A state detection method, device and computer readable storage medium

Abstract

This invention provides a method for detecting the status of a busbar connection. The method includes the following steps: acquiring a first current, the total voltage of a specific sampling channel corresponding to the first current, and a specific cell voltage corresponding to the first current; after a predetermined time, acquiring a second current, the total voltage of a specific sampling channel corresponding to the second current, and a specific cell voltage corresponding to the second current; and determining whether the busbar connection is abnormal based on the first current, the second current, the total voltage of the specific sampling channel corresponding to the first current, the total voltage of the specific sampling channel corresponding to the second current, the specific voltage corresponding to the first current, and the specific cell voltage corresponding to the second current. This invention also discloses a device for detecting the status of a busbar connection and a computer-readable storage medium. This method, device, and computer-readable storage medium can avoid the risk of high-voltage connection failure and reduce the cost of detecting the status of busbar connections.

Description

Technical Field

[0001] This invention relates to the field of automotive power battery technology, and in particular to a method, device, and computer-readable storage medium for detecting the state of batteries. Background Technology

[0002] As is well known, abnormal high-voltage line connections can induce safety hazards in power batteries and even lead to thermal runaway accidents, causing significant safety incidents and property losses. High-voltage connections inside power batteries commonly use bolted busbars. However, in actual production, existing processes cannot guarantee that the bolts are fully tightened to ensure tight contact between the busbars. Furthermore, even if the bolt torque meets requirements, poor bolt quality and impurities during assembly can still prevent the busbars from achieving the designed contact requirements. When the contact surfaces between busbars cannot make tight contact for various reasons, the contact resistance is high. Similarly, the connection between busbars deteriorates to varying degrees with changes in operating conditions, leading to a continuous increase in contact resistance. According to the pure resistance heating formula Q = I²R, within a power battery pack, the higher the contact resistance, the greater the heat generated under the same operating conditions, easily leading to localized overheating and triggering safety accidents. To effectively avoid such accidents, real-time diagnosis of high-voltage line connections is necessary.

[0003] To diagnose high-voltage line connection failures in real time, the current method involves detecting the real-time voltage and operating current of each busbar inside the power battery to determine the contact resistance of each busbar, and then judging whether the high-voltage connection is faulty based on the resistance value. However, this solution requires additional chips for voltage acquisition when there are a large number of busbars, increasing costs, and it cannot detect the connection status of the busbars through voltage signals. Summary of the Invention

[0004] The purpose of this invention is to provide a method, device, and computer-readable storage medium for detecting the status of the bus. By collecting the bus voltage between each module and the voltage of a single cell adjacent to the bus as a voltage signal, the operating current and voltage values ​​at different times are obtained to detect the connection status of the bus, thus solving the problem that the connection status of the bus cannot be detected by voltage signals.

[0005] Specifically, the present invention provides a state detection method for detecting the connection state of a busbar. The method includes the following steps: acquiring a first current flowing through the high-voltage circuit of a power battery, the total voltage of a specific sampling channel corresponding to the first current, and a specific cell voltage corresponding to the first current, wherein the total voltage of the specific sampling channel includes the busbar voltage and the voltage of a single cell adjacent to the busbar, and the specific cell voltage includes the cell voltage adjacent to the single cell adjacent to the busbar; after a predetermined time, acquiring a second current flowing through the high-voltage circuit of the power battery, the total voltage of the specific sampling channel corresponding to the second current, and the specific cell voltage corresponding to the second current; and determining whether the busbar connection is abnormal based on the first current, the second current, the total voltage of the specific sampling channel corresponding to the first current, the specific voltage corresponding to the second current, and the specific cell voltage corresponding to the second current.

[0006] Specifically, the present invention provides a state detection device, the device comprising: a memory and a processor; the memory for storing a computer program; and the processor for executing the computer program to implement the steps of the state detection method described above.

[0007] Specifically, the present invention provides a computer-readable storage medium storing computer program instructions; when the computer program instructions are executed by a processor, they implement the detection method for the state as described above.

[0008] The present invention provides a state detection method, device, and computer-readable storage medium that can acquire a first current flowing through the high-voltage circuit of a power battery, the total voltage of a specific sampling channel corresponding to the first current, and a specific cell voltage corresponding to the first current. After a predetermined time, it acquires a second current flowing through the high-voltage circuit of the power battery, the total voltage of a specific sampling channel corresponding to the second current, and a specific cell voltage corresponding to the second current. Based on the first current, the second current, the total voltage of the specific sampling channel corresponding to the first current, the total voltage of the specific sampling channel corresponding to the second current, the specific voltage corresponding to the first current, and the specific cell voltage corresponding to the second current, it determines whether the busbar connection is abnormal, thereby avoiding the risk of high-voltage connection failure and reducing the detection cost of busbar connection status. Attached Figure Description

[0009] Figure 1 A flowchart of a state detection method provided in an embodiment of the present invention;

[0010] Figure 2 This is a schematic diagram of the sampling connection of an analog front-end acquisition chip according to an embodiment of the present invention;

[0011] Figure 3 This is a partial flowchart of a state detection method provided in an embodiment of the present invention;

[0012] Figure 4 This is a partial flowchart of a state detection method provided in an embodiment of the present invention;

[0013] Figure 5 This is a schematic diagram of the structure of a state detection device provided in an embodiment of the present invention. Detailed Implementation

[0014] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0015] Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] This invention provides a method for detecting a state. Figure 1 This is a flowchart of a state detection method provided in an embodiment of the present invention. Figure 1 As shown, the method includes the following steps:

[0017] Step 110: Obtain the first current flowing through the high-voltage circuit of the power battery, the total voltage of the specific sampling channel corresponding to the first current, and the specific cell voltage corresponding to the first current. The total voltage of the specific sampling channel includes the bus voltage and the voltage of a single cell adjacent to the bus. The specific cell voltage includes the cell voltage adjacent to the single cell adjacent to the bus.

[0018] Specifically, such as Figure 2 As shown, the first current flowing through the high-voltage circuit of the power battery is obtained by the current sensor 10, and at the same time as obtaining the first current, the total voltage of the bus 30 and the single cell 40 in the module 20 and the cell voltage 60 adjacent to the single cell are obtained by the AFE chip 50.

[0019] In one implementation, such as Figure 3 As shown, the steps for obtaining the total voltage of a specific sampling channel corresponding to the first current include:

[0020] Step 310: If the acquisition function of a specific acquisition channel is abnormal, then obtain the chip voltage and the total voltage of other sampling channels besides the specific acquisition channel;

[0021] Specifically, when an abnormality is detected in the acquisition function of a specific acquisition channel, such as a disconnection or poor contact in the voltage line for acquiring the total voltage of the specific acquisition channel, the chip voltage and the total voltage other than that of the specific acquisition channel are acquired simultaneously with the acquisition of the first current flowing through the high-voltage circuit of the power battery via the current sensor 10.

[0022] Step 320: Obtain the total voltage of a specific sampling channel based on the chip voltage and the total voltage of other sampling channels.

[0023] In one embodiment, the step of determining the total voltage of a specific sampling channel based on the chip voltage and the total voltage of other sampling channels includes: obtaining the total voltage U1 of the specific sampling channel according to U1 = U2 - U3, where U2 is the chip voltage and U3 is the total voltage of other sampling channels.

[0024] Step 120: After a predetermined time, acquire the second current flowing through the high-voltage circuit of the power battery, the total voltage of the specific sampling channel corresponding to the second current, and the specific cell voltage corresponding to the second current.

[0025] Specifically, after a predetermined time, the current flowing through the high-voltage circuit of the power battery is collected again by the current sensor. Simultaneously, the total voltage of the busbar 30 and the individual cell 40 in the module 20, as well as the voltage 70 of the cell adjacent to that individual cell, are obtained through the AFE chip 50. The predetermined time can be, but is not limited to, 0.05ms, or 0.5ms, etc. Of course, the predetermined time can also be the time when a specific operating condition occurs. A specific operating condition refers to a condition where the current changes significantly at a certain moment, with the current change value exceeding 10A. The data selection method for the preceding and following moments is to use the two points with the shortest time interval, provided that the voltage sampling is stable. Among these, the fast charging condition is preferred for the condition with significant current changes because the current before and after the change is relatively stable during charging, the voltage sampling is relatively stable, and the larger current change range makes it easier to reflect the busbar resistance value.

[0026] In one implementation, such as Figure 4 As shown, the steps for obtaining the total voltage of a specific sampling channel corresponding to the second current include:

[0027] Step 410: If the acquisition function of a specific acquisition channel is abnormal, then obtain the chip voltage and the total voltage of other sampling channels besides the specific acquisition channel;

[0028] Specifically, when an abnormality is detected in the acquisition function of a specific acquisition channel, such as a disconnection or poor contact in the voltage line for acquiring the total voltage of the specific acquisition channel, the chip voltage and the total voltage other than that of the specific acquisition channel are acquired simultaneously with the acquisition of the second current flowing through the high-voltage circuit of the power battery via the current sensor 10.

[0029] Step 420: Obtain the total voltage of a specific sampling channel based on the chip voltage and the total voltage of other sampling channels.

[0030] In one embodiment, the step of determining the total voltage of a specific sampling channel based on the chip voltage and the total voltage of other sampling channels includes: obtaining the total voltage U1 of the specific sampling channel according to U1 = U2 - U3, where U2 is the chip voltage and U3 is the total voltage of other sampling channels.

[0031] Step 130: Determine whether the bus connection is abnormal based on the first current, the second current, the total voltage of the specific sampling channel corresponding to the first current, the total voltage of the specific sampling channel corresponding to the second current, the specific voltage corresponding to the first current, and the specific cell voltage corresponding to the second current.

[0032] Specifically, the BMS (Battery Management System) determines whether there is an abnormality in the bus connection based on the first current, the second current, the total voltage of the specific sampling channel corresponding to the first current, the total voltage of the specific sampling channel corresponding to the second current, the specific voltage corresponding to the first current, and the specific cell voltage corresponding to the second current.

[0033] In one embodiment, the step of determining whether the bus connection is abnormal based on the first current, the second current, the total voltage of the specific sampling channel corresponding to the first current, the total voltage of the specific sampling channel corresponding to the second current, the specific voltage corresponding to the first current, and the specific cell voltage corresponding to the second current includes: if |U01-U02| is less than a preset value, and if |[(Ua1-Ub1)-(Ua2-Ub2)] / (Ia-Ib)| is greater than R, then the bus connection is considered abnormal, where Ua1 is the total voltage of the specific sampling channel corresponding to the first current, Ub1 is the total voltage of the specific sampling channel corresponding to the second current, Ua2 is the specific voltage corresponding to the first current, Ub2 is the specific cell voltage corresponding to the second current, Ia is the first current, Ib is the second current, R is the bus resistance, U01 is the total voltage of the specific sampling channel under static conditions, and U02 is the specific cell voltage under static conditions.

[0034] Specifically, the preset value can be, but is not limited to, the allowable voltage difference between different cells as calibrated in the test, such as 5V, 7V, etc. The bus resistance R can be, but is not limited to, the resistance value under the condition of bus looseness as calibrated in the test. The static condition can be, but is not limited to, the condition where the vehicle speed is 0. At this time, the current flowing through the high-voltage circuit of the power battery is relatively small, so the voltage U=iR reflected by the bus is small and can be ignored. The total voltage of a specific sampling channel can be regarded as the voltage of a single cell.

[0035] In one embodiment, U01 is the total voltage of a specific sampling channel under static conditions within a preset time period, and U02 is the voltage of a specific battery cell under static conditions within the preset time period.

[0036] Specifically, the preset time period can be, but is not limited to, 24 hours, or 36 hours, etc. For example, the BMS records the total voltage (3V) and the specific cell voltage (5V) of a specific sampling channel under static conditions within a 24-hour period. Static conditions can be, but are not limited to, conditions where the vehicle speed is 0. At this time, the current flowing through the high-voltage circuit of the power battery is relatively small, so the voltage U=iR reflected by the bus is small and can be ignored. The total voltage of the specific sampling channel can be regarded as the voltage of a single cell.

[0037] In one embodiment, the individual cell voltage adjacent to the busbar and the cell adjacent to the individual cell adjacent to the busbar are cells from the same module. This ensures that the cells are from the same batch, with minimal differences between cells, and thus greater comparability with preset values. These preset values ​​can be, but are not limited to, the allowable voltage difference between different cells as determined by testing, such as 5V, 7V, etc.

[0038] This application provides a method for detecting the connection status of the busbars. By collecting the busbar voltage between modules and the voltage of individual cells adjacent to the busbars as a single voltage signal, the method acquires the operating current and voltage values ​​at different times to detect the connection status of the busbars. This avoids the risk of high-voltage connection failure and reduces the cost of detecting the connection status of the busbars. It is suitable for applications with a large number of modules and buses, achieving both the prevention of high-voltage connection failure and saving production costs and space.

[0039] The foregoing has described in detail an embodiment of a state detection method. Based on the state detection method described in the above embodiment, this invention also provides a device corresponding to the method.

[0040] Figure 5 This is a schematic diagram of the composition of a state detection device provided in an embodiment of the present invention, as shown below. Figure 5 As shown, the device includes a memory 51 and a processor 52.

[0041] Memory 51 is used to store computer programs;

[0042] The processor 52 is used to execute a computer program to implement the steps of the state detection method provided in any of the above embodiments. Since the embodiments of the device portion correspond to the embodiments of the method portion, the embodiments of the device portion are described in the method portion description and will not be repeated here.

[0043] This application provides a status detection device that can collect the bus voltage between modules and the voltage of individual cells adjacent to the bus as a single voltage signal. By acquiring the operating current and voltage values ​​at different times, the device can detect the connection status of the bus, thereby avoiding the risk of high-voltage connection failure and reducing the cost of detecting the bus connection status. Suitable for applications with a large number of modules and buses, this device can both prevent high-voltage connection failure and save production costs and space.

[0044] The embodiments of a state detection method have been described in detail above. Based on the state detection method described in the above embodiments, the present invention also provides a computer-readable storage medium corresponding to the method.

[0045] A computer-readable storage medium stores a computer program thereon, and the computer program instructions are stored on the computer storage medium. When the computer program instructions are executed by a processor, they implement the state detection method provided in any of the above embodiments. Since the embodiments of the computer-readable storage medium portion correspond to the embodiments of the method portion, the embodiments of the computer-readable storage medium portion are described in the method portion description, and will not be repeated here.

[0046] This application provides a method, device, and vehicle for detecting the status of a power battery. By acquiring a first current flowing through the high-voltage circuit of a power battery, the total voltage of a specific sampling channel corresponding to the first current, and the voltage of a specific cell corresponding to the first current, and after a predetermined time, acquiring a second current flowing through the high-voltage circuit of the power battery, the total voltage of a specific sampling channel corresponding to the second current, and the voltage of a specific cell corresponding to the second current, and determining whether the busbar connection is abnormal based on the first current, the second current, the total voltage of the specific sampling channel corresponding to the first current, the total voltage of the specific sampling channel corresponding to the second current, the specific voltage corresponding to the first current, and the specific cell voltage corresponding to the second current, the method determines whether the busbar connection is abnormal, thereby avoiding the risk of high-voltage connection failure and reducing the cost of detecting the busbar connection status.

[0047] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0048] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware, or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0049] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for detecting a state, characterized in that, The method for detecting the connection status of a busbar includes the following steps: The system acquires a first current flowing through the high-voltage circuit of the power battery, the total voltage of a specific sampling channel corresponding to the first current, and the specific cell voltage corresponding to the first current. The total voltage of the specific sampling channel includes the bus voltage and the individual cell voltage adjacent to the bus. The specific cell voltage includes the cell voltage adjacent to the individual cell adjacent to the bus. After a predetermined time, the second current flowing through the high-voltage circuit of the power battery, the total voltage of the specific sampling channel corresponding to the second current, and the specific cell voltage corresponding to the second current are obtained. Based on the first current, the second current, the total voltage of the specific sampling channel corresponding to the first current, the total voltage of the specific sampling channel corresponding to the second current, the specific voltage corresponding to the first current, and the specific cell voltage corresponding to the second current, determine whether the bus connection is abnormal; The step of determining whether the bus connection is abnormal based on the first current, the second current, the total voltage of the specific sampling channel corresponding to the first current, the total voltage of the specific sampling channel corresponding to the second current, the specific voltage corresponding to the first current, and the specific cell voltage corresponding to the second current includes: If |U01-U02| is less than a preset value, and |[(Ua1-Ub1)-(Ua2-Ub2)] / (Ia-Ib)| is greater than R, then the bus connection is considered abnormal. Here, Ua1 is the total voltage of the specific sampling channel corresponding to the first current, Ub1 is the total voltage of the specific sampling channel corresponding to the second current, Ua2 is the specific voltage corresponding to the first current, Ub2 is the specific cell voltage corresponding to the second current, Ia is the first current, Ib is the second current, R is the bus resistance, U01 is the total voltage of the specific sampling channel under static conditions, and U02 is the specific cell voltage under static conditions.

2. The state detection method according to claim 1, characterized in that, The steps for obtaining the total voltage of a specific sampling channel corresponding to the first current include: If the acquisition function of the specific sampling channel is abnormal, then the chip voltage and the total voltage of other sampling channels besides the specific sampling channel are acquired. The total voltage of the specific sampling channel is obtained based on the chip voltage and the total voltage of the other sampling channels.

3. The state detection method according to claim 1, characterized in that, The steps for obtaining the total voltage of a specific sampling channel corresponding to the second current include: If the acquisition function of the specific sampling channel is abnormal, then the chip voltage and the total voltage of other sampling channels are obtained; The total voltage of the specific sampling channel is determined based on the chip voltage value and the total voltage of the other sampling channels.

4. The method for detecting the state according to claim 2 or 3, characterized in that, The step of determining the total voltage of a specific sampling channel based on the chip voltage and the total voltage of the other sampling channels includes: The total voltage U1 of the specific sampling channel is obtained according to U1 = U2 - U3, where U2 is the chip voltage and U3 is the total voltage of the other sampling channels.

5. The state detection method according to claim 4, characterized in that, The chip's acquisition function malfunction includes a disconnection of the voltage line used to acquire the total voltage of the specific sampling channel.

6. The state detection method according to claim 5, characterized in that, U01 is the total voltage of the specific sampling channel under static conditions within a preset time period, and U02 is the voltage of the specific battery cell under static conditions within the preset time period.

7. The state detection method according to claim 1, characterized in that, The individual cell voltage adjacent to the busbar and the cell adjacent to the individual cell adjacent to the busbar are cells in the same module.

8. A state detection device, characterized in that, The device includes: a memory and a processor; The memory is used to store computer programs; The processor is used to execute the computer program to implement the steps of the state detection method as described in any one of claims 1-7.

9. A computer-readable storage medium storing computer program instructions; wherein the computer program instructions, when executed by a processor, implement the state detection method as described in any one of claims 1-7.

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