Battery pack current sampling disconnection diagnosis method, storage medium and electronic device

Abstract

The invention discloses a battery pack current sampling disconnection diagnosis method, a storage medium and an electronic device, and relates to the technical field of battery pack diagnosis. The method comprises the following steps: in response to a current sampling chip entering a preset state, obtaining a first voltage of a battery pack at a first moment based on a first sampling channel in the current sampling chip; determining the magnitude relationship between the second voltage and the first voltage of the battery pack at the second moment to obtain a first determination result; determining a magnitude relationship between a third voltage of the battery pack at a third moment and a target voltage value to obtain a second determination result; and performing current sampling disconnection diagnosis on the battery pack based on the switching frequency and a preset switching frequency threshold to obtain a diagnosis result. The technical problem that diagnosis cannot be carried out in the charging and discharging operation process of the battery pack in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of battery pack diagnosis, and in particular to a battery pack current sampling disconnection diagnosis method, storage medium and electronic device. Background Art

[0002] As the core component for obtaining the charging and discharging current information of the battery pack, the reliability of the current sensor is an important prerequisite for ensuring the stable operation of the battery pack. Due to the complex operating conditions of the power battery pack, there is a risk of sensor failure when encountering external shocks such as mechanical vibration. If the sensor failure cannot be effectively identified, it will seriously affect the monitoring of the battery pack status. Among them, the disconnection of the sampling line is a common form of failure and should be diagnosed promptly and accurately.

[0003] At present, the diagnostic schemes for current sampling disconnection mainly include two categories: chip hardware diagnosis and diagnosis based on current and voltage correlation. Chip hardware diagnosis determines whether the sampling circuit is complete (i.e., there is no disconnection) by injecting current excitation into the sampling circuit, and checking whether the pressure difference between the two ends of the shunt changes accordingly. However, during the execution of this type of scheme, current sampling will not be able to be performed normally, which means that the conventional sampling function needs to be shielded during the diagnosis process, and diagnosis often cannot be performed during the charging and discharging operation of the battery pack. The diagnostic scheme based on the correlation between current and voltage is based on the impedance characteristics of the battery pack itself. When the changes (fluctuations) of the sampling voltage and the sampling current do not follow the correlation law, it is regarded as a current sampling fault. However, this method has high requirements on the synchronization and accuracy of current and voltage sampling, and also depends on the accuracy of the current and voltage reference relationship. Summary of the invention

[0004] Embodiments of the present invention provide a battery pack current sampling disconnection diagnosis method, device, storage medium and electronic device to at least solve the technical problem that related technologies cannot perform diagnosis during the battery pack charging and discharging operation.

[0005] According to one embodiment of the present invention, a method for diagnosing a current sampling disconnection of a battery pack is provided, comprising: in response to a current sampling chip entering a preset state, obtaining a first voltage of the battery pack at a first moment based on a first sampling channel in the current sampling chip, wherein the current recorded by the current sampling chip in the preset state is less than a preset current threshold, and the first moment is used to indicate the moment when the current sampling chip enters the preset state; determining a magnitude relationship between a second voltage of the battery pack and the first voltage at the second moment, and obtaining a first determination result, wherein the second moment is later than the first moment; determining a magnitude relationship between a third voltage of the battery pack at a third moment and a target voltage value, and obtaining a second determination result, wherein the target voltage value is determined based on the first determination result, and the third moment is later than the second moment; performing a current sampling disconnection diagnosis on the battery pack based on the number of switching times and a preset number of switching times threshold, and obtaining a diagnosis result, wherein the number of switching times is determined based on the second determination result, and the number of switching times is used to indicate the number of switching times of the voltage change direction of the battery pack.

[0006] Optionally, in response to the current sampling chip entering a preset state, before obtaining a first voltage of the battery pack at a first moment based on a first sampling channel in the current sampling chip, the method also includes: obtaining a shunt voltage value of the shunt based on a second sampling channel in the current sampling chip; determining a shunt current value based on the shunt voltage value; and determining that the current sampling chip enters a preset state in response to the shunt current value being less than or equal to a preset shunt current value.

[0007] Optionally, the target voltage value includes an upper limit voltage value. Before determining the relationship between the third voltage of the battery pack at the third moment and the target voltage value to obtain a second determination result, the method also includes: in response to the first determination result satisfying the first condition, determining that the voltage change direction of the battery pack is rising, wherein the first condition includes: the second voltage is greater than the first voltage, the voltage difference between the second voltage and the first voltage is greater than or equal to a preset voltage difference, and the duration of the voltage difference between the second voltage and the first voltage being greater than or equal to the preset voltage difference is greater than a preset time period; when the voltage change direction is in an rising stage, determining the upper limit voltage value of the battery pack, wherein the upper limit voltage value is the maximum voltage value reached by the battery pack in the rising stage.

[0008] Optionally, determining the relationship between the third voltage of the battery pack at the third moment and the target voltage value to obtain a second determination result includes: determining the relationship between the third voltage of the battery pack at the third moment and the upper limit voltage value to obtain a first sub-determination result; in response to the first sub-determination result satisfying the second condition, updating the switching number, wherein the second condition includes: the upper limit voltage value is greater than the third voltage, the voltage difference between the upper limit voltage value and the third voltage is greater than or equal to a preset voltage difference, and the duration of the voltage difference between the upper limit voltage value and the third voltage being greater than or equal to the preset voltage difference is greater than a preset time period.

[0009] Optionally, the method also includes: determining that the voltage change direction of the battery pack is downward; when the voltage change direction is in the downward stage, determining the lower limit voltage value of the battery pack, wherein the lower limit voltage value is the minimum voltage value reached by the battery pack in the downward stage.

[0010] Optionally, the method further includes: in response to the first sub-determination result not satisfying the second condition, continuing to update the upper limit voltage value of the battery pack and continuing to determine whether the first sub-determination result satisfies the second condition.

[0011] Optionally, the target voltage value also includes a lower limit voltage value, and the method also includes: in response to the first determination result not satisfying the first condition, determining the relationship between the first determination result and a third condition to obtain a third determination result, wherein the third condition includes: the first voltage is greater than the second voltage, the voltage difference between the first voltage and the second voltage is greater than or equal to a preset voltage difference, and the duration of the voltage difference between the first voltage and the second voltage being greater than or equal to the preset voltage difference is greater than a preset time period; in response to the third determination result satisfying the third condition, determining that the voltage change direction of the battery pack is decreasing; when the voltage change direction is in the decreasing stage, determining the lower limit voltage value of the battery pack.

[0012] Optionally, the method further includes: in response to the third determination result not satisfying the third condition, continuing to determine the magnitude relationship between the second voltage and the first voltage.

[0013] Optionally, determining the relationship between the third voltage of the battery pack at the third moment and the target voltage value to obtain a second determination result includes: determining the relationship between the third voltage of the battery pack at the third moment and the lower limit voltage value to obtain a second sub-determination result; in response to the second sub-determination result satisfying a fourth condition, updating the switching number, wherein the fourth condition includes: the third voltage is greater than the upper limit voltage value, the voltage difference between the third voltage and the upper limit voltage value is greater than or equal to a preset voltage difference, and the duration of the voltage difference between the third voltage and the upper limit voltage value being greater than or equal to the preset voltage difference is greater than a preset time period.

[0014] Optionally, the method further includes: determining that the voltage change direction of the battery pack is rising; and determining an upper limit voltage value of the battery pack when the voltage change direction is in the rising stage.

[0015] According to one embodiment of the present invention, a battery pack current sampling disconnection diagnosis system is also provided. The battery pack current sampling disconnection diagnosis system includes: a current sampling chip, a battery pack, a shunt and a load. The battery pack, the shunt and the load are connected in series. The current sampling chip includes a first sampling channel, a second sampling channel and a calculation and processing circuit. The first sampling channel is used to record the voltage value of the battery pack, and the second sampling channel is used to record the voltage value of the shunt. The calculation and processing circuit is used to convert the voltage value recorded by the second sampling channel into a current value and output it. The first sampling channel is connected in parallel with the sampling resistor, and the battery pack, the voltage dividing resistor and the sampling resistor are connected in series. The second sampling channel is connected in parallel with the shunt, the shunt is connected in parallel with the target capacitor, and the shunt is connected in parallel with the target resistor. The battery pack current sampling disconnection diagnosis system is used to execute any of the battery pack current sampling disconnection diagnosis methods mentioned above.

[0016] According to one embodiment of the present invention, a battery pack current sampling disconnection diagnosis device is also provided, including: an acquisition module, used to respond to the current sampling chip entering a preset state, and to acquire a first voltage of the battery pack at a first moment based on a first sampling channel in the current sampling chip, wherein the current recorded by the current sampling chip in the preset state is less than a preset current threshold, and the first moment is used to indicate the moment when the current sampling chip enters the preset state; a first determination module, used to determine the magnitude relationship between the second voltage and the first voltage of the battery pack at the second moment, and obtain a first determination result, wherein the second moment is later than the first moment; a second determination module, used to determine the magnitude relationship between the third voltage of the battery pack at a third moment and a target voltage value, and obtain a second determination result, wherein the target voltage value is determined based on the first determination result, and the third moment is later than the second moment; a diagnosis module, used to perform current sampling disconnection diagnosis on the battery pack based on the switching number and a preset switching number threshold, and obtain a diagnosis result, wherein the switching number is determined based on the second determination result, and the switching number is used to indicate the number of switching times of the voltage change direction of the battery pack.

[0017] Optionally, the acquisition module is also used to acquire a shunt voltage value of the shunt based on a second sampling channel in the current sampling chip; determine a shunt current value based on the shunt voltage value; and determine that the current sampling chip enters a preset state in response to the shunt current value being less than or equal to a preset shunt current value.

[0018] Optionally, the first determination module is also used to determine that the voltage change direction of the battery pack is rising in response to the first determination result satisfying the first condition, wherein the first condition includes: the second voltage is greater than the first voltage, the voltage difference between the second voltage and the first voltage is greater than or equal to a preset voltage difference, and the duration of the voltage difference between the second voltage and the first voltage being greater than or equal to the preset voltage difference is greater than a preset time period; when the voltage change direction is in an rising stage, determine the upper limit voltage value of the battery pack, wherein the upper limit voltage value is the maximum voltage value reached by the battery pack in the rising stage.

[0019] Optionally, the second determination module is also used to determine the relationship between the third voltage of the battery pack at a third moment and the upper limit voltage value to obtain a first sub-determination result; in response to the first sub-determination result satisfying the second condition, the switching number is updated, wherein the second condition includes: the upper limit voltage value is greater than the third voltage, the voltage difference between the upper limit voltage value and the third voltage is greater than or equal to a preset voltage difference, and the duration of the voltage difference between the upper limit voltage value and the third voltage being greater than or equal to the preset voltage difference is greater than a preset time period.

[0020] Optionally, the second determination module is also used to determine that the voltage change direction of the battery pack is downward; when the voltage change direction is in the downward stage, determine the lower limit voltage value of the battery pack, wherein the lower limit voltage value is the minimum voltage value reached by the battery pack in the downward stage.

[0021] Optionally, the second determination module is further configured to, in response to the first sub-determination result not satisfying the second condition, continue to update the upper limit voltage value of the battery pack and continue to determine whether the first sub-determination result satisfies the second condition.

[0022] Optionally, the first determination module is also used to determine the relationship between the first determination result and a third condition in response to the first determination result not satisfying the first condition, and obtain a third determination result, wherein the third condition includes: the first voltage is greater than the second voltage, the voltage difference between the first voltage and the second voltage is greater than or equal to a preset voltage difference, and the duration of the voltage difference between the first voltage and the second voltage being greater than or equal to the preset voltage difference is greater than a preset time period; in response to the third determination result satisfying the third condition, determine that the voltage change direction of the battery pack is decreasing; when the voltage change direction is in the decreasing stage, determine the lower limit voltage value of the battery pack.

[0023] Optionally, the first determination module is further configured to, in response to the third determination result not satisfying the third condition, continue to determine the magnitude relationship between the second voltage and the first voltage.

[0024] Optionally, the second determination module is also used to determine the relationship between the third voltage of the battery pack at a third moment and the lower limit voltage value to obtain a second sub-determination result; in response to the second sub-determination result satisfying the fourth condition, the switching number is updated, wherein the fourth condition includes: the third voltage is greater than the upper limit voltage value, the voltage difference between the third voltage and the upper limit voltage value is greater than or equal to a preset voltage difference, and the duration of the voltage difference between the third voltage and the upper limit voltage value being greater than or equal to the preset voltage difference is greater than a preset time period.

[0025] Optionally, the second determination module is further used to determine that the voltage change direction of the battery pack is rising; when the voltage change direction is in the rising stage, determine the upper limit voltage value of the battery pack.

[0026] According to one embodiment of the present invention, a vehicle is provided, and the vehicle is used to execute any of the above battery pack current sampling disconnection diagnosis methods.

[0027] According to one embodiment of the present invention, a computer-readable storage medium is further provided, in which a computer program is stored, wherein the computer program is configured to execute any of the above-mentioned battery pack current sampling disconnection diagnosis methods when running on a computer or a processor.

[0028] According to one embodiment of the present invention, there is also provided an electronic device, including a memory and a processor, wherein a computer program is stored in the memory, and the processor is configured to run the computer program to execute any of the above battery pack current sampling disconnection diagnosis methods.

[0029] According to one embodiment of the present invention, there is further provided a computer program product, comprising a computer program, which implements any of the above-mentioned battery pack current sampling disconnection diagnosis methods when executed by a processor.

[0030] In an embodiment of the present invention, in response to the current sampling chip entering a preset state, a first voltage of the battery pack at a first moment is obtained based on a first sampling channel in the current sampling chip, wherein the current recorded by the current sampling chip in the preset state is less than a preset current threshold, and the first moment is used to indicate the moment when the current sampling chip enters the preset state; the magnitude relationship between the second voltage of the battery pack at the second moment and the first voltage is determined to obtain a first determination result, wherein the second moment is later than the first moment; the magnitude relationship between the third voltage of the battery pack at a third moment and the target voltage value is determined to obtain a second determination result, wherein the target voltage value is determined based on the first determination result, and the third moment is later than the second moment; a current sampling line break diagnosis is performed on the battery pack based on the switching number and a preset switching number threshold to obtain a diagnosis result, wherein the switching number is determined based on the second determination result, and the switching number is used to indicate the switching number of the voltage change direction of the battery pack, thereby achieving the purpose of not shielding the conventional sampling function during the diagnosis process and being able to perform current sampling normally, thereby achieving the technical effect of real-time diagnosis of the sampling line break fault, thereby ensuring the reliability of the sampled current information, and further solving the technical problem that the related technology cannot perform diagnosis during the charging and discharging operation of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0032] Figure 1 is a flow chart of a battery pack current sampling disconnection diagnosis method according to one embodiment of the present invention;

[0033] Figure 2 is a sampling principle diagram of a battery pack current sampling disconnection diagnosis system according to one embodiment of the present invention;

[0034] Figure 3 is a flow chart of a “zero current” sampling value when a sampling line is disconnected according to one embodiment of the present invention;

[0035] Figure 4 4 is a structural block diagram of a battery pack current sampling and disconnection diagnosis device according to one embodiment of the present invention. DETAILED DESCRIPTION

[0036] To facilitate understanding, some descriptions of concepts related to the embodiments of the present invention are exemplarily provided for reference.

[0037] As shown below:

[0038] Current sensor: A device used to detect and measure the magnitude of current. It measures the magnitude of current by inducing the magnetic field generated by the current and converts this data into a voltage signal or digital signal output. Current sensors are widely used in various fields, such as power systems, industrial automation, electric vehicles, etc., to monitor current changes and protect the safe operation of equipment.

[0039] Battery pack: A component containing multiple battery cells for storing and providing electrical energy. For example, the battery pack of an electric vehicle is usually composed of lithium-ion batteries, and the battery pack is usually installed on the chassis of the electric vehicle or at a specific location on the bottom of the vehicle to provide the electrical energy required by the vehicle.

[0040] Current sampling disconnection: During the current sampling process, the sampling line of the current signal is interrupted due to some reason, and the current signal cannot be collected normally.

[0041] Shunt: An instrument used to measure DC current, based on the principle that voltage is generated across a resistor when DC current passes through it.

[0042] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0043] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In the description of this embodiment, unless otherwise specified, the meaning of "multiple" is two or more. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0044] According to one embodiment of the present invention, an embodiment of a battery pack current sampling disconnection diagnosis method is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0045] The method embodiment can be executed in an electronic device including a memory and a processor, a similar control device or a system. Taking an electronic device as an example, the electronic device may include one or more processors and a memory for storing data. Optionally, the electronic device may also include a communication device and a display device for communication functions. It can be understood by a person of ordinary skill in the art that the above structural description is only illustrative and does not limit the structure of the above electronic device. For example, the electronic device may also include more or fewer components than the above structural description, or have a configuration different from the above structural description.

[0046] The processor may include one or more processing units. For example, the processor may include a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processing (DSP) chip, a microcontroller unit (MCU), a programmable logic device (field-programmable gate array, FPGA), a neural network processor (NPU), a tensor processing unit (TPU), an artificial intelligence (AI) type processor, and the like. Among them, different processing units may be independent components or integrated in one or more processors. In some instances, the electronic device may also include one or more processors.

[0047] The memory can be used to store computer programs, for example, to store the computer program corresponding to the battery pack current sampling disconnection diagnosis method in the embodiment of the present invention. The processor implements the above-mentioned battery pack current sampling disconnection diagnosis method by running the computer program stored in the memory. The memory may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory may further include a memory remotely located relative to the processor, and these remote memories may be connected to the electronic device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0048] The communication device is used to receive or send data via a network. The specific example of the above network may include a wireless network provided by a communication provider of the mobile terminal. In one example, the communication device includes a network adapter (network interface controller, NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the communication device can be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0049] The display device may be, for example, a touch screen type liquid crystal display (LCD) and a touch display (also referred to as a "touch screen" or a "touch display screen"). The liquid crystal display may enable a user to interact with a user interface of the mobile terminal. In some embodiments, the mobile terminal has a graphical user interface (GUI), and a user may interact with the GUI by finger contact and / or gestures on a touch-sensitive surface, wherein the human-computer interaction functions here may optionally include the following interactions: creating web pages, drawing, word processing, making electronic documents, games, video conferencing, instant messaging, sending and receiving emails, call interfaces, playing digital videos, playing digital music and / or web browsing, etc. The executable instructions for executing the above human-computer interaction functions are configured / stored in a computer program product or a readable storage medium executable by one or more processors.

[0050] In this embodiment, a method for diagnosing a battery pack current disconnection running in an electronic device is provided. Figure 1 FIG. 1 is a flow chart of a method for diagnosing a battery pack current disconnection according to one embodiment of the present invention. Figure 1 As shown, the process includes the following steps:

[0051] Step S10, in response to the current sampling chip entering a preset state, obtaining a first voltage of the battery pack at a first moment based on a first sampling channel in the current sampling chip, wherein the current recorded by the current sampling chip in the preset state is less than a preset current threshold, and the first moment is used to indicate the moment when the current sampling chip enters the preset state;

[0052] In the embodiment of the present invention, the current sampling chip can be understood as an integrated circuit chip that integrates a current sensor and a signal processing circuit, which is used to monitor the current value in the circuit in real time, mainly used to measure the current waveform in the circuit in real time, monitor the working status and power consumption of the circuit, so as to protect the circuit and improve system performance.

[0053] The preset state can be understood as the current sampling chip being in a "zero current" state, that is, the recorded current of the current sampling chip is less than a predetermined preset threshold. For example, the recorded current of the current sampling chip can be recorded as I, and the predetermined preset threshold can be recorded as I OpnThrd , when |I|≤I OpnThrd If the current sampling chip has entered the preset state, the preset threshold value I OpnThrd It can be determined based on actual conditions and is not limited here.

[0054] The first sampling channel can be understood as a collection channel for obtaining the first voltage of the battery pack at the first moment. Exemplarily, the first sampling channel can be an auxiliary analog-to-digital conversion channel for real-time collection of the total voltage or the voltage after voltage division at both ends of the battery pack, which is not limited here.

[0055] The first moment can be understood as the moment when the current sampling chip enters a preset state. Exemplarily, the first moment can be the moment when the diagnosis system enters the disconnection diagnosis.

[0056] The first voltage can be understood as the voltage of the battery pack or the single cell voltage when the diagnostic system enters the disconnection diagnosis. For example, the first voltage can be recorded as V Init , no restriction is given here.

[0057] In response to the current sampling chip entering a preset state, the first voltage of the battery pack at the first moment is obtained based on the first sampling channel in the current sampling chip. It can be understood that when the recorded current of the current sampling chip is less than the specified preset threshold, the current sampling chip has entered the preset state, and the voltage of the battery pack is obtained based on the first sampling channel when the diagnostic system enters the disconnection diagnosis.

[0058] In an embodiment of the present invention, when the recorded current of the current sampling chip is less than a specified preset threshold value, that is, when the current sampling chip enters a preset state, the auxiliary analog-to-digital conversion channel can be used to collect in real time the total voltage or the voltage after voltage division at both ends of the battery pack when the diagnostic system enters the line break diagnosis. By acquiring the voltage of the battery pack in real time, possible line break problems in the battery pack can be discovered in time, thereby eliminating safety hazards.

[0059] Step S11, determining a magnitude relationship between a second voltage and a first voltage of the battery pack at a second moment, and obtaining a first determination result, wherein the second moment is later than the first moment;

[0060] In the embodiment of the present invention, the second moment can be understood as a certain moment after the diagnosis system enters the disconnection diagnosis, that is, the second moment is later than the first moment.

[0061] The second voltage may be understood as the voltage at a certain moment after the diagnosis system enters the line break diagnosis, that is, the sampling voltage at the current moment.

[0062] The first determination result can be understood as the magnitude relationship between the second voltage of the battery pack at the second moment and the first voltage. For example, taking the second voltage as V as an example, the voltage direction change threshold is determined to be V Dirchange The first determination result may be the difference between the second voltage V and the first voltage V of the battery pack at the second moment. Init The size relationship between them, that is, judging VV Init ≥V Dirchange or V Init -V ≥ V DirchangeWhether it is established, thereby obtaining the first determination result, is not limited here.

[0063] Determining the magnitude relationship between the second voltage and the first voltage of the battery pack at the second moment to obtain a first determination result can be understood as judging the relationship between the magnitude relationship between the second voltage and the first voltage of the battery pack at the second moment and a preset voltage direction change threshold, thereby obtaining the first determination result.

[0064] In the embodiment of the present invention, at a certain moment after the diagnostic system enters the line break diagnosis, i.e., the second moment, the voltage of the battery pack at the second moment, i.e., the second voltage, is obtained, and the first determination result is obtained by judging the relationship between the magnitude relationship between the second voltage and the first voltage and the preset voltage direction change threshold. By comparing the magnitude relationship between the second voltage and the first voltage with the preset voltage direction change threshold, it is possible to timely and accurately determine whether the state of the battery pack is abnormal.

[0065] Step S12, determining a magnitude relationship between a third voltage of the battery pack at a third moment and a target voltage value, and obtaining a second determination result, wherein the target voltage value is determined based on the first determination result, and the third moment is later than the second moment;

[0066] In the embodiment of the present invention, the third moment can be understood as a moment after the second moment, that is, the third moment is later than the second moment.

[0067] The third voltage can be understood as the voltage of the battery pack at the third moment, that is, the sampled voltage at the current moment.

[0068] The target voltage value can be understood as the maximum value of the battery pack voltage during the rising process or the minimum value during the falling process. For example, the maximum value of the battery pack voltage during the rising process can be recorded as V max The minimum value of the battery pack voltage during the drop process can be recorded as V min , no restrictions are imposed here.

[0069] The second determination result can be understood as the magnitude relationship between the third voltage of the battery pack at the third moment and the target voltage value, that is, the magnitude relationship between the voltage of the battery pack at the current moment and the maximum value of the voltage of the battery pack during the rising process or the minimum value of the voltage of the battery pack during the falling process. For example, taking the third voltage as V as an example, that is, judging V max -V ≥ V Dirchange or VV min ≥V Dirchange Whether it is established, thereby obtaining the second determination result, is not limited here.

[0070] Determining the relationship between the third voltage of the battery pack at the third moment and the target voltage value to obtain the second determination result can be understood as judging the relationship between the current voltage of the battery pack and the maximum value of the voltage of the battery pack in the rising process or the minimum value of the voltage of the battery pack in the falling process, thereby determining the second determination result.

[0071] In the embodiment of the present invention, by judging the magnitude relationship between the voltage of the battery pack at the current moment and the target voltage value, a second determination result can be obtained, that is, the direction of the battery pack voltage change is rising or falling. By judging the direction of the battery pack voltage change, we can understand the charge and discharge status of the battery more accurately.

[0072] Step S13, performing current sampling disconnection diagnosis on the battery pack based on the switching number and the preset switching number threshold to obtain a diagnosis result, wherein the switching number is determined based on the second determination result, and the switching number is used to indicate the switching number of the voltage change direction of the battery pack.

[0073] In the embodiment of the present invention, the switching times can be understood as the number of times the battery pack voltage changes direction, that is, the number of times the battery pack voltage direction changes to rising or falling. For example, the switching times can be recorded as Cntr DirChange , no restriction is given here.

[0074] The preset switching times threshold value can be understood as a value used to determine whether a current sampling disconnection fault occurs. For example, the preset switching times threshold value can be recorded as Cntr OpnThrd , no restriction is given here.

[0075] The diagnosis result can be understood as information on whether the current sampling line is broken or not. DirChange ≥Cntr OpnThrd When , it is determined that the current sampling line is broken and a fault has occurred, which is not restricted here.

[0076] The battery pack is diagnosed for current sampling disconnection based on the switching times and the preset switching times threshold to obtain a diagnosis result. It can be understood that by judging the size relationship between the switching times and the preset switching times threshold, a diagnosis result of whether a current sampling disconnection fault occurs can be obtained.

[0077] In an embodiment of the present invention, the cumulative number of times the battery pack voltage direction changes to rising or falling is compared with a preset switching number threshold to determine whether a current sampling line break failure has occurred, thereby improving the reliability and safety of the battery pack and reducing the occurrence of unexpected situations caused by current sampling line break failures.

[0078] In the embodiment of the present invention, when the recorded current of the current sampling chip is less than the preset threshold value, that is, when the current sampling chip enters the preset state, the auxiliary analog-to-digital conversion channel can be used to collect the total voltage or the voltage after voltage division at both ends of the battery pack when the diagnostic system enters the disconnection diagnosis in real time. By acquiring the voltage of the battery pack in real time, the disconnection problem that may exist in the battery pack can be discovered in time, thereby eliminating safety hazards. When the diagnostic system enters the disconnection diagnosis at a certain moment, that is, the second moment, the voltage of the battery pack at the second moment, that is, the second voltage, is acquired, and the first determination result is obtained by judging the relationship between the magnitude relationship between the second voltage and the first voltage and the preset determination voltage direction change threshold. By comparing the magnitude relationship between the second voltage and the first voltage with the preset determination voltage direction change threshold, it is possible to timely and accurately determine whether the state of the battery pack is abnormal. By judging the magnitude relationship between the voltage of the battery pack at the current moment and the target voltage value, the second determination result can be obtained, that is, the direction of change of the battery pack voltage is rising or falling. By judging the direction of change of the battery pack voltage, we can help us understand the charge and discharge state of the battery more accurately. The accumulated number of times the battery pack voltage changes direction from rising to falling is compared with the preset switching number threshold to determine whether a current sampling line break failure has occurred. This can improve the reliability and safety of the battery pack and reduce the occurrence of unexpected situations caused by current sampling line break failures.

[0079] Through the above steps, in response to the current sampling chip entering a preset state, a first voltage of the battery pack at a first moment is obtained based on the first sampling channel in the current sampling chip, wherein the current recorded by the current sampling chip in the preset state is less than the preset current threshold, and the first moment is used to indicate the moment when the current sampling chip enters the preset state; the magnitude relationship between the second voltage of the battery pack at the second moment and the first voltage is determined to obtain a first determination result, wherein the second moment is later than the first moment; the magnitude relationship between the third voltage of the battery pack at the third moment and the target voltage value is determined to obtain a second determination result, wherein the target voltage value is determined based on the first determination result, and the third moment is later than the second moment; the battery pack is diagnosed for current sampling line break based on the switching number and the preset switching number threshold to obtain a diagnosis result, wherein the switching number is determined based on the second determination result, and the switching number is used to indicate the switching number of the voltage change direction of the battery pack, so that the purpose of performing current sampling normally without shielding the conventional sampling function during the diagnosis process is achieved, thereby achieving the technical effect of real-time diagnosis of sampling line break fault, thereby ensuring the reliability of sampling current information, and thus solving the technical problem that the related technology cannot perform diagnosis during the charging and discharging operation of the battery pack.

[0080] Optionally, in step S10, in response to the current sampling chip entering a preset state, before acquiring a first voltage of the battery pack at a first moment based on a first sampling channel in the current sampling chip, the following execution steps may be included:

[0081] Step S101, acquiring a shunt voltage value of a shunt based on a second sampling channel in a current sampling chip;

[0082] Step S102, determining the shunt current value based on the shunt voltage value;

[0083] Step S103 : in response to the shunt current value being less than or equal to a preset shunt current value, determining that the current sampling chip enters a preset state.

[0084] In the embodiment of the present invention, the second sampling channel can be understood as a collection channel for obtaining the shunt voltage value of the shunt. Exemplarily, the first sampling channel can be a high-precision analog-to-digital conversion channel for real-time sampling and obtaining the voltage across the shunt, which is not limited here.

[0085] A shunt can be understood as a device used to shunt current. It can shunt the total current in the battery pack into multiple partial currents for accurate current sampling and line break diagnosis.

[0086] The shunt current value can be understood as the current value at both ends of the shunt. Exemplarily, the shunt current value is the current value I recorded by the current sampling chip, which is not limited here.

[0087] The preset shunt current value can be understood as a preset threshold value for determining whether the current sampling chip enters a preset state. OpnThrd , no restriction is given here.

[0088] Acquiring the shunt voltage value of the shunt based on the second sampling channel in the current sampling chip can be understood as utilizing the high-precision analog-to-digital conversion channel in the current sampling chip to sample and acquire the voltage across the shunt in real time.

[0089] In response to the shunt current value being less than or equal to the preset shunt current value, it is determined that the current sampling chip enters a preset state. For example, when |I|≤I OpnThrd When the state lasts for a certain period of time, it is determined that the current sampling chip has entered the preset state, which is not restricted here.

[0090] In the embodiment of the present invention, the shunt voltage value of the shunt is first obtained based on the high-precision analog-to-digital conversion channel in the current sampling chip, and then the shunt current value is determined based on the shunt voltage value. If the shunt current value is less than or equal to the preset shunt current value, it is determined that the current sampling chip enters a preset state. By determining that the current sampling chip enters a preset state, the safety and stability of the system can be enhanced.

[0091] Optionally, in step S12, the target voltage value includes an upper limit voltage value, and before determining the magnitude relationship between the third voltage of the battery pack at the third moment and the target voltage value to obtain the second determination result, the following execution steps may be included:

[0092] Step S121, in response to the first determination result satisfying the first condition, determining that the voltage change direction of the battery pack is rising, wherein the first condition includes: the second voltage is greater than the first voltage, the voltage difference between the second voltage and the first voltage is greater than or equal to a preset voltage difference, and the duration of the voltage difference between the second voltage and the first voltage being greater than or equal to the preset voltage difference is greater than a preset time period;

[0093] Step S122: When the voltage change direction is in the rising stage, determine the upper limit voltage value of the battery pack, wherein the upper limit voltage value is the maximum voltage value reached by the battery pack in the rising stage.

[0094] In the embodiment of the present invention, the first condition can be understood as a condition for determining that the voltage change direction of the battery pack is rising for the first time. For example, taking the second voltage as V as an example, when VV Init ≥V Dirchange When it is established, it can be determined that the first determination result satisfies the first condition, which is not limited here.

[0095] The preset voltage difference value may be understood as a preset threshold value for determining whether the first determination result satisfies the first condition. For example, the preset voltage difference value may be recorded as V Dirchange , no restriction is given here.

[0096] The preset time period, illustratively, can be understood as lasting for a period of time, which is not limited here.

[0097] The upper voltage limit value is the maximum voltage value of the battery pack in the rising stage. For example, the upper voltage limit value can be recorded as V max , no restriction is given here.

[0098] In response to the first determination result satisfying the first condition, it is determined that the voltage change direction of the battery pack is rising. It can be understood that if the difference between the current battery pack voltage and the second voltage is greater than the preset voltage difference, it can be determined that the voltage change direction of the battery pack is rising.

[0099] When the voltage change direction is in the rising stage, determining the upper limit voltage value of the battery pack can be understood as recording the maximum voltage value of the battery pack in the rising stage when the voltage change direction of the battery pack is in the rising stage.

[0100] In an embodiment of the present invention, if the difference between the current battery pack voltage and the second voltage is greater than a preset voltage difference, it can be determined that the voltage change direction of the battery pack is rising. When the voltage change direction of the battery pack is in an rising stage, the maximum voltage value of the battery pack in the rising stage is obtained, and the voltage value of the battery pack is recorded to maintain the maximum voltage value in the voltage change direction in the rising stage, so that the voltage change trend of the battery pack can be effectively monitored.

[0101] Optionally, in step S123, determining the magnitude relationship between the third voltage of the battery pack at the third moment and the target voltage value to obtain a second determination result may include the following execution steps:

[0102] Step S1231, determining a magnitude relationship between a third voltage of the battery pack at a third moment and an upper limit voltage value, and obtaining a first sub-determination result;

[0103] Step S1232, in response to the first sub-determination result satisfying the second condition, updating the switching number, wherein the second condition includes: the upper limit voltage value is greater than the third voltage, the voltage difference between the upper limit voltage value and the third voltage is greater than or equal to the preset voltage difference, and the duration of the voltage difference between the upper limit voltage value and the third voltage being greater than or equal to the preset voltage difference is greater than a preset time period.

[0104] In the embodiment of the present invention, the first sub-determination result can be understood as determining the magnitude relationship between the third voltage of the battery pack at the third moment and the upper limit voltage value. For example, taking the third voltage V as an example, determining V max -V ≥ V Dirchange Whether it is established, thereby obtaining the first sub-determination result, is not limited here.

[0105] Updating the switching times can be understood as if the voltage change direction of the battery pack is updated, then the voltage change direction times should also be updated. For example, the switching times can be recorded as Cntr DirChange , then the update switching times can be recorded as Cntr DirChange ++, no restriction here.

[0106] The second condition can be understood as a condition for determining whether the number of switching times needs to be updated. For example, taking the third voltage V as an example, when V max -V ≥ V Dirchange When it is established, the number of switching times is increased by 1, and there is no limit here.

[0107] Determining the magnitude relationship between the third voltage of the battery pack at the third moment and the upper limit voltage value to obtain the first sub-determination result can be understood as obtaining the first sub-determination result based on the magnitude relationship between the third voltage of the battery pack at the third moment and the upper limit voltage value.

[0108] In response to the first sub-determination result satisfying the second condition, the switching number is updated. It can be understood that if the obtained first sub-determination result satisfies the preset judgment condition, the switching number of the voltage change direction of the battery pack is updated.

[0109] In the embodiment of the present invention, the first sub-determination result is obtained according to the magnitude relationship between the third voltage of the battery pack at the third moment and the upper limit voltage value, and if the first sub-determination result satisfies the preset second condition, the number of switching times of the voltage change direction of the battery pack is increased by 1. By obtaining the number of switching times of the voltage change direction of the battery pack, the current working state of the battery pack can be timely understood, so as to better judge whether the current sampling line breakage has a fault.

[0110] Optionally, in step S1231, the following execution steps may be included:

[0111] Step S12311, determining that the voltage change direction of the battery pack is decreasing;

[0112] Step S12312: When the voltage change direction is in a decreasing stage, determine the lower limit voltage value of the battery pack, wherein the lower limit voltage value is the minimum voltage value reached by the battery pack in the decreasing stage.

[0113] In the embodiment of the present invention, the lower limit voltage value, that is, the minimum voltage value of the battery pack in the decreasing stage, can be exemplarily recorded as V min , no restriction is given here.

[0114] In an embodiment of the present invention, if it is determined that the voltage change direction of the battery pack is downward, when the voltage change direction is in the downward stage, the minimum voltage value of the battery pack in the downward stage is determined, and the voltage value of the battery pack is recorded to maintain the minimum voltage value when the voltage change direction is in the downward stage.

[0115] Optionally, in step S1232, the following execution steps may be included:

[0116] Step S12321: In response to the first sub-determination result not satisfying the second condition, continue to update the upper limit voltage value of the battery pack and continue to determine whether the first sub-determination result satisfies the second condition.

[0117] In the embodiment of the present invention, in response to the first sub-determination result not satisfying the second condition, the upper limit voltage value of the battery pack is continuously updated and it is continuously determined whether the first sub-determination result satisfies the second condition. It can be understood that, for example, taking the third voltage V as an example, if Vmax -V ≥ V Dirchange If V>V max , let V max =V, no restriction is imposed here.

[0118] Optionally, in step S121, the target voltage value also includes a lower limit voltage value, which may include the following execution steps:

[0119] Step S1211, in response to the first determination result not satisfying the first condition, determining a relationship between the first determination result and a third condition to obtain a third determination result, wherein the third condition includes: the first voltage is greater than the second voltage, the voltage difference between the first voltage and the second voltage is greater than or equal to a preset voltage difference, and the duration of the voltage difference between the first voltage and the second voltage being greater than or equal to the preset voltage difference is greater than a preset time period;

[0120] Step S1212: in response to the third determination result satisfying the third condition, determining that the voltage change direction of the battery pack is decreasing;

[0121] Step S1213: When the voltage change direction is in a decreasing stage, determine the lower limit voltage value of the battery pack.

[0122] In the embodiment of the present invention, the third condition can be understood as a condition for determining that the voltage change direction of the battery pack is decreasing for the first time. For example, taking the second voltage V as an example, when V Init -V ≥ V Dirchange If it is established, it can be determined that the first determination result satisfies the third condition, which is not limited here.

[0123] The third determination result can be understood as the magnitude relationship between the first determination result and the third condition. For example, taking the second voltage V as an example, judging V Init -V ≥ V Dirchange Whether it is established, thereby obtaining the third determination result, is not limited here.

[0124] In response to the third determination result satisfying the third condition, it is determined that the voltage change direction of the battery pack is downward. It can be understood that if the first voltage is greater than the second voltage, and the difference between the first voltage and the second voltage is greater than the threshold for determining the voltage direction change, it is determined that the voltage change direction of the battery pack is downward.

[0125] When the voltage change direction is in the decreasing stage, determining the lower limit voltage value of the battery pack can be understood as obtaining the minimum voltage value in the decreasing stage when the voltage change direction of the battery pack is decreasing. For example, the lower limit voltage value can be recorded as V min , no restriction is given here.

[0126] In an embodiment of the present invention, when the first determination result does not meet the first condition, the relationship between the first determination result and the third condition is determined to obtain a third determination result. If the first voltage is greater than the second voltage, and the difference between the first voltage and the second voltage is greater than a threshold for determining the voltage direction change, it is determined that the voltage change direction of the battery pack is downward. When the voltage change direction of the battery pack is downward, the minimum voltage value in the downward stage is obtained, and the voltage value of the battery pack is recorded to maintain the minimum voltage value in the voltage change direction in the downward stage, so that the voltage change trend of the battery pack can be effectively monitored.

[0127] Optionally, in step S1212, the following execution steps may be included:

[0128] Step S12121: In response to the third determination result not satisfying the third condition, continue to determine the magnitude relationship between the second voltage and the first voltage.

[0129] In the embodiment of the present invention, if the third determination result does not satisfy the third condition, it is necessary to continue to determine the magnitude relationship between the second voltage and the first voltage for use in a subsequent diagnosis process.

[0130] Optionally, in step S1211, determining the magnitude relationship between the third voltage of the battery pack at the third moment and the target voltage value may include the following execution steps:

[0131] Step S12111, determining a magnitude relationship between a third voltage of the battery pack at a third moment and a lower limit voltage value, and obtaining a second sub-determination result;

[0132] Step S12112, in response to the second sub-determination result satisfying the fourth condition, updating the number of switching times, wherein the fourth condition includes: the third voltage is greater than the upper limit voltage value, the voltage difference between the third voltage and the upper limit voltage value is greater than or equal to the preset voltage difference, and the duration of the voltage difference between the third voltage and the upper limit voltage value being greater than or equal to the preset voltage difference is greater than a preset time period.

[0133] In the embodiment of the present invention, the second sub-determination result can be understood as determining the magnitude relationship between the third voltage of the battery pack at the third moment and the lower limit voltage value. For example, taking the third voltage V as an example, determining VV min ≥V Dirchange Whether it is established, thereby obtaining the second sub-determination result, is not limited here.

[0134] The fourth condition can be understood as a condition for determining whether the number of switching times needs to be updated. For example, taking the third voltage V as an example, when VV min ≥V Dirchange When it is established, the number of switching times is increased by 1, and there is no limit here.

[0135] Determining the magnitude relationship between the third voltage of the battery pack at the third moment and the lower limit voltage value to obtain the second sub-determination result can be understood as obtaining the second sub-determination result based on the magnitude relationship between the third voltage of the battery pack at the third moment and the lower limit voltage value.

[0136] In response to the second sub-determination result satisfying the fourth condition, the switching number is updated. It can be understood that if the obtained second sub-determination result satisfies the preset judgment condition, the switching number of the voltage change direction of the battery pack is updated.

[0137] In the embodiment of the present invention, the second sub-determination result is obtained according to the magnitude relationship between the third voltage of the battery pack at the third moment and the lower limit voltage value, and if the obtained second sub-determination result satisfies the preset judgment condition, the number of switching times of the voltage change direction of the battery pack is increased by 1. By obtaining the number of switching times of the voltage change direction of the battery pack, the current working state of the battery pack can be understood in time, so as to better judge whether the current sampling line breakage has a fault.

[0138] Optionally, in step S12112, the following execution steps may be included:

[0139] Step S121121, determining that the voltage change direction of the battery pack is rising;

[0140] Step S121122: When the voltage change direction is in the rising stage, determine the upper limit voltage value of the battery pack.

[0141] In an embodiment of the present invention, if it is determined that the voltage change direction of the battery pack is rising, when the voltage change direction is in the rising stage, the maximum voltage value of the battery pack in the rising stage is determined, and the voltage value of the battery pack is recorded to maintain the maximum voltage value when the voltage change direction is in the rising stage.

[0142] Figure 2 FIG. 1 is a sampling principle diagram of a battery pack current sampling disconnection diagnosis system according to one embodiment of the present invention. Figure 2 As shown, the battery pack current sampling disconnection diagnosis system includes a load, a shunt, a battery pack, a voltage divider resistor, a sampling resistor, a target resistor, a high-precision analog-to-digital conversion channel, a calculation processing module, an auxiliary analog-to-digital conversion channel and a current sampling chip.

[0143] Among them, the load is used to consume electric energy, the shunt is used to share the current in the circuit, and the shunt and the load are connected in series. The battery pack is used to provide electric energy for the circuit, the sampling resistor is used to feedback the current value of the battery pack, and the voltage divider resistor is used to convert the high voltage into a low voltage to meet the working voltage requirements of certain components in the circuit. The battery pack, the voltage divider resistor and the sampling resistor are connected in series. The target resistor is used to feedback the current value of the shunt. The high-precision analog-to-digital conversion channel of the current sampling chip is used to sample and obtain the voltage at both ends of the shunt in real time, and through reasonable sampling loop hardware design, when the shunt voltage sampling is disconnected, the high-precision analog-to-digital conversion channel sampling value will approach 0, that is, it is in a "zero current" state. The auxiliary analog-to-digital conversion channel of the current sampling chip is used to collect the total voltage or the voltage after voltage division at both ends of the battery pack in real time. Based on the total voltage sampling value, the calculation and processing module in the current sampling chip tracks the direction of the battery pack voltage change in real time and records the number of direction changes. Among them, the method of tracking the overall direction of voltage change can be replaced by other algorithms. The high-precision analog-to-digital conversion channel can collect the voltage value at both ends of the shunt, convert the voltage value into a current value through the calculation and processing module, and finally output the current value from the current sampling chip. The calculation and processing module can determine whether the cumulative number of voltage direction switching times exceeds the threshold in the zero sampling current state, so as to determine whether the current sampling is disconnected. If a current sampling disconnection fault occurs, the current sampling function failure fault is reported. Under the premise that the shunt sampling enters the zero sampling current state after the disconnection, the charge and discharge related information (such as motor torque, etc.) transmitted by the load side (such as the whole vehicle motor, etc.) can also be used as an auxiliary judgment that there is actually a current and the sampling value is 0, thereby determining the shunt sampling disconnection fault. The calculation and processing module can also determine whether the auxiliary sampling channel is disconnected based on whether the total voltage sampling value of the battery pack is within a reasonable range. If an auxiliary voltage sampling disconnection fault occurs, the current sampling diagnostic function failure fault is reported.

[0144] The sampling circuit of the voltage difference across the shunt is implemented. Through reasonable sampling circuit design, when the sampling line is disconnected, the voltage difference of the shunt input to the high-precision analog-to-digital conversion channel approaches 0. The sampling circuit in the sampling schematic diagram is one example. In the original sampling circuit, the differential capacitor and the differential resistor are connected in parallel. When the sampling line is disconnected, the voltage difference at the sampling point of the high-voltage analog front end is first clamped by the capacitor, and as the resistor is discharged, the voltage difference across the high-precision analog-to-digital conversion channel will eventually approach 0. This ensures that when the sampling line is disconnected, it is in the "zero current" sampling value state. After the above circuit design is completed, through actual measurement or simulation of the sampling line disconnection, it can be confirmed that the current sampling absolute value threshold I is in the "zero current" state when the line is disconnected. OpnThrd When the absolute value of the current sampling value during the actual operation of the battery pack |I|≤I OpnThrd, regarded as the "zero current" state. In addition, the sampling circuit of the parallel capacitor and resistor is only an example, which can be replaced by other sampling circuits to achieve the effect that the current sampling value approaches 0 when the line is disconnected. The battery is not an ideal power source or load. When there is a real charging or discharging current, the battery voltage will also change due to the internal resistance and polarization effect. On the contrary, if there is no current passing through the battery, after a period of static, the voltage should eventually stabilize at a constant value.

[0145] Figure 3 is a flow chart of a “zero current” sampling value when a sampling line is disconnected according to one embodiment of the present invention, such as Figure 3 As shown, in the calculation processing module, the steps of determining whether the voltage direction of the battery pack changes and accumulating the number of direction switching times may be:

[0146] Step a: Real-time judgment of whether the absolute value of the sampled current is close to 0. When |I|≤I OpnThrd And when it lasts for a certain period of time, the diagnostic system starts diagnosis and jumps to step b; when |I|≤I OpnThrd And when it continues for a certain period of time, the absolute value of the current is continuously determined.

[0147] Step b: Record the battery pack voltage or single cell voltage V when entering the disconnection diagnosis Init , determine the direction of the first voltage change, if VV Init ≥V DirChange If the voltage changes for the first time and continues for a period of time, it is determined that the voltage changes for the first time and the process jumps to step c; where V is the current sampling voltage, V DirChange To determine the voltage direction change threshold; if V Init -V ≥ V DirChange If the voltage changes for a period of time, it is determined that the voltage changes for the first time in a downward direction, and the process jumps to step d. If VV Init ≥V DirChange And it continues for a period of time and does not satisfy V Init -V ≥ V DirChange And if it continues for a period of time, continue to judge the direction of the first voltage change.

[0148] Step c: Determine whether the change direction is switched during the voltage rising process. If V max -V ≥ V DirChange And it lasts for a period of time, it is judged that the voltage changes direction for the first time and switches to downward, and the cumulative number of voltage direction switching is Cntr DirChange +1, jump to step d; if V is not satisfied max -V ≥ V DirChange And it lasts for a period of time, then the maximum value V during the voltage rise process is maintained continuously max : And when V>V max When V max =V.

[0149] Step d: Determine whether the change direction is switched during the voltage drop process. If VV min ≥V DirChange And it lasts for a period of time, it is judged that the voltage changes direction for the first time and switches to rising, and the cumulative number of voltage direction switching is Cntr DirChange +1, jump to step c; if VV is not satisfied min ≥V DirChange And it lasts for a period of time, continuously maintaining the minimum value V during the voltage drop process min :When V <V min When V min =V.

[0150] The accumulated number of voltage change direction switching times in the "zero current" state indicates whether the battery pack is currently in a state of no current excitation. Under the condition of no current excitation, the battery voltage will only change in one direction (up or down) and eventually stabilize. DirChange With the preset threshold Cntr OpnThrd By comparison, when Cntr DirChange ≥Cntr OpnThrd When the current sampling of the shunt is judged to be disconnected, the preset threshold Cntr OpnThrd The settings are made considering the rapidity and accuracy of the diagnosis. When a current sampling disconnection fault occurs, the core function of the current sensor is lost and the reported current sampling fails. If the total battery voltage obtained by the auxiliary analog-to-digital conversion channel exceeds a reasonable range (such as less than the minimum voltage threshold or greater than the maximum voltage threshold), it is determined that an auxiliary voltage sampling disconnection fault has occurred. The preset threshold Cntr mentioned above OpnThrd , the minimum voltage threshold and the maximum voltage threshold are not set as constant thresholds, and can be set as dynamically changing thresholds considering other factors. Due to the loss of voltage information, the sensor current diagnostic function is lost, but it still has the basic current sampling function, and only the reporting current sensor diagnostic function fails.

[0151] Compared with the chip hardware diagnosis scheme, the diagnosis scenario of the present invention is not restricted and can be executed synchronously during the normal operation of the battery pack current sampling function. This means that abnormal situations such as disconnection of the shunt current sampling can be detected in the first time to avoid continuous adverse effects caused by invalid current. In addition, the present invention is different from the current-voltage correlation diagnosis scheme. It does not need to rely on high synchronization or high precision of sampling. The diagnosis is not affected by abnormal fluctuations in voltage sampling, and the misdiagnosis rate will be greatly reduced.

[0152] It can be seen that the solution provided in the embodiment of the present application firstly makes the current sampling value when the shunt sampling is disconnected have a fixed characteristic (approaching 0) through the reasonable design of the sampling circuit. Then, the total voltage of the battery pack is obtained through the auxiliary sampling channel, and the overall change direction of the voltage is tracked through the calculation and processing module instead of detecting the instantaneous fluctuation of the voltage. Then, the number of switching times of the voltage change direction is used as the judgment value instead of observing the size of the voltage change. Finally, the combination of a reasonable disconnection "zero current" sampling circuit and a voltage direction tracking method is adopted to accurately and effectively complete the diagnosis of the shunt current sampling disconnection.

[0153] Through the description of the above implementation methods, those skilled in the art can clearly understand that the method according to the above embodiment can be implemented by means of software plus a necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, a magnetic disk, or an optical disk), and includes a number of instructions for enabling a terminal device (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present invention.

[0154] In this embodiment, a battery pack current sampling disconnection diagnosis device is also provided, which is used to implement the above-mentioned embodiments and preferred implementation modes, and will not be repeated here. As used below, the term "module" can implement a combination of software and / or hardware for a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation in hardware, or a combination of software and hardware, is also possible and conceivable.

[0155] Figure 4 is a structural block diagram of a battery pack current sampling disconnection diagnosis device according to one embodiment of the present invention, such as Figure 4As shown, a battery pack current sampling disconnection diagnosis device 400 is used as an example, and the device includes: an acquisition module 401, which is used to respond to the current sampling chip entering a preset state, and obtain a first voltage of the battery pack at a first moment based on a first sampling channel in the current sampling chip, wherein the current recorded by the current sampling chip in the preset state is less than a preset current threshold, and the first moment is used to indicate the moment when the current sampling chip enters the preset state; a first determination module 402, which is used to determine the magnitude relationship between the second voltage of the battery pack and the first voltage at the second moment, and obtain a first determination result, wherein the second moment is later than the first moment; a second determination module 403, which is used to determine the magnitude relationship between the third voltage of the battery pack at a third moment and a target voltage value, and obtain a second determination result, wherein the target voltage value is determined based on the first determination result, and the third moment is later than the second moment; a diagnosis module 404, which is used to perform current sampling disconnection diagnosis on the battery pack based on the switching number and a preset switching number threshold, and obtain a diagnosis result, wherein the switching number is determined based on the second determination result, and the switching number is used to indicate the switching number of the voltage change direction of the battery pack.

[0156] Optionally, the acquisition module 401 is also used to acquire a shunt voltage value of the shunt based on a second sampling channel in the current sampling chip; determine a shunt current value based on the shunt voltage value; and determine that the current sampling chip enters a preset state in response to the shunt current value being less than or equal to a preset shunt current value.

[0157] Optionally, the first determination module 402 is also used to determine that the voltage change direction of the battery pack is rising in response to the first determination result satisfying the first condition, wherein the first condition includes: the second voltage is greater than the first voltage, the voltage difference between the second voltage and the first voltage is greater than or equal to a preset voltage difference, and the duration of the voltage difference between the second voltage and the first voltage being greater than or equal to the preset voltage difference is greater than a preset time period; when the voltage change direction is in an rising stage, determine the upper limit voltage value of the battery pack, wherein the upper limit voltage value is the maximum voltage value reached by the battery pack in the rising stage.

[0158] Optionally, the second determination module 403 is also used to determine the relationship between the third voltage of the battery pack at the third moment and the upper limit voltage value to obtain a first sub-determination result; in response to the first sub-determination result satisfying the second condition, the switching number is updated, wherein the second condition includes: the upper limit voltage value is greater than the third voltage, the voltage difference between the upper limit voltage value and the third voltage is greater than or equal to a preset voltage difference, and the duration of the voltage difference between the upper limit voltage value and the third voltage being greater than or equal to the preset voltage difference is greater than a preset time period.

[0159] Optionally, the second determination module 403 is also used to determine that the voltage change direction of the battery pack is decreasing; when the voltage change direction is in the decreasing stage, determine the lower limit voltage value of the battery pack, wherein the lower limit voltage value is the minimum voltage value reached by the battery pack in the decreasing stage.

[0160] Optionally, the second determination module 403 is further configured to, in response to the first sub-determination result not satisfying the second condition, continue to update the upper limit voltage value of the battery pack and continue to determine whether the first sub-determination result satisfies the second condition.

[0161] Optionally, the first determination module 402 is also used to determine the relationship between the first determination result and the third condition in response to the first determination result not satisfying the first condition, and obtain a third determination result, wherein the third condition includes: the first voltage is greater than the second voltage, the voltage difference between the first voltage and the second voltage is greater than or equal to a preset voltage difference, and the duration of the voltage difference between the first voltage and the second voltage being greater than or equal to the preset voltage difference is greater than a preset time period; in response to the third determination result satisfying the third condition, determine that the voltage change direction of the battery pack is decreasing; when the voltage change direction is in the decreasing stage, determine the lower limit voltage value of the battery pack.

[0162] Optionally, the first determination module 402 is further configured to, in response to the third determination result not satisfying the third condition, continue to determine the magnitude relationship between the second voltage and the first voltage.

[0163] Optionally, the second determination module 403 is also used to determine the relationship between the third voltage of the battery pack at the third moment and the lower limit voltage value to obtain a second sub-determination result; in response to the second sub-determination result satisfying the fourth condition, the switching number is updated, wherein the fourth condition includes: the third voltage is greater than the upper limit voltage value, the voltage difference between the third voltage and the upper limit voltage value is greater than or equal to the preset voltage difference, and the duration of the voltage difference between the third voltage and the upper limit voltage value being greater than or equal to the preset voltage difference is greater than a preset time period.

[0164] Optionally, the second determination module 403 is further configured to determine that the voltage change direction of the battery pack is rising; and when the voltage change direction is in the rising stage, determine the upper limit voltage value of the battery pack.

[0165] It should be noted that the above modules can be implemented by software or hardware. For the latter, it can be implemented in the following ways, but not limited to: the above modules are all located in the same processor; or the above modules are located in different processors in any combination.

[0166] An embodiment of the present invention further provides a vehicle, which is used to execute the steps in any of the above method embodiments.

[0167] An embodiment of the present invention further provides a computer-readable storage medium, in which a computer program is stored. The computer program is configured to execute the steps of any of the above method embodiments when running on a computer or a processor.

[0168] Optionally, in this embodiment, the computer-readable storage medium may be configured to store a computer program for performing the following steps:

[0169] Step S10, in response to the current sampling chip entering a preset state, obtaining a first voltage of the battery pack at a first moment based on a first sampling channel in the current sampling chip, wherein the current recorded by the current sampling chip in the preset state is less than a preset current threshold, and the first moment is used to indicate the moment when the current sampling chip enters the preset state;

[0170] Step S11, determining a magnitude relationship between a second voltage and a first voltage of the battery pack at a second moment, and obtaining a first determination result, wherein the second moment is later than the first moment;

[0171] Step S12, determining a magnitude relationship between a third voltage of the battery pack at a third moment and a target voltage value, and obtaining a second determination result, wherein the target voltage value is determined based on the first determination result, and the third moment is later than the second moment;

[0172] Step S13, performing current sampling disconnection diagnosis on the battery pack based on the switching number and the preset switching number threshold to obtain a diagnosis result, wherein the switching number is determined based on the second determination result, and the switching number is used to indicate the switching number of the voltage change direction of the battery pack.

[0173] Optionally, in this embodiment, the above-mentioned computer-readable storage medium may include but is not limited to: a USB flash drive, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk, and other media that can store computer programs.

[0174] An embodiment of the present invention further provides an electronic device, including a memory and a processor, wherein a computer program is stored in the memory, and the processor is configured to run the computer program to execute the steps in any one of the above method embodiments.

[0175] Optionally, in this embodiment, the processor in the electronic device may be configured to run a computer program to perform the following steps:

[0176] Step S10, in response to the current sampling chip entering a preset state, obtaining a first voltage of the battery pack at a first moment based on a first sampling channel in the current sampling chip, wherein the current recorded by the current sampling chip in the preset state is less than a preset current threshold, and the first moment is used to indicate the moment when the current sampling chip enters the preset state;

[0177] Step S11, determining a magnitude relationship between a second voltage and a first voltage of the battery pack at a second moment, and obtaining a first determination result, wherein the second moment is later than the first moment;

[0178] Step S12, determining a magnitude relationship between a third voltage of the battery pack at a third moment and a target voltage value, and obtaining a second determination result, wherein the target voltage value is determined based on the first determination result, and the third moment is later than the second moment;

[0179] Step S13, performing current sampling disconnection diagnosis on the battery pack based on the switching number and the preset switching number threshold to obtain a diagnosis result, wherein the switching number is determined based on the second determination result, and the switching number is used to indicate the switching number of the voltage change direction of the battery pack.

[0180] An embodiment of the present invention further provides a computer program product, including a computer program, which implements the steps in any of the above method embodiments when executed by a processor.

[0181] Optionally, in this embodiment, the computer program in the above computer program product may be configured to perform the following steps when executed by a processor:

[0182] Step S10, in response to the current sampling chip entering a preset state, obtaining a first voltage of the battery pack at a first moment based on a first sampling channel in the current sampling chip, wherein the current recorded by the current sampling chip in the preset state is less than a preset current threshold, and the first moment is used to indicate the moment when the current sampling chip enters the preset state;

[0183] Step S11, determining a magnitude relationship between a second voltage and a first voltage of the battery pack at a second moment, and obtaining a first determination result, wherein the second moment is later than the first moment;

[0184] Step S12, determining a magnitude relationship between a third voltage of the battery pack at a third moment and a target voltage value, and obtaining a second determination result, wherein the target voltage value is determined based on the first determination result, and the third moment is later than the second moment;

[0185] Step S13, performing current sampling disconnection diagnosis on the battery pack based on the switching number and the preset switching number threshold to obtain a diagnosis result, wherein the switching number is determined based on the second determination result, and the switching number is used to indicate the switching number of the voltage change direction of the battery pack.

[0186] Optionally, the specific examples in this embodiment may refer to the examples described in the above embodiments and optional implementation modes, and this embodiment will not be described in detail here.

[0187] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0188] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0189] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0190] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0191] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0192] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM), random access memory (RAM), mobile hard disk, disk or optical disk, etc., various media that can store program codes.

[0193] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A battery pack current sampling disconnection diagnosis method, characterized in that: include: In response to the current sampling chip entering a preset state, acquiring a first voltage of the battery pack at a first moment based on a first sampling channel in the current sampling chip, wherein the current recorded by the current sampling chip in the preset state is less than a preset current threshold, and the first moment is used to indicate the moment when the current sampling chip enters the preset state; Determine a magnitude relationship between a second voltage of the battery pack and the first voltage at a second moment, and obtain a first determination result, wherein the second moment is later than the first moment; Determine a magnitude relationship between a third voltage of the battery pack at a third moment and a target voltage value to obtain a second determination result, wherein the target voltage value is determined based on the first determination result, and the third moment is later than the second moment; The current sampling broken line diagnosis of the battery pack is performed based on the switching number and a preset switching number threshold to obtain a diagnosis result, wherein the switching number is determined based on the second determination result, and the switching number is used to indicate the switching number of the voltage change direction of the battery pack.

2. The method according to claim 1, characterized in that In response to the current sampling chip entering a preset state, before acquiring a first voltage of the battery pack at a first moment based on a first sampling channel in the current sampling chip, the method further includes: Acquire a shunt voltage value of the shunt based on a second sampling channel in the current sampling chip; determining a shunt current value based on the shunt voltage value; In response to the shunt current value being less than or equal to a preset shunt current value, it is determined that the current sampling chip enters the preset state.

3. The method according to claim 1, characterized in that The target voltage value includes an upper limit voltage value. Before determining the magnitude relationship between the third voltage of the battery pack at the third moment and the target voltage value to obtain a second determination result, the method further includes: In response to the first determination result satisfying a first condition, determining that the voltage change direction of the battery pack is rising, wherein the first condition includes: the second voltage is greater than the first voltage, the voltage difference between the second voltage and the first voltage is greater than or equal to a preset voltage difference, and the duration of the voltage difference between the second voltage and the first voltage being greater than or equal to the preset voltage difference is greater than a preset time period; When the voltage change direction is in an ascending stage, the upper limit voltage value of the battery pack is determined, wherein the upper limit voltage value is a maximum voltage value reached by the battery pack in the ascending stage.

4. The method according to claim 3, characterized in that The determining the magnitude relationship between the third voltage of the battery pack at the third moment and the target voltage value to obtain a second determination result includes: Determine a magnitude relationship between the third voltage of the battery pack at the third moment and the upper limit voltage value to obtain a first sub-determination result; In response to the first sub-determination result satisfying the second condition, the switching number is updated, wherein the second condition includes: the upper limit voltage value is greater than the third voltage, the voltage difference between the upper limit voltage value and the third voltage is greater than or equal to the preset voltage difference, and the duration of the voltage difference between the upper limit voltage value and the third voltage being greater than or equal to the preset voltage difference is greater than the preset time period.

5. The method according to claim 4, characterized in that The method further comprises: Determining that the voltage change direction of the battery pack is decreasing; When the voltage change direction is in a decreasing stage, a lower limit voltage value of the battery pack is determined, wherein the lower limit voltage value is a minimum voltage value reached by the battery pack in the decreasing stage.

6. The method according to claim 4, characterized in that The method further comprises: In response to the first sub-determination result not satisfying the second condition, continuing to update the upper limit voltage value of the battery pack and continuing to determine whether the first sub-determination result satisfies the second condition.

7. The method according to claim 3, characterized in that The target voltage value also includes a lower limit voltage value, and the method further includes: In response to the first determination result not satisfying the first condition, determining a relationship between the first determination result and a third condition to obtain a third determination result, wherein the third condition includes: the first voltage is greater than the second voltage, the voltage difference between the first voltage and the second voltage is greater than or equal to the preset voltage difference, and the duration of the voltage difference between the first voltage and the second voltage being greater than or equal to the preset voltage difference is greater than the preset time period; In response to the third determination result satisfying the third condition, determining that the voltage change direction of the battery pack is decreasing; When the voltage change direction is in a decreasing stage, the lower limit voltage value of the battery pack is determined.

8. The method according to claim 7, characterized in that The method further comprises: In response to the third determination result not satisfying the third condition, continuing to determine the magnitude relationship between the second voltage and the first voltage.

9. The method according to claim 7, characterized in that: The determining the magnitude relationship between the third voltage of the battery pack at the third moment and the target voltage value to obtain a second determination result includes: Determine a magnitude relationship between the third voltage of the battery pack at the third moment and the lower limit voltage value to obtain a second sub-determination result; In response to the second sub-determination result satisfying the fourth condition, the switching number is updated, wherein the fourth condition includes: the third voltage is greater than the upper limit voltage value, the voltage difference between the third voltage and the upper limit voltage value is greater than or equal to the preset voltage difference, and the voltage difference between the third voltage and the upper limit voltage value is greater than or equal to the preset voltage difference for a duration greater than the preset time period.

10. The method according to claim 9, characterized in that The method further comprises: Determining that a voltage change direction of the battery pack is rising; When the voltage change direction is in an increasing stage, the upper limit voltage value of the battery pack is determined.

11. A battery pack current sampling disconnection diagnosis system, characterized in that: The battery pack current sampling disconnection diagnosis system includes: a current sampling chip, a battery pack, a shunt and a load, wherein the battery pack, the shunt and the load are connected in series, the current sampling chip includes a first sampling channel, a second sampling channel and a calculation and processing circuit, the first sampling channel is used to record the voltage value of the battery pack, the second sampling channel is used to record the voltage value of the shunt, the calculation and processing circuit is used to convert the voltage value recorded by the second sampling channel into a current value and output it, the first sampling channel is connected in parallel with a sampling resistor, the battery pack, a voltage dividing resistor and the sampling resistor are connected in series, the second sampling channel is connected in parallel with the shunt, the shunt is connected in parallel with a target capacitor, and the shunt is connected in parallel with a target resistor, and the battery pack current sampling disconnection diagnosis system is used to execute the battery pack current sampling disconnection diagnosis method described in any one of claims 1 to 10.

12. A battery pack current sampling disconnection diagnosis device, characterized in that: include: an acquisition module, configured to acquire a first voltage of the battery pack at a first moment based on a first sampling channel in the current sampling chip in response to the current sampling chip entering a preset state, wherein the current recorded by the current sampling chip in the preset state is less than a preset current threshold, and the first moment is used to indicate a moment when the current sampling chip enters the preset state; A first determination module, configured to determine a magnitude relationship between a second voltage of the battery pack at a second moment and the first voltage, to obtain a first determination result, wherein the second moment is later than the first moment; a second determination module, configured to determine a magnitude relationship between a third voltage of the battery pack at a third moment and a target voltage value, and obtain a second determination result, wherein the target voltage value is determined based on the first determination result, and the third moment is later than the second moment; A diagnostic module is used to perform current sampling disconnection diagnosis on the battery pack based on the number of switches and a preset switching number threshold to obtain a diagnostic result, wherein the number of switches is determined based on the second determination result, and the number of switches is used to indicate the number of switches in the voltage change direction of the battery pack.

13. A vehicle, characterized in that: The vehicle is used to execute the battery pack current sampling disconnection diagnosis method described in any one of claims 1 to 10 above.

14. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, wherein the computer program is configured to execute the battery pack current sampling disconnection diagnosis method described in any one of claims 1 to 10 when running on a computer or a processor.

15. An electronic device comprising a memory and a processor, characterized in that: The memory stores a computer program, and the processor is configured to run the computer program to execute the battery pack current sampling disconnection diagnosis method described in any one of claims 1 to 10 above.

16. A computer program product, characterized in that It includes a computer program, which, when executed by a processor, implements the battery pack current sampling disconnection diagnosis method described in any one of claims 1 to 10 above.

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