Battery device and energy storage system

Abstract

The utility model discloses a battery device and an energy storage system, and the battery device comprises a battery unit which comprises a plurality of batteries, and the plurality of batteries comprise at least one standby battery; and the switching control unit is configured to connect the standby battery into the battery unit in series and bypass the battery to be replaced under the condition that the battery to be replaced exists in the plurality of batteries, so that the battery unit is subjected to internal reconfiguration. According to the battery device, the to-be-replaced battery can be autonomously replaced through the standby battery, so that the battery unit is subjected to internal reconstruction, and the battery unit does not lose efficacy due to a battery fault.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage systems, and in particular to a battery device and an energy storage system. Background Art

[0002] With the rapid deterioration of the global environment in recent years, green environmental protection, especially carbon emissions, has received more and more attention and importance. As an important clean energy carrier, lithium batteries have been widely used in power grid energy storage, electric vehicles, electric ships and other fields in recent years, helping to achieve carbon neutrality and emission reduction goals.

[0003] In related technologies, lithium batteries are classified into cells, battery packs, clusters, arrays, etc. from small to large. For large-capacity power consumption scenarios such as ships, cluster or array-level battery structures are usually used. However, when a battery pack fails, the entire cluster corresponding to the battery pack will fail, which will in turn cause the energy storage system to reduce capacity or fail. Utility Model Content

[0004] In view of the above problems, the present application provides a battery device and an energy storage system, which can autonomously replace a battery to be replaced with a backup battery to allow the battery unit to be internally reconstructed so that the battery unit will not fail due to battery failure.

[0005] In a first aspect, the present application provides a battery device comprising: a battery cell, the battery cell comprising a plurality of batteries, the plurality of batteries including at least one backup battery; a switching control unit, the switching control unit being configured to connect the backup battery in series to the battery cell and bypass the battery to be replaced, so as to allow the battery cell to be internally reconstructed when there is a battery to be replaced among the plurality of batteries.

[0006] In the technical solution of the embodiment of the present application, the battery unit of the battery device includes a plurality of batteries, some of which are connected in series in sequence to form a cluster that meets the preset power supply voltage requirement, and at least one backup battery among the plurality of batteries is placed in bypass. During operation, the battery to be replaced and the backup battery used to replace the battery to be replaced are determined based on the battery status of each battery. For example, when the voltage of the battery constituting the cluster is too low and the charging and discharging is abnormal, the battery is determined to be a battery to be replaced, and the backup battery with the best battery status is selected as the backup battery to replace the battery to be replaced according to the battery status of at least one backup battery. The switching control unit connects the corresponding backup battery in series to the battery unit, and bypasses the battery to be replaced out of the battery unit, so as to replace the battery to be replaced by the backup unit, so that the battery unit is internally reconstructed. In this way, the battery to be replaced can be replaced by the backup battery, so that the battery unit is internally reconstructed, so that the battery unit will not fail due to battery failure. In addition, the internal reconstruction can be realized autonomously by the switching control unit, which reduces manual participation and labor costs, and at the same time improves the safety and rapidity of replacement, thereby reducing the reduced capacity operation time and downtime operation time of the energy storage system corresponding to the battery device, and improving the power supply reliability and continuity.

[0007] In some embodiments, the battery device further comprises: a positive DC bus and a negative DC bus, wherein the remaining batteries in the battery unit excluding the backup battery are connected in series between the positive DC bus and the negative DC bus before internal reconstruction.

[0008] Before internal reconstruction, the remaining batteries in the battery unit except the backup battery are connected in series, and the backup battery is placed in bypass. The remaining batteries are connected in series to form a cluster that meets the preset power supply voltage requirements, and the charging and discharging process is performed through the positive DC bus and the negative DC bus.

[0009] In some embodiments, the batteries in the battery unit are connected in series between the positive DC bus and the negative DC bus after internal reconstitution.

[0010] When it is determined that there is a battery to be replaced among the remaining batteries, the spare battery is connected in series to the battery unit, and the battery to be replaced is bypassed out of the battery unit, so that a cluster that meets the preset power supply voltage requirement is formed by connecting the spare battery and the remaining batteries except the battery to be replaced in series in sequence, and the battery unit after internal reconstruction performs the charging and discharging process through the positive DC bus and the negative DC bus.

[0011] In some embodiments, a switching control unit includes: a plurality of first switching switch assemblies and a plurality of second switching switch assemblies, each first switching switch assembly corresponding to the positive electrode setting of each battery in the battery cell, each second switching switch assembly corresponding to the negative electrode setting of each battery in the battery cell, and each first switching switch assembly and each second switching switch assembly are suitable for connecting the corresponding battery in series into the battery cell or bypassing the corresponding battery out of the battery cell.

[0012] Each battery is provided with a first switching switch component and a second switching switch component. By controlling the first switching switch component and the second switching switch component corresponding to each battery, the series connection and bypass of the corresponding battery are realized to internally construct the battery unit and improve the control effect.

[0013] In some embodiments, the first end of the first first switching switch assembly among the multiple first switching switch assemblies is connected to the positive DC bus, the second end of each first switching switch assembly is connected to the positive electrode of the first battery among the multiple batteries, the third end of each first switching switch assembly is connected to the first end of the corresponding second switching switch assembly, the second end of each second switching switch assembly is connected to the negative electrode of each battery, and the first end of the last second switching switch assembly among the multiple second switching switch assemblies is connected to the negative DC bus.

[0014] In the case where the first end of the first switch assembly for controlling the corresponding battery is connected to the second end of the first switch assembly, and the first end of the first switch assembly is disconnected from the third end of the first switch assembly, and the first end of the second switch assembly for controlling the corresponding battery is connected to the second end of the second switch assembly, the corresponding battery is connected in series in the battery unit. In the case where the first end of the first switch assembly for controlling the corresponding battery is connected to the third end of the first switch assembly, and the first end of the first switch assembly is disconnected from the second end of the first switch assembly, and the first end of the second switch assembly for controlling the corresponding battery is disconnected from the second end of the second switch assembly, the corresponding battery is bypassed out of the battery unit.

[0015] This embodiment realizes the series connection or bypass of the battery by controlling the first switching switch assembly and the second switching switch assembly, thereby improving the rapidity of replacement control.

[0016] In some embodiments, each first switching switch component includes: a first switch and a second switch, one end of the first switch is connected to one end of the second switch, and has a first node, the first node serves as the first end of the first switching switch component, the other end of the first switch serves as the second end of the first switching switch component, and the other end of the second switch serves as the third end of the first switching switch component.

[0017] When the first switch is controlled to be closed and the second switch is opened, the positive electrode of the corresponding battery is connected in series to the battery cell; when the first switch is controlled to be opened and the second switch is closed, the positive electrode of the corresponding battery is not connected to the battery cell and is bypassed.

[0018] In some embodiments, each second switching switch assembly includes: a third switch, one end of the third switch serves as the first end of the second switching switch assembly, and the other end of the third switch serves as the second end of the second switching switch assembly.

[0019] When the third switch is controlled to be closed, the negative electrode of the corresponding battery is connected to the circuit of the battery unit. When the third switch is controlled to be open, the negative electrode of the corresponding battery is disconnected from the circuit of the battery unit.

[0020] When controlling the corresponding batteries to be connected in series to the battery cell, this can be achieved by controlling the first switch to be closed, the second switch to be opened, and the third switch to be closed; when controlling the corresponding batteries to be bypassed out of the battery cell, this can be achieved by controlling the first switch to be opened, the second switch to be closed, and the third switch to be opened, so as to increase the internal reconstruction speed of the battery cell.

[0021] In some embodiments, at least one of the first switch, the second switch and the third switch comprises a fully-controlled unidirectional conducting semiconductor switch, and the fully-controlled unidirectional conducting semiconductor switch is adapted to be connected in reverse parallel with a diode.

[0022] By reversely connecting a fully controlled unidirectional conductive semiconductor switch with a diode in parallel, the first switching switch component and the second switching switch component support on-load switching and disconnection, thereby improving power supply continuity, while supporting unidirectional conduction and limiting circulating current.

[0023] In some embodiments, when the first switch corresponding to the backup battery is closed, the second switch is open, and the third switch is closed, the backup battery is connected in series to the battery unit.

[0024] The bypass branch corresponding to the backup battery is disconnected by opening the second switch, and the backup battery is connected in series to the battery unit in coordination with the closed first switch and the closed third switch.

[0025] In some embodiments, when the first switch corresponding to the battery to be replaced is opened, the second switch is closed, and the third switch is opened, the battery to be replaced is bypassed out of the battery unit.

[0026] Based on the disconnected first switch and the disconnected second switch, the positive and negative electrodes of the battery to be replaced are disconnected from the series circuit of the battery cell to bypass the battery cell, and based on the closed second switch, the first end of the first switch component of the battery to be replaced is connected to the third end, so that the series circuit of the battery cell remains conductive.

[0027] In some embodiments, the battery device further includes: a controllable switch, the controllable switch being arranged corresponding to the positive DC bus and the negative DC bus to disconnect the positive DC bus and the negative DC bus from the converter when the battery cell is internally reconstructed.

[0028] During the internal reconstruction of the battery unit, the controllable switch is controlled to be disconnected to disconnect the positive DC bus and the negative DC bus from the converter.

[0029] In some embodiments, the controllable switch is also configured to close after the backup battery is connected in series with the battery cell so that the inverter can charge the battery cell, and when the battery cell is fully charged, the battery to be replaced is bypassed through the first switching switch component and the second switching switch component corresponding to the battery to be replaced.

[0030] When it is determined that there are batteries to be replaced among multiple batteries, the controllable switch is controlled to be disconnected, and after the backup battery is connected in series to the battery unit, the controllable switch is controlled to be closed, and the battery unit is charged by controlling the converter, and the start and stop of charging are controlled according to the voltage of each battery connected in series to the battery unit. After charging is completed, the battery to be replaced is bypassed by controlling the first switching switch assembly and the second switching switch assembly corresponding to the battery to be replaced to complete the internal reconstruction of the battery unit. After the internal reconstruction of the battery unit, the converter is controlled to start discharging, and the discharge process is performed through the internally reconstructed battery unit.

[0031] This embodiment performs a charging process before replacing the unit to be replaced, so that the battery can be charged regularly to increase the service life of the battery and reduce the cost investment caused by the failure of the backup battery due to its long-term existence.

[0032] In some embodiments, the switching control unit is also configured to control a plurality of first switching switch assemblies and a plurality of second switching switch assemblies to bypass the faulty battery and connect the backup battery in series to the battery cell when the battery to be replaced is a faulty battery and the voltage difference between the backup battery and the unreplaced battery in the battery cell is less than a preset voltage threshold.

[0033] In the case that the battery to be replaced is a faulty battery, the status parameters of the backup batteries are obtained, and the backup battery whose voltage is closest to the voltage of the unreplaced battery is selected first, and then the backup battery with the best status is selected to replace the faulty battery.

[0034] If the voltage difference between the backup battery and the unreplaced battery is less than the preset voltage threshold, the backup battery is directly replaced with the battery to be replaced, that is, the battery to be replaced is bypassed out of the battery unit by controlling the first switching switch component and the second switching switch component corresponding to the battery to be replaced, and at the same time, the first switching switch component and the second switching switch component corresponding to the backup battery are controlled to connect the backup battery in series with the battery unit to complete the replacement and increase the replacement speed.

[0035] In some embodiments, each second switching switch assembly also includes: a fourth switch and a voltage balancing branch, one end of the fourth switch is connected to the negative electrode of the corresponding battery, and the other end of the fourth switch is connected to the negative DC bus through the voltage balancing branch, wherein the switching control unit is also configured to, when the voltage difference between the backup battery and the unreplaced battery in the battery unit is greater than or equal to a preset voltage threshold, control the first switching switch assembly and the second switching switch assembly corresponding to the faulty battery to bypass the faulty battery, and then control the first switching switch assembly and the second switching switch assembly corresponding to the unreplaced battery and the backup battery to connect the unreplaced battery and the backup battery in parallel to the positive DC bus and the negative DC bus respectively through the voltage balancing branch.

[0036] In the case that the battery to be replaced is a faulty battery, if the voltage difference between the backup battery and the unreplaced battery is greater than or equal to the preset voltage threshold, then after the controllable switch is controlled to disconnect, the faulty battery is first bypassed out of the battery unit, and then the unreplaced battery and the backup battery are connected in parallel between the positive DC bus and the negative DC bus, and the unreplaced battery and the backup battery are connected in parallel for voltage equalization to automatically achieve voltage balance within the battery unit and suppress cluster circulation.

[0037] After completing the voltage balancing, the unreplaced batteries and the backup batteries are connected in series in sequence to allow the battery cells to be internally reconstructed, and then the controllable switches are controlled to close, thereby controlling the converter to perform the charging and discharging process through the internally reconstructed battery cells.

[0038] In some embodiments, a voltage-equalizing resistor is connected in series in the voltage-equalizing branch, so as to achieve the maximum voltage-equalizing current without overcurrent.

[0039] In some embodiments, the fourth switch includes two fully controlled unidirectional conduction semiconductor switches connected in reverse parallel, so that the fourth switch supports on-load switching to improve power supply continuity, and supports unidirectional conduction to limit circulating current.

[0040] In a second aspect, the present application provides an energy storage system, comprising: an inverter; and at least one of the above-mentioned battery devices, wherein each battery device is connected in parallel to the DC side of the inverter.

[0041] In the technical solution of the embodiment of the present application, the energy storage system includes an inverter and at least one of the above-mentioned battery devices, each battery device is connected in parallel to the DC side of the inverter, and the AC side of the inverter is the output end of the energy storage system. The redundant design of the battery is carried out in each battery device. When a battery to be replaced appears in the battery device, the spare battery can be replaced by the battery to be replaced autonomously, and the internal reconstruction of the battery unit is realized, so that the battery unit will not fail due to battery failure. In addition, the internal reconstruction can be realized autonomously by switching the control unit, which reduces manual participation and labor costs, and at the same time improves the safety and rapidity of replacement, thereby shortening the reduced capacity operation time and downtime operation time of the energy storage system, and improving the power supply reliability and sustainability of the energy storage system.

[0042] In some embodiments, when each battery device is discharged through the converter, the reverse-parallel-connected diode of the first switch in each battery device is turned on and the semiconductor switch is turned off.

[0043] When multiple battery devices are connected in parallel and share one inverter, during the discharge process through the inverter, only the reverse parallel-connected diode in the discharge direction in the first switch of the grid battery pack in each battery device is controlled to be turned on, and the semiconductor switch is disconnected, so that it can be unidirectionally conductive without a circulation channel, thereby achieving circulation suppression between the battery devices.

[0044] In some embodiments, when a discharge circuit of any battery device that discharges through the converter fails, each third switch in the battery device is disconnected. For example, when a discharge circuit fails such as overcurrent, undervoltage, or overvoltage, each third switch in the battery device is controlled to be disconnected to disconnect the discharge circuit of each battery.

[0045] In some embodiments, when a charging circuit of any battery device charged by the converter fails, each first switch in the battery device is disconnected. For example, when a charging circuit fails such as overcurrent, undervoltage, or overvoltage, the first switch corresponding to each battery in the battery device is controlled to be disconnected to disconnect the charging circuit of each battery.

[0046] In some embodiments, each battery device further comprises a controllable switch, which is adapted to disconnect the faulty battery device from the DC side of the converter and connect a spare battery device to the DC side of the converter when a corresponding battery device fails.

[0047] When a battery device connected in parallel on the DC side of the converter fails, the backup battery device is replaced with the failed battery device by controlling the controllable switch to achieve internal reconstruction of the energy storage system, thereby improving the safety and rapidity of replacement, thereby shortening the reduced capacity operation time and downtime operation time of the energy storage system, and improving the power supply reliability and continuity of the energy storage system.

[0048] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred 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:

[0050] Figure 1 A block diagram of a battery device according to some embodiments of the present application;

[0051] Figure 2 A circuit of a battery device according to some embodiments of the present application Figure 1 ;

[0052] Figure 3 The circuit of the first switching switch assembly of some embodiments of the present application Figure 1 ;

[0053] Figure 4 The circuit of the first switching switch assembly of some embodiments of the present application Figure 2 ;

[0054] Figure 5 The circuit of the second switching switch assembly of some embodiments of the present application Figure 1 ;

[0055] Figure 6 The circuit of the second switching switch assembly of some embodiments of the present application Figure 2 ;

[0056] Figure 7 Circuit of the energy storage system of some embodiments of the present application Figure 1 ;

[0057] Figure 8 A circuit of a battery device according to some embodiments of the present application Figure 2 ;

[0058] Fig. 9The circuit of the second switching switch assembly of some embodiments of the present application Figure 3 ;

[0059] Fig.10 The circuit of the second switching switch assembly of some embodiments of the present application Figure 4 ;

[0060] Fig.11 A block diagram of an energy storage system according to some embodiments of the present application.

[0061] Reference numerals:

[0062] Battery device 100, battery cell 10, battery 11, switching control unit 20, first switching switch component 21, second switching switch component 22, voltage balancing branch 221, controllable switch 30, inverter 200, charge and discharge control system 300, reconstruction and balancing controller / battery management system 400, energy storage system 1000. DETAILED DESCRIPTION

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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).

[0069] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0070] 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.

[0071] Lithium battery systems are usually used as power sources or electric energy buffer devices in various energy systems. Through proper control of charging and discharging, lithium battery systems can store electric energy, supply power to the outside, help the power grid to smooth out peaks and fill valleys, improve the response speed and quality of the power grid, or serve as a backup power source. Lithium batteries are divided into cells, battery packs, clusters, arrays, etc. from small to large. In practical applications, based on the requirements of voltage, power and capacity, as well as considerations of safety, reliability, maintainability and other factors, multiple standard cells can be connected in series and parallel to form a battery pack with standardized voltage and capacity. Further, multiple battery packs can be connected in series to form a cluster that meets the actual power supply voltage requirements. Furthermore, multiple clusters can be connected in parallel to form an array to meet the actual power and capacity requirements of the power supply.

[0072] In related technologies, cluster or array-level battery structures are used for large-capacity power consumption scenarios such as ships, where the number of battery packs in each cluster is strictly configured according to voltage and capacity requirements. However, in actual applications, when a battery pack fails, the entire cluster will fail, which will in turn cause the energy storage system to reduce capacity or fail.

[0073] Considering safety, the replacement of modules in the energy storage system usually requires professionals. For ships, this means that they must wait until the ship docks or professionals go on board to replace them. Even if the crew is allowed to replace them by themselves, a spare battery pack must be equipped on board. Therefore, either method will affect the normal operation of the battery and even the ship, and also increase manpower and maintenance costs. Especially for pure battery-powered ships, the impact is more serious and can cause the ship to be shut down for a long time.

[0074] In order to solve the above technical problems, the present application proposes a battery device, wherein the battery device is a cluster-level battery structure formed by a plurality of battery packs connected in series, wherein the number of battery packs in each cluster is strictly configured according to the voltage and capacity requirements. Specifically, the battery unit of the battery device includes a plurality of batteries, some of which are connected in series in sequence to form a cluster that meets the preset power supply voltage requirements, and at least one backup battery among the plurality of batteries is placed in bypass. During operation, the battery to be replaced and the backup battery used to replace the battery to be replaced are determined based on the battery status of each battery. For example, when the voltage of the battery constituting the cluster is too low or the charging and discharging is abnormal, the battery is determined to be the battery to be replaced, and the backup battery with the best battery status is selected as the backup battery to replace the battery to be replaced according to the battery status of at least one backup battery. The switching control unit connects the corresponding backup battery in series to the battery unit, and bypasses the battery to be replaced out of the battery unit, so as to replace the battery to be replaced by the backup unit, so that the battery unit is internally reconstructed. Thereby, the battery unit will not fail due to battery failure. In addition, internal reconstruction can be achieved autonomously by switching the control unit, which reduces manual participation and labor costs, while improving the safety and speed of replacement, thereby reducing the reduced capacity operation time and downtime operation time of the energy storage system corresponding to the battery device, and improving the reliability and continuity of power supply.

[0075] For the convenience of explanation, the following embodiments are combined Figure 1 The battery device of the present application will be described.

[0076] like Figure 1 As shown, the battery device 100 in the present application may include: a battery unit 10 and a switching control unit 20 .

[0077] The battery unit 10 includes a plurality of batteries 11, and the plurality of batteries 11 include at least one backup battery. The switching control unit 20 is configured to connect the backup battery in series to the battery unit 10 and bypass the battery to be replaced when there is a battery to be replaced among the plurality of batteries 11, so that the battery unit 10 is internally reconstructed.

[0078] Specifically, the battery 11 is a battery pack with standardized voltage and capacity formed by connecting a plurality of standard battery cells in series and parallel, wherein the battery device is a cluster-level battery structure formed by connecting a plurality of batteries 11 in series in sequence.

[0079] The multiple batteries 11 in the battery unit 10 include at least one backup battery and multiple grid-connected batteries. Among them, the grid-connected battery refers to the battery 11 connected in series to the battery unit 10. The grid-connected batteries are connected in series in sequence to form a series loop, thereby forming a cluster that meets the actual power supply voltage requirements. The backup battery refers to a battery pack of the same specification as the grid-connected battery. During the application process, the backup battery bypasses the battery unit 10 and serves as a replacement battery for the grid-connected battery. When the grid-connected battery fails, or it is determined according to the preset replacement strategy that the grid-connected battery needs to be replaced, the grid-connected battery is replaced by the backup battery, that is, the backup battery replaces the corresponding grid-connected battery and is connected in series to the battery unit 10 to reconstruct a cluster that meets the actual power supply voltage requirements.

[0080] The battery to be replaced refers to an on-line battery that has failed, or an on-line battery that needs to be replaced according to a preset replacement strategy. The specific judgment conditions can be set according to actual conditions. For example, when it is determined that the voltage of the on-line battery is abnormal, the number of times the battery pack is charged reaches a preset threshold, etc., it is determined that the on-line battery is not a battery to be replaced.

[0081] Internal reconstruction refers to replacing one or more on-grid batteries and reconnecting new batteries 11 in series to form a cluster that meets the actual power supply voltage requirement.

[0082] The switching control unit 20 may be composed of an electrically controlled mechanical switch (e.g., a single-pole single-throw switch) or a power electronic switching circuit (e.g., a MOS (Metal-Oxide-Semiconductor Field-Effect Transistor) tube, an IGBT (Insulate Gate Bipolar Transistor)), and is used to control the connection state of the series circuit between the battery 11 and the battery cell 10. Specifically, a controllable switch may be set between the battery 11 and the series circuit between the battery cell 10, and the battery 11 may be bypassed or connected in series by controlling the controllable switch of the switching control unit 20.

[0083] In addition, the control of the switching control unit 20 can be implemented by an independent controller or integrated into a BMS (Battery Management System). Specifically, the battery to be replaced and the available backup battery can be determined based on the status of each battery 11, and the backup battery can be connected in series to the battery unit 10 through the switching control unit 20, and the battery to be replaced can be bypassed out of the battery unit 10, so that the battery unit 10 can be internally reconstructed. In addition, the switching control unit 20 can also be controlled to bypass or connect the battery 11 based on a preset replacement strategy, such as a periodic replacement strategy, so as to autonomously realize the internal reconstruction of the battery unit 10 and enable the battery unit 10 to operate normally.

[0084] The present application performs redundant design of the battery unit 10 with the battery 11 as the unit, that is, in each cluster of battery units 10, a number of batteries are equipped as backup batteries based on the number of batteries 11 actually required, and the specific number of backup batteries can be determined according to the cluster size. During the operation of the battery device 100, when it is determined that the on-grid battery fails or meets the preset replacement strategy, the switching control unit 20 is controlled by the corresponding control program to complete the replacement of the battery to be replaced by the backup battery, realize the autonomous reconstruction of the series circuit in the battery unit 10, and complete the internal reconstruction of the battery unit. No personnel participation is required, which reduces manpower and maintenance costs. At the same time, it can improve the safety of battery 11 replacement, greatly improve the rapidity of replacement, and shorten the reduced capacity operation time and downtime of the energy storage system constructed by the battery device 100, and enhance the power supply reliability and continuity of the energy storage system.

[0085] Furthermore, the battery device 100 of the present application can also support a wider range of output voltage and power adjustment based on the redundant design of the battery 11. For example, the number of batteries 11 connected in series to the battery unit 10 can be increased or decreased by switching the control unit 20 based on the output voltage or power requirement.

[0086] According to some embodiments of the present application, the battery device 100 further includes: a positive DC bus and a negative DC bus, wherein the remaining batteries in the battery unit 10 excluding the backup battery are connected in series between the positive DC bus and the negative DC bus before internal reconstruction.

[0087] The battery unit 10 sequentially connects the remaining batteries except the backup battery in series to form a cluster that meets the preset power supply voltage requirement, and performs the charging and discharging process through the positive DC bus and the negative DC bus. The remaining battery is an on-grid battery before internal reconstruction, and the backup battery is designed as a redundant battery, so that when the on-grid battery fails or it is determined based on a preset replacement strategy that the on-grid battery needs to be replaced, the on-grid battery can be replaced by the backup battery to achieve internal reconstruction of the battery unit 10.

[0088] According to some embodiments of the present application, the batteries 11 in the battery unit 10 are connected in series between the positive DC bus and the negative DC bus after internal reconstruction.

[0089] When it is determined that the grid-connected battery fails or it is determined based on the preset replacement strategy that the grid-connected battery needs to be replaced, the grid-connected battery that needs to be replaced in the battery unit 10 is determined, and the grid-connected battery is the battery to be replaced, and the other grid-connected batteries are the batteries that have not been replaced. The required backup battery is determined according to the battery to be replaced, and then the backup battery is connected in series with the battery unit 10 through the switching control unit 20, and the battery to be replaced is bypassed, that is, the backup battery and the battery that has not been replaced are connected in series in sequence to reconstruct a cluster, and the reconstructed cluster continues the charging and discharging process through the positive DC bus and the negative DC bus.

[0090] See also Figure 2 As shown, according to some embodiments of the present application, the switching control unit 20 includes: a plurality of first switching switch assemblies 21 and a plurality of second switching switch assemblies 22, each first switching switch assembly 21 corresponding to the positive pole setting of each battery 11 in the battery cell 10, each second switching switch assembly 22 corresponding to the negative pole setting of each battery 11 in the battery cell 10, and each first switching switch assembly 21 and each second switching switch assembly 22 are suitable for connecting the corresponding battery 11 in series with the battery cell 10 or bypassing the corresponding battery 11 out of the battery cell 10.

[0091] Specifically, the first switching switch assembly 21 is used to control the on-off between the positive electrode of the corresponding battery 11 and the series circuit. The second switching switch assembly 22 is used to control the on-off between the negative electrode of the corresponding battery 11 and the series circuit. In addition, at least one of the first switching switch assembly 21 and the second switching switch assembly 22 needs to control the branch bypassing the corresponding battery 11 so that the series circuit in the battery unit 10 is in a conducting state. Among them, the first switching switch assembly 21 and the second switching switch assembly 22 can adopt an electrically controlled mechanical switching switch or a power electronic switching circuit.

[0092] For example, the first switching switch assembly 21 includes a switch 1 and a switch 2, wherein the switch 1 is used to control the on-off between the series circuit and the positive electrode of the corresponding battery 11, and the switch 2 is used to control the on-off between the series circuits. The second switching switch assembly 22 includes a switch 3 and a switch 4, wherein the switch 3 is used to control the on-off between the series circuit and the negative electrode of the corresponding battery 11, and the switch 4 is used to control the on-off between the series circuits. Specifically, one end of the switch 1 is connected to the series circuit, the other end of the switch 1 is connected to the positive electrode of the battery 11, one end of the switch 2 is connected to the other end of the switch 1, the other end of the switch 2 is connected to one end of the switch 4, the other end of the switch 4 is connected to one end of the switch 3, and the other end of the switch 3 is connected to the negative electrode of the battery 11. When the switch 1 and the switch 3 corresponding to the corresponding battery 11 are controlled to be closed and the switch 2 and the switch 4 are disconnected, the battery 11 is connected in series with the battery unit 10; when the switch 1 and the switch 3 corresponding to the corresponding battery 11 are controlled to be disconnected and the switch 2 and the switch 4 are closed, the switch 2 and the switch 4 in the closed state make the bypass branch of the battery conductive, and the battery 11 bypasses the battery unit 10.

[0093] Therefore, this embodiment controls the first switching switch assembly 21 and the second switching switch assembly 22 corresponding to the corresponding battery 11 to realize the corresponding battery 11 being connected in series to the battery cell 10 or the corresponding battery 11 being bypassed out of the battery cell 10, thereby improving the replacement speed.

[0094] According to some embodiments of the present application, the first end A of the first first switching switch assembly among multiple first switching switch assemblies 21 is connected to the positive DC bus, the second end B of each first switching switch assembly 21 is connected to the positive electrode of the first battery among multiple batteries, the third end E of each first switching switch assembly 21 is connected to the first end C of the corresponding second switching switch assembly 22, the second end F of each second switching switch assembly 22 is connected to the negative electrode of each battery, and the first end of the last second switching switch assembly among the multiple second switching switch assemblies 22 is connected to the negative DC bus.

[0095] Specifically, see Figure 2 As shown, each battery 11 is correspondingly provided with a first switching switch component 21 and a second switching switch component 22, the second end B of the first switching switch component 21 is connected to the positive electrode of the corresponding battery 11, and the second end F of the second switching switch component 22 is connected to the negative electrode of the corresponding battery 11.

[0096] When the first end A of the first switching switch component 21 corresponding to the control battery 11 is connected to the second end B, the first end A is disconnected from the third end E, and the first end C of the second switching switch component 21 is connected to the second end F, the corresponding battery 11 is connected in series with the battery cell 10; when the first end A of the first switching switch component 21 corresponding to the control battery 11 is disconnected from the second end B, the first end A is connected to the third end E, and the first end C of the second switching switch component 21 is disconnected from the second end F, the corresponding battery 11 bypasses the battery cell 10.

[0097] This embodiment controls the connection or disconnection of each end of the first switching switch assembly 21 and the second switching switch assembly 22 to achieve the series connection or bypass of the battery 11, thereby improving the rapidity of replacement control.

[0098] Combination Figure 3 As shown, according to some embodiments of the present application, each first switching switch component 21 includes: a first switch K1 and a second switch K2, one end of the first switch K1 is connected to one end of the second switch K2, and has a first node, the first node serves as the first end A of the first switching switch component 21, the other end of the first switch K1 serves as the second end B of the first switching switch component 21, and the other end of the second switch K2 serves as the third end E of the first switching switch component 21.

[0099] Specifically, the first switch K1 is used to control the on / off of the first end A and the second end B of the first switching switch component 21 , and the second switch K2 is used to control the on / off of the first end A and the second end B of the first switching switch component 21 .

[0100] The first switch K1 and the second switch K2 can be mechanical switches, such as contactors, etc. For details, please refer to Figure 3 As shown; it can also be formed by connecting a fully controlled unidirectional conductive semiconductor switch and a diode in reverse parallel. The fully controlled unidirectional conductive semiconductor switch can be an IGBT, etc. For details, please refer to Figure 4 As shown, the reverse parallel connection refers to the full-controlled unidirectional conduction semiconductor switch and the diode being connected in parallel, and the conduction current directions of the full-controlled unidirectional conduction semiconductor switch and the diode are opposite. Specifically, Figure 4 The semiconductor switch Q1 and diode D1 in Figure 3 The first switch K1, the semiconductor switch Q2 and the diode D2 form Figure 3 The second switch K2, the semiconductor switch Q1 and the semiconductor switch Q2 are NMOS (N-Metal-Oxide-Semiconductor) tubes, the cathodes of the diodes D1 and D2 are connected to the drains of the semiconductor switches Q1 and Q2 respectively, and the anodes of the diodes D1 and D2 are connected to the sources of the semiconductor switches Q1 and Q2 respectively to form a reverse parallel connection.

[0101] by Figure 2 use Figure 3 Taking the first switching switch assembly 21 as an example, when the first switch K1 is closed, the first end A of the first switching switch assembly 21 is connected to the second end B, and the positive electrode of the corresponding battery 11 is connected to the loop. When the second switch K2 is closed, the first end A of the first switching switch assembly 21 is connected to the third end E. At this time, the bypass branch of the corresponding battery 11 is controlled to be turned on by the second switch K2 in the closed state.

[0102] Furthermore, when the first switch K1 and the second switch K2 are mechanical switches, the first switch assembly 21 has a simple structure and low cost, but does not support on-load switching and circulating current suppression, and only supports battery replacement when the output end of the battery unit 20 is disconnected. When the first switch K1 and the second switch K2 are fully controlled unidirectional conductive semiconductor switches with reverse-parallel diodes, the first switch assembly 21 supports on-load switching to ensure continuous power supply, and supports unidirectional conduction based on the reverse-parallel diodes to limit circulating current.

[0103] According to some embodiments of the present application, each second switching switch assembly 22 includes: a third switch K3, one end of the third switch K3 serves as the first end C of the second switching switch assembly 22, and the other end of the third switch serves as the second end F of the second switching switch assembly 22.

[0104] Specifically, the third switch K3 is used to control the on / off of the first end C and the second end F of the second switching switch assembly 22. The third switch K3 can be a mechanical switch, such as a contactor, etc. Figure 5 As shown; you can also use a fully controlled unidirectional conduction semiconductor switch with a diode in reverse parallel, such as IGBT, etc. For details, please refer to Figure 6 As shown, Figure 6 The semiconductor switch Q3 and diode D3 in Figure 5 The third switch K3, specifically, the semiconductor switch Q3 is an NMOS tube, the cathode of the diode D3 is connected to the drain of the semiconductor switch Q3, and the anode of the diode D3 is connected to the source of the semiconductor switch Q3 to form a reverse parallel connection.

[0105] When the third switch K3 is closed, the first end C of the second switching switch assembly 22 is connected to the second end F to connect the negative electrode of the corresponding battery 11 to the circuit; when the third switch K3 is disconnected, the first end C of the second switching switch assembly 22 is disconnected from the second end F to disconnect the negative electrode of the corresponding battery 11 from the circuit.

[0106] Furthermore, when the third switch K3 adopts a mechanical switch, the second switch assembly 22 has a simple structure and low cost, but does not support on-load switching and circulating current suppression, and only supports battery pack replacement when the controllable switch is disconnected. When the third switch K3 adopts an anti-parallel fully controlled unidirectional conduction semiconductor switch, the second switch assembly 22 supports on-load switching to ensure continuous power supply, and supports unidirectional conduction based on the anti-parallel diode to limit the circulating current.

[0107] According to some embodiments of the present application, at least one of the first switch K1 , the second switch K2 and the third switch K3 comprises a fully-controlled unidirectional conducting semiconductor switch, and the fully-controlled unidirectional conducting semiconductor switch is suitable for being reversely connected in parallel with a diode.

[0108] Specifically, the first switching switch component 21 is as follows Figure 4 As shown, the second switch assembly 22 is as shown in Figure 6 As shown, the series connection or bypass of the corresponding battery is controlled by a fully controlled unidirectional conductive semiconductor switch with a diode connected in reverse parallel, so that the switching control unit 20 supports load switching, improves the power supply continuity of the battery device 100, and supports unidirectional conduction to limit the circulating current.

[0109] For example, in the case where the energy storage system includes a plurality of battery devices 100 connected in parallel, during the discharge process, the semiconductor switch Q1 in the first switch K1 is controlled to be disconnected, and only the parallel diode in the discharge direction is turned on between the first end A and the second end B of the first switching switch component 21 corresponding to the grid battery. The semiconductor switch Q1 is not turned on without a trigger signal, and there is no circulation channel, thereby achieving the purpose of supporting unidirectional conduction and limiting circulation.

[0110] According to some embodiments of the present application, when the first switch K1 corresponding to the backup battery is closed, the second switch K2 is opened, and the third switch K3 is closed, the backup battery is connected in series to the battery unit 10 .

[0111] During operation, by controlling the first switch K1 to be closed, the first end A of the first switching switch assembly 21 corresponding to the backup battery is connected to the second end B, and the positive electrode of the backup battery is connected to the series circuit. By controlling the third switch K3 to be closed, the first end C of the second switching switch assembly 22 corresponding to the backup battery is connected to the second end F, so that the negative electrode of the backup battery is connected to the series circuit. At the same time, by controlling the second switch K2 to be opened, the branch bypassing the backup battery is disconnected, and the backup battery is connected in series with the battery unit 10.

[0112] According to some embodiments of the present application, when the first switch K1 corresponding to the battery to be replaced is opened, the second switch K2 is closed, and the third switch K3 is opened, the battery to be replaced is bypassed out of the battery unit 10 .

[0113] During operation, the first switch K1 is controlled to be disconnected, so that the first end A and the second end B of the first switching switch assembly 21 corresponding to the battery to be replaced are disconnected, so that the positive electrode of the battery to be replaced is disconnected from the series circuit. The third switch K3 is controlled to be disconnected, so that the first end C and the second end F of the second switching switch assembly 22 corresponding to the battery to be replaced are disconnected, so that the negative electrode of the battery to be replaced is disconnected from the series circuit. At the same time, the second switch K2 is controlled to be closed, so that the branch for bypassing the backup battery is turned on, and the current in the series circuit is kept in the on state through the closed second switch K2, so as to complete the bypass of the battery to be replaced out of the battery unit 10.

[0114] Combination Figure 7 As shown, according to some embodiments of the present application, the battery device 100 also includes: a controllable switch 30, and the controllable switch 30 is set corresponding to the positive DC bus and the negative DC bus to disconnect the connection between the positive DC bus and the negative DC bus and the inverter 200 when the battery cell 10 is internally reconstructed.

[0115] The converter 200 is an electrical device that can change the voltage, frequency, number of phases and other electrical quantities or characteristics of the power supply. For example, the converter 200 can convert AC power into DC power, convert DC power into AC power, and realize constant power constant current charging and discharging and smooth fluctuating power output. Among them, one converter 200 can be connected to only one battery device 100, or it can be connected to multiple parallel battery devices 100 at the same time, which will not be described in detail here.

[0116] Specifically, when it is determined that there is a battery to be replaced in the grid-connected battery, the controllable switch 30 is controlled to be disconnected to disconnect the connection between the battery cell 10 and the converter 200, and the charging and discharging process of the battery cell 10 is stopped. Then the switching control unit 20 connects the backup battery in series to the battery cell 10, and bypasses the battery to be replaced out of the battery cell 10 to complete the internal reconstruction of the battery cell 10. Then the controllable switch 30 is controlled to be closed, and the charging and discharging process is continued through the battery cell 10 that has completed the internal reconstruction.

[0117] According to some embodiments of the present application, the controllable switch 30 is also configured to close after the backup battery is connected in series with the battery cell 10, so that the inverter 200 charges the battery cell 10, and when the battery cell 10 is fully charged, the battery to be replaced is bypassed through the first switching switch component 21 and the second switching switch component 22 corresponding to the battery to be replaced.

[0118] Specifically, when the battery unit 10 has a backup battery, the backup battery needs to be charged regularly to reduce the cost increase caused by the failure of the backup battery due to long-term storage. To this end, the application can preset a regular replacement strategy, which is as follows:

[0119] First, evaluate the battery status parameters of the grid-connected batteries, such as voltage, SOH (State Of Health), SOS (State Of Safety), and battery charging times. Use the parameter data to evaluate and sort the battery status of the grid-connected batteries, and determine the grid-connected batteries with poor battery status as batteries to be replaced, and other grid-connected batteries as unreplaced batteries. The number of batteries to be replaced can be determined based on the number of backup batteries and the allowable value of the charging voltage. At the same time, evaluate and sort the battery status of the backup batteries based on the battery status parameters of multiple backup batteries, and select several backup batteries with the best battery status to compare with the batteries to be replaced, so as to replace the batteries to be replaced with poor status.

[0120] When it is determined that the grid-connected battery is replaced based on a preset periodic replacement strategy, the first switching switch assembly 21 and the second switching switch assembly 22 are controlled before the battery is charged, and the converter 200 is controlled to suspend operation and the controllable switch 30 is disconnected.

[0121] Before performing the replacement control, the states of the first switch assembly 21 and the second switch assembly 22 of the battery to be replaced are: the first end A of the first switch assembly 21 is connected to the second end B, the first end A is disconnected from the third end E, and the first end C of the second switch assembly 22 is connected to the second end F. The states of the first switch assembly 21 and the second switch assembly 22 of the backup battery are: the first end A of the first switch assembly 21 is disconnected from the second end B, the first end A is connected to the third end E, and the first end C of the second switch assembly 22 is disconnected from the second end F.

[0122] When performing replacement, if the charging voltage allows, first connect the backup battery in series to the battery unit 10, that is, control the first end A of the first switching switch component 21 corresponding to the backup battery to connect with the second end B, disconnect the first end A from the third end E, and connect the first end C of the second switching switch component 22 to the second end F. At this time, the battery connected in series to the battery unit 10 is the grid-connected battery, including the battery to be replaced, the battery not replaced, and the backup battery. Then, adjust the charge and discharge limit of the battery management system according to the number of grid-connected batteries, control the controllable switch 30 to close, and control the converter 200 to charge the battery unit 10. During the charging process, the start and stop of charging is controlled according to the voltage of each grid-connected battery, and finally the charging of the battery unit 10 is completed.

[0123] After charging is completed, the first terminal A and the second terminal B of the first switching switch assembly 21 corresponding to the battery pack to be replaced are controlled to be disconnected, the first terminal A and the third terminal E are connected, and the first terminal C and the second terminal F of the second switching switch assembly 22 are disconnected, so as to bypass the battery pack to be replaced out of the battery unit 10 and realize the internal reconstruction of the battery unit 10. After the internal reconstruction of the battery unit 10 is completed, the converter 200 is controlled to start discharging.

[0124] It should be noted that the converter 200 can be controlled by the charge and discharge control system 300 in the energy storage system, wherein the energy storage system may include only one battery device 100 or multiple battery devices 100 connected in parallel. The charge and discharge control system 300 can control the converter 200 to perform the charging and discharging process of the battery unit 10 under different working conditions according to the actual needs of the energy storage system. During the charging process, the charge and discharge control system 300 will adjust the charging current and charging time according to the current power level and charging demand of the energy storage system, so that the energy storage system can fully store electricity and maintain a stable power level. During the discharging process, the charge and discharge control system 300 will adjust the discharge current and discharge time according to the current load demand and power level of the energy storage system, so that the energy storage system can provide a stable power output.

[0125] Furthermore, the charge and discharge control system 300 can determine the current power status and charging requirements of the energy storage system based on the reconstruction and balancing controller / battery management system 400. The reconstruction and balancing controller / battery management system 400 can monitor the status of the battery 11, such as voltage, temperature, number of charging times, etc., to prevent the battery 11 from being overcharged and over-discharged, so as to extend the service life of the battery 11. In addition, the reconstruction and balancing controller / battery management system 400 can also control the first switching switch component 21 and the second switching switch component 22 based on the acquired battery status.

[0126] This embodiment connects the backup battery in series with the battery unit 10 before executing battery charging to realize the charging of the backup battery. The backup battery can be charged regularly based on a preset periodic replacement strategy to prevent the backup battery from failing due to long-term storage, thereby improving the scientific storage of the backup battery and the overall service life of the battery and the energy storage system. At the same time, no additional special storage space and charging equipment are required, saving additional investment in storage environment construction.

[0127] According to some embodiments of the present application, the switching control unit 20 is also configured to control a plurality of first switching switch components 21 and a plurality of second switching switch components 22 to bypass the faulty battery and connect the backup battery in series to the battery cell 10 when the battery to be replaced is a faulty battery and the voltage difference between the backup battery and the unreplaced battery in the battery cell 10 is less than a preset voltage threshold.

[0128] The faulty battery can be determined based on the battery parameters, such as voltage, temperature, internal resistance, etc., and the fault judgment conditions can be set based on actual needs. In addition to the faulty battery, the other batteries connected in series to the battery unit 10 are the unreplaced batteries of the battery unit 10.

[0129] When replacing a faulty battery, the replacement operation is performed immediately to improve the power supply continuity of the battery device 100 .

[0130] First, the faulty battery is determined based on the preset conditions and the status parameters of the online battery, and the faulty battery is used as the battery to be replaced. Then, the backup battery for the replacement operation is determined based on the voltage of the unreplaced battery in the battery unit 10. The backup battery with the voltage closest to the unreplaced battery can be selected as the backup battery for replacing the battery to be replaced, and the backup battery with the best status can be selected as the backup battery for replacing the battery to be replaced. The status of the battery can be evaluated and sorted based on the obtained battery parameters. After determining the backup battery for replacement, the voltage difference between the unreplaced battery and the backup battery is obtained. If the voltage difference is less than the preset voltage threshold, the replacement is performed directly. The preset voltage threshold can be set according to the actual situation.

[0131] Specifically, before replacement, the first end A of the first switching switch assembly 21 corresponding to the battery to be replaced is connected to the second end B, the first end A and the third end E are disconnected, and the first end C of the second switching switch assembly 22 is connected to the second end F; the first end A of the first switching switch assembly 21 corresponding to the backup battery is disconnected from the second end B, the first end A and the third end E are connected, and the first end C of the second switching switch assembly 22 is disconnected from the second end F.

[0132] During replacement, the first terminal A of the first switching switch assembly 21 corresponding to the battery to be replaced is disconnected from the second terminal B, the first terminal A is connected to the third terminal E, and the first terminal C of the second switching switch assembly 22 is disconnected from the second terminal F, so that the battery to be replaced is bypassed out of the battery unit 10. At the same time, the first terminal A of the first switching switch assembly 21 corresponding to the backup battery is connected to the second terminal B, the first terminal A is disconnected from the third terminal E, and the first terminal C of the second switching switch assembly 22 is connected to the second terminal F, so that the backup battery is connected in series to the battery unit 10. The replacement of the backup battery with the battery to be replaced is completed, and the internal reconstruction of the battery unit 10 is completed.

[0133] In this embodiment, when the grid battery fails, the backup battery with the voltage closest to the unreplaced battery in the battery unit 10 is preferred for battery replacement operation. If the voltage difference between the backup battery and the unreplaced battery in the battery unit 10 is less than the preset voltage threshold, the replacement is performed directly to increase the replacement speed.

[0134] Combination Figure 7-10As shown, according to some embodiments of the present application, each second switching switch assembly 22 also includes: a fourth switch K4 and a voltage balancing branch 221, one end of the fourth switch K4 is connected to the negative electrode of the corresponding battery 11, and the other end of the fourth switch K4 is connected to the negative DC bus through the voltage balancing branch 221, wherein the switching control unit 20 is also configured to, when the voltage difference between the backup battery and the unreplaced battery in the battery unit 10 is greater than or equal to a preset voltage threshold, control the first switching switch assembly 21 and the second switching switch assembly 22 corresponding to the faulty battery to bypass the faulty battery, and then control the first switching switch assembly 21 and the second switching switch assembly 22 corresponding to the unreplaced battery and the backup battery so that the unreplaced battery and the backup battery are respectively connected in parallel to the positive DC bus and the negative DC bus through the voltage balancing branch 221.

[0135] Specifically, one end of the fourth switch K4 is connected to the negative electrode of the corresponding battery 11 through the second end F of the second switching switch assembly 22, and the other end of the fourth switch K4 is connected to one end of the voltage balancing branch 22, and the other end of the voltage balancing branch 22 is connected to the negative DC bus through the third end D of the second switching switch assembly 22. Figure 3 As shown, the second switch assembly 22 is as shown Fig. 9 The three states of the battery 11 are described by taking the figure as an example.

[0136] 1) When the battery 11 is connected in series to the battery unit 10, the first switch K1 and the third switch K3 corresponding to the battery 11 are closed, and the second switch K2 and the fourth switch K4 are opened;

[0137] 2) When the battery 11 is in a state of bypassing the battery unit 10, the first switch K1, the third switch K3 and the fourth switch K4 corresponding to the battery 11 are disconnected, and the second switch K2 is closed;

[0138] 3) When the battery 11 is in the voltage-equalizing state, the corresponding first switch K1, second switch K2 and fourth switch K4 of the other batteries except the last battery are closed, and the third switch K3 is disconnected; for the last battery, since the third terminal E corresponding to the last battery is directly connected to the negative DC bus, if the second switch K2 corresponding to the last battery is controlled to be closed, all parallel batteries will be short-circuited, so in the voltage-equalizing state, the first switch K1 and fourth switch K4 corresponding to the last battery are closed, and the second switch K2 and third switch K3 are disconnected. It should be noted that the batteries 11 are arranged in sequence in the direction away from the controllable switch 30, and are sequentially connected in series or in parallel. For multiple batteries 11 connected in series or in parallel, the last battery refers to the battery 11 farthest from the controllable switch 30, that is, the battery 11 farthest from the controllable switch 30 along the series circuit. The third terminal E of the first switching switch component 21, the first terminal C and the third terminal D of the second switching switch component 22 corresponding to the last battery are connected to the negative DC bus.

[0139] In the case where the battery to be replaced is a faulty battery, if the voltage difference between the backup battery and the unreplaced battery in the battery unit 10 is greater than or equal to the preset voltage threshold, the battery voltage equalization control in the battery unit 10 is first performed before replacement. Among them, in the case of single-cluster power supply, that is, the converter 200 is connected to one battery unit 10, before the battery voltage equalization control is performed, the converter 200 is first stopped in sequence and the controllable switch 30 is controlled to be disconnected; in the case of multi-cluster parallel power supply, that is, the converter 200 is connected to multiple parallel battery units 10, before the battery voltage equalization control is performed, the controllable switch 30 corresponding to the corresponding battery unit 10 can be directly disconnected, so that the energy storage system can continue to supply power based on the remaining battery units 10.

[0140] Next, the first switch assembly 21 is used as Figure 3 As shown, the second switch assembly 22 is as shown Fig. 9 The figure is taken as an example to illustrate the battery replacement process when the voltage difference between the backup battery and the unreplaced battery in the battery unit 10 is greater than or equal to the preset voltage threshold.

[0141] Before replacement, the first switch K1 and the third switch K3 corresponding to the grid battery are closed, and the second switch K2 and the fourth switch K4 are opened. The grid battery includes the battery to be replaced, i.e., the faulty battery and the unreplaced battery. The first switch K1, the third switch K3 and the fourth switch K4 corresponding to the backup battery are opened, and the second switch K2 is closed.

[0142] First, the first switch K1 and the third switch K3 corresponding to the faulty battery are controlled to be opened, the second switch K2 is closed, and the fourth switch K4 is kept in an open state, so as to bypass the faulty battery out of the battery unit 10 .

[0143] Then, the second switch K2 and the fourth switch K4 corresponding to the unreplaced battery are controlled to be closed, the third switch K3 is disconnected, and the first switch K1 is kept closed. The first switch K1 and the fourth switch K4 corresponding to the backup battery are controlled to be closed, and the second switch K2 is kept closed and the third switch K3 is kept disconnected. In addition, the second switch K2 is disconnected before the last battery 11 connected in series to the battery unit 10 is voltage-balanced. At this time, the unreplaced battery is connected in parallel with the backup battery to perform voltage-balanced operation.

[0144] That is, during the voltage balancing control process, the first switch K1 and the fourth switch K4 corresponding to the last battery 11 in series in the battery unit 10 are controlled to be closed, the second switch K2 and the third switch K3 are disconnected, and the first switch K1, the second switch K2 and the fourth switch K4 corresponding to the remaining batteries 11 are closed, and the third switch is disconnected. After the voltage balancing is completed, the second switch K2 and the fourth switch K4 corresponding to all selected batteries 11, i.e., the batteries used for internal reconstruction, are controlled to be disconnected, and the third switch K3 is closed, so as to connect all selected batteries 11 in series between the positive DC bus and the negative DC bus, so as to complete the replacement of the faulty battery and realize the internal reconstruction of the battery unit 10.

[0145] After the faulty battery is replaced, in the case of multiple clusters connected in parallel, the controllable switch 30 is controlled to be closed, and then the converter 200 is controlled to operate according to the parallel connection situation.

[0146] In this embodiment, when the voltage difference between the backup battery and the unreplaced battery in the battery unit 10 is greater than or equal to the preset voltage threshold, the backup battery and the unreplaced battery are first connected in parallel to balance the voltage, so as to automatically achieve voltage balance in the battery unit 10. After completing the voltage balance control, the unreplaced battery and the backup battery are controlled to be connected in series between the positive DC bus and the negative DC bus in sequence, so as to complete the replacement of the faulty battery and the internal reconstruction of the battery unit 10.

[0147] Further, in addition to the voltage equalization control performed when a faulty battery is replaced as described above, conventional voltage equalization may also be performed when the battery 11 is normal.

[0148] Specifically, the battery 11 in the battery unit 10 can be monitored in real time by the reconstruction and balancing controller / battery management system 400 to determine whether the voltage balancing control is the voltage balancing before the replacement of the faulty battery or the conventional voltage balancing. Conventional voltage balancing refers to the voltage balancing operation of the grid-connected battery. The above content has given an example of voltage balancing before the replacement of the faulty battery, which will not be repeated here. Figure 3 As shown, the second switch assembly 22 is as shown Fig. 9 The figure is taken as an example to illustrate the conventional pressure equalization process.

[0149] Before performing conventional voltage balancing, the first switch K1 and the third switch K3 corresponding to the grid battery are closed, and the second switch K2 and the fourth switch K4 are opened.

[0150] When performing conventional voltage balancing, the third switch K3 corresponding to the grid-connected battery is controlled to be disconnected, and the second switch K2 and the fourth switch K4 are controlled to be closed, and the first switch K1 is kept closed. For the last battery, the corresponding second switch K2 and the third switch K3 are controlled to be disconnected, and the fourth switch K4 is closed, and the first switch K1 is kept closed, so that the grid-connected batteries are connected in parallel to perform the voltage balancing operation.

[0151] After conventional voltage balancing, the first switch K1 and the third switch K3 corresponding to all the grid-connected batteries are controlled to be closed, and the second switch K2 and the fourth switch K4 are disconnected, so as to enter a series working state.

[0152] According to some embodiments of the present application, a voltage-equalizing resistor is connected in series in the voltage-equalizing branch 221, so that the voltage-equalizing current can reach the maximum without causing overcurrent.

[0153] According to some embodiments of the present application, the fourth switch K4 includes two fully-controlled unidirectional conducting semiconductor switches connected in reverse parallel.

[0154] like Fig.10 As shown, the semiconductor switch Q4 and the semiconductor switch Q5 are connected in reverse parallel to form a fourth switch K4 for parallel control. Specifically, the semiconductor switch Q4 and the semiconductor switch Q5 use NMOS tubes, wherein the source of the semiconductor switch Q4 is connected to the drain of the semiconductor switch Q5, and the drain of the semiconductor switch Q4 is connected to the source of the semiconductor switch Q5 to complete the reverse parallel connection. The application of the fully controlled unidirectional conduction semiconductor switch connected in reverse parallel enables the fourth switch K4 to support on-load switching to ensure continuous power supply, support unidirectional conduction, and limit circulating current.

[0155] It should be noted that the first switching switch assembly 21 and the second switching switch assembly 22 are used as follows Figure 4 , 6 In the case of the embodiment shown in FIG. 10 , the control of turning on or off the switch refers to the control of the corresponding semiconductor switches Q1 , Q2 , Q3 , Q4 , Q5 .

[0156] To summarize, the battery device of the present application can realize automatic internal reconstruction based on circuit design and control strategy, improve the safety of battery failure replacement, greatly improve the speed of replacement, and at the same time realize on-demand charging and fault protection of batteries and battery clusters, improve the scientific storage of backup batteries, thereby increasing the overall service life from batteries to energy storage systems, while eliminating additional investment in storage environment construction.

[0157] Corresponding to the above embodiments, the present application also proposes an energy storage system.

[0158] like Fig.11 As shown, the energy storage system 1000 of the present application includes: an inverter 200; and at least one of the above-mentioned battery devices 100, wherein each battery device 100 is connected in parallel to the DC side of the inverter 200.

[0159] The battery device 100 is a cluster-level battery structure, and the energy storage system 1000 is an array-level battery structure composed of multiple battery devices 100 connected in parallel to meet the power and capacity requirements of actual power supply.

[0160] In the technical solution of the embodiment of the present application, the energy storage system 1000 includes an inverter 200 and at least one of the above-mentioned battery devices 100, each battery device 100 is connected in parallel to the DC side of the inverter 200, and the AC side of the inverter 200 is the output end of the energy storage system 1000. When the energy storage system 1000 is charged, the inverter 200 converts the AC power into DC power and outputs it to the battery device 100, and when the energy storage system 1000 is discharged, the inverter 200 converts the DC power output by the battery device 100 into AC power and outputs it.

[0161] Each battery device 100 of this embodiment is designed with battery redundancy. When a faulty battery appears in the battery device 100, or when a battery replacement is required according to a preset control strategy, the switching control unit in the battery device 100 can flexibly and quickly complete the replacement of the battery to be replaced by the backup battery, so that the battery unit can achieve autonomous internal reconstruction and restore power supply, so that the energy storage system 1000 can continue to operate. In the event of a battery failure, the present application can greatly shorten the reduced capacity operation time or failure time of the energy storage system 1000 based on the autonomous reconstruction of the battery device 100. At the same time, based on the charge and discharge control system and the reconstruction and balancing controller / battery management system in the energy storage system 1000, the converter 200 and the controllable switches and switching control units in each battery device 100 can be controlled to work together, and the replacement of the battery to be replaced can be completed flexibly and quickly and autonomously without the participation of personnel, thereby reducing manpower and maintenance costs and enabling the energy storage system 1000 to provide sustainable power supply.

[0162] According to some embodiments of the present application, when each battery device 100 is discharged through the converter 200 , the reverse parallel diode of the first switch in each battery device 100 is turned on and the semiconductor switch is turned off.

[0163] Specifically, the first switch in the battery device 100 is as follows: Figure 4 As shown, the first switch K4 includes a semiconductor switch Q1 and a diode D1 , wherein the semiconductor switch Q1 may be an IGBT.

[0164] In the case where multiple battery devices 100 are connected in parallel and share one converter 200, during the process of the multiple battery devices 100 discharging through the converter 200, the semiconductor switch Q1 in the first switch K1 of the grid battery in each battery device 100 is controlled to be disconnected, and only the reverse parallel diode in the first switch K1 is turned on, so that the current flows in one direction, leaving no circulation channel, thereby achieving circulation suppression between the battery devices 100.

[0165] According to some embodiments of the present application, when a discharge circuit of any battery device 100 that discharges through the converter 200 fails, each third switch in the battery device 100 is disconnected respectively.

[0166] Specifically, for example, when overcurrent, undervoltage, overvoltage, etc. occur in the discharge circuit, it is considered that the discharge circuit fails, and the third switch K3 of the battery device 100 is controlled to be disconnected, thereby disconnecting the negative electrode of the grid-connected battery from the circuit and stopping the corresponding battery from continuing to discharge.

[0167] According to some embodiments of the present application, when a charging circuit of any battery device 100 charged by the converter 200 fails, each first switch in the battery device 100 is disconnected respectively.

[0168] Specifically, for example, when overcurrent, undervoltage, overvoltage, etc. occur in the charging circuit, it is considered that the charging circuit fails, and the first switch corresponding to each battery in the battery device 100 is controlled to be disconnected respectively, thereby disconnecting the connection between the positive electrode of the battery and the series circuit to stop charging the corresponding battery.

[0169] According to some embodiments of the present application, Figure 7 and Fig.11 As shown, each battery device 100 further includes a controllable switch 30 , which is suitable for disconnecting the faulty battery device from the DC side of the converter 200 and switching a spare battery device into the DC side of the converter 200 when a fault occurs in the corresponding battery device 100 .

[0170] The energy storage system 100 includes a plurality of battery devices 100. During application, at least one of the plurality of battery devices 100 is connected in parallel to the DC side of the converter 200 to form an array-level battery structure that meets the power and capacity requirements of the actual power supply. Other battery devices 100 in the plurality of battery devices 100 are used as backup battery devices and are not connected to the DC side of the converter 200. When a battery device 100 connected in parallel to the DC side of the converter 200 fails, or when it is determined according to a preset replacement strategy that the battery device 100 connected in parallel to the DC side of the converter 200 needs to be replaced, the backup battery device is used to replace the battery device, so as to reconstruct an array-level battery structure that meets the power and capacity requirements of the actual power supply.

[0171] That is to say, in this embodiment, while each battery device 100 is separately designed with redundant batteries, redundant design of the battery device 100 is also performed in the energy storage system 1000. By controlling the controllable switch 30, the backup battery device can flexibly and quickly replace the faulty battery device, so that the energy storage system 1000 can achieve autonomous internal reconstruction and restore power supply, while improving the safety and rapidity of replacement, thereby shortening the reduced capacity operation time and downtime operation time of the energy storage system 1000, and improving the power supply reliability and continuity of the energy storage system 1000.

[0172] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery device, characterized in that: include: a battery unit, the battery unit comprising a plurality of batteries, the plurality of batteries including at least one backup battery; A switching control unit is configured to connect the backup battery in series to the battery unit and bypass the battery to be replaced, so that the battery unit can be internally reconstructed when there is a battery to be replaced among the multiple batteries.

2. The battery device according to claim 1, characterized in that: Also includes: A positive DC bus and a negative DC bus, wherein the remaining batteries in the battery unit excluding the backup battery are connected in series between the positive DC bus and the negative DC bus before internal reconstruction.

3. The battery device according to claim 2, characterized in that: The batteries in the battery unit are connected in series between the positive DC bus and the negative DC bus after internal reconstruction.

4. The battery device according to claim 2 or 3, characterized in that: The switching control unit comprises: A plurality of first switching switch assemblies and a plurality of second switching switch assemblies, each of the first switching switch assemblies is arranged corresponding to the positive pole of each battery in the battery cell, each of the second switching switch assemblies is arranged corresponding to the negative pole of each battery in the battery cell, and each of the first switching switch assemblies and each of the second switching switch assemblies are suitable for connecting the corresponding battery in series into the battery cell or bypassing the corresponding battery out of the battery cell.

5. The battery device according to claim 4, characterized in that: The first end of the first first switching switch assembly among the multiple first switching switch assemblies is connected to the positive DC bus, the second end of each of the first switching switch assemblies is connected to the positive electrode of the first battery among the multiple batteries, the third end of each of the first switching switch assemblies is connected to the first end of the corresponding second switching switch assembly, the second end of each of the second switching switch assemblies is connected to the negative electrode of each battery, and the first end of the last second switching switch assembly among the multiple second switching switch assemblies is connected to the negative DC bus.

6. The battery device according to claim 5, characterized in that: Each of the first switching switch components includes: a first switch and a second switch, one end of the first switch is connected to one end of the second switch and has a first node, the first node serves as the first end of the first switching switch component, the other end of the first switch serves as the second end of the first switching switch component, and the other end of the second switch serves as the third end of the first switching switch component.

7. The battery device according to claim 6, characterized in that: Each of the second switching switch components includes: a third switch, one end of the third switch serves as the first end of the second switching switch component, and the other end of the third switch serves as the second end of the second switching switch component.

8. The battery device according to claim 7, characterized in that: At least one of the first switch, the second switch and the third switch comprises a fully-controlled unidirectional conductive semiconductor switch, and the fully-controlled unidirectional conductive semiconductor switch is adapted to be connected in reverse parallel with a diode.

9. The battery device according to claim 7, characterized in that: When the first switch corresponding to the backup battery is closed, the second switch is opened, and the third switch is closed, the backup battery is connected in series to the battery unit.

10. The battery device according to claim 7, characterized in that: When the first switch corresponding to the battery to be replaced is opened, the second switch is closed, and the third switch is opened, the battery to be replaced is bypassed out of the battery unit.

11. The battery device according to claim 4, characterized in that: Also includes: A controllable switch is provided corresponding to the positive DC bus and the negative DC bus to disconnect the positive DC bus and the negative DC bus from the converter when the battery unit is internally reconstructed.

12. The battery device according to claim 11, characterized in that: The controllable switch is also configured to close after the backup battery is connected in series with the battery cell so that the inverter can charge the battery cell, and when the battery cell is fully charged, the battery to be replaced is bypassed through the first switching switch component and the second switching switch component corresponding to the battery to be replaced.

13. The battery device according to claim 4, characterized in that: The switching control unit is also configured to control a plurality of the first switching switch assemblies and a plurality of the second switching switch assemblies to bypass the faulty battery and connect the backup battery in series to the battery cell when the battery to be replaced is a faulty battery and the voltage difference between the backup battery and the unreplaced battery in the battery cell is less than a preset voltage threshold.

14. The battery device according to claim 13, characterized in that: Each of the second switching switch components also includes: a fourth switch and a voltage balancing branch, one end of the fourth switch is connected to the negative electrode of the corresponding battery, and the other end of the fourth switch is connected to the negative DC bus through the voltage balancing branch, wherein the switching control unit is also configured to, when the voltage difference between the backup battery and the unreplaced battery in the battery unit is greater than or equal to a preset voltage threshold, control the first switching switch component and the second switching switch component corresponding to the faulty battery to bypass the faulty battery, and then control the first switching switch component and the second switching switch component corresponding to the unreplaced battery and the backup battery to connect the unreplaced battery and the backup battery in parallel to the positive DC bus and the negative DC bus respectively through the voltage balancing branch.

15. The battery device according to claim 14, characterized in that: A voltage balancing resistor is connected in series in the voltage balancing branch.

16. The battery device according to claim 14, characterized in that: The fourth switch includes two fully-controlled unidirectional conducting semiconductor switches connected in anti-parallel.

17. An energy storage system, characterized in that: include: Converter; At least one battery device according to any one of claims 1 to 16, wherein each of the battery devices is connected in parallel on the DC side of the converter.

18. The energy storage system according to claim 17, characterized in that: When each of the battery devices is discharged through the converter, the reverse-parallel-connected diode of the first switch in each of the battery devices is turned on and the semiconductor switch is turned off.

19. The energy storage system according to claim 17, characterized in that: In the event of a failure in a discharge circuit of any one of the battery devices through the converter, each third switch in the battery device is disconnected.

20. The energy storage system according to claim 17, characterized in that: In the event of a fault in a charging circuit of any battery device charged by the converter, each first switch in the battery device is disconnected.

21. The energy storage system according to claim 17, characterized in that: Each of the battery devices further comprises a controllable switch, which is suitable for disconnecting the faulty battery device from the DC side of the converter and switching a spare battery device into the DC side of the converter when a corresponding battery device fails.

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