. The energy storage submodule according to claim 8, characterized in that: The power module includes a plurality of power devices; the submodule controller is connected to each of the power devices respectively.

10. An energy storage system, characterized in that: The energy storage system comprises a system controller and a plurality of energy storage submodules according to any one of claims 1 to 9, wherein the plurality of energy storage submodules are connected in series and connected to a DC bus; The system controller is connected to the submodule controllers of each of the energy storage submodules.

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