A high-voltage battery pack device and a charge and discharge control method

Abstract

This invention proposes a high-voltage battery pack device and a charging / discharging control method. The device includes a high-voltage battery pack module, a charging module, a discharging module, and a data acquisition and control module. The high-voltage battery pack module includes multiple battery cells. The charging module is located between a DC high-voltage power supply and the high-voltage battery pack module, and includes a charging unit and a calibration unit. The discharging module is located between the high-voltage battery pack module and the electrical device. The data acquisition and control module collects signals from the charging module, the high-voltage battery pack module, and the discharging module in real time, performs real-time analysis on the signals, and generates control commands to be sent to the charging module and the discharging module. This not only improves the power capacity of the high-voltage battery pack to a certain extent, but also enhances the safety and reliability of the high-voltage battery pack.

Description

Technical Field

[0001] This invention belongs to the field of automatic control technology, and more specifically, relates to a high-voltage battery pack device and a charging and discharging control method. Background Technology

[0002] With the promotion of green and energy-saving concepts, various high-voltage battery packs have become a key focus of the new energy industry. High-voltage batteries refer to batteries with higher voltages compared to ordinary batteries. Generally, when the voltage increases, for the same capacity and discharge time, a normal-voltage battery will discharge in a shorter time than a high-voltage battery. This means that high-voltage batteries can extend battery life; it also implies that high-voltage batteries possess high energy density and a high discharge platform. Because high-voltage batteries can release more capacity under the same operating conditions, their range is longer and their power is stronger.

[0003] However, high-voltage batteries also suffer from poor stability and safety. Theoretically, the smaller the voltage difference between cells, the higher the cell consistency, meaning higher battery stability and safety. However, even cells from the same batch will inevitably have some voltage differences and capacity variations during manufacturing. Especially in high-voltage batteries, the higher the cell voltage, the more prone they are to excessive voltage differences, which affects the battery's storage capacity and the stability of the battery pack, resulting in lower battery pack safety.

[0004] On the other hand, most high-voltage battery packs currently available both domestically and internationally are assembled by connecting battery boxes in series. If any one of these battery boxes malfunctions, the entire battery pack will be unable to output power. Furthermore, high-voltage battery packs also suffer from issues such as inadequate control systems leading to low reliability, and the use of ternary lithium batteries in high-voltage cells resulting in poor safety. Summary of the Invention

[0005] To address the shortcomings or improvement needs of the existing technology, this invention provides a high-voltage battery pack device and a charging and discharging method. This not only corrects the voltage difference of the high-voltage battery pack but also increases the stability and reliability of the battery by using a parallel connection of battery boxes. Furthermore, it enables real-time acquisition of battery information and automatic control of battery charging and discharging, adds a protection zone, and replaces cell materials to increase battery safety.

[0006] To achieve the above objectives, the present invention adopts the following technical solution.

[0007] A high-voltage battery pack device, the device comprising:

[0008] High-voltage battery pack module, comprising multiple individual battery cells;

[0009] A charging module is disposed between the DC high-voltage power supply and the high-voltage battery pack module, and includes a charging unit and a correction unit;

[0010] A discharge module is disposed between the high-voltage battery pack module and the electrical equipment;

[0011] The acquisition and control module acquires signals from the charging module, the high-voltage battery pack module, and the discharging module in real time, performs real-time analysis on the signals, and generates control commands to be sent to the charging module and the discharging module.

[0012] When all signals acquired by the acquisition and control module are normal, the charging unit receives instructions from the acquisition and control module to charge the high-voltage battery pack module.

[0013] When the differential voltage signal of a battery cell in the signal acquired by the acquisition and control module is greater than a threshold, the correction unit receives an instruction from the acquisition and control module to perform charging correction on the corresponding battery cell, so that the differential voltage signal is less than the threshold, and returns an instruction to the charging unit.

[0014] Furthermore, the high-voltage battery pack module includes multiple parallel battery boxes, each battery box including multiple battery cells connected in series; each battery cell is connected to one of the correction units.

[0015] Furthermore, the battery cell is a lithium titanate battery.

[0016] Furthermore, both the charging module and / or the discharging module are provided with a safety zone.

[0017] Furthermore, the signals also include charging current, discharging current, battery cell capacity, and battery cell temperature.

[0018] According to another aspect of the present invention, a charging and discharging control method for a high-voltage battery pack is also provided, the method comprising:

[0019] S1: Real-time acquisition of signals from all individual cells in the high-voltage battery pack, and real-time analysis of the signals;

[0020] S2: Generate different control commands based on the results of the real-time analysis;

[0021] When all the signals are determined to be normal, corresponding charge / discharge commands are generated for all battery cells.

[0022] When it is determined that the signal is abnormal, a power-off command is first generated for the battery cell corresponding to the abnormal signal, and then step S3 is executed;

[0023] S3: Analyze whether the abnormal signal includes a differential pressure abnormal signal;

[0024] If included, a differential voltage correction charging command is generated for the corresponding battery cell. After the differential voltage of the corresponding battery cell returns to normal, step S1 is executed.

[0025] If not included, a power-off isolation command is generated for the corresponding battery box composed of the battery cells.

[0026] Furthermore, the high-voltage battery pack includes multiple identical battery boxes connected in parallel; each battery box includes multiple identical battery cells connected in series; and each battery cell is connected to a differential pressure correction unit.

[0027] Furthermore, the battery cell is a lithium titanate battery.

[0028] Furthermore, both the charging and discharging ends of the battery box are equipped with safety zones.

[0029] Furthermore, the signals also include charging current, discharging current, battery cell capacity, and battery cell temperature.

[0030] In summary, compared with the prior art, the present invention provides a high-voltage battery pack device and a charging and discharging control method, which have the following beneficial effects:

[0031] (1) The high voltage battery pack device and charging and discharging control method provided by the present invention adds a differential pressure correction unit. When the differential pressure of the battery pack exceeds the threshold or the differential pressure of the battery cell exceeds the threshold, the differential pressure correction unit can first charge and correct the battery cell separately. By charging, the voltage reaches a fixed value. After the voltage of the battery cell reaches equilibrium, that is, the differential pressure is less than the threshold, the charging unit is used to charge the battery pack separately to ensure that the voltage of each battery pack is basically consistent, thereby ensuring the stability and safety of the high voltage battery pack.

[0032] (2) The high-voltage battery pack device and charging and discharging control method provided by the present invention adopts the method of first connecting multiple battery cells in series to form a battery box, and then connecting multiple battery boxes in parallel to form a high-voltage battery pack. The charging module is equipped with a safety zone to isolate the charging unit, and the discharging module is also equipped with a safety zone to isolate the battery box. This allows the other battery boxes to continue to output power when one battery box has a problem, without affecting the use of the entire battery device. This not only improves the power of the battery box to a certain extent, but also improves the reliability of the device and method.

[0033] (3) The high voltage battery pack device and charging and discharging control method provided by the present invention adopts a perfect control strategy, which can not only realize the information acquisition, automatic charging and discharging control and differential voltage correction of the high voltage battery pack device, but also automatically cut off the charging and discharging when the high voltage battery pack module has problems such as undervoltage, overvoltage, overcurrent and overtemperature, thereby protecting the high voltage battery pack.

[0034] (4) In addition, the high voltage battery pack device and charging and discharging control method provided by the present invention use lithium titanate batteries as the battery cells, which can be charged quickly, provide a high discharge current of 10C, have a higher cycle number than conventional lithium-ion batteries, have higher safety and excellent low temperature discharge characteristics, and improve safety and reliability to a certain extent. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 A schematic diagram of the overall framework of a high-voltage battery pack device and a charging and discharging control method provided by the present invention;

[0037] Figure 2 The diagram shows a charging module and a high-voltage battery pack module for a high-voltage battery pack device and a charging and discharging control method provided by the present invention. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0039] Figure 1 This is a schematic diagram of the overall framework of a high-voltage battery pack device and a charging / discharging control method according to the present invention. The device includes:

[0040] High-voltage battery module, comprising multiple individual battery cells; used for storing electrical energy;

[0041] The charging module, located between the DC high-voltage power supply and the high-voltage battery module, includes a charging unit and a calibration unit; it is used to charge the high-voltage battery module to complete energy storage or to calibrate the high-voltage battery module.

[0042] A discharge module is located between the high-voltage battery pack module and the electrical equipment; it is used to supply the electrical equipment with the electricity stored in the high-voltage battery pack module.

[0043] The acquisition and control module collects signals from the charging module, high-voltage battery pack module, and discharging module in real time, performs real-time analysis on the signals, and generates control commands to be sent to the charging module and discharging module.

[0044] Specifically, the acquisition module collects signals such as current, voltage, and temperature from the charging and discharging modules in real time; it also collects signals such as current, voltage, charge, and temperature from the battery box and individual cells of the high-voltage battery pack module in real time. The internal processor then analyzes the relevant signals in real time and generates control commands to control the charging and discharging modules.

[0045] The charging module includes a charging unit and a calibration unit;

[0046] The charging unit receives instructions from the acquisition and control module to charge the high-voltage battery module when all signals acquired by the acquisition and control module are normal.

[0047] When the differential pressure signal of a battery cell acquired by the acquisition and control module is greater than a threshold, the correction unit receives the instruction from the acquisition and control module to perform charging correction on the corresponding battery cell, so that the differential pressure signal is less than the threshold, and returns the instruction to the charging unit.

[0048] The charging unit receives a charging command to charge the high-voltage battery module, and stops charging when it receives a disconnect command; the calibration unit receives a calibration command to charge and calibrate the high-voltage battery module; the discharging module receives a discharging command to supply the stored power of the high-voltage battery module to the electrical equipment, and stops discharging when it receives a disconnect command.

[0049] It is worth noting that even battery cells from the same batch will have some voltage difference and capacity difference during the manufacturing process. High-voltage battery packs, in particular, not only consist of multiple battery cells but also have a higher voltage than ordinary batteries, making them more prone to excessive voltage differences.

[0050] Therefore, when the voltage difference of a single battery cell exceeds the threshold, the high-voltage battery pack module needs to be charged and corrected to make the voltage difference less than the threshold. Then, the acquisition and control module sends a charging command to the charging unit and a discharging command to the discharging module.

[0051] It should be noted that the signals are acquired and analyzed in real time throughout the entire charging and discharging process. If any signal is abnormal, the acquisition and control module will issue a disconnect command to the charging unit and the discharging module to automatically disconnect the charging and discharging process, protect the battery device, and prevent fire or explosion. If the abnormal signal includes differential pressure, the device will automatically disconnect the charging module and perform differential pressure correction. After the correction is completed, the acquisition and control module will acquire and analyze the signal in real time. Charging will continue only when all signals are in a normal state.

[0052] High-voltage battery packs of different capacities have different charging currents, voltages, and output currents and voltages, so it is necessary to control the high-voltage battery pack module for precise charging and discharging. Since both the charging unit and the discharging module have CAN bus communication capabilities, they can communicate with the data acquisition and control module to precisely control the charging current and voltage, and the discharging voltage and current, thereby meeting the needs of different electrical equipment.

[0053] As a further improvement of the present invention, the high-voltage battery pack module includes multiple battery boxes connected in parallel, each battery box including multiple battery cells connected in series; each battery cell is connected to a correction unit.

[0054] Therefore, when the voltage difference of a single battery cell exceeds the threshold, or when the voltage difference of the battery pack exceeds the threshold due to the single battery cell, the single battery cell is first charged and calibrated by the calibration unit. The voltage of the single battery cell is brought to a fixed value, i.e., the voltage difference is less than the threshold, and then the battery pack is charged by the charging unit to ensure that the voltage of each battery pack is basically the same, thereby ensuring the stability and reliability of the battery pack.

[0055] As a further improvement of the present invention, the battery cell adopts a lithium titanate battery. The lithium titanate battery uses lithium manganese oxide or NMC as the positive electrode and titanate as the negative electrode. The lithium titanate battery can be charged quickly, provides a high discharge current of 10C, has a higher cycle life than conventional lithium-ion batteries, and can provide 80% of its capacity at -30°C, with high safety and excellent low-temperature discharge characteristics.

[0056] As a further improvement of the present invention, the charging unit is provided with a safety zone, which can isolate the charging unit when it fails, without affecting the operation of other charging units; the discharging module is also provided with a safety zone, which can isolate the output voltage of the battery box and prevent the battery boxes from charging and discharging each other; in short, the safety zones of the charging unit and the discharging module are both for improving the safety and reliability of the device.

[0057] As a further improvement of the present invention, the signals acquired by the acquisition module also include charging current, discharging current, battery cell capacity, and battery cell temperature.

[0058] The device can only charge and discharge when all acquired signals are normal. If any abnormality occurs in the acquired signals, such as overvoltage, undervoltage, overcurrent, short circuit, high temperature, low temperature, overcharge, or over-discharge, the acquisition and control module will issue a disconnect command to the charging unit and the discharging module to automatically disconnect the charging power. This protects the high-voltage battery pack module, prevents fire and explosion, and makes the entire device safer, more reliable, and more stable.

[0059] In order to clearly and completely describe the technical solutions in the embodiments of the present invention, the following will be combined with Figure 2 The present invention will further explain and describe a high-voltage battery pack device. Figure 2 The diagram shows a charging module and a high-voltage battery pack module for a high-voltage battery pack device and a charging and discharging control method provided by the present invention.

[0060] In one embodiment of the invention, the charging unit consists of two parallel redundant chargers charging the high-voltage battery pack module; that is, the chargers are connected in parallel to the high-voltage bus to charge and store energy for the high-voltage battery pack. The calibration unit is a power module, consisting of six modules connected in series, each used to charge and calibrate a corresponding battery cell. More specifically, the charger input voltage range is 400V to 750V, and the charger output voltage range is 0V to 590V. The charger output power can be adjusted according to the battery pack's capacity. The charger has CAN bus communication functionality, enabling communication with the control circuit. The charger outputs precisely according to the voltage and current required by the battery pack. The charger has input overvoltage and undervoltage protection, output overvoltage and overcurrent protection functions to ensure its own safety and the safety of the battery pack. Furthermore, each charger input terminal is equipped with a fuse, and the output port is connected in series with a diode. When one charger fails, it can be isolated without affecting the normal operation of other chargers, improving the reliability of the device.

[0061] In addition, the discharge module also has a safety zone, mainly including a high-voltage contactor, fuse, and isolation diode. The high-voltage contactor controls the discharge, the fuse provides overcurrent protection, and the isolation diode isolates the output voltage of the battery pack, preventing mutual charging and discharging between battery packs. In short, the safety zones in both the charging unit and the discharge module are designed to improve the safety and reliability of the device.

[0062] The high-voltage battery module consists of three identical battery boxes connected in parallel to increase energy storage for both energy storage and discharge. Each battery box contains six identical battery cells connected in series, with a rated capacity of 25Ah, a rated voltage of 540V, a float charge voltage of 590V, and a discharge rate of 10C.

[0063] More specifically, the battery box is connected to a charger for charging, and each battery cell is connected to a power module for calibration. That is, the charger corresponds to the battery box; the power module corresponds one-to-one with the battery cell. The charger receives charging commands to charge the battery box; the power module receives calibration commands to charge and calibrate the battery cells.

[0064] The reason for correcting voltage differences to maintain a relatively consistent voltage between individual battery cells or the power module is to ensure that the cells can be fully charged and completely discharged. In a batch of batteries, charging is based on the highest voltage; once a battery cell reaches its highest voltage, charging stops. Discharging is based on the lowest voltage; once a battery cell reaches its lowest voltage, discharging stops. Therefore, it is essential to ensure that the voltage of all battery cells is consistent, allowing for simultaneous charging and discharging, and ensuring that the cells reach a fully charged state and can completely release their energy. Therefore, when a voltage difference exceeds a threshold when a battery cell or battery pack is replaced, the power module will perform charging correction to ensure the safety of the parallel connection of the battery packs.

[0065] As an embodiment of the present invention, the battery cell uses a lithium titanate battery. Currently, common lithium-ion batteries mainly include lithium cobalt oxide, lithium manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium iron phosphate, and lithium titanate. Lithium cobalt oxide batteries use lithium cobalt oxide as the positive electrode and graphite as the negative electrode, exhibiting high specific energy, but with generally poor safety and cycle life. Lithium manganese oxide batteries use lithium manganese oxide as the positive electrode and graphite as the negative electrode, but their characteristic parameters are not ideal, and their application is not widespread. Lithium nickel cobalt manganese oxide batteries use nickel manganese cobalt oxide as the positive electrode and graphite as the negative electrode, offering good economy and overall performance, but cobalt resources are increasingly scarce and expensive. Lithium nickel cobalt aluminum oxide batteries use lithium nickel cobalt aluminum oxide as the positive electrode and graphite as the negative electrode, exhibiting high specific energy and long lifespan, but with poor safety and high cost. Lithium iron phosphate (LFP) batteries use lithium iron phosphate as the positive electrode and graphite as the negative electrode. They exhibit good electrochemical performance and low resistance, high rated current, and long cycle life, along with good thermal stability and safety. However, their nominal voltage results in lower specific energy, poor low-temperature performance, high self-discharge, and aging-related imbalance issues. Lithium titanate (LTI) batteries use lithium manganese oxide or NMC as the positive electrode and titanate as the negative electrode. They can be fast-charged, providing a high discharge current of 10C, and have a higher cycle life than conventional lithium-ion batteries. Even at -30°C, they can still provide 80% of their capacity, offering high safety and excellent low-temperature discharge characteristics. In summary, lithium cobalt oxide and lithium nickel cobalt manganese oxide batteries have low thermal runaway temperatures but poor safety, failing to meet safety requirements. Lithium cobalt oxide, lithium manganese oxide, and lithium nickel cobalt aluminum oxide batteries have short cycle lives, failing to meet lifespan requirements. Lithium iron phosphate batteries have poor low-temperature performance. Therefore, considering safety, cycle life, specific energy, and other comprehensive factors, lithium titanate batteries are the preferred choice for individual cells.

[0066] As another aspect of the present invention, a charging and discharging control method for a high-voltage battery pack is also proposed, the method comprising:

[0067] S1: Real-time acquisition of signals from all individual cells in the high-voltage battery pack, and real-time analysis of the signals;

[0068] Specifically, the system collects signals such as current, voltage, charge, and temperature of all individual battery cells in real time, and then analyzes the signals in real time through an internal processor.

[0069] S2: Generates different control commands based on the results of real-time analysis;

[0070] When all signals are determined to be normal, corresponding charge / discharge commands are generated for all battery cells.

[0071] Specifically, when all collected signals are normal: a charging command is generated to charge the individual battery cells, completing energy storage; a discharging command is generated to discharge the individual battery cells, providing the stored energy to the electrical equipment.

[0072] When an abnormality is detected in the signal, a power-off command is first generated for the battery cell corresponding to the abnormal signal, and then step S3 is executed.

[0073] When abnormalities occur, such as overvoltage, undervoltage, overcurrent, short circuit, high temperature, low temperature, overcharge, or over-discharge, it should be noted that the signals are collected and analyzed in real time throughout the entire charging and discharging process. As long as there is an abnormal signal, a power-off command will be generated to automatically stop charging and discharging, thereby protecting the high-voltage battery pack, preventing fire and explosion, and making the high-voltage battery pack safer, more reliable, and more stable.

[0074] S3: Analyze whether the abnormal signals include differential pressure signals;

[0075] If included, a differential voltage correction charging command is generated for the corresponding battery cell. After the differential voltage of the corresponding battery cell returns to normal, step S1 is executed.

[0076] If not included, a power-off isolation command for the corresponding battery box composed of individual battery cells will be generated.

[0077] It is worth noting that even battery cells from the same batch will have some voltage difference and capacity difference during the manufacturing process. High-voltage battery packs, in particular, not only consist of multiple battery cells but also have a higher voltage than ordinary batteries, making them more prone to excessive voltage differences.

[0078] Therefore, when abnormal signals in the real-time acquired signals include differential pressure signals (i.e., differential pressure is less than the threshold), a differential pressure correction charging command will be generated to charge and correct the corresponding battery cell, so that the differential pressure of the battery cell returns to normal. Then, the signals of all battery cells in the high-voltage battery pack will be acquired in real time and analyzed in real time. Based on the results of the real-time analysis, different control commands will be generated.

[0079] If all signals are normal, corresponding charge / discharge commands are generated for all battery cells. If there is an abnormal signal (excluding voltage difference abnormal signals), a power-off command is first generated for the battery cell corresponding to the abnormal signal to automatically stop charging and discharging. Then, a power-off isolation command is generated for the corresponding battery box composed of battery cells. Even if one battery box has a problem, it will not affect the normal operation of other battery boxes.

[0080] As a further improvement of the present invention, the high-voltage battery pack includes multiple identical battery boxes connected in parallel; each battery box includes multiple identical battery cells connected in series; and each battery cell is connected to a differential pressure correction unit.

[0081] Therefore, when the voltage difference of a single battery cell exceeds the threshold, or when the voltage difference of the battery pack exceeds the threshold due to the single battery cell, the single battery cell is first charged and corrected by the voltage difference correction unit. After the voltage of the single battery cell reaches a fixed value, that is, the voltage difference is less than the threshold, the battery pack is then charged to ensure that the voltage of each battery pack is basically the same, thereby ensuring the stability and reliability of the high-voltage battery pack charging and discharging.

[0082] As a further improvement of the present invention, the battery cell adopts a lithium titanate battery. The lithium titanate battery uses lithium manganese oxide or NMC as the positive electrode and titanate as the negative electrode. It can be charged quickly, provides a high discharge current of 10C, and has a higher cycle life than conventional lithium-ion batteries. Moreover, it can provide 80% of its capacity at -30°C, and has high safety and excellent low-temperature discharge characteristics.

[0083] As a further improvement of the present invention, both the charging and discharging ends of the battery box are provided with safety zones. When a battery box malfunctions, it can be isolated to prevent charging and discharging between battery boxes without affecting the operation of other battery boxes. In short, the safety zones are also intended to improve the safety and reliability of the high-voltage battery pack's charging and discharging.

[0084] As a further improvement of the present invention, the collected signals also include charging current, discharging current, battery cell capacity, and battery cell temperature.

[0085] Only when all collected signals are normal can a charging command be generated to charge the individual battery cells and complete energy storage; a discharging command is generated to discharge the individual battery cells and provide the stored energy to the electrical equipment. In the event of abnormal conditions such as overvoltage, undervoltage, overcurrent, short circuit, high temperature, low temperature, overcharge, or over-discharge, a power-off command will be generated to automatically stop charging and discharging, thereby protecting the high-voltage battery pack, preventing fires and explosions, and making the high-voltage battery pack safer, more reliable, and more stable.

[0086] In order to clearly and completely describe the technical solutions in the embodiments of the present invention, the charging and discharging control method of the high-voltage battery pack provided by the present invention will be further explained and described based on the above-described high-voltage battery pack device.

[0087] The high-voltage battery module consists of three identical battery boxes connected in parallel to increase energy storage for both energy storage and discharge. Each battery box contains six identical battery cells connected in series, with a rated capacity of 25Ah, a rated voltage of 540V, a float charge voltage of 590V, and a discharge rate of 10C.

[0088] More specifically, the battery box is connected to a charger for charging, and each battery cell is connected to a power module for calibration. That is, the charger corresponds to the battery box; the power module corresponds one-to-one with the battery cell. The charger receives charging commands to charge the battery box; the power module receives calibration commands to charge and calibrate the battery cells.

[0089] The differential voltage correction unit is a power module used to perform charging calibration on the corresponding battery cells. More specifically, the charger's input voltage range is 400V to 750V, the charger's output voltage range is 0V to 590V, and the charger's output power can be adjusted according to the battery pack's capacity.

[0090] Furthermore, both the charging and discharging ends of the battery box are equipped with fuse zones. The charging input is equipped with a fuse, and the output port has a diode connected in series. In addition, the discharging end also has a fuse zone, mainly including a high-voltage contactor, a fuse, and an isolation diode. The high-voltage contactor controls the discharge, the fuse provides overcurrent protection, and the isolation diode isolates the output voltage of the battery box. When one battery box malfunctions, it can be isolated to prevent mutual charging and discharging between battery boxes, without affecting the normal operation of other battery boxes.

[0091] As an embodiment of the present invention, the battery cell uses a lithium titanate battery. Currently, common lithium-ion batteries mainly include lithium cobalt oxide, lithium manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium iron phosphate, and lithium titanate. Lithium cobalt oxide batteries use lithium cobalt oxide as the positive electrode and graphite as the negative electrode, exhibiting high specific energy, but with generally poor safety and cycle life. Lithium manganese oxide batteries use lithium manganese oxide as the positive electrode and graphite as the negative electrode, but their characteristic parameters are not ideal, and their application is not widespread. Lithium nickel cobalt manganese oxide batteries use nickel manganese cobalt oxide as the positive electrode and graphite as the negative electrode, offering good economy and overall performance, but cobalt resources are increasingly scarce and expensive. Lithium nickel cobalt aluminum oxide batteries use lithium nickel cobalt aluminum oxide as the positive electrode and graphite as the negative electrode, exhibiting high specific energy and long lifespan, but with poor safety and high cost. Lithium iron phosphate (LFP) batteries use lithium iron phosphate as the positive electrode and graphite as the negative electrode. They exhibit good electrochemical performance and low resistance, high rated current, and long cycle life, along with good thermal stability and safety. However, their nominal voltage results in lower specific energy, poor low-temperature performance, high self-discharge, and aging-related imbalance issues. Lithium titanate (LTI) batteries use lithium manganese oxide or NMC as the positive electrode and titanate as the negative electrode. They can be fast-charged, providing a high discharge current of 10C, and have a higher cycle life than conventional lithium-ion batteries. Even at -30°C, they can still provide 80% of their capacity, offering high safety and excellent low-temperature discharge characteristics. In summary, lithium cobalt oxide and lithium nickel cobalt manganese oxide batteries have low thermal runaway temperatures but poor safety, failing to meet safety requirements. Lithium cobalt oxide, lithium manganese oxide, and lithium nickel cobalt aluminum oxide batteries have short cycle lives, failing to meet lifespan requirements. Lithium iron phosphate batteries have poor low-temperature performance. Therefore, considering safety, cycle life, specific energy, and other comprehensive factors, lithium titanate batteries are the preferred choice for individual cells.

[0092] In summary, this invention provides a high-voltage battery pack device and a charging and discharging control method. It adds a correction unit and employs a method of connecting multiple battery cells in series to form a battery box, and connecting multiple battery boxes in parallel to form a high-voltage battery pack, ensuring that the output voltage of each battery box is basically consistent. Furthermore, the presence of safety zones at both the charging and discharging ends of the battery boxes improves the stability and reliability of the entire high-voltage battery pack to a certain extent. In addition, the adoption of a sophisticated control strategy allows for automatic control of charging, discharging, and power-off, making it more convenient and reliable.

[0093] For the foregoing method embodiments, in order to simplify the description, they are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, because according to the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0094] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0095] In the several embodiments provided by this invention, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some service interface; the indirect coupling or communication connection between devices or units may be electrical or other forms.

[0096] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0097] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0098] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage device (CMD). Based on this understanding, the technical solution of this invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned memory includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0099] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, which may include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, etc.

[0100] The foregoing description is merely an exemplary embodiment of this disclosure and should not be construed as limiting the scope of this disclosure. Any equivalent changes and modifications made in accordance with the teachings of this disclosure shall still fall within the scope of this disclosure. Those skilled in the art will readily conceive of other embodiments of this disclosure upon considering the specification and practicing the disclosure herein. This invention is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not described herein. The specification and embodiments are to be considered exemplary only, and the scope and spirit of this disclosure are defined by the claims.

[0101] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0102] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A charge-discharge control method of a high-voltage battery pack, characterized by, The method is implemented using a high-voltage battery pack device, the method comprising: S1: Real-time acquisition of signals from all individual cells in the high-voltage battery pack, and real-time analysis of the signals; S2: Generates different control commands based on the results of real-time analysis; When all the signals are determined to be normal, corresponding charge / discharge commands are generated for all battery cells. When it is determined that the signal is abnormal, a power-off command is first generated for the battery cell corresponding to the abnormal signal, and then step S3 is executed. S3: Analyze whether the abnormal signal includes a differential pressure abnormal signal; If included, a differential voltage correction charging command is generated for the corresponding battery cell. After the differential voltage of the corresponding battery cell returns to normal, step S1 is executed. If not included, a power-off isolation command is generated for the corresponding battery box composed of the battery cells. The high-voltage battery pack assembly includes: A high-voltage battery pack module, comprising multiple identical battery boxes connected in parallel, each battery box comprising multiple identical battery cells connected in series; each battery cell is connected to a correction unit. A charging module is disposed between the DC high-voltage power supply and the high-voltage battery pack module, and includes a charging unit and a correction unit; the charging module is provided with a protection zone to isolate the charging unit; A discharge module is disposed between the high-voltage battery pack module and the electrical equipment; the discharge module is provided with a fuse area to isolate the output voltage of the battery box; The acquisition and control module acquires signals from the charging module, the high-voltage battery pack module, and the discharging module in real time, performs real-time analysis on the signals, and generates control commands to be sent to the charging module and the discharging module. When all signals acquired by the acquisition and control module are normal, the charging unit receives instructions from the acquisition and control module to charge the high-voltage battery pack module. When the differential voltage signal of a battery cell in the signal acquired by the acquisition and control module is greater than a threshold, or when the differential voltage of the battery pack is greater than a threshold due to a battery cell, the correction unit receives an instruction from the acquisition and control module to perform charging correction on the corresponding battery cell. First, the voltage of the battery cell is brought to a fixed value through charging, so that the differential voltage signal is less than the threshold. Then, an instruction is returned to the charging unit, and the charging unit charges the battery pack to ensure that the voltage of each battery pack is consistent.

2. The charging and discharging control method for a high-voltage battery pack as described in claim 1, characterized in that, The battery cell is a lithium titanate battery.

3. The charging and discharging control method for a high-voltage battery pack as described in claim 1, characterized in that, The signals also include charging current, discharging current, battery cell capacity, and battery cell temperature.

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