A sodium-ion battery backup power system

Abstract

The present application relates to the technical field of sodium ion battery, in particular to a kind of sodium ion battery backup power system, comprising: a plurality of the sodium ion battery cluster is made into a group of power supply unit;Each power supply unit is connected to control system via a group of switch box respectively;The control system estimates the total state of charge and total health value of current system by reading the opening and closing information of switch box and voltage information, temperature information of power supply unit.For the problem that the maintenance time of sodium ion energy storage system in the prior art is longer, a certain number of sodium ion battery clusters are assembled into power supply units and connected to the control system via switch boxes, and each power supply unit can be independently cut off to realize modular maintenance, a modular three-level main circuit architecture is realized, and the control system itself automatically calculates the new system SOC value and system SOH value after maintenance, reduces the time for system debugging and calibration after maintenance, and improves the equipment availability.

Description

Technical Field

[0001] This invention relates to the field of sodium-ion battery technology, and more specifically to a sodium-ion battery backup power system. Background Technology

[0002] Backup power systems are core equipment ensuring continuous power supply for critical scenarios such as communication base stations, data centers, industrial control systems, and rail transportation. Their modularity, ease of operation and maintenance, and safety protection capabilities directly determine the reliability of the power supply system. Currently, most mainstream backup power systems use lead-acid or lithium-ion batteries as energy storage units, which have inherent drawbacks such as short cycle life, inability to charge at low temperatures or poor charge / discharge performance, insufficient environmental friendliness, and high safety risks. Sodium-ion batteries, with their abundant sodium resources, excellent safety and rate discharge performance under high and low temperature conditions, and high intrinsic safety, have become an ideal alternative in the backup power field.

[0003] For example, patent application CN202310299582.7 discloses a sodium-ion battery energy storage module, which relates to the field of energy storage battery technology. The main technical solution is as follows: a control module is used to determine the total amount of electricity for the current charging behavior of the energy storage cabinet, generate the charging time for the current charging behavior according to the charging strategy, and divide the charging time according to the charging strategy to obtain the first charging time and the charged energy of each charging stage of the charging strategy; calculate the second charging time of each charging stage of the charging strategy according to the charging coefficient of the sodium-ion battery and the current charging information; if the time difference between the first charging time and the second charging time meets the preset time threshold, determine the energy loss of each charging stage according to the real-time electricity and input energy of each sodium-ion battery under the first charging time, simulate the temperature data of each sodium-ion battery according to the energy loss of each charging stage and the size information of the sodium-ion battery; and adjust the output power of the cooling system according to the temperature data to perform heat dissipation management of multiple sodium-ion batteries.

[0004] For example, patent application CN202511328813.8 discloses a modular energy storage system for sodium-ion batteries, including a battery cell rack. Multiple battery cell racks are arranged vertically and stacked. Trapezoidal frames are fixedly installed on both sides of the battery cell rack. One end of each rotating shaft is rotatably connected to the inner wall of the trapezoidal frame or the inner wall of the battery cell rack. Output batteries are placed above each set of rotating shafts. Multiple output batteries are located inside the battery cell rack. A spare battery is placed on top of the battery cell rack. A replacement component is provided on one side of the spare battery. A transport component is provided on one side of each output battery. When the spare battery is located on the side of the overheated battery, the overheated battery can automatically detach from the module during the process of the spare battery entering the battery cell rack, improving the overall safety and reliability of the system. Furthermore, the replacement component facilitates the collection and management of the overheated battery.

[0005] However, in actual implementation, the inventors found that because sodium-ion batteries have a relatively short cycle life at the current stage, they need to be replaced and maintained more often when applied to energy storage systems, resulting in low reliability of energy storage systems and requiring a lot of maintenance time. Summary of the Invention

[0006] In view of the above-mentioned problems in the prior art, a sodium-ion battery backup power system is provided.

[0007] The specific technical solution is as follows: A sodium-ion battery backup power system includes multiple sodium-ion battery clusters; Multiple sodium-ion battery clusters form a power supply unit; Each of the power supply units is connected to the control system via a set of switch boxes; The control system estimates the current total state of charge and total health value of the system by reading the opening and closing information of the switch box and the voltage and temperature information of the power supply unit.

[0008] On the other hand, the sodium-ion battery cluster includes: Multiple battery modules, each of which is provided with multiple strings of sodium-ion cells; Each of the battery modules is equipped with a corresponding monitoring unit; The battery modules are connected in series to the output bus of the sodium-ion battery cluster; The monitoring unit collects the voltage and temperature information of each sodium-ion battery cell and sends them to the control system via a bus.

[0009] On the other hand, the control system includes: The first acquisition module collects the power supply unit information of the power supply unit and the switch box information of the switch box respectively. A fault diagnosis module, wherein the fault diagnosis module is connected to the first acquisition module; The fault detection module performs verification based on the power supply unit information and the switch box information to determine the faulty power supply unit or faulty switch box. A cut-off module, which is connected to the fault detection module; The disconnection module disconnects the fault switch box, or the fault switch box corresponding to the fault power supply unit.

[0010] On the other hand, the control system includes: The first SOC determination module receives voltage information from each of the power supply units and determines the first state of charge value of the sodium-ion battery cluster based on the voltage information. A low-power matching module, wherein the low-power matching module is connected to the first SOC discrimination module; The low-power matching module matches the first state of charge value and the preset first over-discharge threshold to obtain a low-power sodium-ion battery cluster, and generates a corresponding low-power alarm signal and configures a current limit for the low-power sodium-ion battery cluster. Over-discharge protection module, which is connected to the low-power matching module; The over-discharge protection module matches the over-discharge protection value according to the first state of charge value or the voltage information, and cuts off the corresponding switch box when an over-discharged sodium-ion battery cluster occurs.

[0011] On the other hand, the control system includes: The relay control module selects the corresponding switch box to disconnect or connect according to the fault information and generates initialization information. SOC estimation module, wherein the SOC estimation module is connected to the relay control module; The SOC estimation module estimates the current system SOC value of the power supply unit as a whole based on the initialization information. SOH estimation module, wherein the SOH estimation module is connected to the relay control module; The SOH estimation module estimates the current system SOH value of the power supply unit as a whole based on the initialization information. On the other hand, the SOC estimation module includes: The second acquisition module determines the polarization information of each sodium-ion battery cluster based on the voltage information, the temperature information, and the pre-collected battery cycle number. The first lifetime estimation module estimates the first health value of the sodium-ion battery cluster based on the polarization information. A weighted charge prediction module, wherein the weighted charge prediction module is connected to the first lifetime estimation module; The weighted charge estimation module estimates the cluster charge value of each sodium-ion battery cluster based on the voltage information and the first health value, and obtains the system SOC value by weighted averaging the cluster charge values.

[0012] On the other hand, the SOH estimation module includes: The third acquisition module determines the polarization information of each sodium-ion battery cluster based on the voltage information, the temperature information, and the pre-collected battery cycle number. An internal resistance measurement module, wherein the internal resistance measurement module is connected to the third acquisition module; The internal resistance measurement module calculates the polarization-corrected internal resistance of each sodium-ion battery cluster based on the polarization information. A power SOH calculation module, wherein the power SOH calculation module is connected to the internal resistance measurement module; The power SOH calculation module calculates the DC internal resistance based on the polarization-corrected internal resistance to obtain the system SOH value.

[0013] On the other hand, the control system also includes: An adjustment module acquires the system SOC value and generates a target SOC value for the newly connected power supply unit based on the system SOC value. The adjustment module adjusts the charge of the newly connected power supply unit according to the target SOC value.

[0014] On the other hand, the control system also includes: A current limiting module controls the current limit of each power supply unit according to the temperature information.

[0015] The above technical solution has the following advantages or beneficial effects: To address the issue of long maintenance times required for existing sodium-ion energy storage systems, this solution assembles a number of sodium-ion battery clusters into power supply units and connects them to the control system via a switch box. Each power supply unit can be independently disconnected to achieve modular maintenance, realizing a modular three-level main circuit architecture. Furthermore, the control system automatically calculates new system SOC and SOH values ​​after maintenance, reducing the time required for post-maintenance system re-adjustment and calibration, and improving equipment reliability. Attached Figure Description

[0016] Embodiments of the invention will be described more fully with reference to the accompanying drawings. However, the drawings are for illustration and explanation only and do not constitute a limitation on the scope of the invention.

[0017] Figure 1 This is an overall schematic diagram of an embodiment of the present invention; Figure 2 This is a schematic diagram of the fault detection module in an embodiment of the present invention; Figure 3 This is a schematic diagram of the low-power matching module in an embodiment of the present invention; Figure 4 This is a schematic diagram of the relay control module in an embodiment of the present invention; Figure 5 This is a schematic diagram of the first lifetime estimation module in an embodiment of the present invention; Figure 6 This is a schematic diagram of the internal resistance measurement module in an embodiment of the present invention; Figure 7 This is a schematic diagram of the adjustment module in an embodiment of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0021] This invention includes: A sodium-ion battery backup power system, such as Figure 1 As shown, it includes multiple sodium-ion battery clusters A1; Multiple sodium-ion battery clusters A1 form a power supply unit A2; Each power supply unit A2 is connected to the control system A4 via a set of switch boxes A3; The control system A4 estimates the current system SOC and SOH values ​​by reading the opening and closing information of the switch box A3 and the voltage and temperature information of the power supply unit A2.

[0022] Specifically, addressing the issue of long maintenance times required for existing sodium-ion energy storage systems, this solution assembles a certain number of sodium-ion battery clusters A1 into power supply units A2 and connects them to the control system A4 via switch box 3. Each power supply unit A2 can be independently disconnected to achieve modular maintenance, realizing a modular three-level main circuit architecture. Furthermore, the control system A4 automatically calculates new system SOC and SOH values ​​after maintenance, reducing the time required for post-maintenance system re-adjustment and calibration, and improving equipment reliability.

[0023] In one embodiment, the sodium-ion battery cluster A1 includes: Multiple battery modules A11, each containing multiple strings of sodium-ion cells A12; Each battery module A11 is equipped with a corresponding monitoring unit A13; Battery modules A11 are connected in series to the output bus of sodium-ion battery cluster A1; The monitoring unit A13 collects the voltage and temperature information of each sodium-ion battery cell A12 and sends it to the control system A4 via the bus.

[0024] Specifically, the above structure forms a three-level series main circuit architecture consisting of a sodium-ion battery cluster A1, a switch box A3, and a control system A4. This architecture achieves complete modular separation of the energy storage unit, manual isolation unit, and control unit, facilitating integrated installation and independent operation and maintenance. At the same time, the switch box A3 is set at the battery output end as the first line of safety protection, significantly improving system safety.

[0025] In actual implementation, a single sodium-ion battery cluster A1 is usually used as the smallest unit of operation and maintenance. It contains multiple battery modules A11 connected in series, and each battery module A11 is connected to a corresponding monitoring unit A13 as a unified detection unit.

[0026] In some embodiments, the battery adopts a 64-series 4-parallel architecture, consisting of four sets of power supply units with identical structure and electrical performance parameters connected in parallel to form a 4-parallel output structure. Each power supply unit consists of 64 sodium-ion cells with a nominal voltage of 3.0V connected in series, with an overall nominal voltage of 192V and an operating voltage range of 128V~224V, which is compatible with the 192V voltage requirement of UPS power supplies in the backup power industry. The positive electrode material of the sodium-ion cells is a polyanionic sodium iron pyrophosphate composite positive electrode, the negative electrode material is a hard carbon-based composite negative electrode, and the electrolyte is a wide-temperature-range sodium salt composite electrolyte. A single cell supports low-temperature discharge and charging at -40℃, and the capacity recovery rate after 72 hours of 0V over-discharge is ≥97%, with a 1C charge-discharge cycle life of ≥4000 times, which is fully suitable for the application scenarios of long-term float charging and occasional deep discharge in backup power supplies.

[0027] The control system includes a main control unit, a relay execution unit, and a power supply unit. The CAN communication unit communicates with the cell acquisition slave board within the sodium-ion battery cluster, constructing a CAN bus acquisition network to achieve real-time transmission of voltage and temperature data for each cell. The communication baud rate supports adaptive speeds of 250kbps / 500kbps / 1Mbps, exhibiting strong anti-interference capabilities, stable data transmission, and adaptability to the distributed acquisition requirements of multiple parallel battery clusters. The relay execution unit is electrically connected to the main control unit and includes a main positive relay and diode connected in series in the main circuit. Based on the system's operating status and protection logic, the main control unit uses the relay execution unit to achieve power-on, normal on / off control, and emergency fault disconnection of the main circuit, working in conjunction with the switch box to achieve dual electrical isolation and protection.

[0028] Each monitoring unit A13 communicates with the control system via a CAN bus, enabling independent acquisition of voltage and temperature data for a single battery cell string. It also supports parallel equalization management of four battery strings, accurately identifying voltage differences between parallel and series strings. Combined with an active equalization circuit, it achieves consistent management of all battery cells in the cluster, avoiding issues such as circulating current and uneven cell degradation in a multi-parallel architecture.

[0029] The switch box includes a housing, a manual disconnect switch, a short-circuit protection fuse, a maintenance grounding terminal, status indicator lights, and a terminal block. The manual disconnect switch is connected in series in the main circuit, with a rated current capacity ≥ 1.5 times the system's maximum charge / discharge current. It is used for manual electrical isolation between the battery pack and the downstream system. During integrated installation, the switch can be disconnected first to complete wiring. During maintenance, the battery-side power supply can be completely cut off, completely avoiding the risk of live work. The short-circuit protection fuse is connected in series at the front end of the manual disconnect switch, adjacent to the battery pack output end. It has a rated breaking capacity ≥ 150kA and is used for rapid short-circuit protection at the battery pack output end. The short-circuit response time is ≤ 10ms. When a short circuit occurs at the battery pack outlet, it can quickly cut off the circuit, preventing the fault from spreading to the cells and downstream equipment. The maintenance grounding terminal is electrically connected to the housing and the negative terminal of the battery pack for circuit grounding discharge during maintenance, ensuring operational safety. The status indicator lights are linked to the auxiliary contacts of the manual disconnect switch, allowing for intuitive indication of the main circuit's on / off status without opening the cover, further enhancing operational safety.

[0030] In one embodiment, such as Figure 2 As shown, the control system includes: The first acquisition module B1 collects the power supply unit information A2 of the power supply unit and the switch box information of the switch box A3 respectively; Fault detection module B2 is connected to the first acquisition module B1; The fault diagnosis module B2 performs verification based on the power supply unit information and switch box information to determine the faulty power supply unit or faulty switch box. Cut off module B3; cut off module B3 is connected to fault detection module B2. The disconnection module B3 disconnects the fault switch box or the fault switch box corresponding to the fault power supply unit.

[0031] Specifically, to achieve a better fault isolation effect, in this embodiment, the first acquisition module B1 collects the power supply unit information of the power supply unit and the switch box information of the switch box. The power supply unit information includes cell-level monitoring information collected by the corresponding monitoring unit A13 for each sodium-ion battery cluster A1 in the power supply unit, mainly including the current, voltage, and temperature of the individual cell. This allows the fault judgment module B2 to verify and determine whether the individual cell has experienced overcurrent, overvoltage, or overtemperature faults according to preset rules.

[0032] Furthermore, short-circuit protection information is collected from the short-circuit protection fuse in the switch box to serve as switch box information, thereby identifying the faulty power supply unit or faulty switch box. The faulty power supply unit is determined by analyzing the aforementioned power supply unit information to identify the faulty individual battery cell, and then by reverse-engineering the corresponding sodium-ion battery cluster A1 and power supply unit A2.

[0033] Subsequently, the disconnection module B3 disconnects the fault switch box, and locates the switch box at the very beginning of the circuit in the direction of the fault power supply unit and disconnects it as the fault switch box to facilitate maintenance.

[0034] In one embodiment, such as Figure 3 As shown, the control system includes: The first SOC discrimination module C1 receives the voltage information of each power supply unit A2 and determines the first state of charge value of the sodium-ion battery cluster A1 based on the voltage information. Low battery matching module C2 is connected to the first SOC discrimination module C1. The low-power matching module C2 matches the first state of charge value and the preset first over-discharge threshold to obtain a low-power sodium-ion battery cluster, and generates a corresponding low-power alarm signal and configures a current limit for the low-power sodium-ion battery cluster. Over-discharge protection module C3 is connected to low-power matching module C2. The over-discharge protection module C3 matches the over-discharge protection value based on the first state of charge value or voltage information, and cuts off the corresponding switch box when an over-discharged sodium-ion battery cluster occurs.

[0035] Specifically, to achieve better protection for the battery clusters, in this embodiment, the voltage information of each power supply unit A2 is first received by the first SOC discrimination module C1. Simultaneously, the rated capacity and upper and lower voltage boundaries of the sodium-ion battery clusters A1 configured in each power supply unit have been pre-collected. Based on this, the first state of charge value of the sodium-ion battery cluster A1 can be calculated by normalizing it with the current voltage information.

[0036] Then, the low-power matching module C2 matches the first state of charge value and the preset first over-discharge threshold to obtain low-power sodium-ion battery clusters, such as sodium-ion battery clusters with a first state of charge value of less than 20%, and generates a low-power alarm signal to indicate the potential over-discharge risk of a single sodium-ion battery cluster.

[0037] Furthermore, to address the risk of over-discharge in this sodium-ion battery cluster, a current limit is configured to reduce the discharge current on this branch, thereby slowing down the onset of over-discharge. Since there are four parallel power supply units A2 on the bus of control system A4, when a current limit is configured on one of them, the overall load limit is reduced, but other branches can handle a larger proportion of the discharge demand when not at full load.

[0038] Finally, the over-discharge protection module C3 matches the over-discharge protection value based on the first state-of-charge value or voltage information, and disconnects the corresponding switch box when an over-discharged sodium-ion battery cluster occurs to avoid battery over-discharge. Subsequently, maintenance personnel replace the over-discharged sodium-ion battery cluster A1 individually.

[0039] In one embodiment, such as Figure 4 As shown, the control system includes: Relay control module D1 selects the corresponding switch box to cut off or connect according to the fault information and generates initialization information; SOC estimation module D2 is connected to the relay control module; The SOC estimation module estimates the current system SOC value of the power supply unit based on the initialization information. SOH estimation module D3 is connected to relay control module D1; The SOH estimation module D3 estimates the current system SOH value of the power supply unit based on the initialization information.

[0040] Specifically, to achieve better fault maintenance efficiency, in this embodiment, the relay control module D1 first selects the corresponding switch box to disconnect or connect according to the fault information, and then initializes the system and generates initialization information. When a new power supply unit A2 is connected or an existing power supply unit A2 is isolated, the overall load capacity of the system will change, and the SOC / SOH values ​​corresponding to sodium-ion battery clusters A1 with different cycle lives will also be different. In the prior art, after a new battery pack is added, the SOC / SOH values ​​are usually calibrated by individually charging and discharging all battery packs over a relatively long period. During this process, the monitoring function of relevant indicators is unavailable.

[0041] To address this, this embodiment introduces a SOC estimation module D2 to estimate the current system SOC value of the power supply unit based on initialization information, and a SOH estimation module D3 to estimate the current system SOH value of the power supply unit based on initialization information, thereby completing the rapid initialization of SOC / SOH values ​​and reducing the overall maintenance time.

[0042] In one embodiment, such as Figure 5 As shown, the SOC estimation module D2 includes: The second acquisition module D21 determines the polarization information of each sodium-ion battery cluster based on voltage information, temperature information, and the pre-collected battery cycle number. The first lifetime estimation module D22 estimates the first health value of the sodium-ion battery cluster based on polarization information. Weighted charge prediction module D23 is connected to the first lifetime estimation module D22; The weighted charge estimation module D23 estimates the cluster charge value of each sodium-ion battery cluster based on voltage information and the first health value, and obtains the system SOC value by weighted averaging of the cluster charge values.

[0043] Specifically, to achieve better SOC estimation results, in this embodiment, the second acquisition module D21 first acquires voltage information, temperature information, and pre-collected battery cycle count. The voltage and temperature information are voltage and temperature sequence information about the sodium-ion battery cluster pre-stored in a cache by the control system. Combined with the battery cycle count, this information is input into a pre-trained prediction model to generate the change in the battery's polarization resistance as polarization information.

[0044] Subsequently, the first lifetime estimation module D22 determines the aging degree of the sodium-ion battery cluster based on the polarization information, and then estimates the SOH value of the sodium-ion battery cluster to obtain the first health value. Based on the first health value, the upper and lower boundaries of the rated voltage of the sodium-ion battery cluster after aging under the current SOH state can be mapped. Combined with the actual voltage information and the cluster charge value of the sodium-ion battery cluster, the system SOC value is obtained by weighted averaging based on the cluster charge value.

[0045] In one embodiment, such as Figure 6 As shown, the SOH estimation module D3 includes: The third acquisition module D31 determines the polarization information of each sodium-ion battery cluster based on voltage information, temperature information, and the pre-collected battery cycle number. Internal resistance measurement module D32 is connected to the third acquisition module D31; The internal resistance measurement module D32 calculates the polarization-corrected internal resistance of each sodium-ion battery cluster based on the polarization information; Power SOH calculation module D33 is connected to internal resistance measurement module D32; The power SOH calculation module D33 calculates the DC internal resistance based on the polarization-corrected internal resistance to obtain the system SOH value.

[0046] Specifically, to achieve a better measurement of the SOH value, this paper introduces a power SOH value based on internal resistance estimation. First, voltage information, temperature information, and pre-collected battery cycle count are acquired through the third acquisition module D31. The voltage and temperature information are voltage and temperature sequences of the sodium-ion battery cluster pre-stored in the cache by the control system. Combined with the battery cycle count, these are input into a pre-trained prediction model to generate the change in the battery's polarization internal resistance as polarization information.

[0047] Then, the internal resistance measurement module D32 calculates the polarization-corrected internal resistance of each sodium-ion battery cluster according to the polarization information, and the power SOH calculation module D33 calculates the DC internal resistance based on the polarization-corrected internal resistance to obtain the overall system DC internal resistance of multiple power supply units. The system DC internal resistance is then mapped to a pre-calibrated internal resistance range to obtain the system SOH value.

[0048] In one embodiment, such as Figure 7 As shown, the control system also includes: Adjustment module D4 acquires the system SOC value and generates the target SOC value for the newly connected power supply unit based on the system SOC value. The adjustment module D4 adjusts the charge of the newly connected power supply unit according to the target SOC value.

[0049] Specifically, to reduce the fluctuations in the displayed SOC value caused by the mismatch between the SOC value of newly connected power supply units and the SOC value, an adjustment module D4 is pre-configured in this embodiment. The adjustment module D4 is used to collect the SOC value of the system after the removal of a group of power supply units, and then generate a target SOC value for the newly connected power supply units based on the system SOC value. Based on this target SOC value, the charge and discharge capacity of the newly connected power supply units are adjusted, including the charging and discharging process, to ensure that they have a SOC value consistent with the overall system before being connected to the line.

[0050] In one embodiment, the control system further includes: The current limiting module controls the current limit of each power supply unit based on temperature information.

[0051] Specifically, to achieve better over-temperature protection, this embodiment also includes a current-limiting module. This module receives temperature information from each lithium-ion battery cluster and compares it with a pre-configured temperature threshold. When the temperature exceeds the preset threshold, the current-limiting module adjusts the current limit of the corresponding parallel power supply unit to reduce the risk of over-temperature.

[0052] The above are merely preferred embodiments of the present invention and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should recognize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A sodium-ion battery backup power system, characterized in that, Includes multiple sodium-ion battery clusters; Multiple sodium-ion battery clusters form a power supply unit; Each of the power supply units is connected to the control system via a set of switch boxes; The control system estimates the current system SOC and SOH values ​​by reading the opening and closing information of the switch box and the voltage and temperature information of the power supply unit.

2. The sodium-ion battery backup power system according to claim 1, characterized in that, The sodium-ion battery cluster includes: Multiple battery modules, each of which is provided with multiple strings of sodium-ion cells; Each of the battery modules is equipped with a corresponding monitoring unit; The battery modules are connected in series to the output bus of the sodium-ion battery cluster; The monitoring unit collects the voltage and temperature information of each sodium-ion battery cell and sends them to the control system via a bus.

3. The sodium-ion battery backup power system according to claim 1, characterized in that, The control system includes: The first acquisition module collects the power supply unit information of the power supply unit and the switch box information of the switch box respectively. A fault diagnosis module, which is connected to the first acquisition module; The fault detection module performs verification based on the power supply unit information and the switch box information to determine the faulty power supply unit or faulty switch box. A cut-off module, which is connected to the fault detection module; The disconnection module disconnects the fault switch box, or the fault switch box corresponding to the fault power supply unit.

4. The sodium-ion battery backup power system according to claim 1, characterized in that, The control system includes: The first SOC determination module receives voltage information from each of the power supply units and determines the first state of charge value of the sodium-ion battery cluster based on the voltage information. A low-power matching module, wherein the low-power matching module is connected to the first SOC discrimination module; The low-power matching module matches the first state of charge value and the preset first over-discharge threshold to obtain a low-power sodium-ion battery cluster, and generates a corresponding low-power alarm signal and configures a current limit for the low-power sodium-ion battery cluster. Over-discharge protection module, which is connected to the low-power matching module; The over-discharge protection module matches the over-discharge protection value according to the first state of charge value or the voltage information, and cuts off the corresponding switch box when an over-discharged sodium-ion battery cluster occurs.

5. The sodium-ion battery backup power system according to claim 1, characterized in that, The control system includes: The relay control module selects the corresponding switch box to disconnect or connect according to the fault information and generates initialization information. SOC estimation module, wherein the SOC estimation module is connected to the relay control module; The SOC estimation module estimates the current system SOC value of the power supply unit based on the initialization information. SOH estimation module, wherein the SOH estimation module is connected to the relay control module; The SOH estimation module estimates the current system SOH value of the power supply unit based on the initialization information.

6. The sodium-ion battery backup power system according to claim 5, characterized in that, The SOC estimation module includes: The second acquisition module determines the polarization information of each sodium-ion battery cluster based on the voltage information, the temperature information, and the pre-collected battery cycle number. The first lifetime estimation module estimates the first health value of the sodium-ion battery cluster based on the polarization information. A weighted charge prediction module, wherein the weighted charge prediction module is connected to the first lifetime estimation module; The weighted charge estimation module estimates the cluster charge value of each sodium-ion battery cluster based on the voltage information and the first health value, and obtains the system SOC value by weighted averaging the cluster charge values.

7. The sodium-ion battery backup power system according to claim 5, characterized in that, The SOH estimation module includes: The third acquisition module determines the polarization information of each sodium-ion battery cluster based on the voltage information, the temperature information, and the pre-collected battery cycle number. An internal resistance measurement module, wherein the internal resistance measurement module is connected to the third acquisition module; The internal resistance measurement module calculates the polarization-corrected internal resistance of each sodium-ion battery cluster based on the polarization information. A power SOH calculation module, wherein the power SOH calculation module is connected to the internal resistance measurement module; The power SOH calculation module calculates the DC internal resistance based on the polarization-corrected internal resistance to obtain the system SOH value.

8. The sodium-ion battery backup power system according to claim 5, characterized in that, The control system further includes: An adjustment module acquires the system SOC value and generates a target SOC value for the newly connected power supply unit based on the system SOC value. The adjustment module adjusts the charge of the newly connected power supply unit according to the target SOC value.

9. The sodium-ion battery backup power system according to claim 1, characterized in that, The control system further includes: A current limiting module controls the current limit of each power supply unit according to the temperature information.

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