Energy storage system, and discharging method and charging method of energy storage system
By employing multiple switch modules connected by a switch topology in the energy storage system, and utilizing a combination of unidirectional and multidirectional switches, dynamic switching of battery cells can be achieved, solving the problem of excessive number of switches, reducing costs, and improving control convenience.
Patent Information
- Application Number
- CN202511436890.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-09
- Publication Date
- 2025-12-16
AI Technical Summary
Existing energy storage systems suffer from high costs due to the large number of modules, resulting in an excessive number of switches.
A switch module with multiple switch topologies is used to achieve dynamic switching of battery cells by combining unidirectional and multidirectional switches, thereby reducing the number of switches.
It reduces switching costs, improves control convenience, reduces the number of switches, and enhances the economics of energy storage systems.
Smart Images
Figure CN121150262A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of energy storage technology, and in particular to energy storage systems, methods for discharging energy storage systems, and methods for charging energy storage systems. Background Technology
[0002] Due to the inconsistency of a large number of batteries throughout their entire life cycle, energy storage systems exhibit a significant bottleneck effect. The more significant this effect, the greater the reduction factor between the cycle life of a single battery cell and the cycle life of the energy storage system, which seriously affects the economics of the energy storage system.
[0003] To fundamentally solve this problem, a dynamic reconfiguration strategy within the cluster has been proposed, which includes multiple technical routes in parallel and series directions. However, all of these technologies are based on each module working with 1 to 2 switches to be responsible for the dynamic switching of that module.
[0004] Existing dynamic switching methods result in a large number of switches and high costs due to the large number of modules contained in the energy storage system. Summary of the Invention
[0005] This application provides an energy storage system, a method for discharging the energy storage system, and a method for charging the energy storage system, in order to at least solve the problem of a large number of dynamically switched switches in related technologies.
[0006] This application provides an energy storage system, including: multiple battery cells and a switching module; Multiple switches are connected in a topology to form a switch module, which is connected to the battery cell and is used to control the switching state of each battery cell.
[0007] In some alternative implementations, the switching module includes: Multiple switching units, each switching unit is connected to a preset number of battery units, and each switching unit is used to control the access and disconnection status of the first preset number of battery units; The switching unit includes a switch topology connection with a preset number of switches.
[0008] In some alternative embodiments, the switching unit includes: At least one first switch group, wherein the first switch group is a combination of a first one-way switch and a second one-way switch connected together; At least one second switch group, wherein the second switch group is a combination connection of a third unidirectional switch and a first multidirectional switch; At least one first switch group and at least one second switch group are topologically connected.
[0009] In some alternative implementations, the first multidirectional switch is a first bidirectional switch; The first end of the first one-way switch is connected to the first end of the second one-way switch, the first end of the third one-way switch, and the common end of the first multi-way switch. The second ends of the first one-way switch, the second ends of the second one-way switch, the second ends of the third one-way switch, and each connection end of the first multi-way switch are connected to the battery cells. The connection ends of the first two-way switch are connected to the two ends of the multiple battery cells.
[0010] In some alternative embodiments, the battery unit includes: a first battery unit, a second battery unit, a third battery unit, and a fourth battery unit; The first terminal of the first one-way switch is connected to the first terminal of the first battery cell; The first end of the second one-way switch is connected to the second end of the first one-way switch, and the second end of the second one-way switch is connected to the first end of the second battery cell. The first end of the third one-way switch is connected to the first end of the second one-way switch, and the second end of the third one-way switch is connected to the first end of the third battery unit. The common terminal of the first bidirectional switch is connected to the first terminal of the third unidirectional switch, the first contact terminal of the first bidirectional switch is connected to the second terminal of the first battery cell, and the second contact terminal of the first bidirectional switch is connected to the first terminal of the fourth battery cell.
[0011] In some alternative embodiments, the switching unit includes: At least one third switch group, wherein the third switch group is a combination of a fourth unidirectional switch and a second multidirectional switch; When the switching unit includes multiple third switch groups, the multiple first switch groups are topologically connected.
[0012] In some alternative embodiments, the second multi-directional switch is a second bidirectional switch; The first end of the fourth unidirectional switch is connected to the common end of the second bidirectional switch, and the second end of the fourth unidirectional switch and each connection end of the second bidirectional switch are respectively connected to the battery cell. However, each connection end of the second bidirectional switch is not simultaneously connected to both ends of each battery cell.
[0013] In some alternative implementations, the battery unit is a battery module or a battery cell.
[0014] This application also provides a discharge method for an energy storage system, wherein the discharge method is applied to the energy storage system described above, and the discharge method includes: Among all battery cells, identify the first preset number of target battery cells with the lowest voltage and identify the target battery cells that have dropped to the discharge cutoff voltage, and control the switching module to cut off the target battery cells; The target battery cell is identified in all battery cells at preset time intervals until all battery cells are discharged to the discharge cutoff voltage.
[0015] This application also provides a charging method for an energy storage system, wherein the charging method is applied to the energy storage system described above, and the charging method includes: Among all battery cells, identify the second preset number of target battery cells with the highest voltage and identify the target battery cells that have risen to the charging cutoff voltage, and control the switching module to cut off the target battery cells; The target battery cell is identified among all battery cells at preset time intervals until all battery cells are charged to the charging cut-off voltage. Attached Figure Description
[0016] To more clearly illustrate the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 A structural diagram of an energy storage system provided in an embodiment of this application; Figure 2 A structural diagram of another energy storage system provided in this application embodiment; Figure 3 A structural diagram of another energy storage system provided in the embodiments of this application; Figure 4 A structural diagram of another energy storage system provided in the embodiments of this application; Figure 5 A structural diagram of an energy storage system provided in this application embodiment; Figure 6 A flowchart illustrating a charging method for an energy storage system provided in this application embodiment; Figure 7 A flowchart of a discharge method for an energy storage system provided in an embodiment of this application. Detailed Implementation
[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this application.
[0019] It should be noted that, in the description of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. The terms "first," "second," etc., in this application are used to distinguish similar objects and are not used to describe a specific order or sequence.
[0020] Due to the inconsistency of a large number of batteries throughout their entire life cycle, energy storage systems exhibit a significant bottleneck effect. The more significant this effect, the greater the reduction factor between the cycle life of a single battery cell and the cycle life of the energy storage system, which seriously affects the economics of the energy storage system.
[0021] To fundamentally solve this problem, a dynamic reconfiguration strategy within the cluster has been proposed, which includes multiple technical routes in parallel and series directions. However, all of these technologies are based on each module working with 1 to 2 switches to be responsible for the dynamic switching of that module.
[0022] Existing dynamic switching methods result in a large number of switches and high costs due to the large number of modules contained in the energy storage system.
[0023] An embodiment of this application provides an energy storage system, including: a plurality of battery cells 10 and a switching module 20; Multiple switches are connected in a topology to form a switch module 20, which is connected to the battery unit 10. The switch module 20 is used to control the switching state of each battery unit.
[0024] Specifically, refer to Figure 1 The battery cells are designated B1 to Bn, and the switches are designated S1 to Shr. Dynamic switching of n-1 battery cells is achieved through the topological connection of S1 to Shr. Each row has switches S1 to Sr, and there is a Sh column. Optionally, the topological connection refers to the connection between switches according to a preset method, that is, one end of a switch is connected to another switch without being directly connected to a battery cell.
[0025] Optionally, the switch includes a one-way switch and a multi-way switch, which are topologically connected together as switch module 20. (Reference) Figure 2Three unidirectional switches and one multidirectional switch are connected together in a topology to form a switch module.
[0026] The energy storage system provided in this application uses multiple switch topologies connected as a switch module to achieve dynamic switching of individual battery cells, any two battery cells, any three battery cells, ..., and any n-1 battery cells. Compared to traditional energy storage systems that require two switches for each battery cell, this application significantly reduces the number of switches, thereby reducing costs. Simultaneously, it improves control convenience.
[0027] In some feasible implementations, the switching module includes: Multiple switching units, each switching unit is connected to a preset number of battery units, and each switching unit is used to control the access and disconnection status of the first preset number of battery units; The switching unit includes a switch topology connection with a preset number of switches.
[0028] For example, refer to Figure 2 , Figure 2 It can be a single switch unit, with each switch unit connected to every four battery units. The number of battery units can be expanded by connecting multiple switch units to multiple preset battery units.
[0029] Specifically, the topology connection can be a arrangement of multiple switching units in a preset manner.
[0030] In some feasible implementations, such as Figure 2 As shown, the switching unit includes: At least one first switch group K1, wherein the first switch group K1 is a combination connection of a first one-way switch and a second one-way switch; At least one second switch group K2, wherein the second switch group K2 is a combination connection of a third unidirectional switch and a first multidirectional switch; At least one first switch group and at least one second switch group are topologically connected.
[0031] Specifically, the topological connection of at least one first switch group and at least one second switch group refers to the connection between the connection terminals of the first unidirectional switch and the second unidirectional switch in the first switch group and the connection terminals of the third unidirectional switch and the first multidirectional switch in the second switch group.
[0032] For example, refer to Figure 2 The first multi-directional switch is a bidirectional switch. The switch unit includes a K1 and a second switch group K2, where K1 consists of S1 and S2, and the second switch group K2 consists of S3 and S4. Among them, S1, S2, and S4 are unidirectional switches, and S3 is a bidirectional switch.
[0033] For example, refer to Figure 3 The switching unit includes two K1 switches and a second switch group K2. The first K1 switches are S5 and S6, the second K1 switches are S7 and S8, and the second switch group K2 switches are S9 and S10. Among them, S5, S6, S7, S8, and S10 are unidirectional switches, and S9 is a bidirectional switch.
[0034] In some feasible implementations, such as Figure 2 As shown, the first multi-directional switch is a first bi-directional switch; The first end of the first one-way switch is connected to the first end of the second one-way switch, the first end of the third one-way switch, and the common end of the first multi-way switch. The second ends of the first one-way switch, the second ends of the second one-way switch, the second ends of the third one-way switch, and each connection end of the first multi-way switch are connected to the battery cells. The connection ends of the first two-way switch are connected to the two ends of the multiple battery cells.
[0035] For example, refer to Figure 2 Terminal a of S3 is connected to the left end of B1, and terminal b of S3 is connected to the right end of B4. (See reference) Figure 3 The a end of S9 is connected to the left end of B1, and the b end of S3 is connected to the right end of B6.
[0036] In some feasible implementations, such as Figure 2 As shown, the battery unit includes: a first battery unit, a second battery unit, a third battery unit, and a fourth battery unit; The first terminal of the first one-way switch is connected to the first terminal of the first battery cell; The first end of the second one-way switch is connected to the second end of the first one-way switch, and the second end of the second one-way switch is connected to the first end of the second battery cell. The first end of the third one-way switch is connected to the first end of the second one-way switch, and the second end of the third one-way switch is connected to the first end of the third battery unit. The common terminal of the first bidirectional switch is connected to the first terminal of the third unidirectional switch, the first contact terminal of the first bidirectional switch is connected to the second terminal of the first battery cell, and the second contact terminal of the first bidirectional switch is connected to the first terminal of the fourth battery cell.
[0037] Specifically, refer to Figure 2 and Figure 3 The topological connection between the first unidirectional switch, the second unidirectional switch, the third unidirectional switch, and the first bidirectional switch.
[0038] For example, B1, B2, B3, and B4 are four modules or batteries. If they are in one module, they are four batteries; if they are in one cluster, they are four modules. S1, S2, S3, and S4 are four switches. S1 and S4 are unidirectional switches with only two states: closed and open. S2 and S3 are bidirectional switches with three states: closed in direction a, closed in direction b, and open.
[0039] When all switches are turned off, all four batteries or modules are put into system operation; When S1 and S3-a are closed and other switches are open, B1 will be bypassed. When S1 and S2-b are closed and other switches are open, B2 will be bypassed. When S4 and S2-b are closed and other switches are open, B3 will be bypassed. When S1 and S3-b are closed and other switches are open, B4 will be bypassed. When S2-b and S3-a are closed and other switches are open, B1+B2 will be bypassed. When S1 and S4 are closed and other switches are open, B2+B3 will be bypassed. When S2-b and S3-b are closed and other switches are open, B3+B4 will be bypassed. When S4 and S3-a are closed and other switches are open, B1+B2+B3 will be bypassed. When S1 and S3-b are closed and other switches are open, B2+B3+B4 will be bypassed.
[0040] For a module consisting of four batteries or a cluster of four modules, the switching architecture based on the present invention can realize the switching of any, any two, or any three adjacent batteries / modules.
[0041] In some feasible implementations, such as Figure 4 As shown, the switching unit includes: At least one third switch group c, wherein the third switch group c is a combination of a fourth unidirectional switch and a second multidirectional switch; When the switching unit includes multiple third switch groups c, the multiple first switch groups c are topologically connected.
[0042] For example, refer to Figure 4 The second multi-directional switch is a bidirectional switch, namely S11, S14, and S15. The fourth unidirectional switch is S12, S13, and S16. The switching unit includes three third switch groups c, namely S11 and S12, S13 and S14, and S15 and S16.
[0043] Specifically, the topological connection between multiple third switch groups c refers to the connection between the connection terminals of the fourth unidirectional switch and the second multidirectional switch in each third switch group c.
[0044] It should be noted that multi-way switches can be three-way switches, four-way switches, etc., in addition to two-way switches.
[0045] In some feasible implementations, such as Figure 4 and Figure 5 As shown, the second multi-directional switch is a second bidirectional switch; The first end of the fourth unidirectional switch is connected to the common end of the second bidirectional switch, and the second end of the fourth unidirectional switch and each connection end of the second bidirectional switch are respectively connected to the battery cell. However, each connection end of the second bidirectional switch is not simultaneously connected to both ends of each battery cell.
[0046] For example, refer to Figure 4 The topology is specifically designed so that the common terminal of S11 is connected to the common terminal of S14, the common terminal of S15, the first terminal of S12, the first terminal of S13, and the first terminal of S16. For example, the connection terminal of S11 will not be connected to both ends of B1 or both ends of B2 simultaneously, that is, it will not be connected to both ends of any battery cell from B1 to B8.
[0047] refer to Figure 5 The topology is specifically designed so that the common terminal of S17 and the common terminal of S18, the common terminal of S21, the first terminal of S18, the first terminal of S20, and the first terminal of S22 are connected. For example, the connection terminal of S17 will not be connected to both ends of B1 or both ends of B2 simultaneously, that is, it will not be connected to both ends of any battery cell from B1 to B8.
[0048] In some feasible implementations, the battery unit is a battery module or a battery cell.
[0049] Specifically, multiple battery units can be modules composed of n (4~100) lithium-ion batteries, sodium-ion batteries, solid-state batteries, aqueous sodium-ion batteries, lead-acid batteries, etc., all connected in series, or battery clusters composed of n (4~100) modules connected in series.
[0050] Dynamic switching of any single or adjacent two, three...n-1 cells / modules is achieved through switch linkage. The voltage difference generated during cell / module switching is addressed by the adjustment capabilities of conventional DC / DC modules or PCS, which will not be elaborated upon in this invention.
[0051] Embodiments of this application provide a discharge method for an energy storage system, such as... Figure 6As shown, the discharge method of the energy storage system is applied to the energy storage system described above, and the discharge method of the energy storage system includes: Step 1: Among all battery cells, identify the first preset number of target battery cells with the lowest voltage and identify the target battery cells that have dropped to the discharge cutoff voltage, and control the switching module to cut off the target battery cells; Step 2: At preset time intervals, identify the target battery cell among all battery cells until all battery cells are discharged to the discharge cutoff voltage.
[0052] Specifically, during the charging phase, the n cells or modules with the highest voltage are selected and bypassed. After a period of time t, the voltage is re-monitored. If the voltage of the bypassed cell or module is lower than that of a certain cell or module (or its adjacent combination), the system switches to the cell or module with the highest voltage at that moment (or its adjacent combination). This process is repeated. If, during the dynamic switching interval t, a certain cell or module (or its adjacent combination) reaches the charging cutoff voltage, it is bypassed first, and the cells or modules that have not completed full charging continue to charge. At the same time, the input power of the PCS is reduced until all cells or modules in the entire module or cluster reach the charging cutoff voltage, thereby achieving 100% full charge. n can be 1 to 10, and if it is greater than 1, it refers to adjacent cells or modules.
[0053] Embodiments of this application provide a discharge method for an energy storage system, such as... Figure 7 As shown, the charging method for the energy storage system is applied to the energy storage system described above, and the charging method for the energy storage system includes: Step (1): Among all battery cells, identify the second preset number of target battery cells with the highest voltage and identify the target battery cells that have risen to the charging cutoff voltage, and control the switching module to cut off the target battery cells; Step (2): Identify the target battery cell among all battery cells at preset time intervals until all battery cells are charged to the charging cut-off voltage.
[0054] Specifically, during the discharge phase, the n cells or modules with the lowest voltage are selected and bypassed. After a period of time t, the voltage is re-monitored. If the voltage of the bypassed cell or module is higher than that of a certain cell or module (or its adjacent combination), the system switches to the cell or module with the lowest voltage at that moment (or its adjacent combination). This process is repeated. If, during the dynamic switching interval t, a cell or module (or its adjacent combination) reaches the discharge cutoff voltage, it is bypassed first, and the cells or modules that have not completed full discharge continue to discharge. At the same time, the output power of the PCS (Power Conversion System) is reduced until all cells or modules in the entire module or cluster reach the discharge cutoff voltage, thereby achieving 100% full discharge. n can be 1 to 10, and if it is greater than 1, it represents adjacent cells or modules.
[0055] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.
[0056] The energy storage system, its discharge method, and its charging method provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only intended to help understand the method and core ideas of this application. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this application.
Claims
1. An energy storage system, characterized in that, include: Multiple battery cells and switch modules; Multiple switches are connected in a topology to form a switch module, which is connected to the battery cell and is used to control the switching state of each battery cell.
2. The energy storage system according to claim 1, characterized in that, The switching module includes: Multiple switching units, each switching unit is connected to a preset number of battery units, and each switching unit is used to control the access and disconnection status of the first preset number of battery units; The switching unit includes a switch topology connection with a preset number of switches.
3. The energy storage system according to claim 2, characterized in that, The switching unit includes: At least one first switch group, wherein the first switch group is a combination of a first one-way switch and a second one-way switch connected together; At least one second switch group, wherein the second switch group is a combination connection of a third unidirectional switch and a first multidirectional switch; At least one first switch group and at least one second switch group are topologically connected.
4. The energy storage system according to claim 3, characterized in that, The first multi-directional switch is a first bidirectional switch; The first end of the first one-way switch is connected to the first end of the second one-way switch, the first end of the third one-way switch, and the common end of the first multi-way switch. The second ends of the first one-way switch, the second ends of the second one-way switch, the second ends of the third one-way switch, and each connection end of the first multi-way switch are connected to the battery cells. The connection ends of the first two-way switch are connected to the two ends of the multiple battery cells.
5. The energy storage system according to claim 4, characterized in that, The battery unit includes: a first battery unit, a second battery unit, a third battery unit, and a fourth battery unit; The first terminal of the first one-way switch is connected to the first terminal of the first battery cell; The first end of the second one-way switch is connected to the second end of the first one-way switch, and the second end of the second one-way switch is connected to the first end of the second battery cell. The first end of the third one-way switch is connected to the first end of the second one-way switch, and the second end of the third one-way switch is connected to the first end of the third battery unit. The common terminal of the first bidirectional switch is connected to the first terminal of the third unidirectional switch, the first contact terminal of the first bidirectional switch is connected to the second terminal of the first battery cell, and the second contact terminal of the first bidirectional switch is connected to the first terminal of the fourth battery cell.
6. The energy storage system according to claim 2, characterized in that, The switching unit includes: At least one third switch group, wherein the third switch group is a combination of a fourth unidirectional switch and a second multidirectional switch; When the switching unit includes multiple third switch groups, the multiple first switch groups are topologically connected.
7. The energy storage system according to claim 6, characterized in that, The second multi-directional switch is a second bidirectional switch; The first end of the fourth unidirectional switch is connected to the common end of the second bidirectional switch, and the second end of the fourth unidirectional switch and each connection end of the second multidirectional switch are respectively connected to the battery unit. However, each connection end of the second bidirectional switch is not simultaneously connected to both ends of each battery unit.
8. The energy storage system according to claim 2, characterized in that, The battery unit is either a battery module or a battery cell.
9. A discharge method for an energy storage system, characterized in that, The discharge method of the energy storage system is applied to the energy storage system as described in any one of claims 1 to 8, wherein the discharge method of the energy storage system includes: Among all battery cells, identify the first preset number of target battery cells with the lowest voltage and identify the target battery cells that have dropped to the discharge cutoff voltage, and control the switching module to cut off the target battery cells; The target battery cell is identified in all battery cells at preset time intervals until all battery cells are discharged to the discharge cutoff voltage.
10. A charging method for an energy storage system, characterized in that, The charging method for the energy storage system is applied to the energy storage system as described in any one of claims 1 to 8, and the charging method for the energy storage system includes: Among all battery cells, identify the second preset number of target battery cells with the highest voltage and identify the target battery cells that have risen to the charging cutoff voltage, and control the switching module to cut off the target battery cells; The target battery cell is identified among all battery cells at preset time intervals until all battery cells are charged to the charging cut-off voltage.