Battery voltage sampling abnormity diagnosis method, battery management system and equipment

Abstract

The invention discloses a battery voltage sampling abnormity diagnosis method comprising the following steps: obtaining voltage values of adjacent batteries in a battery module and / or voltage values of all batteries in the battery module, the voltage values of the adjacent batteries comprising a voltage value of a first battery and a voltage value of a second battery; a first average value and / or a second average value are / is calculated, the first average value is defined as the voltage average value of the first battery and the second battery, and the second average value is defined as the voltage average value of all batteries in the battery module; the absolute value of the difference between the voltage value of the first battery and the first average value and the absolute value of the difference between the voltage value of the second battery and the first average value are both larger than a first threshold value and lasts for a first duration, and / or the absolute value of the difference between the voltage value of the first battery and the second average value and the absolute value of the difference between the voltage value of the second battery and the second average value are both larger than a second threshold value and lasts for a second duration; and / or when the absolute value of the difference between the voltage value of the first battery and the voltage value of the second battery is greater than a third threshold and lasts for a third duration, determining that the battery voltage sampling is abnormal.

Description

Technical Field

[0001] The present application belongs to the field of battery management technology, and in particular relates to a method for diagnosing abnormal battery voltage sampling, a battery management system, and a device. Background Art

[0002] The battery management system (BMS) samples the voltage of the connected battery module through a battery voltage acquisition circuit. The battery voltage acquisition circuit includes an AFE (Analog Front End) chip or a voltage acquisition circuit built using discrete components. The battery module contains multiple single cells (hereinafter referred to as batteries). The battery voltage acquisition circuit is connected to the batteries in the battery module through an acquisition wiring harness to sample the battery voltage and send the voltage sample value to the BMS control circuit (such as MCU, Microcontroller Unit), thereby monitoring the battery voltage and ensuring the safe and stable operation of the battery module. Summary of the Invention

[0003] During the use of the battery module, the battery voltage sampling is abnormal due to abnormalities in the battery itself, loose acquisition harness, broken acquisition harness, poor acquisition harness manufacturing process, poor cold and heat resistance of the acquisition harness, and acquisition harness affected by temperature. Because there are multiple situations that lead to abnormal battery voltage sampling, if the same measure (such as turning off the charge and discharge switch, and / or disconnecting the air switch) is used to deal with the battery voltage sampling abnormalities caused by the above multiple situations, it is easy to cause false alarms, false triggering of fault protection, or failure to trigger fault protection, etc., which in turn leads to frequent SOC jumps and power interruptions in the battery module, and in severe cases may trigger thermal runaway. In view of this, it is necessary to diagnose and identify abnormal battery voltage sampling.

[0004] The embodiments of the present application provide a method for diagnosing abnormal battery voltage sampling, a battery management system, and a device, which improve the diagnostic accuracy of abnormal battery cell voltage sampling.

[0005] In a first aspect, an embodiment of the present application provides a method for diagnosing abnormal battery voltage sampling, comprising: obtaining voltage values ​​of adjacent batteries in a battery module and / or voltage values ​​of all batteries in the battery module, the voltage values ​​of adjacent batteries including the voltage value of a first battery and the voltage value of a second battery; calculating a voltage average value, the voltage average value including a first average value and / or a second average value, the first average value being defined as the voltage average value of the first battery and the second battery, and the second average value being defined as the voltage average value of all batteries in the battery module; in response to the absolute value of the difference between the voltage value of the first battery and the first average value being greater than a first threshold value and lasting for a first time period, and the voltage value of the second battery being greater than a first threshold value and lasting for a first time period, The absolute value of the difference between the first average value and the second average value is greater than the first threshold and lasts for a first time period, determining that the battery voltage sampling is abnormal; and / or in response to the absolute value of the difference between the voltage value of the first battery and the second average value being greater than the second threshold and lasting for a second time period, and the absolute value of the difference between the voltage value of the second battery and the second average value being greater than the second threshold and lasting for a second time period, determining that the battery voltage sampling is abnormal; and / or in response to the absolute value of the difference between the voltage value of the first battery and the voltage value of the second battery being greater than the third threshold and lasting for a third time period, determining that the battery voltage sampling is abnormal, the third threshold is greater than or equal to twice the first threshold, or the third threshold is greater than or equal to twice the second threshold.

[0006] In this technical solution, (1) the voltage sampling values ​​of two adjacent batteries in the battery module are obtained, and the voltage sampling average value (such as the first average value and / or the second average value mentioned above) is calculated, the voltage sampling values ​​of the two batteries are respectively subtracted from the voltage sampling average value, and the absolute value of the difference is taken. Further, the two difference absolute values ​​are compared with the first threshold value, and when the two difference absolute values ​​are both greater than the first threshold value and the duration meets the requirement, and / or, the two difference absolute values ​​are compared with the second threshold value, and when the two difference threshold values ​​are both greater than the second threshold value and the duration meets the requirement, the battery voltage sampling abnormality is determined; and / or, (2) the voltage sampling values ​​of two adjacent batteries in the battery module are obtained, the absolute value of the difference between the voltage sampling values ​​of the two adjacent batteries is calculated, and when the absolute value of the difference between the voltage sampling values ​​of the two batteries is greater than the third threshold value, the battery voltage sampling abnormality is determined. In this way, the battery voltage sampling abnormality can be detected when the acquisition harness is abnormal, thereby improving the diagnostic accuracy of the battery voltage sampling abnormality.

[0007] In combination with the first aspect, in one or more embodiments, the method includes: in response to an abnormality in battery voltage sampling, stopping balancing the battery module.

[0008] In this technical solution, the battery management system balances the battery module based on the battery voltage sampling value. After an abnormality occurs in the battery voltage sampling, the battery voltage sampling value cannot accurately reflect the true voltage value of the battery. If balancing is performed at this time, it will lead to inaccurate balancing, which may further expand the inconsistency of the batteries in the battery module. Stopping balancing the battery module can reduce false alarm faults and / or false triggering of battery fault protection caused by inaccurate balancing.

[0009] In combination with the first aspect, in one or more embodiments, the above method includes: in response to an abnormality in battery voltage sampling, updating the voltage display value of the first battery and the voltage display value of the second battery to a first average value or a second average value; or, in response to an abnormality in battery voltage sampling, updating the voltage display value of the first battery and the voltage display value of the second battery based on an adjustment strategy; the adjustment strategy includes: determining a voltage variable every fourth time period, adjusting the first average value or the second average value based on the voltage variable to obtain an adjustment value, and updating the voltage display value of the first battery and the voltage display value of the second battery to the adjustment value; or, determining the first voltage variable and the second voltage variable every fourth time period, adjusting the first average value or the second average value based on the first voltage variable to obtain a first adjustment value, updating the voltage display value of the first battery to the first adjustment value, adjusting the first average value or the second average value based on the second voltage variable to obtain a second adjustment value, and updating the voltage display value of the second battery to the second adjustment value.

[0010] In this technical solution, after an abnormality occurs in the battery voltage sampling, the collected voltage value is inaccurate. If the collected voltage value continues to be displayed, it may cause a misjudgment, thereby falsely triggering the fault protection. By adjusting the voltage display values ​​of the first battery and the second battery, false triggering of the fault protection can be reduced.

[0011] In combination with the first aspect, in one or more embodiments, the above method includes: in response to an abnormality in battery voltage sampling, increasing the overvoltage threshold and / or decreasing the undervoltage threshold; wherein the overvoltage threshold is a voltage threshold for triggering battery overvoltage protection, and the undervoltage threshold is a voltage threshold for triggering battery undervoltage protection.

[0012] In this technical solution, if the battery voltage sampling is abnormal due to reasons such as loose acquisition harness or excessive temperature of the acquisition harness, the battery can continue to be used by increasing the overvoltage threshold and / or reducing the undervoltage threshold, effectively reducing the battery management system from falsely triggering fault protection based on the over- and undervoltage judgment logic.

[0013] In combination with the first aspect, in one or more embodiments, the above method includes: in response to an abnormality in battery voltage sampling, comparing the current maximum voltage value of the battery module with the increased overvoltage threshold, and in response to the current maximum voltage value being greater than the increased overvoltage threshold, determining that the battery voltage is abnormal; and / or, in response to an abnormality in battery voltage sampling, comparing the current minimum voltage value of the battery module with the reduced undervoltage threshold, and in response to the current minimum voltage value being less than the reduced undervoltage threshold, determining that the battery voltage is abnormal.

[0014] In this technical solution, it is possible to detect battery voltage anomalies caused by a broken acquisition harness and / or voltage anomalies caused by battery overcharge or over-discharge, thereby reducing the problem of failure to trigger fault protection due to abnormal battery voltage sampling.

[0015] In combination with the first aspect, in one or more embodiments, the above method includes: in response to an abnormality in battery voltage sampling, comparing the current first average value with the overvoltage threshold and the undervoltage threshold, and / or comparing the current second average value with the overvoltage threshold and the undervoltage threshold, the current first average value being the average of the current voltage value of the first battery and the current voltage value of the second battery, and the current second average value being the average of the current voltage values ​​of all batteries in the battery module; in response to at least one of the current first average value and the current second average value being greater than the overvoltage threshold, determining that the battery voltage is abnormal; or, in response to at least one of the current first average value and the current second average value being less than the undervoltage threshold, determining that the battery voltage is abnormal; wherein the overvoltage threshold is a voltage threshold for triggering battery overvoltage protection, and the undervoltage threshold is a voltage threshold for triggering battery undervoltage protection.

[0016] In this technical solution, it is possible to detect battery voltage anomalies caused by a broken acquisition harness and / or voltage anomalies caused by battery overcharge or over-discharge, thereby reducing the problem of failure to trigger fault protection due to abnormal battery voltage sampling.

[0017] In combination with the first aspect, in one or more embodiments, the method includes: in response to an abnormality in the battery voltage, turning off the charging switch and the discharging switch.

[0018] In this technical solution, by turning off the charging switch and the discharging switch, the charging or discharging of the battery is stopped, the battery is prevented from being used further, and the further expansion of the battery voltage anomaly is reduced, thereby reducing the risk of thermal runaway of the battery.

[0019] In combination with the first aspect, in one or more embodiments, the method includes: in response to a battery voltage abnormality, turning off a charging switch and a discharging switch; after turning off the charging switch and the discharging switch, in response to the battery voltage abnormality lasting for a fifth period of time, determining that the acquisition harness is broken.

[0020] In this technical solution, it is possible to identify whether the collection harness has a broken wire abnormality.

[0021] In combination with the first aspect, in one or more embodiments, the method includes: in response to an abnormality in battery voltage sampling, determining whether the voltage of the battery in the battery module meets the recovery condition; in response to the voltage of the battery in the battery module meeting the recovery condition, determining that the battery voltage sampling abnormality is eliminated; the recovery condition includes at least one of the following: 1) the absolute value of the difference between the current voltage value of the first battery and the current first average value is less than the fifth threshold value and lasts for a sixth time period, and the current first average value is the average value of the current voltage value of the first battery and the current voltage value of the second battery; 2) the absolute value of the difference between the current voltage value of the second battery and the current first average value is less than the fifth threshold value and lasts for a sixth time period, and the current first average value is the current The absolute value of the difference between the current voltage value of the first battery and the current second average value is less than the fifth threshold value and continues for the sixth time period, and the current second average value is the average value of the current voltage values ​​of all batteries in the battery module; The absolute value of the difference between the current voltage value of the second battery and the current second average value is less than the fifth threshold value and continues for the sixth time period, and the current second average value is the average value of the current voltage values ​​of all batteries in the battery module; The absolute value of the difference between the current maximum voltage value of the battery module and the third average value is less than the fifth threshold value and continues for the sixth time period, and the current maximum voltage value is the voltage value of the battery with the largest voltage in the current battery module, and the third average value is the current maximum voltage value. The absolute value of the difference between the current minimum voltage value of the battery module and the third average value is less than the fifth threshold value and lasts for a sixth time period. The third average value is the average of the current maximum voltage value and the current minimum voltage value. The average of the current minimum voltage value is the voltage value of the battery with the smallest voltage in the current battery module. The current maximum voltage value is the voltage value of the battery with the largest voltage in the current battery module. The absolute value of the difference between the current maximum voltage value of the battery module and the current second average value is less than the fifth threshold value and lasts for a sixth time period. The current maximum voltage value is the voltage value of the battery with the largest voltage in the current battery module. voltage value, the current second average value is the average value of the current voltage values ​​of all batteries in the battery module; 8) the absolute value of the difference between the current minimum voltage value of the battery module and the current second average value is less than the fifth threshold value and lasts for a sixth time period, the average value of the current minimum voltage value is the voltage value of the battery with the smallest voltage in the current battery module, and the current second average value is the average value of the current voltage values ​​of all batteries in the battery module; 9) all adjacent batteries in the battery module meet at least one of the following conditions: the absolute value of the difference between the current voltage value of at least one of the adjacent batteries and the fourth average value is less than the fifth threshold value and lasts for a sixth time period, and the fourth average value is the average value of the current voltage values ​​of two batteries in the adjacent batteries;The difference between the current voltage value of at least one of the adjacent batteries and the current second average value is less than a fifth threshold value and persists for a sixth duration, where the current second average value is the average value of the current voltage values ​​of all batteries in the battery module; wherein the fifth threshold value is less than the first threshold value, and / or the fifth threshold value is less than the second threshold value.

[0022] In this technical solution, after an abnormality occurs in battery voltage sampling, it is possible to further identify whether the abnormality in battery voltage sampling is restored.

[0023] In combination with the first aspect, in one or more embodiments, the above method includes: obtaining a voltage threshold and a voltage coefficient corresponding to the battery module; determining a first threshold based on the voltage threshold, the voltage coefficient and the first average value; and determining a second threshold based on the voltage threshold, the voltage coefficient and the second average value.

[0024] In this technical solution, the first threshold, the second threshold and the third threshold can change dynamically with the change of the acquired voltage value, so as to adapt to different working conditions and scenarios. Compared with the use of fixed thresholds, the use of dynamically changing thresholds can further improve the accuracy of diagnosis.

[0025] In combination with the first aspect, in one or more embodiments, the above method includes: obtaining a voltage threshold, a voltage coefficient, an influence factor value and an influence factor coefficient corresponding to the battery module, the influence factor value including at least one of the following: the temperature value of the acquisition harness, the current flowing through the acquisition harness; the influence factor coefficient including at least one of the following: the temperature coefficient, the current coefficient; determining a first threshold based on the voltage threshold, the voltage coefficient, the first average value, the influence factor value and the influence factor coefficient; determining a second threshold based on the voltage threshold, the voltage coefficient, the second average value, the influence factor value and the influence factor coefficient.

[0026] In this technical solution, the first threshold, the second threshold and the third threshold can change dynamically with the changes in the collected voltage value, the temperature of the collection harness and / or the current flowing through the collection harness, thereby adapting to different working conditions and scenarios and reducing the impact of temperature and current. Compared with using fixed thresholds, using dynamically changing thresholds can improve the accuracy of diagnosis.

[0027] In a second aspect, the present application provides a battery management system, which includes: an acquisition circuit and a microcontroller; the acquisition circuit is configured to acquire parameters of batteries in a battery module through an acquisition harness, the parameters including voltage values; the microcontroller includes a memory and a processor; the memory is used to store computer program instructions; the processor is configured to implement the method for diagnosing battery voltage abnormalities as in the first aspect when executing the computer program instructions stored in the memory.

[0028] In a third aspect, the present application provides a battery device, including a battery module and a battery management system as in the second aspect.

[0029] In a fourth aspect, the present application provides an electrical device, including a load and a battery device as described in the third aspect, wherein the battery device is used to supply power to the load. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, a brief introduction to the drawings required for use in the embodiments of the present application is given below.

[0031] Figure 1 This is a schematic diagram of a battery module and a collection harness provided in an embodiment of the present application;

[0032] Figure 2 1 is a flow chart of a method for diagnosing abnormal battery voltage provided by an embodiment of the present application;

[0033] Figure 3 It is a structural diagram of the battery management system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0034] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the objectives, technical solutions, and advantages of the present application more clearly understood, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the examples of the present application are provided to provide a better understanding of the present application, and the specific embodiments described herein are intended only to explain the present application, not to limit the present application.

[0035] It will be understood that, herein, relational terms such as first and second, etc., are merely used to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any actual relationship or order between these entities or operations.

[0036] In related technologies, the battery management system identifies faults based on the maximum and minimum cell voltages of the collected battery module. After identifying a fault, it triggers the corresponding fault protection, such as turning off the charge and discharge switches, and / or disconnecting the fuse (such as the air switch) to ensure the safe and stable operation of the battery module. Due to abnormalities in the battery itself, the battery collection harness, or the voltage collection circuit (for example, damage to the AFE chip), the battery voltage value collected by the collection harness will be inaccurate, that is, the battery voltage sampling value will be inconsistent with the actual battery voltage value, which will lead to false alarms, false triggering of fault protection, or failure to trigger fault protection. As a result, the battery module frequently experiences SOC jumps and power interruptions, and in severe cases, thermal runaway may be triggered.

[0037] The applicant discovered that two adjacent batteries in a battery module share a collection harness connected to the collection circuit in the battery management system. When the collection harness shared by the two adjacent batteries is disconnected, the voltage value of the low-cell battery collected by the collection circuit will drop to close to 0V, and the voltage value of the high-cell battery collected will rise to close to the sum of the voltage values ​​of the two batteries. The low-cell battery refers to the battery close to the negative pole of the battery module among the two adjacent batteries, and the high-cell battery refers to the battery close to the positive pole of the battery module among the two adjacent batteries. For example, see Figure 1 The battery module 100 includes two adjacent batteries, namely battery 110 and battery 120. The negative pole of battery 110 and the positive pole of battery 120 are connected to the data acquisition harness 130. When the data acquisition harness 130 is disconnected, the voltage sampling value of battery 110 will rise to a value close to the sum of the actual voltage values ​​of battery 110 and battery 120, and the voltage sampling value of battery 120 will drop to a value close to 0V.

[0038] The applicant further discovered that when an abnormality occurs in two adjacent batteries themselves, or the collection harness connecting the two adjacent batteries becomes loose and / or the temperature of the collection harness is too high, the voltage value of the low-cell battery collected by the voltage collection circuit shows a downward trend, and the voltage value of the high-cell battery collected shows an upward trend.

[0039] Based on this, the applicant has developed a method for diagnosing battery voltage sampling anomalies, an electronic device, a battery device, and an electrical device. The method diagnoses battery voltage sampling anomalies based on the voltage sampling values ​​of two adjacent batteries. It is understood that the aforementioned data acquisition harness anomalies include: loose data acquisition harness, overheated data acquisition harness, and broken data acquisition harness.

[0040] It should be noted that Figure 1 The number and structure of the battery modules, batteries and collection harnesses are only an example and do not constitute a limitation on the number and structure of the battery modules, batteries and collection harnesses in this application.

[0041] The following first describes the method for diagnosing abnormal battery voltage sampling provided by an embodiment of the present application.

[0042] In one or more embodiments of the present application, the method for diagnosing abnormal battery voltage sampling is executed by a battery management system.

[0043] Figure 2 A flow chart of a method for diagnosing abnormal battery voltage provided in an embodiment of the present application is shown in FIG. Figure 2 As shown, the method includes the following steps S210-S250.

[0044] S210. Obtain voltage values ​​of adjacent batteries in the battery module and / or voltage values ​​of all batteries in the battery module, where the voltage values ​​of adjacent batteries include the voltage value of a first battery and the voltage value of a second battery.

[0045] Here, the voltage value obtained is the battery voltage sampling value, that is, the battery voltage value collected by the voltage acquisition circuit and the acquisition harness. If there is no abnormality in the acquisition harness connected to the battery in the battery module, the battery voltage value collected by the voltage acquisition circuit is roughly equal to the actual battery voltage value. It is understandable that "roughly equal" takes into account the sampling accuracy of the voltage acquisition circuit (such as the AFE chip) and / or ADC (analog-to-digital converter), the impact of temperature on the components in the voltage acquisition circuit, and other factors.

[0046] The voltage acquisition circuit in the BMS acquires the voltage values ​​of adjacent cells and / or the voltage values ​​of all cells in the battery module. For example, the BMS MCU communicates with the voltage acquisition circuit to acquire the voltage sampling values ​​of adjacent cells and / or the voltage sampling values ​​of all cells.

[0047] In the above step S210 , the voltage values ​​of two adjacent batteries in the battery module are obtained. For ease of description, the two adjacent batteries are referred to as a first battery and a second battery.

[0048] In the above step S210 , the voltage values ​​of all batteries in the battery module are obtained, and the voltage values ​​of all batteries include the voltage values ​​of any two adjacent batteries.

[0049] S220. Calculate the voltage average value, where the voltage average value includes a first average value and / or a second average value, where the first average value is defined as the voltage average value of the first battery and the second battery, and the second average value is defined as the voltage average value of all batteries in the battery module.

[0050] After obtaining the voltage values ​​of adjacent batteries in the battery module and / or the voltage values ​​of all batteries in the battery module, an average voltage value is calculated based on the obtained voltage values. For example, a calculation module of an MCU in the BMS calculates the first average value and / or the second average value.

[0051] In some embodiments, when the voltage values ​​of the first battery and the second battery are obtained in step S210, an average of the voltage values ​​of the first battery and the second battery is calculated and used as a first average value. If an abnormality occurs in a data acquisition harness shared by the first battery and the second battery, and no abnormality occurs in other data acquisition harnesses connected to the first battery and the second battery, the first average value is approximately equal to the average of the actual voltage of the first battery and the actual voltage of the second battery.

[0052] In some embodiments, after obtaining the voltage values ​​of all batteries in the battery module in step S210, an average of the voltage values ​​of all batteries is calculated and used as the second average value. Alternatively, the voltage values ​​of the first battery and the second battery are extracted from the voltage values ​​of all batteries, and the average of the voltage values ​​of the first battery and the second battery is calculated as the first average value. The second average value is calculated here because, in the acquisition harnesses connected to adjacent batteries, in addition to the acquisition harness shared by the adjacent batteries, other acquisition harnesses may also experience an abnormality. For example, if acquisition harness 1 connected to the first and second batteries experiences an abnormality, and acquisition harness 2 connected to the second and third batteries also experiences an abnormality, the first average value will no longer be approximately equal to the average of the actual voltages of the first and second batteries. Consequently, the first average value cannot be used to diagnose whether the battery voltage sampling is abnormal, and the diagnosis of battery voltage sampling abnormality based on the first average value is invalid. Therefore, to improve the effectiveness of the diagnostic method, a second average value is calculated, and the second average value is used to diagnose whether the battery voltage sampling is abnormal.

[0053] S230 : In response to the voltage values ​​of the first battery and the second battery satisfying the sampling line abnormality determination condition, determine that the battery voltage sampling is abnormal.

[0054] According to the previous analysis, due to an abnormality in the adjacent first and second batteries themselves, or an abnormality in the acquisition wiring harness, the voltage value of the low-cell battery collected by the voltage acquisition circuit will drop to close to 0, and the voltage value of the high-cell battery will rise to close to the sum of the voltage values ​​of the two batteries. Alternatively, the voltage value of the low-cell battery collected by the voltage acquisition circuit will show a downward trend, while the voltage value of the high-cell battery collected will show an upward trend. Based on the above characteristics of the sampled battery voltage, the judgment conditions set by this application for diagnosing whether the battery voltage sampling is abnormal include at least one of the following:

[0055] 1) The absolute value of the difference between the voltage of the first battery and the first average value is greater than a first threshold value and lasts for a first time period, and the absolute value of the difference between the voltage of the second battery and the first average value is greater than the first threshold value and lasts for a first time period;

[0056] 2) The absolute value of the difference between the voltage of the first battery and the second average value is greater than the second threshold value and lasts for a second time period, and the absolute value of the difference between the voltage of the second battery and the second average value is greater than the second threshold value and lasts for a second time period;

[0057] 3) If the absolute value of the difference between the voltage value of the first battery and the voltage value of the second battery is greater than a third threshold and persists for a third period of time, it is determined that an abnormality has occurred in the collection harness for collecting the battery voltages, and the third threshold is greater than or equal to twice the first threshold, or the third threshold is greater than or equal to twice the second threshold.

[0058] It can be understood that "the determination conditions include at least one of the following" means including: 1) one of the above three conditions; 2) any two of the above three conditions; 3) including the above three conditions at the same time.

[0059] The first threshold, the second threshold, and the third threshold serve as thresholds for judging whether the voltage value of the first battery and the voltage value of the second battery meet the thresholds for abnormal battery voltage sampling. The first threshold and the second threshold are determined according to the characteristics of the battery module. The differences in battery type, chemical composition, and manufacturer will also cause the first threshold and the second threshold to differ. Therefore, in the actual application of the diagnostic method of the present application, appropriate first and second thresholds are selected based on the above factors. The present application does not make specific limitations on the first and second thresholds. The third threshold is determined based on the first threshold and / or the second threshold. For example, the third threshold is greater than or equal to twice the first threshold, or the third threshold is greater than or equal to twice the second threshold.

[0060] The first duration, the second duration, and the third duration are used to determine whether the above conditions are continuously met over a period of time. By setting the duration, instantaneous voltage fluctuations are avoided from being misjudged as abnormal battery voltage sampling, thereby improving the accuracy of diagnosis. Among them, the first duration, the second duration, and the third duration can be the same or different. For example, the first duration, the second duration, and the third duration are all 0.5 seconds, 1 second, 1.5 seconds, or 2 seconds. The first duration, the second duration, and the third duration are set according to actual needs and are not specifically limited in this application.

[0061] In some embodiments, in order to be able to diagnose battery voltage sampling abnormalities in a timely manner, the first time length, the second time length, and the third time length are not too large, and the value range of the first time length, the second time length, and the third time length is set to (0s, 5s], optionally, the value range of the first time length, the second time length, and the third time length is set to [1s, 3s].

[0062] After obtaining the voltage values ​​of the first battery and the second battery, the battery management system determines whether the voltage values ​​of the first battery and the second battery meet any one of the above-mentioned battery voltage sampling abnormality determination conditions. If the voltage values ​​of the first battery and the second battery meet any one of the determination conditions, it is determined that the battery voltage sampling is abnormal.

[0063] In the present application: (1) the voltage sampling values ​​of two adjacent batteries in the battery module are obtained, and the voltage sampling average value (such as the first average value and / or the second average value mentioned above) is calculated, the voltage sampling values ​​of the two batteries are respectively subtracted from the voltage sampling average value, and the absolute value of the difference is taken. Further, the two difference absolute values ​​are compared with the first threshold value, and when the two difference absolute values ​​are both greater than the first threshold value and the duration meets the requirement, and / or, the two difference absolute values ​​are compared with the second threshold value, and when the two difference threshold values ​​are both greater than the second threshold value and the duration meets the requirement, the battery voltage sampling abnormality is determined; and / or, (2) the voltage sampling values ​​of two adjacent batteries in the battery module are obtained, the absolute value of the difference between the voltage sampling values ​​of the two adjacent batteries is calculated, and when the absolute value of the difference between the voltage sampling values ​​of the two batteries is greater than the third threshold value, the battery voltage sampling abnormality is determined. In this way, the battery voltage sampling abnormality can be detected in time when the acquisition harness is abnormal, the battery itself is abnormal, etc., thereby improving the diagnostic accuracy of the battery voltage sampling abnormality.

[0064] In some embodiments, to more accurately diagnose whether battery voltage sampling is abnormal, the first threshold, the second threshold, and the third threshold are dynamically set based on the characteristics of the battery module, the characteristics of the voltage acquisition circuit, and environmental factors. Based on this, the first threshold and the second threshold are determined through the following steps S310-S330.

[0065] S310. Obtain the voltage threshold and voltage coefficient corresponding to the battery module.

[0066] The voltage threshold of a battery module is determined by the characteristics of the battery module, such as the battery type, chemical composition, and manufacturer. The voltage threshold may vary depending on the battery type, chemical composition, and manufacturer. For example, the battery threshold may be 100mV.

[0067] The voltage coefficient is a parameter set according to the characteristics of the battery module. The voltage coefficient is a value greater than 0 and less than 0.1. For example, the voltage coefficient is 0.5%.

[0068] S320. Determine a first threshold based on the voltage threshold, the voltage coefficient, and the first average value.

[0069] The first threshold is calculated according to the following formula (1):

[0070] ΔV1=X+kV avg1 (1)

[0071] In the above formula (1), ΔV1 represents the first threshold, X represents the voltage threshold, k represents the voltage coefficient, V avb1 Indicates the first average value.

[0072] S330. Determine a second threshold based on the voltage threshold, the voltage coefficient, and the second average value.

[0073] The second threshold is calculated according to the following formula (2):

[0074] ΔV2=X+kV avg2 (2)

[0075] In the above formula (2), ΔV2 represents the second threshold, X represents the voltage threshold, k represents the voltage coefficient, V avg2 Indicates the first average value.

[0076] The third threshold is set based on the first threshold or the second threshold. After the first threshold or the second threshold is determined, the third threshold is determined based on the relationship between the first threshold or the second threshold and the third threshold. For example, the third threshold may be set to be greater than or equal to twice the first threshold, or the third threshold may be set to be greater than or equal to twice the second threshold.

[0077] The first threshold, the second threshold, and the third threshold can change dynamically with the acquired voltage value to adapt to different operating conditions and scenarios. Compared with using fixed thresholds, using dynamically changing thresholds can improve the accuracy of diagnosing whether battery voltage sampling is abnormal.

[0078] In one or more embodiments of the present application, the data acquisition harness is connected to the battery management system via a connector. Poor contact in the data acquisition harness connector may cause impedance variations in the voltage acquisition circuit comprised of the connector and the data acquisition harness. This impedance also varies with temperature. When high current flows through the connector, the temperature rise at the poor contact point is significant, causing voltage fluctuations in the data acquisition harness. Therefore, to mitigate the influence of factors such as current and temperature and further improve diagnostic accuracy, the first and second thresholds are determined through the following steps S410-S430.

[0079] S410. Obtain a voltage threshold, voltage coefficient, impact factor value, and impact factor coefficient corresponding to the battery module. The impact factor value includes at least one of the following: battery temperature and battery current; the impact factor coefficient includes at least one of the following: temperature coefficient and current coefficient.

[0080] For the voltage threshold and voltage coefficient, please refer to the relevant description in the above embodiment, and will not be described again here to avoid repetition.

[0081] The influencing factor affects the accuracy of the voltage values ​​collected by the acquisition harness. The influencing factor value is the parameter value of the influencing factor, and the influencing factor coefficient is the coefficient corresponding to the influencing factor. In this embodiment, the influencing factor includes at least one of the temperature of the acquisition harness and the current flowing through the acquisition harness. Therefore, the influencing factor value includes at least one of the temperature value of the acquisition harness and the current flowing through the acquisition harness, and the influencing factor coefficient includes at least one of the temperature coefficient and the current coefficient.

[0082] The impact factor value is obtained during the diagnosis process. The impact factor coefficient is set based on the material and temperature sensitivity of the acquisition harness. The impact factor coefficients vary depending on the material and temperature sensitivity of the acquisition harness. For example, the temperature coefficient is 1.5 and the current coefficient is 0.5. This embodiment does not specifically limit the values ​​of the impact factor coefficients.

[0083] In some embodiments, the voltage coefficient and / or impact factor coefficient are predicted using a trained neural network model. The neural network model is a self-learning neural network model trained using data collected when an abnormality occurs in the battery module's wiring harness.

[0084] S420. Determine a first threshold based on the voltage threshold, the voltage coefficient, the first average value, the impact factor value, and the impact factor coefficient.

[0085] When the influencing factor includes the temperature of the acquisition harness, the first threshold is calculated according to the following formula (3):

[0086] ΔV1=X+kV avg1 +α(T-T0) (3)

[0087] In the above formula (3), α represents the temperature coefficient, T represents the temperature value of the acquisition harness, T0 represents the temperature threshold, and T0 is a temperature constant, for example, T0=25° C. The present application does not impose any specific limitation on the value of T0.

[0088] In the case where the influencing factor includes the current flowing through the acquisition harness, the first threshold is calculated according to the following formula (4):

[0089] ΔV1=X+kV avg1 +βI (4)

[0090] In the above formula (4), β represents the current coefficient, and I represents the current value of the collection harness.

[0091] When the influencing factors include the temperature of the acquisition harness and the current flowing through the acquisition harness, the first threshold is calculated according to the following formula (5):

[0092] ΔV1=X+kV avg1 +α(T-T0)+βI (5)

[0093] S430. Determine a second threshold based on the voltage threshold, the voltage coefficient, the second average value, the impact factor value, and the impact factor coefficient.

[0094] When the influencing factor includes the temperature of the acquisition harness, the second threshold is calculated according to the following formula (6):

[0095] ΔV2=X+kV avg2 +α(T-T0) (6)

[0096] In the case where the influencing factor includes the current flowing through the acquisition harness, the second threshold is calculated according to the following formula (7):

[0097] ΔV2=X+kV avg2 +βI (7)

[0098] When the influencing factors include the temperature of the acquisition harness and the current flowing through the acquisition harness, the first threshold is calculated according to the following formula (8):

[0099] ΔV2=X+kV avg2 +α(T-T0)+βI (8)

[0100] The third threshold is set according to the first threshold or the second threshold. After the first threshold or the second threshold is determined, the third threshold is determined based on the relationship between the first threshold or the second threshold and the third threshold.

[0101] In this technical solution, the first threshold, the second threshold and the third threshold can change dynamically with the changes in the collected voltage value, the temperature of the collection harness and / or the current flowing through the collection harness, thereby adapting to different working conditions and scenarios and reducing the impact of influencing factors. Compared with using fixed thresholds, using dynamically changing thresholds can improve the accuracy of diagnosis.

[0102] As previously mentioned, abnormalities in the battery voltage sampling may occur due to abnormalities in the battery itself, abnormalities in the battery acquisition wiring harness, or abnormalities in the voltage acquisition circuit (for example, damage to the AFE chip). When abnormalities occur in the battery voltage sampling, the battery voltage sampling value often cannot accurately reflect the actual battery voltage value. Regarding abnormalities in battery voltage sampling, the applicant has further researched how to reduce false alarms and / or false triggering of battery fault protection (for example, disconnecting the charge and discharge switch and / or disconnecting the air switch) caused by abnormal battery voltage sampling, thereby interrupting the battery's charging or discharging.

[0103] In one or more embodiments of the present application, in order to reduce false alarms and / or false triggering of battery fault protection due to abnormal battery voltage sampling, after determining that the battery voltage sampling is abnormal, at least one of the following operations 1 and 2 is performed.

[0104] Action 1: Stop balancing the battery modules.

[0105] The battery management system balances the battery module based on the battery voltage sampling value. After an abnormality occurs in the battery voltage sampling, the battery voltage sampling value cannot accurately reflect the actual voltage value of the battery. If balancing is performed at this time, it will lead to inaccurate balancing, which may further expand the inconsistency of the batteries in the battery module. By stopping balancing the battery module, false alarms and / or false triggering of battery fault protection caused by inaccurate balancing can be reduced.

[0106] Operation 2: Update the displayed voltage value of the first battery and the displayed voltage value of the second battery to the first average value or the second average value; or, in response to an abnormality in battery voltage sampling, update the displayed voltage value of the first battery and the second battery based on an adjustment strategy. The adjustment strategy includes: determining a voltage variable every fourth time period, adjusting the first average value or the second average value based on the voltage variable to obtain an adjustment value, and updating the displayed voltage value of the first battery and the second battery to the adjustment value; or, determining a first voltage variable and a second voltage variable every fourth time period, adjusting the first average value or the second average value based on the first voltage variable to obtain a first adjustment value, updating the displayed voltage value of the first battery to the first adjustment value, adjusting the first average value or the second average value based on the second voltage variable to obtain a second adjustment value, and updating the displayed voltage value of the second battery to the second adjustment value. The fourth time period is set according to actual needs and reflects the update frequency of the displayed voltage value of the first battery and the second battery, and the displayed voltage value of the first battery and the second battery are updated once every fourth time period. The voltage variable, the first voltage variable and / or the second voltage variable are randomly obtained from a set voltage variable interval, and the voltage variable interval is [0mV, 20mV].

[0107] The diagnostic scheme of the present application is applied to some specific electrical equipment. A display can be set on the electrical equipment, or the display can be set at a position convenient for the user to view. The display can display the voltage value of each battery in the battery module. The voltage value of the battery displayed by the display is called the voltage display value. The user determines whether the battery has an abnormality based on the voltage display value, and manually takes corresponding fault protection when the abnormality is determined. For example, the user determines whether the battery has an overvoltage fault or an undervoltage fault by checking the voltage display value of the battery. When it is determined that the battery has an overvoltage fault or an undervoltage fault, the charging switch and the discharging switch are manually turned off. For example, a trigger device (such as a button) is set on the electrical equipment, and the user presses the trigger device to trigger the BMS to send an instruction to turn off the charge and discharge switches, thereby turning off the charge switch and the discharge switch, or the user manually turns off the fuse (such as an air switch) provided on the electrical equipment.

[0108] Operation 2 includes two parallel solutions, referred to as Solution 1 and Solution 2 for ease of description. Solution 1 updates the displayed voltage value of the first battery and the displayed voltage value of the second battery to the first average value or the second average value. Solution 2 updates the displayed voltage value of the first battery and the displayed voltage value of the second battery based on the adjustment strategy.

[0109] For Solution 1, the first average value or the second average value is displayed as the voltage value of the first battery and the second battery. In the event of an abnormality in battery voltage sampling, the first average value and the second average value are close to the actual voltage of the single battery in the battery module, that is, close to the actual voltage value of the first battery and the second battery. Therefore, the first average value or the second average value is displayed as the voltage value of the first battery and the second battery, avoiding erroneous operation such as interruption of battery charging or discharging due to abnormal battery voltage sampling.

[0110] For Solution 2, the battery voltage display value remains unchanged due to two possible reasons: one is that the battery is not in a charging or discharging state; the other is that the battery is in a charging or discharging state, but due to a program abnormality or poor network, the updated battery voltage value fails to be successfully transmitted to the display, and the voltage display value has not been updated. In view of this, in order to facilitate the user to judge whether there is a program abnormality or a poor network, the above-mentioned Solution 2 is adopted, and a random number is added or subtracted based on the first average value or the second average value every fourth time period, that is, the first voltage variable and / or the second voltage variable are added or subtracted as the voltage values ​​of the first battery and the second battery for display. The random numbers added and subtracted at different times are different, so that the voltage display value of the first battery and the voltage display value of the second battery present a dynamic change process. When the user sees that the voltage display value changes dynamically, he can determine that there is no program abnormality or poor network. Otherwise, it is determined that there is a program abnormality or poor network.

[0111] While developing this application, the applicant discovered that battery management systems generally include overvoltage and undervoltage judgment logic. This logic compares the maximum voltage value in the battery module collected by the acquisition harness with the overvoltage threshold, and the minimum voltage value in the battery module collected by the acquisition harness with the undervoltage threshold. If the maximum voltage value is greater than the overvoltage threshold, it is determined that the battery has an overvoltage fault; if the minimum voltage value is less than the undervoltage threshold, it is determined that the battery has an undervoltage fault. Based on the overvoltage and undervoltage judgment logic, the battery management system determines whether the batteries in the battery module have an overvoltage fault or an undervoltage fault, and triggers the corresponding fault protection when it is determined that the battery has an overvoltage fault and / or an undervoltage fault. However, in the event of an abnormality in battery voltage sampling, the collected voltage values ​​of the first battery and the second battery do not truly reflect the actual voltages of the first battery and the second battery. If the original overvoltage threshold and original undervoltage threshold are used to determine overvoltage and undervoltage faults in the battery module according to the overvoltage and undervoltage judgment logic, the battery module may be incorrectly judged to have an overvoltage fault and / or an undervoltage fault, causing the battery management system to falsely trigger fault protection, thereby interrupting the battery's charging or discharging, and preventing the battery from continuing to be used. In view of this, in order to reduce the battery management system's false triggering of fault protection based on the overvoltage and undervoltage judgment logic, the following operation 3 is performed after an abnormality in battery voltage sampling occurs.

[0112] Operation 3: Increase the overvoltage threshold and / or decrease the undervoltage threshold, where the overvoltage threshold is the voltage threshold for triggering battery overvoltage protection, and the undervoltage threshold is the voltage threshold for triggering battery undervoltage protection.

[0113] Increasing the overvoltage threshold refers to increasing the third voltage variable based on the preset original overvoltage threshold. Reducing the undervoltage threshold refers to decreasing the fourth voltage variable based on the preset original undervoltage threshold. The third and fourth voltage variables are set based on actual needs and are not specifically limited in this application.

[0114] In one or more embodiments of the present application, if the battery voltage sampling is abnormal due to the looseness of the acquisition harness or the excessive temperature of the acquisition harness, the battery can continue to be used by increasing the overvoltage threshold and / or reducing the undervoltage threshold, effectively reducing the battery management system from falsely triggering fault protection based on the over- and undervoltage judgment logic.

[0115] The applicant has discovered that in some related technologies, in order to reduce the false triggering of fault protection due to abnormal battery voltage sampling, some processing methods are to stop judging battery overvoltage or undervoltage. This may result in the failure to trigger fault protection after the actual battery voltage is abnormal, thereby causing safety risks (such as battery thermal runaway). In view of this, the applicant further proposes the following solution: after determining that the battery voltage sampling is abnormal, in order to reduce the problem of failure to trigger fault protection due to the inability to detect abnormal battery voltage, at least one of the following operations 4 and 5 is performed.

[0116] Operation 4: After increasing the overvoltage threshold and / or decreasing the undervoltage threshold, compare the current maximum voltage of the battery module with the increased overvoltage threshold. In response to the current maximum voltage being greater than the increased overvoltage threshold, determine that the battery voltage is abnormal; and / or compare the current minimum voltage of the battery module with the decreased undervoltage threshold. In response to the current minimum voltage being less than the decreased undervoltage threshold, determine that the battery voltage is abnormal. It is understandable that after determining that the battery voltage sampling is abnormal, increase the original overvoltage threshold and / or decrease the original undervoltage threshold to allow the battery to continue to be used. When the battery is overcharged, the battery voltage rises. When the battery is discharged, the battery voltage drops. The current maximum voltage value is the voltage value of the battery with the highest voltage in the battery module under the current use state, and the current minimum voltage value is the voltage value of the battery with the lowest voltage in the battery module under the current use state.

[0117] Operation 5: Compare the current first average value with the overvoltage threshold and the undervoltage threshold, and / or compare the current second average value with the overvoltage threshold and the undervoltage threshold, where the current first average value is the average of the current voltage value of the first battery and the current voltage value of the second battery, and the current second average value is the average of the current voltage values ​​of all batteries in the battery module; in response to at least one of the current first average value and the current second average value being greater than the overvoltage threshold, determine that the battery voltage is abnormal; or, in response to at least one of the current first average value and the current second average value being less than the undervoltage threshold, determine that the battery voltage is abnormal. The overvoltage threshold is the voltage threshold used to trigger the battery overvoltage protection, and the undervoltage threshold is the voltage threshold used to trigger the battery undervoltage protection. It is understandable that the overvoltage threshold and undervoltage threshold in Operation 5 are the original overvoltage threshold and undervoltage threshold, respectively, without adjustment.

[0118] For ease of explanation, the judgment logic of operation 4 is referred to as the first over-voltage and under-voltage judgment logic. After the above operation 4 increases the overvoltage threshold and / or reduces the undervoltage threshold through operation 3, the battery module is judged for over-voltage and under-voltage according to the first over-voltage and under-voltage judgment logic to determine whether the battery module has an over-voltage or under-voltage fault. After increasing the overvoltage threshold, if it is determined based on the first over-voltage and under-voltage judgment logic that the current maximum voltage value of the battery module is greater than the increased overvoltage threshold, it means that the battery voltage may be abnormal due to a disconnection in the acquisition harness. Similarly, after reducing the undervoltage threshold, if it is determined based on the first over-voltage and under-voltage judgment logic that the current minimum voltage value of the battery module is less than the reduced overvoltage threshold, it means that the battery voltage may be abnormal due to a disconnection in the acquisition harness.

[0119] Operation 5 above adds new overvoltage / undervoltage judgment logic. For ease of explanation, this judgment logic is referred to as the second overvoltage / undervoltage judgment logic. Without changing the original overvoltage and undervoltage thresholds, the second overvoltage / undervoltage judgment logic compares the current first average value with the overvoltage threshold and / or undervoltage threshold, and / or compares the current second average value with the overvoltage threshold and / or undervoltage threshold. If at least one of the current first average value and the current second average value is less than the undervoltage threshold, the battery voltage abnormality may be caused by overdischarge. If at least one of the current first average value and the current second average value is greater than the overvoltage threshold, the battery voltage abnormality may be caused by overcharging.

[0120] Through the above operation 4 and / or operation 5, it is possible to detect battery voltage abnormalities caused by a broken acquisition harness and / or voltage abnormalities caused by battery overcharge or over-discharge, thereby reducing the problem of failure to trigger fault protection due to abnormal battery voltage sampling.

[0121] Optionally or additionally, in order to reduce problems such as thermal runaway caused by abnormal battery voltage, the following operation 6 may be performed after the above operation 4 and / or operation 5.

[0122] Operation 6: In response to the abnormality in the battery voltage, turning off the charge switch and the discharge switch.

[0123] By turning off the charging switch and the discharging switch, the charging or discharging of the battery is stopped, the battery is prevented from being used, and the further expansion of the battery voltage abnormality is reduced, thereby reducing the risk of thermal runaway of the battery.

[0124] In one or more embodiments of the present application, the battery voltage abnormality determined in the above-mentioned operation 4 may be caused by a disconnection of the acquisition harness. To further confirm whether the acquisition harness is disconnected, the applicant has discovered that: for battery voltage abnormalities that are not caused by a disconnection of the acquisition harness (for example, poor contact between the acquisition harness and the connector, or excessively high temperature of the acquisition harness), the abnormality of the acquisition harness can be restored to normal over time (for example, the acquisition harness and the connector are properly reconnected, and the temperature of the acquisition harness returns to a normal level). After the abnormality is restored, the battery voltage abnormality will also be eliminated. However, for battery voltage abnormalities caused by a disconnection of the acquisition harness, which is an abnormality that cannot be self-recovered, the battery voltage abnormality will not be eliminated over time. Based on this, after determining that the battery voltage abnormality is determined in accordance with operation 4, the duration of the battery voltage abnormality is used to determine whether the acquisition harness is disconnected. Therefore, to determine whether the acquisition harness is disconnected, the following operation 7 is performed after the above-mentioned operation 4.

[0125] Operation 7: In response to the battery voltage being abnormal, turning off the charging switch and the discharging switch, and after turning off the charging switch and the discharging switch, in response to the battery voltage being abnormal for a fifth time period, determining that the acquisition harness is disconnected.

[0126] The fifth duration is set according to actual needs, for example, the fifth duration is 3 hours. This application does not specifically limit the value of the fifth duration.

[0127] In this technical solution, after determining a battery voltage abnormality through operation 4, the charging and discharging switches are turned off to protect the battery module. After turning off the charging and discharging switches, the maximum and minimum voltage values ​​of the battery module are continuously obtained, and based on operation 4, it is continuously determined whether the battery voltage abnormality still exists. If the duration of the battery voltage abnormality is determined to be greater than or equal to the fifth duration, it is determined that an abnormality has occurred in the data acquisition harness that cannot be self-recovered, and thus the data acquisition harness is disconnected. In this way, it is possible to identify whether the abnormality in the data acquisition harness is a disconnection abnormality.

[0128] Optionally or additionally, after determining that the battery voltage sampling is abnormal, the following operation 8 is performed to further determine whether the battery voltage sampling abnormality is eliminated.

[0129] Operation 8: Determine whether the voltage of the battery in the battery module meets the recovery condition. In response to the voltage of the battery in the battery module meeting the recovery condition, determine that the abnormality of the battery sampling line is eliminated.

[0130] The restoration conditions include at least one of the following conditions 1) to 9):

[0131] 1) The absolute value of the difference between the current voltage value of the first battery and the current first average value is less than the fifth threshold and lasts for a sixth time period, and the current first average value is the average value of the current voltage value of the first battery and the current voltage value of the second battery.

[0132] 2) The absolute value of the difference between the current voltage value of the second battery and the current first average value is less than the fifth threshold and lasts for a sixth time period, and the current first average value is the average value of the current voltage value of the first battery and the current voltage value of the second battery.

[0133] 3) The absolute value of the difference between the current voltage value of the first battery and the current second average value is less than the fifth threshold value and lasts for a sixth time period, and the current second average value is the average value of the current voltage values ​​of all batteries in the battery module.

[0134] 4) The absolute value of the difference between the current voltage value of the second battery and the current second average value is less than the fifth threshold value and lasts for a sixth time period, and the current second average value is the average value of the current voltage values ​​of all batteries in the battery module.

[0135] 5) The absolute value of the difference between the current maximum voltage value of the battery module and the third average value is less than the fifth threshold value and lasts for a sixth time period. The third average value is the average of the current maximum voltage value and the current minimum voltage value. The current maximum voltage value is the voltage value of the battery with the largest voltage in the current battery module, and the current minimum voltage value is the voltage value of the battery with the smallest voltage in the current battery module.

[0136] 6) The absolute value of the difference between the current minimum voltage value of the battery module and the third average value is less than the fifth threshold and lasts for a sixth time period. The third average value is the average of the current maximum voltage value and the current minimum voltage value. The current minimum voltage value is the voltage value of the battery with the smallest voltage in the current battery module, and the current maximum voltage value is the voltage value of the battery with the largest voltage in the current battery module.

[0137] 7) The absolute value of the difference between the current maximum voltage value of the battery module and the current second average value is less than the fifth threshold and lasts for a sixth time period. The current maximum voltage value is the voltage value of the battery with the largest voltage in the current battery module, and the current second average value is the average value of the current voltage values ​​of all batteries in the battery module.

[0138] 8) The absolute value of the difference between the current minimum voltage value of the battery module and the current second average value is less than the fifth threshold value and lasts for a sixth time period. The average value of the current minimum voltage value is the voltage value of the battery with the lowest voltage in the current battery module, and the current second average value is the average value of the current voltage values ​​of all batteries in the battery module.

[0139] 9) All adjacent batteries in the battery module meet at least one of the following conditions:

[0140] an absolute value of a difference between a current voltage value of at least one of the adjacent batteries and a fourth average value is less than a fifth threshold value and lasts for a sixth time period, where the fourth average value is an average of the current voltage values ​​of two of the adjacent batteries;

[0141] The difference between the current voltage value of at least one of the adjacent batteries and the current second average value is less than a fifth threshold value and lasts for a sixth time period, where the current second average value is an average value of the current voltage values ​​of all batteries in the battery module;

[0142] The fifth threshold is smaller than the first threshold, and / or the fifth threshold is smaller than the second threshold.

[0143] Because the voltage of the batteries in the battery module is not fixed and changes as the batteries charge or discharge, the battery voltage changes. Therefore, in operation 8, the corresponding judgment is made based on the current voltage of the batteries in the battery module. It should be understood that the current voltage of the battery refers to the latest voltage value of the battery sampled by the voltage acquisition circuit when executing operation 8.

[0144] The fifth threshold is a threshold value set for judging whether the acquisition harness anomaly has recovered. The fifth threshold value is less than the first threshold value and / or the second threshold value. The fifth threshold value is set according to the first threshold value and / or the second threshold value of the battery module. For battery modules with poor consistency, in order to improve the accuracy of anomaly detection, the first threshold value and / or the second threshold value are usually larger, so the fifth threshold value is larger. For battery modules with good consistency, in order to improve the accuracy of anomaly detection, the first threshold value and / or the second threshold value are usually smaller, so the fifth threshold value is smaller. For example, taking lithium iron phosphate batteries as an example, their consistency is poor, so the first threshold value is larger. Assuming that the first threshold value is 100mV, the fifth threshold value can be set to 50mV. Taking ternary batteries as an example, their consistency is better, so the first threshold value can be smaller. Assuming that the first threshold value is 50mV, the fifth threshold value can be set to 30mV.

[0145] The value of the sixth time duration is set according to actual needs. For example, the sixth time duration is 10 seconds, which is not specifically limited in this embodiment.

[0146] When the voltage of the battery module satisfies at least one of the above conditions 1) to 9), it is determined that the abnormality of the acquisition harness of the battery module has been recovered.

[0147] Through this technical solution, it is possible to identify whether the battery voltage sampling anomaly has recovered.

[0148] Figure 3 A schematic diagram of the hardware structure of the battery management system provided in an embodiment of the present application is shown.

[0149] The battery management system 300 may include a voltage acquisition circuit 301 and a microcontroller 302 .

[0150] The voltage acquisition circuit 301 is electrically connected to the battery through an acquisition harness to sample the voltage value of the battery.

[0151] The microcontroller 302 includes a memory 3021 and a processor 3022. The memory 3021 is used to store computer program instructions. The processor 3022 is configured to read and execute the computer program instructions stored in the memory 3021 to implement any of the methods for diagnosing battery voltage abnormality in the above-mentioned embodiments.

[0152] In some embodiments, the voltage acquisition circuit 301 includes but is not limited to an AFE chip or a voltage differential acquisition circuit constructed by discrete components.

[0153] In some embodiments, the processor 3022 includes a central processing unit (CPU), or an application specific integrated circuit (ASIC), or can be configured to implement one or more integrated circuits of the embodiments of the present application.

[0154] Memory 3021 may include a large-capacity memory for data or instructions. By way of example, and not limitation, the memory may include a hard disk drive (HDD), a floppy disk drive, flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive, or a combination of two or more of these. Where appropriate, memory 3021 may include removable or non-removable (or fixed) media. Where appropriate, memory 3021 may be internal or external to the integrated gateway disaster recovery device. In a specific embodiment, memory 3021 is a non-volatile solid-state memory. Memory 3021 may include read-only memory (ROM), random access memory (RAM), a magnetic disk storage media device, an optical storage media device, a flash memory device, or an electrical, optical, or other physical / tangible memory storage device. Therefore, typically, memory 3021 includes one or more tangible (non-transitory) computer-readable storage media (e.g., a memory device) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it may perform the operations described in any of the methods for diagnosing battery voltage abnormalities in the above-described embodiments.

[0155] In combination with the battery management system in the above embodiment, an embodiment of the present application provides a battery device. The battery device includes a battery module and the above battery management system. It is understandable that the battery device of the present application is applied to a variety of different scenarios. For example, the battery device is used for electric vehicles (electric two-wheeled vehicles, electric tricycles or electric vehicles), aircraft (unmanned aerial vehicles, manned aerial vehicles), power tools (electric drills, sweeping robots, electric vacuum cleaners, etc.), and photovoltaic energy storage. It is understandable that the battery device has different product forms when applied to different scenarios, and the present application does not limit the specific product form of the battery device.

[0156] In conjunction with the battery device in the above embodiment, embodiments of the present application provide an electrical device. The electrical device includes a load and the above battery device, with the battery device connected to the load to power the load. It is understood that the electrical device includes electric vehicles, aircraft, power tools, energy storage systems, and the like.

[0157] In addition, in conjunction with the method for diagnosing abnormal battery voltage in the above-mentioned embodiment, the present application can provide a computer storage medium for implementation. The computer storage medium stores computer program instructions; when the computer program instructions are executed by a processor, any of the methods for diagnosing abnormal battery voltage in the above-mentioned embodiment is implemented.

[0158] It should be understood that the present application is not limited to the specific configurations and processes described above and illustrated in the figures. For the sake of brevity, a detailed description of known methods is omitted here. In the above embodiments, several specific steps are described and illustrated as examples. However, the method process of the present application is not limited to the specific steps described and illustrated. Those skilled in the art can make various changes, modifications, and additions, or change the order of the steps after understanding the spirit of the present application.

[0159] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps. In other words, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0160] Aspects of the present disclosure have been described above with reference to the flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to the embodiments of the present disclosure. It should be understood that each box in the flowchart and / or block diagram and the combination of each box in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the implementation of the function / action specified in one or more boxes of the flowchart and / or block diagram. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor or a field programmable logic circuit. It is also understood that each box in the block diagram and / or flowchart and the combination of the boxes in the block diagram and / or flowchart can also be implemented by dedicated hardware that performs the specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0161] The above is only a specific implementation method of the present application. Those skilled in the art can clearly understand that for the convenience and conciseness of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

Claims

1. A method for diagnosing abnormal battery voltage sampling, characterized in that: include: Obtaining voltage values ​​of adjacent batteries in a battery module and / or voltage values ​​of all batteries in the battery module, wherein the voltage values ​​of the adjacent batteries include the voltage value of a first battery and the voltage value of a second battery; Calculating a voltage average value, where the voltage average value includes a first average value and / or a second average value, where the first average value is defined as an average value of the voltages of the first battery and the second battery, and the second average value is defined as an average value of the voltages of all batteries in the battery module; In response to an absolute value of a difference between the voltage value of the first battery and the first average value being greater than a first threshold value and lasting for a first time period, and an absolute value of a difference between the voltage value of the second battery and the first average value being greater than the first threshold value and lasting for the first time period, determining that an abnormality occurs in battery voltage sampling; and / or In response to the absolute value of the difference between the voltage value of the first battery and the second average value being greater than a second threshold and lasting for a second time period, and the absolute value of the difference between the voltage value of the second battery and the second average value being greater than the second threshold and lasting for the second time period, determining that an abnormality occurs in the battery voltage sampling; and / or In response to the absolute value of the difference between the voltage value of the first battery and the voltage value of the second battery being greater than a third threshold and lasting for a third time period, it is determined that an abnormality has occurred in the battery voltage sampling, and the third threshold is greater than or equal to twice the first threshold, or the third threshold is greater than or equal to twice the second threshold.

2. The method according to claim 1, characterized in that The method comprises: In response to an abnormality in the battery voltage sampling, balancing the battery module is stopped.

3. The method according to claim 1 or 2, characterized in that The method comprises: In response to an abnormality in the battery voltage sampling, updating the voltage display value of the first battery and the voltage display value of the second battery to the first average value or the second average value; or, In response to an abnormality in the battery voltage sampling, updating the voltage display value of the first battery and the voltage display value of the second battery based on an adjustment strategy; The adjustment strategies include: every fourth time period, determining a voltage variable, adjusting the first average value or the second average value based on the voltage variable to obtain an adjusted value, and updating the displayed voltage value of the first battery and the displayed voltage value of the second battery to the adjusted value; or Every fourth time period, the first voltage variable and the second voltage variable are determined, the first average value or the second average value is adjusted based on the first voltage variable to obtain a first adjustment value, and the voltage display value of the first battery is updated to the first adjustment value. The first average value or the second average value is adjusted based on the second voltage variable to obtain a second adjustment value, and the voltage display value of the second battery is updated to the second adjustment value.

4. The method according to any one of claims 1 to 3, characterized in that The method comprises: In response to an abnormality in the battery voltage sampling, increasing an overvoltage threshold and / or decreasing an undervoltage threshold; The overvoltage threshold is a voltage threshold for triggering battery overvoltage protection, and the undervoltage threshold is a voltage threshold for triggering battery undervoltage protection.

5. The method according to claim 4, characterized in that The method comprises: In response to an abnormality in the battery voltage sampling, comparing the current maximum voltage value of the battery module with the increased overvoltage threshold, and in response to the current maximum voltage value being greater than the increased overvoltage threshold, determining that the battery voltage is abnormal; and / or In response to an abnormality in the battery voltage sampling, the current minimum voltage value of the battery module is compared with a reduced undervoltage threshold value, and in response to the current minimum voltage value being less than the reduced undervoltage threshold value, it is determined that the battery voltage is abnormal.

6. The method according to any one of claims 1 to 3, characterized in that The method comprises: In response to an abnormality in the battery voltage sampling, comparing a current first average value with an overvoltage threshold and an undervoltage threshold, and / or comparing a current second average value with the overvoltage threshold and the undervoltage threshold, wherein the current first average value is an average value of a current voltage value of the first battery and a current voltage value of the second battery, and the current second average value is an average value of the current voltage values ​​of all batteries in the battery module; In response to at least one of the current first average value and the current second average value being greater than the overvoltage threshold, determining that the battery voltage is abnormal; or, In response to at least one of the current first average value and the current second average value being less than the under-voltage threshold, determining that the battery voltage is abnormal; The overvoltage threshold is a voltage threshold for triggering battery overvoltage protection, and the undervoltage threshold is a voltage threshold for triggering battery undervoltage protection.

7. The method according to claim 5 or 6, characterized in that The method comprises: In response to the battery voltage being abnormal, the charging switch and the discharging switch are turned off.

8. The method according to claim 5, characterized in that The method comprises: In response to an abnormality in the battery voltage, turning off the charging switch and the discharging switch; After the charging switch and the discharging switch are turned off, in response to the battery voltage being abnormal for a fifth time period, it is determined that the acquisition harness is disconnected.

9. The method according to any one of claims 1 to 7, characterized in that The method comprises: In response to an abnormality in the battery voltage sampling, determining whether the voltage of the battery in the battery module meets a recovery condition; In response to the voltage of the battery in the battery module satisfying the recovery condition, determining that the battery voltage sampling abnormality is eliminated; The recovery condition includes at least one of the following: 1) The absolute value of the difference between the current voltage value of the first battery and a current first average value is less than a fifth threshold and lasts for a sixth duration, where the current first average value is the average of the current voltage value of the first battery and the current voltage value of the second battery; 2) The absolute value of the difference between the current voltage value of the second battery and a current first average value is less than a fifth threshold and lasts for a sixth duration, where the current first average value is the average of the current voltage value of the first battery and the current voltage value of the second battery; 3) The absolute value of the difference between the current voltage value of the first battery and a current second average value is less than a fifth threshold value and persists for a sixth duration, where the current second average value is the average of the current voltage values ​​of all batteries in the battery module; 4) the absolute value of the difference between the current voltage value of the second battery and the current second average value is less than a fifth threshold value and lasts for a sixth time period, the current second average value being the average value of the current voltage values ​​of all batteries in the battery module; 5) the absolute value of the difference between the current maximum voltage of the battery module and a third average value is less than a fifth threshold value and persists for a sixth duration, the third average value being the average of the current maximum voltage and the current minimum voltage, the current maximum voltage being the voltage of the battery with the highest voltage in the battery module, and the current minimum voltage being the voltage of the battery with the lowest voltage in the battery module; 6) the absolute value of the difference between the current minimum voltage value of the battery module and a third average value is less than a fifth threshold value and persists for a sixth duration, the third average value being the average of the current maximum voltage value and the current minimum voltage value, the current minimum voltage value being the voltage value of the battery with the lowest voltage in the battery module, and the current maximum voltage value being the voltage value of the battery with the highest voltage in the battery module; 7) The absolute value of the difference between the current maximum voltage value of the battery module and the current second average value is less than a fifth threshold value and persists for the sixth duration, the current maximum voltage value is the voltage value of the battery with the highest voltage in the battery module, and the current second average value is the average of the current voltage values ​​of all batteries in the battery module; 8) The absolute value of the difference between the current minimum voltage value of the battery module and the current second average value is less than a fifth threshold value and persists for the sixth duration, the average value of the current minimum voltage value is the voltage value of the battery with the lowest voltage in the battery module, and the current second average value is the average value of the current voltage values ​​of all batteries in the battery module; 9) All adjacent batteries in the battery module meet at least one of the following conditions: an absolute value of a difference between a current voltage value of at least one of the adjacent batteries and a fourth average value is smaller than a fifth threshold value and lasts for the sixth time period, the fourth average value being an average of the current voltage values ​​of two of the adjacent batteries; The difference between the current voltage value of at least one of the adjacent batteries and the current second average value is less than a fifth threshold value and lasts for the sixth time period, the current second average value being the average value of the current voltage values ​​of all batteries in the battery module; The fifth threshold is smaller than the first threshold, and / or the fifth threshold is smaller than the second threshold.

10. The method according to any one of claims 1 to 9, characterized in that: The method comprises: Obtaining a voltage threshold and a voltage coefficient corresponding to the battery module; determining the first threshold based on the voltage threshold, the voltage coefficient, and the first average value; The second threshold is determined based on the voltage threshold, the voltage coefficient, and the second average value.

11. The method according to any one of claims 1 to 9, characterized in that: The method comprises: Obtaining a voltage threshold, a voltage coefficient, an impact factor value, and an impact factor coefficient corresponding to the battery module, wherein the impact factor value includes at least one of the following: a temperature value of the acquisition harness and a current flowing through the acquisition harness; and the impact factor coefficient includes at least one of the following: a temperature coefficient and a current coefficient; determining the first threshold based on the voltage threshold, the voltage coefficient, the first average value, the impact factor value, and the impact factor coefficient; The second threshold is determined based on the voltage threshold, the voltage coefficient, the second average value, the impact factor value, and the impact factor coefficient.

12. A battery management system, characterized in that: The battery management system includes: a voltage acquisition circuit and a microcontroller; The voltage acquisition circuit is connected to the battery in the battery module through an acquisition harness to acquire the voltage value of the battery; The microcontroller includes a memory and a processor; The memory is used to store computer program instructions; The processor is configured to read and execute the computer program instructions stored in the memory to implement the method for diagnosing abnormal battery voltage sampling according to any one of claims 1 to 11.

13. A battery device, characterized in that: It comprises a battery module and the battery management system as claimed in claim 12.

14. An electrical device, characterized in that: The invention comprises a load and the battery device according to claim 13, wherein the battery device is used to power the load.

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