A battery overcurrent detection method, a battery management system, and a battery

Abstract

This application relates to the field of battery technology, and in particular to a battery overcurrent detection method, a battery management system, and a battery. Based on a pre-set detection current determination strategy, the current detection current is determined, ensuring its accuracy. Secondly, the current threshold is determined based on the battery's charge / discharge state and current temperature, taking into account the influence of these factors on the current threshold, thus ensuring a more precise match between the current threshold and the charge / discharge state and current temperature. Finally, when comparing the current detection current with the current threshold, if the current detection current exceeds the current threshold and meets preset conditions, an overcurrent fault is determined, ensuring accurate detection results. In other words, by ensuring the accuracy of the current detection current, setting an accurate and reasonable current threshold, and setting preset conditions during the comparison process, overcurrent detection becomes more accurate and reliable, effectively reducing false alarms, and thus accurately detecting battery overcurrent faults.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery overcurrent detection method, a battery management system, and a battery. Background Technology

[0002] With the development of green energy, batteries are being used more and more widely, especially in the emerging fields of new energy vehicles, information appliances, and photovoltaic power generation in recent years. Batteries are used as important energy storage and power supply devices, for example, to power new energy vehicles or terminal devices, and to store energy for solar panels.

[0003] Batteries are manufactured using highly active chemical materials through complex processes. During charging and discharging, they are prone to problems such as overcurrent, overcharge voltage, or overheating. A Battery Management System (BMS) is a protection and management unit specifically designed for batteries. Specifically, the BMS manages the charging and discharging of the battery and disconnects it for protection when a fault occurs (such as an overcurrent fault). When the battery current exceeds a set threshold, an overcurrent fault is detected, triggering the disconnection of the battery from external devices (charging or power supply equipment). It is understandable that overcurrent detection is a prerequisite for determining an overcurrent fault; therefore, the accuracy of overcurrent detection is crucial, as it directly affects the judgment of an overcurrent fault. Summary of the Invention

[0004] In view of the above problems, this application provides a battery overcurrent detection method, a battery management system and a battery, which can accurately detect battery overcurrent faults.

[0005] In a first aspect, this application provides a battery overcurrent detection method, comprising: acquiring a first current at the negative terminal of the battery and a second current at the positive terminal of the battery; determining a current detection current from the first current and the second current according to a detection current determination strategy; acquiring the charge / discharge state of the battery and the current temperature of the battery; determining a current threshold based on the current temperature and the charge / discharge state; and determining an overcurrent fault in the battery if the current detection current exceeds the current threshold and meets a preset condition.

[0006] In the above embodiments of this application, firstly, based on a pre-set detection current determination strategy, the current detection current is determined from the first current at the negative terminal of the battery and the second current at the positive terminal of the battery. This ensures the accuracy of the current detection current and effectively prevents inaccurate detection current due to acquisition errors of the first or second current compared to directly using the first or second current. Secondly, the current threshold is determined based on the battery's charge / discharge state and current temperature, taking into account the influence of the charge / discharge state and current temperature on the current threshold. For example, the required current threshold differs at high and low temperatures, and between charging and discharging states, making the current threshold more precise and matching the charge / discharge state and current temperature. Finally, when comparing the current detection current with the current threshold, if the current detection current exceeds the current threshold and meets preset conditions, an overcurrent fault is determined, ensuring accurate detection results. In other words, by ensuring the accuracy of the current detection current, setting an accurate and reasonable current threshold, and setting preset conditions during the comparison process, overcurrent detection becomes more accurate and reliable, effectively reducing false alarms and thus accurately detecting battery overcurrent faults.

[0007] In one possible implementation of the first aspect, the aforementioned determination of the current detection current from the first current and the second current based on the detection current determination strategy includes: performing validity checks on the first current and the second current respectively, performing rationality checks on the first current and the second current, and determining the current detection current based on the results of the validity checks and the rationality checks.

[0008] In the above embodiments of this application, the validity and rationality of the first current and the second current are verified respectively to obtain the validity and rationality of the first current and the second current. Then, the current detection current is determined accordingly. That is, the current detection current is determined after considering the validity and rationality of the first current and the second current, which is more accurate and helps to improve the accuracy of overcurrent detection.

[0009] In one possible implementation of the first aspect, the aforementioned validity verification of the first current and the second current includes: if the first current is within a first preset measurement range and the zero drift value of the first current is less than or equal to a first preset zero drift threshold, then the first current is determined to be valid; or, if the second current is within a second preset measurement range and the zero drift value of the second current is less than or equal to a second preset zero drift threshold, then the second current is determined to be valid; wherein, the first preset measurement range is the measurement range of the first current sensor used to measure the first current, and the second preset measurement range is the measurement range of the second current sensor used to measure the second current.

[0010] In the above embodiments of this application, by combining the measurement range of the first current sensor and the first preset zero drift threshold, the validity of the first current can be accurately determined. If the first current is valid, then the first current is within the first preset measurement range and its zero drift value is reasonable, indicating that the first current sensor is normal and the first current is obtained when the state of the first current sensor is stable, and is less affected by interference.

[0011] Similarly, by combining the measurement range of the second current sensor and the second preset zero drift threshold, the validity of the second current can be accurately determined. If the second current is valid, it is within the second preset measurement range and its zero drift value is reasonable, indicating that the second current sensor is normal and was obtained when the second current sensor is in a stable state, thus experiencing minimal interference.

[0012] In one possible implementation of the first aspect, the aforementioned rationality check of the first current and the second current includes: if the difference between the first current and the second current is within a preset deviation range, then the first current and the second current are determined to be rational; or, if the difference between the first current and the second current is not within the preset deviation range, then the first current and the second current are determined to be unreasonable.

[0013] In the above embodiments of this application, the first current and the second current are currents in the same circuit and under the same state, and are detected by different sensors. Theoretically, the first current and the second current should be the same or similar. Therefore, by comparing whether the difference between the first current and the second current is within the preset deviation range, the rationality of the first current and the second current can be determined, ensuring that the first current and the second current collected are currents in the same circuit and under the same state, so as to avoid the current detection current determined based on the first current and the second current being inaccurate due to the acquisition delay of the first current or the second current, which would affect the final detection result.

[0014] In one possible implementation of the first aspect, determining the current detection current based on the results of validity verification and rationality verification includes: if both the first current and the second current are valid and both are reasonable, then the current detection current is determined to be the first current; or, if both the first current and the second current are valid and both are unreasonable, then the current detection current is determined to be the larger of the first current and the second current; or, if one of the first current and the second current is valid and the other is invalid, then the current detection current is determined to be a valid current; or, if both the first current and the second current are invalid, and the first current is greater than or equal to the upper limit of the first preset measurement range and the second current is greater than or equal to the upper limit of the second preset measurement range, then the current detection current is determined to be the larger of the first current and the second current; or, if both the first current and the second current are invalid, and the first current is less than the upper limit of the first preset measurement range and / or the second current is less than the upper limit of the second preset measurement range, then the current detection current is determined to be the detection current of the previous detection cycle.

[0015] In the above embodiments of this application, when both the first current and the second current are valid and reasonable, historical experimental data shows that selecting the first current at the negative terminal as the current detection current is more accurate. When both the first current and the second current are valid but unreasonable, selecting the larger of the two as the current detection current makes the detection result more cautious and accurate. When one of the first current and the second current is valid and the other is invalid, determining the current detection current as the valid current is more appropriate. When both the first current and the second current are invalid, and the first current exceeds the upper limit of the measurement range of the first current sensor and the second current exceeds the upper limit of the measurement orientation of the second current sensor, i.e., both the first current and the second current have exceeded the limit error, determining the current detection current as the larger of the first current and the second current makes the detection result more cautious and accurate. When both the first current and the second current are invalid, and neither of the first current nor the second current has exceeded the limit error, determining the current detection current as the detection current of the previous detection cycle makes the detection result more cautious and accurate.

[0016] In one possible implementation of the first aspect, the first current sensor and the second current sensor operate on different principles. The first current sensor is powered by a first power supply unit, and the second current sensor is powered by a second power supply unit. The first power supply unit and the second power supply unit are independent of each other.

[0017] In the above embodiments of this application, since the first current sensor and the second current sensor operate on different principles, they are essentially two different types of current sensors. This avoids the two current sensors failing due to the same cause, i.e., it prevents them from failing due to a common cause. When the first current sensor and the second current sensor operate on different principles, the risk of both failing simultaneously is reduced, making the current detection more accurate and thus improving the accuracy of the detection results. Furthermore, the first current sensor and the second current sensor are powered by two independent power supply units, preventing simultaneous failure of both current sensors due to power supply issues. In other words, through the above method, the first current and the second current are acquired through two independent acquisition paths, without affecting each other, making the current detection more accurate and thus improving the accuracy of the detection results.

[0018] In one possible implementation of the first aspect, a first current sensor outputs a first signal, which is then converted into a first current by a first analog-to-digital converter; a second current sensor outputs a second signal, which is then converted into a second current by a second analog-to-digital converter; wherein the first and second analog-to-digital converters are independent of each other.

[0019] In the above embodiments of this application, the first current is obtained by processing the first signal collected by the first current sensor by the first analog-to-digital converter, and the second current is obtained by processing the second signal collected by the second current sensor by the second analog-to-digital converter. The two analog-to-digital conversion paths are independent of each other, which can reduce the risk of sampling failure due to analog-to-digital conversion failure, making the current detection current more accurate and helping to improve the accuracy of the detection results.

[0020] In one possible implementation of the first aspect, determining the current threshold based on the current temperature and the charging / discharging state includes: looking up the corresponding current threshold in a preset temperature threshold relationship table based on the current temperature and the charging / discharging state; wherein the charging / discharging state includes a charging state or a discharging state, and the temperature threshold relationship table includes the correspondence between temperature, charging state and current threshold, as well as the correspondence between temperature, discharging state and current threshold.

[0021] In the above embodiments of this application, a temperature threshold relationship table is pre-set. This table includes the correspondence between temperature, charging state, and current threshold, as well as the correspondence between temperature, discharging state, and current threshold. Therefore, when the current temperature and charging / discharging state are obtained, the corresponding current threshold can be determined by looking up the temperature threshold relationship table. Since the found current threshold is adapted not only to the current temperature but also to the current charging / discharging state, the found current threshold is more accurate and refined. Compared to setting a coarse current threshold regardless of high or low temperature or charging / discharging state, the method of setting a temperature threshold relationship table and determining the current threshold by looking it up is not only more reasonable and accurate but also simple and convenient.

[0022] In one possible implementation of the first aspect, the aforementioned preset condition includes a preset number of times the current detected current exceeds the current threshold. The statement that if the current detected current exceeds the current threshold and the preset condition is met, then an overcurrent fault is determined in the battery includes: if the preset number is once, then the current detected current exceeds the current threshold, and an overcurrent fault is determined in the battery; or, if the preset number is multiple times, then when the current detected current exceeds the current threshold, a new first current and a new second current are reacquired, and a new current is determined from the new first current and the new second current according to the current detection strategy; and when the new current detected current exceeds the current threshold, the corresponding number is accumulated until the current detected current exceeds the current threshold a preset number of times, at which point an overcurrent fault is determined in the battery.

[0023] In the above embodiments of this application, in addition to the case where the preset number of times is set to once, there is also the case where the preset number of times is set to multiple times. When the preset number of times is set to multiple times, the current detection current is updated multiple times and compared with whether the current detection current exceeds the current threshold. The corresponding number of times is accumulated until the current detection current exceeds the current threshold and reaches the preset number of times. Then, it is determined that the battery has an overcurrent fault. That is, after multiple detections of the overcurrent fault, the overcurrent fault is finally determined to have occurred. This can prevent false alarms and make the final detection result more accurate.

[0024] Secondly, this application provides a battery overcurrent detection device, comprising: a current acquisition module for acquiring a first current at the negative terminal of the battery and a second current at the positive terminal of the battery; a current detection current determination module for determining a current detection current from the first current and the second current according to a current detection determination strategy; a state acquisition module for acquiring the charging and discharging state of the battery; a temperature acquisition module for acquiring the current temperature of the battery; a threshold determination module for determining a current threshold based on the current temperature and the charging and discharging state; and a fault determination module for determining that an overcurrent fault has occurred in the battery if the current detection current exceeds the current threshold and meets a preset condition.

[0025] In the above embodiments of this application, the current detection current determination module determines the current detection current from the first current at the negative terminal and the second current at the positive terminal of the battery based on a pre-set detection current determination strategy. This ensures the accuracy of the current detection current and effectively prevents inaccuracies caused by acquisition errors of the first or second current compared to directly using the first or second current. Secondly, the current threshold is determined by the threshold determination module based on the battery's charge / discharge state and current temperature. This takes into account the influence of the charge / discharge state and current temperature on the current threshold. For example, the required current threshold differs between high and low temperatures, and between charging and discharging states, making the current threshold more precise and aligned with the charge / discharge state and current temperature. Finally, when the fault determination module compares the current detection current with the current threshold, if the current detection current exceeds the current threshold and meets preset conditions, an overcurrent fault is determined, ensuring accurate detection results. In other words, by ensuring the accuracy of the current detection current, setting an accurate and reasonable current threshold, and setting preset conditions during the comparison process, overcurrent detection becomes more accurate and reliable, effectively reducing false alarms and thus accurately detecting battery overcurrent faults.

[0026] Thirdly, this application provides a battery management system, including: a first current sensor for acquiring a first current at the negative terminal of the battery; a second current sensor for acquiring a second current at the positive terminal of the battery; a temperature sensor for acquiring the current temperature of the battery; a processor, which is communicatively connected to the first current sensor, the second current sensor, and the temperature sensor respectively, to acquire the first current, the second current, and the current temperature; and a memory, which is communicatively connected to the processor and stores instructions executable by the processor, which are executed by the processor to enable the processor to perform the battery overcurrent detection method of the first aspect.

[0027] In the embodiments described above in this application, the battery management system is able to achieve accurate and reliable overcurrent detection.

[0028] Fourthly, this application provides a battery, including the battery management system of the third aspect.

[0029] In the embodiments described above in this application, the battery has accurate and reliable overcurrent detection and overcurrent protection functions, making it safer and more reliable.

[0030] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0031] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0032] Figure 1 This is a schematic diagram of the battery structure in some embodiments of this application;

[0033] Figure 2 This is a schematic diagram of the connection of the switching circuit in some embodiments of this application;

[0034] Figure 3 This is a flowchart illustrating the battery overcurrent detection method in some embodiments of this application;

[0035] Figure 4 for Figure 3 A schematic diagram of a sub-process of step S20 in the method shown;

[0036] Figure 5 for Figure 4 A schematic diagram of a sub-process of step S21 in the method shown;

[0037] Figure 6 for Figure 4 A schematic diagram of a sub-process of step S22 in the method shown;

[0038] Figure 7 for Figure 4 A schematic diagram of a sub-process of step S23 in the method shown;

[0039] Figure 8 for Figure 3 A schematic diagram of a sub-process of step S40 in the method shown;

[0040] Figure 9 for Figure 3 A schematic diagram of a sub-process of step S50 in the method shown;

[0041] Figure 10 This is a schematic diagram of a battery overcurrent detection device in some embodiments of this application;

[0042] Figure 11 This is a schematic diagram of the battery management system in some embodiments of this application. Detailed Implementation

[0043] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0045] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0046] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0047] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0048] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0049] With the development of green energy, batteries are being used more and more widely, especially in the emerging fields of new energy vehicles, information appliances, and photovoltaic power generation. Batteries serve as important energy storage and power supply devices, for example, powering new energy vehicles or terminal devices, and storing energy for solar panels. As the application areas of batteries continue to expand, the market demand for them is also constantly increasing.

[0050] To ensure battery safety and prevent damage during charging and discharging due to overcurrent, overcharge voltage, or overheating, a Battery Management System (BMS) is designed as the battery's protection and management unit. For example... Figure 1As shown, the battery 100 includes a battery body 10 and a battery management system 20. The battery body 10 can be a battery cell or one or more battery cell modules.

[0051] The battery management system 20 includes a voltage sampling module 21, a current sampling module 22, a temperature sensor 23, a controller 24, and a switching circuit 25. The voltage sampling module 21 is used to collect real-time data on the voltage and passive equalization charge of the battery body 10. The current sampling module 22 samples the current of the battery body 10 during charging and discharging. The temperature sensor 23 collects real-time data on the temperature of the battery body 10. The voltage sampling module 21 and the current sampling module 22 transmit the collected data to the controller 24 (MCU). The controller 24 determines the necessary protection measures for abnormal states of the battery 100, such as undervoltage, overvoltage, overcurrent, short circuit, overtemperature, and low temperature, based on the collected data. Then, according to the determined protection measures, the controller controls the switching circuit 25 to selectively disconnect or connect the battery 100 to the external device 30 (load or charger) to implement the determined protection measures. It is understood that the voltage sampling module 21 and the current sampling module 22 can be implemented using existing chip modules (e.g., integrated circuits IC) or conventional circuits in the art; the circuit structure of the voltage sampling module 21 and the current sampling module 22 will not be described in detail here. Temperature sensor 23 can be implemented using existing resistance temperature detectors (RTDs) or thermocouples, etc. The structure and principle of temperature sensor 23 will not be described in detail here.

[0052] The switching circuit 25 can be implemented using existing MOSFETs and fuses. In some implementations, such as Figure 2 As shown, the switching circuit 25 includes two MOSFETs 251 and a fuse 252. The two MOSFETs 251 and the fuse 252 are connected in series, and the control terminals of the two MOSFETs 251 are respectively connected to the controller 24. Then, the switching circuit 25 connects the battery body 10 and the external device 30 (load or charger), which is equivalent to the switching circuit 25 being connected in series with the external device 30. It can be understood that the MOSFETs 251 can be turned on and off under the driving voltage applied by the controller 24 within the current threshold range or voltage threshold range. When the controller 24 determines that an abnormal state such as overcurrent, overcharge current, or overtemperature has occurred based on the data collected by the voltage sampling module 21, the current sampling module 22, and the temperature sensor 23, it controls the MOSFETs 251 to turn off, thereby disconnecting the battery 100 from the external device 30 (load or charger) to prevent the battery 100 from igniting or exploding due to overcurrent, overvoltage, or overtemperature.

[0053] Specifically, when the detected current of battery 100 exceeds a preset current threshold, an overcurrent fault is determined, triggering MOSFET 251 to disconnect battery 100 from external device 30 (charging device or power supply device). It is understandable that the accuracy of the detected current and the precise reasonableness of the current threshold directly affect the accuracy of overcurrent fault detection.

[0054] To accurately detect battery overcurrent faults, the inventors of this application have discovered through research that the accuracy of the detection current can be improved, making the detection current more effective and reasonable, and accurately reflecting the current in the current circuit of the battery. For example, a high-precision current sensor can be used to collect the detection current, or multiple current sensors can be used to collect current and determine the final detection current from multiple currents. The accuracy and reasonableness of the current threshold can also be optimized, making the current threshold more appropriate for the battery's state. For example, the influence of the battery's charging / discharging state or battery temperature on the current threshold can be considered. It is understandable that when the battery temperature is high, if the current threshold is too high, the battery is prone to overheating due to the large current, which can easily lead to combustion or explosion. When the battery is charging, if the current threshold is too high, the battery is prone to high-current charging, making it difficult to fully charge.

[0055] Specifically, to improve the accuracy of the detected current, a first current at the negative terminal of the battery and a second current at the positive terminal are acquired. Based on a detection current determination strategy, the current to be detected is determined from the first and second currents. That is, the first and second currents are collected from the positive and negative terminals of the battery respectively, and the current to be detected is determined from the first and second currents according to a preset detection current determination strategy. This reduces the risk of inaccurate current detection due to acquisition failures and ensures the accuracy of the current detected current. Compared to directly using the first or second current, this effectively prevents inaccurate current detection due to acquisition errors of the first or second current.

[0056] To optimize the accuracy and rationality of the current threshold, firstly, the battery's charge / discharge state and current temperature are obtained. Then, based on the current temperature and charge / discharge state, a current threshold is determined. If the current detected current exceeds the current threshold and meets preset conditions, an overcurrent fault is determined in the battery. The current threshold is determined based on the battery's charge / discharge state and current temperature, taking into account the influence of these factors. For example, the required current threshold differs at high and low temperatures, and between charging and discharging states, ensuring a more precise match between the current threshold and the charge / discharge state and current temperature. Finally, when comparing the current detected current with the current threshold, if the current detected current exceeds the current threshold and meets preset conditions, an overcurrent fault is determined in the battery, ensuring accurate detection results.

[0057] In other words, by ensuring the accuracy of the current detection current, setting an accurate and reasonable current threshold, and setting preset conditions during the comparison process, the overcurrent detection becomes more accurate and reliable, effectively reducing false alarms, and thus accurately detecting battery overcurrent faults.

[0058] The batteries disclosed in this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft. A power system comprising such an electrical device can be constructed using batteries disclosed in this application. Thus, based on the battery's accurate and reliable overcurrent detection and protection functions, the electrical device and power system become safer and more reliable.

[0059] This application provides an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0060] According to some embodiments of this application, please refer to Figure 3 , Figure 3 This is a flowchart illustrating the battery overcurrent detection method provided in an embodiment of this application. Method S100 may specifically include the following steps:

[0061] S10: Obtain the first current at the negative terminal of the battery and the second current at the positive terminal of the battery.

[0062] The first current is the current sampled from the negative terminal of the battery. Specifically, sensor A collects the current signal A at the negative terminal of the battery, and this signal A is processed by analog-to-digital conversion to obtain the first current; sensor B collects the current signal B at the positive terminal of the battery, and this signal B is processed by analog-to-digital conversion to obtain the second current. It can be understood that the first and second currents are currents sampled from different locations within the same circuit; theoretically, the first and second currents should be similar or identical.

[0063] S20: Determine the current detection current from the first current and the second current based on the detection current determination strategy.

[0064] The detection current determination strategy is used to guide the determination of the current detection current from the first current and the second current. It is understandable that if the first current (or the second current) is directly used as the current detection current, and there is a fault in the acquisition of the first current (or the second current), the error of the first current (or the second current) will be large, making the current detection current inaccurate.

[0065] Based on a pre-set detection current determination strategy, the current detection current is determined from the first current at the negative terminal of the battery and the second current at the positive terminal of the battery. This ensures the accuracy of the current detection current. Compared with directly using the first or second current, it can effectively prevent the current detection current from being inaccurate due to the acquisition error of the first or second current.

[0066] S30: Obtain the charge / discharge status and current temperature of the battery.

[0067] It is understandable that a battery's state of charge / discharge includes either a charging state or a discharging state. When the battery is connected to a charger, it is in a charging state; when the battery is connected to a load, it is in a discharging state. The current direction is opposite in the charging and discharging states, and the controller in the battery management system can determine the charging / discharging state based on the current direction.

[0068] The current temperature of a battery is typically detected by a temperature sensor. For example, a temperature sensor can be attached to the surface of the battery cell module to collect temperature signals, which are then converted into the current temperature. In essence, the temperature sensor collects temperature signals in real time to obtain the current temperature.

[0069] S40: Determine the current threshold based on the current temperature and charge / discharge status.

[0070] The current threshold is used to compare with the currently detected current. If the current detected current exceeds the current threshold, an overcurrent fault can be identified. The current threshold is determined based on the battery's charge / discharge state and the current temperature. This means that the influence of the charge / discharge state and the current temperature on the current threshold is taken into account. For example, the current threshold required at high and low temperatures is different, and the current threshold required in the charging and discharging states is different, making the current threshold more precisely matched with the charge / discharge state and the current temperature.

[0071] S50: If the current detected current exceeds the current threshold and meets the preset conditions, then it is determined that the battery has an overcurrent fault.

[0072] When comparing the current detected current with a current threshold, if the current detected current exceeds the current threshold, a preset condition is met, confirming an overcurrent fault in the battery and ensuring accurate detection results. It is understood that the preset condition limits the current detected current from exceeding the current threshold. To make the detection results more cautious and accurate, the condition could be, for example, that the current detected current exceeds the current threshold by a certain percentage.

[0073] In the above implementation, firstly, based on a pre-set detection current determination strategy, the current detection current is determined from the first current at the negative terminal and the second current at the positive terminal of the battery. This ensures the accuracy of the current detection current and effectively prevents inaccuracies caused by acquisition errors of the first or second current compared to directly using the first or second current. Secondly, the current threshold is determined based on the battery's charge / discharge state and current temperature, taking into account the influence of the charge / discharge state and current temperature on the current threshold. For example, the required current threshold differs at high and low temperatures, and between charging and discharging states, making the current threshold more precisely matched to the charge / discharge state and current temperature. Finally, when comparing the current detection current with the current threshold, if the current detection current exceeds the current threshold and meets preset conditions, an overcurrent fault is determined, ensuring accurate detection results. In other words, by ensuring the accuracy of the current detection current, setting an accurate and reasonable current threshold, and setting preset conditions during the comparison process, overcurrent detection becomes more accurate and reliable, effectively reducing false alarms and thus accurately detecting battery overcurrent faults.

[0074] According to some embodiments of this application, optionally, please refer to... Figure 4 Step S20 specifically includes:

[0075] S21: Verify the validity of the first current and the second current respectively.

[0076] S22: Perform a rationality check on the first current and the second current.

[0077] S23: Determine the current detection current based on the results of the validity check and the rationality check.

[0078] Validity verification can be understood as verifying whether a fault has occurred in the current acquisition process, and confirming that the current acquisition process is normal. For example, if the first current is much smaller than or much larger than the sensor's detection range, it indicates that the first current acquisition process has failed, and the first current is invalid.

[0079] It's understandable that the first current and the second current are currents sampled from different locations within the same circuit. Theoretically, the first current and the second current should have little difference or be the same. Therefore, the rationality check can be understood as verifying whether the first current and the second current are currents from the same circuit. It's also understandable that if the difference between the first current and the second current is abnormally large, then the first current and the second current are clearly unreasonable.

[0080] In the above implementation, the validity and rationality of the first current and the second current are verified respectively to obtain the validity and rationality of the first current and the second current. Then, the current detection current is determined based on these results. That is, the current detection current is determined after considering the validity and rationality of the first current and the second current, which is more accurate and helps to improve the accuracy of overcurrent detection.

[0081] According to some embodiments of this application, optionally, please refer to... Figure 5 Step S21 specifically includes:

[0082] S211: If the first current is within the first preset measurement range and the zero drift value of the first current is less than or equal to the first preset zero drift threshold, then the first current is determined to be valid.

[0083] S212: If the second current is within the second preset measurement range and the zero drift value of the second current is less than or equal to the second preset zero drift threshold, then the second current is determined to be valid.

[0084] Wherein, the first preset measurement range is the measurement range of the first current sensor used to measure the first current, and the second preset measurement range is the measurement range of the second current sensor used to measure the second current.

[0085] Understandably, the first preset zero-drift threshold is a threshold reflecting the zero-point drift of the first current sensor. The second preset zero-drift threshold is a threshold reflecting the zero-point drift of the second current sensor. Zero-point drift refers to the slow output voltage generated when the amplifier circuit has no input signal and a sensitive DC meter measures the output terminal; that is, the baseline of the current signal waveform deviates from the zero line.

[0086] If the first current is within the first preset measurement range, it indicates that the first current sensor is normal. If the zero drift value of the first current is less than or equal to the first preset zero drift threshold, it indicates that the first current sensor is stable. Therefore, the first current is valid when both conditions are met.

[0087] If the second current is within the second preset measurement range, it indicates that the second current sensor is normal. If the zero drift value of the second current is less than or equal to the second preset zero drift threshold, it indicates that the second current sensor is stable. Therefore, the second current is valid when both conditions are met. It can be understood that stable operation means stable temperature and input voltage, and minimal interference.

[0088] In the above embodiments of this application, by combining the measurement range of the first current sensor and the first preset zero drift threshold, the validity of the first current can be accurately determined. If the first current is valid, then the first current is within the first preset measurement range and its zero drift value is reasonable, indicating that the first current sensor is normal and the first current is obtained when the state of the first current sensor is stable, and is less affected by interference.

[0089] Similarly, by combining the measurement range of the second current sensor and the second preset zero drift threshold, the validity of the second current can be accurately determined. If the second current is valid, it is within the second preset measurement range and its zero drift value is reasonable, indicating that the second current sensor is normal and was obtained when the second current sensor is in a stable state, thus experiencing minimal interference.

[0090] According to some embodiments of this application, optionally, please refer to... Figure 6 Step S22 specifically includes:

[0091] S221: If the difference between the first current and the second current is within the preset deviation range, then the first current and the second current are determined to be reasonable.

[0092] S222: If the difference between the first current and the second current is not within the preset deviation range, then the first current and the second current are determined to be unreasonable.

[0093] Since the first current and the second current are currents collected from different locations within the same circuit, theoretically, the first current and the second current should have little difference or be the same. To characterize the magnitude of the difference, a preset deviation range is used as the basis for judgment. It is understood that the preset deviation range is a current range, which can be determined by those skilled in the art based on the accuracy of the two current sensors and actual test conditions.

[0094] In the above implementation, the first current and the second current are currents in the same circuit and under the same state, and are detected by different sensors. Theoretically, the first current and the second current should be the same or similar. Therefore, by comparing whether the difference between the first current and the second current is within the preset deviation range, the rationality of the first current and the second current can be determined, ensuring that the first current and the second current collected are currents in the same circuit and under the same state. This is to avoid the current being inaccurate due to the delay in the collection of the first current or the second current, which would affect the final detection result.

[0095] According to some embodiments of this application, optionally, please refer to... Figure 7 Step S23 specifically includes:

[0096] S231: If both the first current and the second current are valid, and the first current and the second current are reasonable, then the current being detected is determined to be the first current.

[0097] The inventors of this application discovered in historical experiments that current sensors at the negative terminal have higher accuracy. Therefore, when both the first current and the second current are valid and reasonable, selecting the first current at the negative terminal as the current detection current is more accurate. The historical experiments included collecting multiple sets of valid and reasonable first and second currents, using the first current as the current detection current and the second current as the current detection current respectively, performing overcurrent detection, and statistically analyzing the accuracy of the detection results in these two cases. It was found that the accuracy of the detection results was higher when the first current was used as the current detection current.

[0098] S232: If both the first current and the second current are valid, and the first current and the second current are unreasonable, then the current detection current is determined to be the larger value of the first current and the second current.

[0099] If both the first and second currents are valid but unreasonable, choosing the smaller of the two as the current detection current for comparison with the current detection threshold can easily lead to misjudgments. Conversely, choosing the larger of the two as the current detection current makes the detection results more cautious and accurate.

[0100] S233: If one of the first current and the second current is valid and the other is invalid, then the current being detected is determined to be a valid current.

[0101] It is understandable that, given that one of the first and second currents is valid while the other is invalid, it is more appropriate to determine that the current being detected is valid.

[0102] S234: If both the first current and the second current are invalid, and the first current is greater than or equal to the upper limit of the first preset measurement range and the second current is greater than or equal to the upper limit of the second preset measurement range, then the current detection current is determined to be the larger value of the first current and the second current.

[0103] When both the first and second currents are invalid, and the first current exceeds the upper limit of the measurement range of the first current sensor, while the second current exceeds the upper limit of the measurement orientation of the second current sensor—that is, when both the first and second currents exceed their limits—selecting the smaller of the two as the current detection current for comparison with the current detection threshold can easily lead to misjudgment. Conversely, selecting the larger of the two as the current detection current makes the detection results more cautious and accurate.

[0104] S235: If both the first current and the second current are invalid, and the first current is less than the upper limit of the first preset measurement range and / or the second current is less than the upper limit of the second preset measurement range, then the current detection current is determined to be the detection current of the previous detection cycle.

[0105] If both the first and second current sensors are invalid and neither exceeds its limit, it indicates that the first current is less than the lower limit of the measurement range of the first current sensor, and the second current is less than the lower limit of the measurement range of the second current sensor; both are invalid. Selecting either one as the current detection current would result in a large error. Therefore, determining the current detection current to be the detection current from the previous detection cycle makes the detection results more cautious and accurate.

[0106] In the above embodiments, when both the first current and the second current are valid and reasonable, historical experimental data shows that selecting the first current at the negative terminal as the current detection current is more accurate. When both the first current and the second current are valid but unreasonable, selecting the larger of the two as the current detection current makes the detection results more cautious and accurate. When one of the first current and the second current is valid and the other is invalid, determining the current detection current as the valid current is appropriate. When both the first current and the second current are invalid, and the first current exceeds the upper limit of the measurement range of the first current sensor, and the second current exceeds the upper limit of the measurement orientation of the second current sensor, i.e., both the first current and the second current have exceeded the limit error, determining the current detection current as the larger of the first current and the second current makes the detection results more cautious and accurate. When both the first current and the second current are invalid, and neither of the first current nor the second current has exceeded the limit error, determining the current detection current as the detection current of the previous detection cycle makes the detection results more cautious and accurate.

[0107] According to some embodiments of this application, optionally, the first current sensor and the second current sensor operate on different principles. The first current sensor is powered by the first power supply unit, and the second current sensor is powered by the second power supply unit. The first power supply unit and the second power supply unit are independent of each other.

[0108] The first and second current sensors are of different types and operate on different principles. For example, the first current sensor can be an existing Hall effect current sensor, while the second current sensor can be an existing Rogowski coil current sensor. By having two current sensors with different operating principles collect current separately, it is possible to avoid both current sensors failing due to the same cause, i.e., to prevent both current sensors from failing due to a single cause.

[0109] If the first and second current sensors are connected to the battery, unstable battery voltage can easily cause significant zero drift in both the first and second current sensors, affecting the accuracy of the current detection. Therefore, having the first current sensor powered by a first power supply unit (e.g., battery #1) and the second current sensor powered by a second power supply unit (e.g., battery #2) can improve the accuracy of the current detection and prevent both current sensors from failing simultaneously due to power supply issues.

[0110] In the above embodiments, since the first and second current sensors operate on different principles, they are essentially two different types of current sensors. This avoids the two current sensors failing due to the same cause, i.e., it prevents them from failing due to a common cause. When the first and second current sensors operate on different principles, the risk of both failing simultaneously is reduced, making the current detection more accurate and thus improving the accuracy of the detection results. Furthermore, the first and second current sensors are powered by two independent power supply units, preventing simultaneous failure due to power supply issues. In other words, through the above method, the first and second currents are acquired through two independent acquisition paths, without affecting each other, making the current detection more accurate and thus improving the accuracy of the detection results.

[0111] According to some embodiments of this application, optionally, a first current sensor outputs a first signal, which is then converted to a first current by a first analog-to-digital converter. A second current sensor outputs a second signal, which is then converted to a second current by a second analog-to-digital converter. The first and second analog-to-digital converters are independent of each other.

[0112] Understandably, the first analog-to-digital converter (ADC) performs analog-to-digital conversion on the first signal to obtain the first current. The type of the first current sensor determines the first signal, which can be a current signal, a voltage signal, or something similar. Similarly, the second ADC performs analog-to-digital conversion on the second signal to obtain the second current. The type of the second current sensor determines the second signal, which can be a current signal, a voltage signal, or something similar.

[0113] To reduce the risk of sampling failure due to analog-to-digital converter (ADC) malfunction, the first and second ADCs are independent of each other. In some embodiments, the first ADC may be an analog-to-digital converter (ADC). It is understood that the ADC can be calibrated before sampling, for example, by acquiring a preset voltage signal (e.g., a 2.5V voltage signal), converting it through the ADC, and if the converted voltage is approximately 2.5V, then the ADC is considered to be functioning correctly.

[0114] In some embodiments, the second analog-to-digital converter (ADC) can be another ADC, or a voltage detector of model AME8550. The second ADC can also be calibrated before data acquisition; the specific calibration method can be designed by those skilled in the art and will not be elaborated here.

[0115] In the above embodiment, the first current is obtained by processing the first signal collected by the first current sensor through the first analog-to-digital converter, and the second current is obtained by processing the second signal collected by the second current sensor through the second analog-to-digital converter. The two analog-to-digital conversion paths are independent of each other, which can reduce the risk of sampling failure due to analog-to-digital conversion failure, making the current detection current more accurate and helping to improve the accuracy of the detection results.

[0116] According to some embodiments of this application, optionally, please refer to... Figure 8 Step S40 specifically includes:

[0117] S41: Based on the current temperature and charging / discharging state, find the corresponding current threshold in the preset temperature threshold relationship table.

[0118] It is understandable that charge / discharge states include charging state or discharging state. For example, when the battery is connected to the charger, it is in the charging state, and when the battery is connected to the load, it is in the discharging state.

[0119] The temperature threshold relationship table includes the correspondence between temperature, charging state, and current threshold, as well as the correspondence between temperature, discharging state, and current threshold. Therefore, once the current temperature and charging / discharging state are obtained, the corresponding current threshold can be determined by looking up the temperature threshold relationship table. For example, the temperature threshold relationship table can be shown in Table 1 below:

[0120] Table 1. Relationship between temperature thresholds

[0121]

[0122]

[0123] Table 1 is merely an illustrative example. It is understood that for temperatures between the two boundary temperatures in Table 1, the corresponding current threshold can be determined using linear interpolation. For example, if the current temperature is T = -12℃, and we know that T0 = -15℃ corresponds to a current threshold I0 = 650A, and T1 = -10℃ corresponds to a current threshold I1 = 840A, then the current threshold I corresponding to the current temperature T can be obtained using the following interpolation formula.

[0124]

[0125] The fault tolerance time interval in Table 1 refers to the time interval during which the battery must be disconnected for protection when an overcurrent fault occurs, i.e., the connection between the battery and external devices must be cut off.

[0126] In the above embodiments, a temperature threshold relationship table is pre-set. This table includes the correspondence between temperature, charging state, and current threshold, as well as the correspondence between temperature, discharging state, and current threshold. Therefore, when the current temperature and charging / discharging state are obtained, the corresponding current threshold can be determined by looking up the temperature threshold relationship table. Since the found current threshold is adapted not only to the current temperature but also to the current charging / discharging state, the found current threshold is more accurate and refined. Compared to setting a coarse current threshold regardless of high or low temperature or charging / discharging state, the method of setting a temperature threshold relationship table and determining the current threshold by looking it up is not only more reasonable and accurate but also simple and convenient.

[0127] According to some embodiments of this application, optionally, the preset conditions include a preset number of times the current detected current exceeds the current threshold. For example, the preset number can be 1 time, 2 times, 3 times, etc., and can be set according to the actual situation.

[0128] Please see Figure 9 The aforementioned step S50 specifically includes:

[0129] S51: If the preset number of times is one, the current detected current exceeds the current threshold, and the battery is determined to have an overcurrent fault.

[0130] If the preset number of attempts is one, the current detected current and the current threshold are compared once. If the current detected current exceeds the current threshold, it is determined that the battery has an overcurrent fault.

[0131] S52: If the preset number of times is multiple, when the current detected current exceeds the current threshold, a new first current and a new second current are reacquired, and a new current detected is determined from the new first current and the new second current according to the detection current determination strategy; and when the new current detected current exceeds the current threshold, the corresponding number of times is accumulated until the current detected current exceeds the current threshold to reach the preset number of times, at which point the battery is determined to have an overcurrent fault.

[0132] For example, if the preset number of detections is 3, then if the current detected in the first detection exceeds the current threshold, a new first current and a new second current are acquired for the second detection. For example, the original first signal and the second signal are reprocessed by analog-to-digital conversion to obtain a new first current and a new second current. The new current detected is determined from the new first current and the new second current. When the new current detected exceeds the current threshold, a new first current and a new second current are acquired for the third detection, the fourth detection, and so on, until the new current detected exceeds the current threshold 3 times, at which point an overcurrent fault is determined to have occurred in the battery.

[0133] In this embodiment, by repeatedly updating the current detection current and comparing whether the current detection current exceeds the current threshold, the corresponding number of times is accumulated until the current detection current exceeds the current threshold for a preset number of times, at which point it is determined that the battery has an overcurrent fault. That is, after multiple detections of the overcurrent fault, the overcurrent fault is finally determined to have occurred, which can prevent false alarms and make the final detection result more accurate.

[0134] According to some embodiments of this application, a current overcurrent detection method is provided, including:

[0135] (1) Two independent paths are used to collect and obtain the first current at the negative terminal of the battery and the second current at the positive terminal of the battery, respectively. The independent path corresponding to the first current includes a first current sensor, a first analog-to-digital converter, and a first power supply unit that powers the first current sensor. The independent path corresponding to the second current includes a second current sensor, a second analog-to-digital converter, and a second power supply unit that powers the second current sensor.

[0136] (2) Determine the current detection current from the first current and the second current according to the detection current determination strategy in Table 2 below.

[0137] Table 2 Strategy for Determining Detected Current

[0138]

[0139]

[0140] Other errors in Table 2 are non-over-limit errors. Combining the detection current determination strategy in Table 2, the validity and rationality of the first and second currents are verified. Based on the validity and rationality verification results, the current detection current is determined, making the current detection current accurate, the detection results more cautious, and the accuracy higher.

[0141] (3) Based on the current temperature and charging / discharging state, find the corresponding current threshold in the preset temperature threshold relationship table. The temperature threshold relationship table includes the correspondence between temperature, charging state, and current threshold, as well as the correspondence between temperature, discharging state, and current threshold.

[0142] (4) If the current detected current exceeds the current threshold for a preset number of times (e.g., 3 times), it is determined that the battery has an overcurrent fault.

[0143] By establishing a temperature threshold relationship table that includes the correspondence between temperature, charging state, and current threshold, as well as the correspondence between temperature, discharging state, and current threshold, the corresponding current threshold can be determined by looking up the table once the current temperature and charging / discharging state are obtained. Since the found current threshold is adapted not only to the current temperature but also to the current charging / discharging state, the current threshold is more accurate and precise. Compared to setting a coarse current threshold regardless of high or low temperature or charging / discharging state, the method described above, which uses a temperature threshold relationship table and determines the current threshold by looking it up, is not only more reasonable and accurate but also simple and convenient.

[0144] When comparing the current detected current with the current threshold, if the current detected current exceeds the current threshold a preset number of times, it is determined that the battery has an overcurrent fault, thus ensuring accurate detection results.

[0145] According to some embodiments of this application, please refer to Figure 10 This application also provides a battery overcurrent detection device 300, including: a current acquisition module 301, a current detection current determination module 302, a status acquisition module 303, a temperature acquisition module 304, a threshold determination module 305, and a fault determination module 306.

[0146] The system includes the following modules: a current acquisition module 301, used to acquire the first current at the negative terminal of the battery and the second current at the positive terminal; a current detection determination module 302, used to determine the current detection current from the first and second currents according to a current detection determination strategy; a status acquisition module 303, used to acquire the charging and discharging status of the battery; a temperature acquisition module 304, used to acquire the current temperature of the battery; a threshold determination module 305, used to determine a current threshold based on the current temperature and the charging and discharging status; and a fault determination module 306, used to determine that an overcurrent fault has occurred in the battery if the current detection current exceeds the current threshold and meets preset conditions.

[0147] In the above embodiments, the current detection current determination module 302 determines the current detection current from the first current at the negative terminal and the second current at the positive terminal of the battery based on a pre-set detection current determination strategy. This ensures the accuracy of the current detection current and effectively prevents inaccuracies caused by acquisition errors of the first or second current compared to directly using the first or second current. Secondly, the current threshold is determined by the threshold determination module based on the battery's charge / discharge state and current temperature. This takes into account the influence of the charge / discharge state and current temperature on the current threshold. For example, the required current threshold differs between high and low temperatures, and between charging and discharging states, making the current threshold more precise and matching the charge / discharge state and current temperature. Finally, when the fault determination module 306 compares the current detection current with the current threshold, if the current detection current exceeds the current threshold and meets preset conditions, it determines that the battery has an overcurrent fault, ensuring accurate detection results. In other words, by ensuring the accuracy of the current detection current, setting an accurate and reasonable current threshold, and setting preset conditions during the comparison process, overcurrent detection becomes more accurate and reliable, effectively reducing false alarms and thus accurately detecting battery overcurrent faults.

[0148] According to some embodiments of this application, please refer to Figure 11 This application also provides a battery management system 400, including: a first current sensor 401, a second current sensor 402, a temperature sensor 403, a processor 404, and a memory 405.

[0149] The first current sensor 401 is connected to the negative terminal of the battery to collect the first current at the negative terminal, and the second current sensor 402 is connected to the positive terminal of the battery to collect the second current at the positive terminal. The temperature sensor 403 can be attached to the surface of the cell module in the battery to collect the current temperature of the battery.

[0150] The processor 404 is communicatively connected to the first current sensor 401, the second current sensor 402, and the temperature sensor 403 to acquire the first current, the second current, and the current temperature. The memory 405 is communicatively connected to the processor 404 and stores instructions that can be executed by the processor 404 to enable the processor 404 to perform the battery overcurrent detection method of the first aspect.

[0151] The memory 405 may include read-only memory and random access memory, and provides instructions and data to the processor 404. A portion of the memory 405 may also include non-volatile random access memory (NVRAM). The memory 405 stores operation instructions, executable modules, or data structures, or subsets thereof, or extended sets thereof.

[0152] Processor 404 can be an integrated circuit chip with signal processing capabilities. In implementation, each step of the aforementioned overcurrent detection method can be completed through integrated logic circuits in the hardware of processor 404 or through software instructions. Processor 404 can be a general-purpose processor, a digital signal processor (DSP), a microprocessor, or a microcontroller, and may further include application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. This processor can implement or execute the aforementioned battery overcurrent detection method.

[0153] Based on the fact that the battery management system 400 can execute the aforementioned battery overcurrent detection method, the battery management system 400 can achieve accurate and reliable overcurrent detection function.

[0154] According to some embodiments of this application, this application also provides a battery, including the aforementioned battery management system.

[0155] In the above embodiments, the battery has accurate and reliable overcurrent detection and overcurrent protection functions, making it safer and more reliable.

[0156] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery overcurrent detection method, characterized in that, The method includes: Obtain the first current at the negative terminal of the battery and the second current at the positive terminal of the battery; Based on the current detection strategy, the current detection current is determined from the first current and the second current; Obtain the charge / discharge state of the battery and the current temperature of the battery; Determine the current threshold based on the current temperature and the charge / discharge state; If the current detected current exceeds the current threshold and meets the preset condition, then it is determined that the battery has an overcurrent fault; The step of determining the current detection current from the first current and the second current according to the detection current determination strategy includes: The validity of the first current and the second current is verified respectively; The rationality of the first current and the second current is verified; The current detection current is determined based on the results of the validity check and the rationality check. The validity verification of the first current and the second current respectively includes: If the first current is within a first preset measurement range, and the zero drift value of the first current is less than or equal to a first preset zero drift threshold, then the first current is determined to be valid; or, If the second current is within the second preset measurement range, and the zero drift value of the second current is less than or equal to the second preset zero drift threshold, then the second current is determined to be valid. Wherein, the first preset measurement range is the measurement range of the first current sensor used to measure the first current, and the second preset measurement range is the measurement range of the second current sensor used to measure the second current.

2. The method according to claim 1, characterized in that, The rationality verification of the first current and the second current includes: If the difference between the first current and the second current is within a preset deviation range, then the first current and the second current are determined to be reasonable; or, If the difference between the first current and the second current is not within the preset deviation range, then the first current and the second current are determined to be unreasonable.

3. The method according to claim 2, characterized in that, Determining the current detection current based on the results of the validity check and the rationality check includes: If both the first current and the second current are valid, and both the first current and the second current are reasonable, then the currently detected current is determined to be the first current; or, If both the first current and the second current are valid, and the first current and the second current are unreasonable, then the current being detected is determined to be the larger of the first current and the second current; or, If one of the first current and the second current is valid and the other is invalid, then the currently detected current is determined to be a valid current; or, If both the first current and the second current are invalid, and the first current is greater than or equal to the upper limit of the first preset measurement range, and the second current is greater than or equal to the upper limit of the second preset measurement range, then the current being detected is determined to be the larger of the first current and the second current; or, If both the first current and the second current are invalid, and the first current is less than the upper limit of the first preset measurement range and / or the second current is less than the upper limit of the second preset measurement range, then the current detection current is determined to be the detection current of the previous detection cycle.

4. The method according to any one of claims 1-3, characterized in that, The first current sensor and the second current sensor operate on different principles. The first current sensor is powered by the first power supply unit, and the second current sensor is powered by the second power supply unit. The first power supply unit and the second power supply unit are independent of each other.

5. The method according to claim 4, characterized in that, The first current sensor outputs a first signal, and the first signal is processed by the first analog-to-digital converter to obtain the first current. The second current sensor outputs a second signal, which is then processed by a second analog-to-digital converter to obtain the second current. The first analog-to-digital converter and the second analog-to-digital converter are independent of each other.

6. The method according to claim 1, characterized in that, Determining the current threshold based on the current temperature and the charge / discharge state includes: Based on the current temperature and the charging / discharging state, the corresponding current threshold is looked up in the preset temperature threshold relationship table; The charge / discharge state includes a charging state or a discharging state, and the temperature threshold relationship table includes the correspondence between temperature, charging state and current threshold, as well as the correspondence between temperature, discharging state and current threshold.

7. The method according to claim 1, characterized in that, The preset conditions include the number of times the current detected current exceeds the current threshold reaching a preset number, and if the current detected current exceeds the current threshold and the preset conditions are met, then it is determined that the battery has an overcurrent fault, including: If the preset number of attempts is one, then if the current detected current exceeds the current threshold, it is determined that the battery has experienced an overcurrent fault; or, If the preset number of times is multiple, when the current detected current exceeds the current threshold, a new first current and a new second current are reacquired, and a new current is determined from the new first current and the new second current according to the detection current determination strategy; and when the new current detected current exceeds the current threshold, the corresponding number of times is accumulated until the current detected current exceeds the current threshold to reach the preset number of times, at which point it is determined that the battery has an overcurrent fault.

8. A battery overcurrent detection device, characterized in that, include: A current acquisition module is used to acquire a first current at the negative terminal of the battery and a second current at the positive terminal of the battery; The current detection current determination module is used to determine the current detection current from the first current and the second current according to the current detection determination strategy; A status acquisition module is used to acquire the charging and discharging status of the battery; A temperature acquisition module is used to acquire the current temperature of the battery; A threshold determination module is used to determine a current threshold based on the current temperature and the charging / discharging state; The fault determination module is used to determine that the battery has an overcurrent fault if the current detected current exceeds the current threshold and meets a preset condition. The step of determining the current detection current from the first current and the second current according to the detection current determination strategy includes: performing validity verification on the first current and the second current respectively; performing reasonableness verification on the first current and the second current; and determining the current detection current based on the results of the validity verification and the reasonableness verification. The validity verification of the first current and the second current includes: if the first current is within a first preset measurement range and the zero drift value of the first current is less than or equal to a first preset zero drift threshold, then the first current is determined to be valid; or, if the second current is within a second preset measurement range and the zero drift value of the second current is less than or equal to a second preset zero drift threshold, then the second current is determined to be valid; wherein, the first preset measurement range is the measurement range of the first current sensor used to measure the first current, and the second preset measurement range is the measurement range of the second current sensor used to measure the second current.

9. A battery management system, characterized in that, include: The first current sensor is used to collect the first current at the negative terminal of the battery. The second current sensor is used to collect the second current at the positive terminal of the battery. A temperature sensor is used to collect the current temperature of the battery; The processor is communicatively connected to the first current sensor, the second current sensor, and the temperature sensor to acquire the first current, the second current, and the current temperature. A memory, communicatively connected to the processor, stores instructions executable by the processor, which are executed by the processor to enable the processor to perform the method as described in any one of claims 1-7.

10. A battery, characterized in that, Includes the battery management system as described in claim 9.

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