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

Abstract

The application 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 the current sampling chip entering a preset state, obtaining a first voltage of the battery pack at a first time based on a first sampling channel in the current sampling chip; determining the size relationship between a second voltage of the battery pack at a second time and the first voltage to obtain a first determination result; determining the size relationship between a third voltage of the battery pack at a third time 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 times and a preset switching time threshold to obtain a diagnosis result. The application solves the technical problem that related technologies cannot diagnose in the process of battery pack charging and discharging operation.

Description

TECHNICAL FIELD

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

[0002] The current sensor is a core component for obtaining the charge and discharge current information of the battery pack, and its reliability is an important prerequisite for ensuring the stable operation of the battery pack. Due to the complex operating conditions of the power battery pack, the sensor has a risk of failure when subjected to external impacts such as mechanical vibration. If the sensor failure cannot be effectively identified, it will seriously affect the monitoring of the state of the battery pack, and the sampling line disconnection is a common failure mode that should be diagnosed in a timely and accurate manner.

[0003] Currently, the diagnosis schemes for current sampling disconnection mainly include two types: chip hardware diagnosis and diagnosis based on the correlation between current and voltage. The chip hardware diagnosis injects current excitation into the sampling loop, and judges whether the sampling loop is complete (i.e. without disconnection) according to whether the voltage difference between the two ends of the sampling shunt changes accordingly. However, this type of scheme cannot normally perform current sampling during execution, which means that the normal sampling function needs to be shielded during diagnosis, and often cannot be diagnosed during the charging and discharging operation of the battery pack. The diagnosis scheme based on the correlation between current and voltage considers that when the sampling voltage and sampling current change (fluctuate) do not follow the correlation rule, it is considered as a current sampling fault. However, this method has high requirements for the synchronization and accuracy of current and voltage sampling, and also depends on the accuracy of the current and voltage reference relationship. SUMMARY

[0004] The embodiments of the present application provide a battery pack current sampling disconnection diagnosis method, device, storage medium and electronic device to at least solve the technical problem that the related art cannot diagnose during the charging and discharging operation of the battery pack.

[0005] According to one embodiment of the present invention, a method for diagnosing a battery pack current sampling disconnection 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 at a second moment and the first voltage to obtain 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 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; performing a current sampling disconnection diagnosis on the battery pack based on the number of switching times and a preset switching number threshold to obtain 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 in the voltage change direction of the battery pack.

[0006] Optionally, in response to the current sampling chip entering a preset state, before obtaining the first voltage of the battery pack at the first moment based on the first sampling channel in the current sampling chip, the method also includes: obtaining a shunt voltage value of the shunt based on the 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 the 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 magnitude relationship between the third voltage of the battery pack at the third moment and the target voltage value and obtaining the second determination result, the method further 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 the preset voltage difference, and the duration of the voltage difference between the second voltage and the first voltage is greater than or equal to the preset voltage difference is greater than a preset time period; when the voltage change direction is in the 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 number of switching times, 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 is greater than or equal to the preset voltage difference is greater than a preset time period.

[0009] Optionally, the method further comprises: determining that the voltage variation direction of the battery pack is a decrease; and determining a lower limit voltage value of the battery pack in a decrease phase of the voltage variation direction, wherein the lower limit voltage value is a minimum voltage value reached by the battery pack in the decrease phase.

[0010] Optionally, 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 continuously determining whether the first sub-determination result satisfies the second condition.

[0011] Optionally, the target voltage value further comprises a lower limit voltage value, and the method further comprises: 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 comprises: the first voltage is greater than the second voltage, a voltage difference between the first voltage and the second voltage is greater than or equal to a preset voltage difference, and a duration for which the voltage difference between the first voltage and the second voltage is 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 variation direction of the battery pack is a decrease; and determining the lower limit voltage value of the battery pack in a decrease phase of the voltage variation direction.

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

[0013] Optionally, the method further comprises: in response to the third determination result not satisfying the third condition, continuing to determine the size relationship between the second voltage and the first voltage.

[0014] Optionally, the method further comprises: determining that the voltage variation direction of the battery pack is an increase; and determining the upper limit voltage value of the battery pack in an increase phase of the voltage variation direction.

[0015] According to one of the embodiments of the present application, a battery pack current sampling disconnection diagnosis system is also provided, which comprises 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 comprises a first sampling channel, a second sampling channel and a calculation 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, and the calculation processing circuit is used to convert the voltage value recorded by the second sampling channel into a current value and output, the first sampling channel is connected in parallel with a sampling resistor, the battery pack and a voltage dividing resistor are connected in series with the sampling resistor, 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 in any of the above.

[0016] According to one of the embodiments of the present application, a battery pack current sampling disconnection diagnosis device is also provided, which comprises an acquisition module, a first determination module, a second determination module and a diagnosis module, the acquisition module is used to acquire a first voltage of a battery pack at a first time based on a first sampling channel in a 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 time is used to represent the time when the current sampling chip enters the preset state; the first determination module is used to determine the size relationship between a second voltage of the battery pack at a second time and the first voltage, and obtain a first determination result, wherein the second time is later than the first time; the second determination module is used to determine the size relationship between a third voltage of the battery pack at a third time 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 time is later than the second time; and the diagnosis module is used to perform current sampling disconnection diagnosis on the battery pack based on a 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 represent the switching number of the voltage change direction of the battery pack.

[0017] Optionally, the acquisition module is further 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 the 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 further used to determine that the voltage change direction of the battery pack is rising in response to the first determination result satisfying a first condition, wherein the first condition comprises that the second voltage is greater than the first voltage, a voltage difference between the second voltage and the first voltage is greater than or equal to a preset voltage difference, and a duration in which the voltage difference between the second voltage and the first voltage is greater than or equal to the preset voltage difference is greater than a preset time period; and determine an upper limit voltage value of the battery pack in the rising stage of the voltage change direction, wherein the upper limit voltage value is the maximum voltage value reached by the battery pack in the rising stage.

[0019] Optionally, the second determining module is further configured to determine a size relationship between a third voltage of the battery pack at a third time and the upper limit voltage value, to obtain a first sub-determination result; and in response to the first sub-determination result satisfying a second condition, update the switching times, wherein the second condition comprises that the upper limit voltage value is greater than the third voltage, a voltage difference between the upper limit voltage value and the third voltage is greater than or equal to a preset voltage difference, and a duration for which the voltage difference between the upper limit voltage value and the third voltage is greater than or equal to the preset voltage difference is greater than a preset time period.

[0020] Optionally, the second determining module is further configured to determine that the voltage variation direction of the battery pack is downward; and in a downward phase of the voltage variation direction, determine a lower limit voltage value of the battery pack, wherein the lower limit voltage value is a minimum voltage value reached by the battery pack in the downward phase.

[0021] Optionally, the second determining 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 continuously determine whether the first sub-determination result satisfies the second condition.

[0022] Optionally, the first determining module is further configured to, in response to the first determination result not satisfying the first condition, determine a relationship between the first determination result and a third condition, to obtain a third determination result, wherein the third condition comprises that the first voltage is greater than the second voltage, a voltage difference between the first voltage and the second voltage is greater than or equal to a preset voltage difference, and a duration for which the voltage difference between the first voltage and the second voltage is 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 variation direction of the battery pack is downward; and in a downward phase of the voltage variation direction, determine a lower limit voltage value of the battery pack.

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

[0024] Optionally, the second determining module is further configured to determine a size relationship between a third voltage of the battery pack at a third time and the lower limit voltage value, to obtain a second sub-determination result; and in response to the second sub-determination result satisfying a fourth condition, update the switching times, wherein the fourth condition comprises that the third voltage is greater than the upper limit voltage value, a voltage difference between the third voltage and the upper limit voltage value is greater than or equal to a preset voltage difference, and a duration for which the voltage difference between the third voltage and the upper limit voltage value is greater than or equal to the preset voltage difference is greater than a preset time period.

[0025] Optionally, the second determining module is further configured to determine that the voltage variation direction of the battery pack is upward; and in an upward phase of the voltage variation direction, determine the upper limit voltage value of the battery pack.

[0026] According to an embodiment of the present application, a vehicle is also provided, which is configured to perform the battery pack current sampling disconnection diagnosis method in any of the above.

[0027] According to an embodiment of the present application, a computer readable storage medium is also provided, which stores a computer program, wherein the computer program is configured to perform the battery pack current sampling disconnection diagnosis method in any of the above when running on a computer or a processor.

[0028] According to an embodiment of the present application, an electronic device is also provided, which comprises a memory and a processor, the memory stores a computer program, and the processor is configured to run the computer program to perform the battery pack current sampling disconnection diagnosis method in any of the above.

[0029] According to an embodiment of the present application, a computer program product is also provided, which comprises a computer program, and the computer program is configured to implement the battery pack current sampling disconnection diagnosis method in any of the above when executed by a processor.

[0030] In the embodiment of the present application, the first voltage of the battery pack at the first time is obtained based on the first sampling channel in the current sampling chip in response to the current sampling chip entering the preset state, wherein the current recorded by the current sampling chip in the preset state is less than the preset current threshold, and the first time is used to represent the time when the current sampling chip enters the preset state; the size relationship between the second voltage of the battery pack at the second time and the first voltage is determined to obtain a first determination result, wherein the second time is later than the first time; the size relationship between the third voltage of the battery pack at the third time 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 time is later than the second time; the current sampling disconnection diagnosis of the battery pack is performed 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 represent the switching number of the voltage change direction of the battery pack. The purpose of not shielding the normal sampling function during the diagnosis process and normally performing the current sampling is achieved, so that the real-time diagnosis of the sampling line disconnection fault is realized, thereby ensuring the reliability of the sampling current information, and further solving the technical problem that the related art cannot diagnose during the battery pack charging and discharging operation. BRIEF DESCRIPTION OF DRAWINGS

[0031] The drawings described herein are used to provide further understanding of the present application, and form a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application, and do not constitute improper limitations on the present application. In the drawings:

[0032] Figure 1 is a flowchart of the battery pack current sampling disconnection diagnosis method according to an embodiment of the present application;

[0033] Figure 2 is a sampling schematic diagram of a battery pack current sampling broken line diagnosis system according to an embodiment of the present application;

[0034] Figure 3 is a flowchart of a "zero current" sampling value when the sampling line is broken according to an embodiment of the present application;

[0035] Figure 4 is a structural block diagram of a battery pack current sampling broken line diagnosis device according to an embodiment of the present application. DETAILED DESCRIPTION

[0036] For the convenience of understanding, some exemplary explanations of concepts related to embodiments of the present application are given for reference.

[0037] As follows:

[0038] Current sensor: a device for detecting and measuring the size of current, which measures the size of current by sensing the magnetic field generated by current and converts these data into voltage signals or digital signal outputs. Current sensors are widely used in various fields, such as power systems, industrial automation, electric vehicles, etc., for monitoring changes in current and protecting safe operation of equipment.

[0039] Battery pack: a component containing multiple battery monomers for storing and providing electrical energy. Exemplarily, 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 in a specific location at the bottom of the vehicle to provide the required electrical energy for the vehicle.

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

[0041] Shunt: an instrument for measuring direct current, made according to the principle that a voltage is generated across a resistor when direct current passes through it.

[0042] In order for those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should be within the scope of protection of the present application.

[0043] It is to be understood that the terms "first", "second", and the like, used in the description and the claims of the application as well as the above description of the drawings merely specify a certain order, and cannot be understood as meaning that a particular order is required in the implementation of the application. It is to be understood that the data thus used can be interchanged, where appropriate, so that the embodiments of the application described herein can be implemented in orders other than those illustrated or described herein. In the description of the embodiments, the term "a plurality" means two or more, unless otherwise specified. In addition, the terms "comprise" and "have" and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or apparatus that includes a list of steps or units is not necessarily limited to those steps or units that are clearly listed, but can include other steps or units that are not clearly listed or inherent to such processes, methods, products, or apparatuses.

[0044] According to an embodiment of the application, a method for diagnosing a broken wire of a battery pack current sampling is provided. It is to be understood that the steps shown in the flowcharts of the drawings can be executed in a computer system, such as a set of computer-executable instructions, and although a logical order is shown in the flowcharts, 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, a similar control device or system comprising a memory and a processor. Taking the electronic device as an example, the electronic device can include one or more processors and a memory for storing data. Optionally, the electronic device can further include a communication device for communication function and a display device. Those skilled in the art can understand that the above structural description is merely illustrative, and does not limit the structure of the electronic device. For example, the electronic device can include more or less components than the above structural description, or have a different configuration from the above structural description.

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

[0047] The memory can be used to store a computer program, for example, a computer program corresponding to the battery pack current sampling disconnection diagnosis method in the embodiments of the present application. The processor realizes the above-mentioned battery pack current sampling disconnection diagnosis method by running the computer program stored in the memory. The memory can include a high-speed random access memory, and can also include a non-volatile memory, such as one or more magnetic storage devices, flash memories, or other non-volatile solid-state memories. In some examples, the memory can further include a memory remotely arranged with respect to the processor, which can be connected to the electronic device through 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 a combination thereof.

[0048] The communication device is used to receive or send data via a network. Specific examples of the above-mentioned network can include a wireless network provided by a communication provider of a mobile terminal. In one example, the communication device includes a 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 in a wireless manner.

[0049] The display device can be, for example, a liquid crystal display (LCD) and a touch display (also referred to as a "touch screen" or "touch display screen") in the form of a touch screen. The liquid crystal display can enable a user to interact with a user interface of the mobile terminal. In some embodiments, the mobile terminal described above has a graphical user interface (GUI) that can be interacted with by a user through finger contacts and / or gestures on the touch-sensitive surface. The human-machine interface functions can optionally include one or more of the following: creating a webpage, drawing, text editing, preparing an electronic document, playing a game, video conferencing, instant messaging, composing an email, a call interface, playing digital video, playing digital music, and / or web browsing, and the like, executable instructions for performing the human-machine interface functions are configured / stored in a computer program product or a readable storage medium executable by one or more processors.

[0050] A battery pack current sampling disconnection diagnosis method running on an electronic device is provided in the embodiment, Figure 1 is a flowchart of the battery pack current sampling disconnection diagnosis method according to an embodiment of the present application, as shown in Figure 1 , the flowchart includes the following steps:

[0051] Step S10, in response to the current sampling chip entering a preset state, acquiring a first voltage of the battery pack at a first time 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 time is used to represent the time when the current sampling chip enters the preset state;

[0052] In the embodiment of the present application, the current sampling chip can be understood as an integrated circuit chip integrating 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 state and power consumption of the circuit, and protect the circuit and improve the system performance.

[0053] The preset state can be understood as the "zero current" state of the current sampling chip, that is, the recorded current of the current sampling chip is less than the specified preset threshold. Exemplarily, the recorded current of the current sampling chip can be denoted as I, and the specified preset threshold can be denoted as I OpnThrd When |I|≤I OpnThrd and for a certain time, it can be considered that the current sampling chip has entered the preset state. The preset threshold I OpnThrd may be determined according to the actual situation, which 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 time. Exemplarily, the first sampling channel can be an auxiliary analog-to-digital conversion channel, which is used to collect the total voltage or the voltage after voltage division between the battery pack in real time, which is not limited here.

[0055] The first time can be understood as the time when the current sampling chip enters the preset state. Exemplarily, the first time can be the time when the diagnostic system enters the broken line 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 broken line diagnosis. Exemplarily, the first voltage can be denoted as V Init , which is not limited here.

[0057] In response to the current sampling chip entering the preset state, the first voltage of the battery pack at the first time is obtained based on the first sampling channel in the current sampling chip, which can be understood as 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 when the diagnostic system enters the broken line diagnosis is obtained based on the first sampling channel.

[0058] In the embodiment of the application, when the recorded current of the current sampling chip is less than the specified preset threshold, 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 between the battery pack when the diagnostic system enters the broken line diagnosis in real time. By obtaining the voltage of the battery pack in real time, the broken line problem that may exist in the battery pack can be found in time, so as to eliminate the safety hazard.

[0059] In step S11, the size relationship between the second voltage of the battery pack at the second time and the first voltage is determined, and a first determination result is obtained, wherein the second time is later than the first time.

[0060] In the embodiment of the application, the second time can be understood as a certain time after the diagnostic system enters the broken line diagnosis, that is, the second time is later than the first time.

[0061] The second voltage can be understood as the voltage at a certain time after the diagnostic system enters the broken line diagnosis, that is, the sampling voltage at the current time.

[0062] The first determination result can be understood as the size relationship between the second voltage of the battery pack at the second time and the first voltage. Exemplarily, taking the second voltage as V as an example, the voltage direction change threshold is V Dirchange , and the first determination result can be the size relationship between the second voltage V of the battery pack at the second time and the first voltage V Init , that is, it is judged that V-V Init ≥ V Dirchange or V Init -V ≥ V Dirchangewhether the first determination result is established, and the first determination result is not limited here.

[0063] The first determination result can be understood as judging the relationship between the magnitude relationship between the second voltage of the battery pack at the second time and the first voltage and the preset determination voltage direction change threshold, so that the first determination result can be obtained.

[0064] In the embodiment of the application, when the diagnostic system enters a certain time after the broken line diagnosis, that is, the second time, the voltage of the battery pack at the second time, that is, the second voltage, 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, the first determination result is obtained. By comparing the magnitude relationship between the second voltage and the first voltage with the preset determination voltage direction change threshold, the state of the battery pack can be determined whether there is an abnormality in time and accurately.

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

[0066] In the embodiment of the application, the third time can be understood as a certain time after the second time, that is, the third time is later than the second time.

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

[0068] The target voltage value can be understood as the maximum value of the voltage of the battery pack in the rising process or the minimum value in the falling process. Exemplarily, the maximum value of the voltage of the battery pack in the rising process can be denoted as V max , and the minimum value of the voltage of the battery pack in the falling process can be denoted as V min , which is not limited here.

[0069] The second determination result can be understood as the magnitude relationship between the third voltage of the battery pack at the third time and the target voltage value, that is, the magnitude relationship between the voltage of the battery pack at the current time and the maximum value of the voltage of the battery pack in the rising process or the minimum value in the falling process. Exemplarily, taking the third voltage V max as an example, it is judged whether V Dirchange -V≥V min or V-V Dirchange is established, and the second determination result is obtained, which is not limited here.

[0070] The size 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, which can be understood as judging the size relationship between the current voltage of the battery pack and the maximum value in the rising process or the minimum value in the falling process of the voltage of the battery pack, so as to determine the second determination result.

[0071] In the embodiment of the application, by judging the size relationship between the voltage of the battery pack at the current moment and the target voltage value, the second determination result that the voltage change direction of the battery pack is rising or falling can be obtained. By judging the change direction of the voltage of the battery pack, we can more accurately understand the charging and discharging state of the battery.

[0072] In step S13, current sampling disconnection 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 represent the switching number of the voltage change direction of the battery pack.

[0073] In the embodiment of the application, the switching number can be understood as the number of times of the voltage change direction of the battery pack, that is, the number of times of the voltage direction of the battery pack changing to rising or falling. For example, the switching number can be denoted as Cntr DirChange , which is not limited here.

[0074] The preset switching number threshold can be understood as a value for judging whether the current sampling disconnection fails. For example, the preset switching number threshold can be denoted as Cntr OpnThrd , which is not limited here.

[0075] The diagnosis result can be understood as information about whether the current sampling disconnection fails. For example, when Cntr DirChange ≥ Cntr OpnThrd , it is determined that the current sampling disconnection fails, which is not limited here.

[0076] Based on the switching number and the preset switching number threshold, the current sampling disconnection diagnosis is performed on the battery pack to obtain a diagnosis result, which can be understood as judging the size relationship between the switching number and the preset switching number threshold to obtain the diagnosis result about whether the current sampling disconnection fails.

[0077] In the embodiment of the application, the cumulative number of times of the voltage direction of the battery pack changing to rising or falling is compared with the preset switching number threshold to determine whether the current sampling disconnection fails, so that the reliability and safety of the battery pack can be improved, and the occurrence of unexpected situations caused by the current sampling disconnection failure can be reduced.

[0078] When the recorded current of the current sampling chip is less than the predetermined preset threshold, that is, when the current sampling chip enters the preset state, the auxiliary analog-digital conversion channel can be used to collect the total voltage or the voltage after voltage division of the battery pack when the diagnostic system enters the broken line diagnosis in real time. By obtaining the voltage of the battery pack in real time, the broken line problem that may exist in the battery pack can be found in time, so as to eliminate the safety hazard. At a certain moment after the diagnostic system enters the broken line diagnosis, that is, at the second moment, the voltage of the battery pack at the second moment, that is, the second voltage, is obtained. By judging the relationship between the second voltage and the first voltage and the relationship between the preset determined voltage direction change threshold, a first determination result is obtained. By comparing the relationship between the second voltage and the first voltage and the preset determined voltage direction change threshold, whether the state of the battery pack is abnormal can be determined in time and accurately. By judging the 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 voltage change direction of the battery pack is rising or falling. By judging the change direction of the voltage of the battery pack, we can more accurately understand the charging and discharging state of the battery. The cumulative number of times that the voltage direction of the battery pack changes to rising or falling is compared with the preset switching number threshold, so as to determine whether the current sampling broken line fails, thereby improving the reliability and safety of the battery pack and reducing the occurrence of unexpected situations caused by current sampling broken line failure.

[0079] Through the above steps, by responding to the current sampling chip entering the 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, 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 represent the moment when the current sampling chip enters the preset state; the size 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 size 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 current sampling broken line of the battery pack is diagnosed 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 represent the switching number of the voltage change direction of the battery pack. The purpose of normal current sampling without shielding the normal sampling function during diagnosis is achieved, so that real-time diagnosis of the sampling line broken line failure is realized, thereby ensuring the reliability of the sampled current information, and further solving the technical problem that the related art cannot diagnose during the charging and discharging operation of the battery pack.

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

[0081] In step S101, the shunt voltage value of the shunt is obtained based on the second sampling channel in the current sampling chip.

[0082] In step S102, the shunt current value is determined based on the shunt voltage value.

[0083] In step S103, 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 the preset state.

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

[0085] The shunt can be understood as a device for shunting current, which can shunt the total current in the battery pack into multiple partial currents, so as to accurately sample the current and diagnose the broken line.

[0086] The shunt current value can be understood as the current value across the shunt. For example, the shunt current value, i.e. the current value I recorded by the current sampling chip, is not limited here.

[0087] The preset shunt current value can be understood as a preset threshold for determining whether the current sampling chip enters the preset state. For example, the preset shunt current value can be I OpnThrd , which is not limited here.

[0088] Obtaining the shunt voltage value of the shunt based on the second sampling channel in the current sampling chip can be understood as using the high-precision analog-to-digital conversion channel in the current sampling chip to sample and obtain 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 the preset state. For example, when |I|≤I OpnThrd for a certain period of time, it is determined that the current sampling chip has entered the preset state, which is not limited here.

[0090] In the embodiment of the present application, first, the shunt voltage value of the shunt is obtained based on the high-precision analog-to-digital conversion channel in the current sampling chip, then the shunt current value is determined based on the shunt voltage value, and 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 the preset state. By determining that the current sampling chip enters the 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, before determining the size 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 step can be included:

[0092] Step S121, in response to the first determination result satisfying the first condition, determining that the voltage variation 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 the preset voltage difference, and the duration that the voltage difference between the second voltage and the first voltage is greater than or equal to the preset voltage difference is greater than the preset time period;

[0093] Step S122, in the rising stage of the voltage variation direction, determining the upper limit voltage value of the battery pack, wherein the upper limit voltage value is the maximum voltage value of the battery pack in the rising stage.

[0094] In the embodiment of the present application, the first condition can be understood as a condition for determining that the voltage variation direction of the battery pack is rising for the first time. For example, when V-V Init ≥V Dirchange 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 can be understood as a preset threshold for determining whether the first determination result satisfies the first condition. For example, the preset voltage difference can be denoted as V Dirchange , which is not limited here.

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

[0097] The upper limit voltage value, i.e., the maximum voltage value of the battery pack in the rising stage, can be denoted as V max , which is not limited here.

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

[0099] In the voltage change direction is in the rising stage, the upper limit voltage value of the battery pack is determined, which 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 the embodiment of the application, if the difference between the current battery pack voltage and the second voltage is greater than the preset voltage difference, the voltage change direction of the battery pack can be determined to be rising, and when the voltage change direction of the battery pack is in the 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 remain at 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 size relationship between the third voltage of the battery pack at the third time and the target voltage value to obtain a second determination result can include the following execution steps:

[0102] Step S1231, determining the size relationship between the third voltage of the battery pack at the third time and the upper limit voltage value to obtain a first sub-determination result;

[0103] Step S1232, updating the switching frequency in response to the first sub-determination result satisfying a second condition, 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 for which the voltage difference between the upper limit voltage value and the third voltage is greater than or equal to the preset voltage difference is greater than a preset time period.

[0104] In the embodiment of the application, the first sub-determination result can be understood as judging the size relationship between the third voltage of the battery pack at the third time and the upper limit voltage value. For example, taking the third voltage V as an example, whether V max -V≥V Dirchange is established, thereby obtaining the first sub-determination result, which is not limited here.

[0105] Updating the switching frequency can be understood as updating the voltage change direction frequency if the voltage change direction of the battery pack is updated. For example, the switching frequency can be denoted as Cntr DirChange , and updating the switching frequency can be denoted as Cntr DirChange ++, which is not limited here.

[0106] The second condition can be understood as a condition for judging whether the switching frequency needs to be updated. For example, taking the third voltage V as an example, when V max -V≥V Dirchange is established, the switching frequency is incremented by 1, which is not limited here.

[0107] The size relationship between the third voltage of the battery pack at the third moment and the upper limit voltage value is determined to obtain a first sub-determination result, which can be understood as obtaining the first sub-determination result according to the size 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, which can be understood as updating the switching number of the voltage change direction of the battery pack if the obtained first sub-determination result satisfies the preset judgment condition.

[0109] In the embodiment of the application, the first sub-determination result is obtained according to the size 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 switching number of the voltage change direction of the battery pack is increased by 1. By obtaining the switching number of the voltage change direction of the battery pack, the working state of the current battery pack can be understood in time, so that whether the current sampling wire is faulty can be better judged.

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

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

[0112] Step S12312, determining the lower limit voltage value of the battery pack in the voltage change direction in the downward phase, wherein the lower limit voltage value is the minimum voltage value of the battery pack in the downward phase.

[0113] In the embodiment of the application, the lower limit voltage value, that is, the minimum voltage value of the battery pack in the downward phase, is exemplarily denoted as V min Herein, no limitation is given.

[0114] In the embodiment of the application, if it is determined that the voltage change direction of the battery pack is downward, the minimum voltage value of the battery pack in the downward phase is determined, and the voltage value of the battery pack is recorded to be kept at the minimum voltage value in the voltage change direction in the downward phase.

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

[0116] Step S12321, 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 continuously judging whether the first sub-determination result satisfies the second condition.

[0117] In the embodiment of the application, 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 judged whether the first sub-determination result satisfies the second condition, which can be understood as exemplarily taking the third voltage V as an example, if Vmax -V≥V Dirchange If V>V max , let V max =V, no restriction here.

[0118] Optionally, in step S121, the target voltage value further 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 the 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 meets 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, that is, 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 phase, determining the lower limit voltage value of the battery pack can be understood as obtaining the minimum voltage value in the decreasing phase when the voltage change direction of the battery pack is decreasing. For example, the lower limit voltage value can be recorded as V min , there is no restriction here.

[0126] In the embodiment of the present application, when the first determination result does not satisfy 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 determination voltage direction change threshold, 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 be maintained at the minimum voltage value in the voltage change direction in the downward stage. Therefore, the voltage change trend of the battery pack can be effectively monitored.

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

[0128] In step S12121, in response to the third determination result not satisfying the third condition, the size relationship between the second voltage and the first voltage is continuously determined.

[0129] In the embodiment of the present application, if the third determination result does not satisfy the third condition, the size relationship between the second voltage and the first voltage needs to be continuously determined, thereby being used for subsequent diagnosis processes.

[0130] Optionally, in step S1211, the size relationship between the third voltage of the battery pack at the third time and the target voltage value can include the following execution steps:

[0131] In step S12111, the size relationship between the third voltage of the battery pack at the third time and the lower limit voltage value is determined to obtain a second sub-determination result.

[0132] In step S12112, in response to the second sub-determination result satisfying a fourth condition, the switching frequency is updated, wherein the fourth condition includes that 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, the duration that the voltage difference between the third voltage and the upper limit voltage value is greater than or equal to the preset voltage difference is greater than a preset time period.

[0133] In the embodiment of the present application, the second sub-determination result can be understood as judging the size relationship between the third voltage of the battery pack at the third time and the lower limit voltage value. For example, taking the third voltage V as an example, whether V-V min ≥V Dirchange is established is judged, thereby obtaining the second sub-determination result, which is not limited here.

[0134] The fourth condition can be understood as a condition for judging whether the switching frequency needs to be updated. For example, taking the third voltage V as an example, when V-V min ≥V Dirchange is established, the switching frequency is increased by 1, which is not limited 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 this embodiment of the present invention, a second sub-determination result is obtained based on the magnitude relationship between the third voltage of the battery pack at the third moment and the lower voltage limit. If the second sub-determination result satisfies a preset judgment condition, the number of times the battery pack's voltage change direction switches is incremented by 1. By obtaining the number of times the battery pack's voltage change direction switches, the current operating status of the battery pack can be promptly understood, thereby better determining whether a current sampling line disconnection has occurred.

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

[0139] Step S121121: Determine 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 and 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 and processing module, an auxiliary analog-to-digital conversion channel, and a current sampling chip.

[0143] 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 feed back the current value of the battery pack, the voltage dividing resistor is used to convert high voltage into low voltage to meet the working voltage requirement of some elements in the circuit, and the battery pack, the voltage dividing resistor and the sampling resistor are connected in series. The target resistor is used to feed back the current value of the shunt, the high-precision analog-to-digital conversion channel of the current sampling chip is used to acquire the voltage across the shunt in real time, and through reasonable sampling loop hardware design, when the shunt voltage sampling occurs, the sampling value of the high-precision analog-to-digital conversion channel will tend to 0, that is, in the "zero current" state. The auxiliary analog-to-digital conversion channel of the current sampling chip is used to acquire the total voltage across the battery pack or the voltage after voltage division in real time. Based on the total voltage sampling value, the calculation processing module in the current sampling chip tracks the voltage change direction of the battery pack in real time and records the number of direction changes, wherein the method of tracking the overall voltage change direction can be replaced by other algorithms. The high-precision analog-to-digital conversion channel can acquire the voltage value across the shunt, convert the voltage value into a current value through the calculation processing module, and finally output the current value obtained by the current sampling chip. The calculation processing module can determine whether the number of voltage direction switching times accumulated in the zero sampling current state exceeds a threshold value, so as to determine whether the current sampling exists a disconnection. If the current sampling disconnection fault occurs, the current sampling function failure fault is reported. Under the premise that the shunt sampling is disconnected and enters the zero sampling current state, the charging and discharging related information (such as motor torque) transmitted by the load side (such as vehicle motor) can also be used as auxiliary judgment that the actual current exists and the sampling value is 0, so as to determine the shunt sampling disconnection fault. The calculation processing module can also determine whether the auxiliary sampling channel exists a disconnection according to whether the total voltage sampling value of the battery pack is within a reasonable range. If the auxiliary voltage sampling disconnection fault occurs, the current sampling diagnosis function failure fault is reported.

[0144] The sampling loop of the voltage difference across the shunt is implemented, and through reasonable sampling circuit design, when the sampling line is disconnected, the voltage difference across the shunt input to the high-precision analog-to-digital conversion channel tends to 0. The sampling loop in the sampling principle diagram is one of the examples. In the original sampling loop, a differential capacitor and a differential resistor are connected in parallel. When the sampling line is disconnected, the voltage difference of the high-voltage analog front-end sampling point is first clamped by the capacitor, and then the voltage difference across the high-precision analog-to-digital conversion channel tends to 0 with the discharge of the resistor. Thus, when the sampling line is disconnected, the "zero current" sampling value state is ensured. After the above circuit design is completed, through actual measurement or simulation of the sampling disconnection, it can be confirmed that when the sampling line is disconnected, the absolute value threshold I OpnThrd When the current sampling value absolute value |I| of the battery pack in the actual running process is less than or equal to the absolute value threshold I OpnThrd, the state is regarded as "zero current" state. In addition, the parallel capacitor and resistor sampling circuit is only an example, which can be replaced by other sampling circuits to achieve the effect of the sampling value approaching 0 when the wire is broken. The battery is not an ideal power supply or load, and when there is a real charging or discharging current, the battery voltage will also change due to internal resistance and polarization effect. On the contrary, if there is no current through the battery, the voltage should eventually stabilize at a constant value after a period of rest.

[0145] Figure 3 is a flowchart of the sampling wire breakage in the "zero current" sampling value according to an embodiment of the application, as shown in the calculation processing module, the steps of judging whether the voltage direction of the battery pack changes and accumulating the direction switching times can be: Figure 3

[0146] Step a, real-time judge whether the sampling current absolute value is close to 0, when |I|≤I OpnThrd and lasts for a certain time, the diagnosis system starts diagnosis, and jumps to step b; when |I|>I OpnThrd and lasts for a certain time, the current absolute value is continuously judged.

[0147] Step b, record the battery pack voltage or single cell voltage V Init when entering the broken wire diagnosis, judge the first change direction of the voltage, if V-V Init ≥V DirChange and lasts for a period of time, judge that the first change direction of the voltage is rising, jump to step c; wherein, V is the current sampling voltage, V DirChange is the determined voltage direction change threshold; if V Init -V≥V DirChange and lasts for a period of time, judge that the first change direction of the voltage is falling, jump to step d; if V-V Init ≥V DirChange and lasts for a period of time, and V Init -V≥V DirChange and lasts for a period of time, continue to judge the first change direction of the voltage.

[0148] Step c, judge whether the change direction is switched during the voltage rising process, if V-V max ≥V DirChange and lasts for a period of time, judge that the first change direction of the voltage is switched to falling, and the voltage direction switching cumulative times Cntr DirChange +1, jump to step d; if V-V max ≥V DirChange and lasts for a period of time, continue to maintain the maximum value V max in the voltage rising process: and when V>V max , V max =V.​

[0149] Step d, determine whether the change direction switches during the voltage drop process, if V-V min ≥V DirChange and for a period of time, determine that the voltage first change direction switches to rise, the voltage direction switch cumulative number Cntr DirChange +1, jump to step c; if not V-V min ≥V DirChange and for a period of time, maintain the minimum value V min during the voltage drop process; when V min , let V min =V.

[0150] The cumulative number of voltage change direction switches in the "zero current" state indicates whether the current battery pack is in a state of no current excitation. Under the condition of no current excitation, the battery voltage will only change in one direction (rise or fall) and eventually tend to be stable. The cumulative number of voltage change direction switches Cntr DirChange is compared with the preset threshold Cntr OpnThrd , when Cntr DirChange ≥Cntr OpnThrd , it is determined that the shunt current sampling is disconnected. The preset threshold Cntr OpnThrd is set considering the speed and accuracy of diagnosis. After the current sampling is disconnected, the current sensor loses its core function and reports that the current sampling is invalid. If the total battery voltage obtained by the auxiliary analog-to-digital conversion channel exceeds the reasonable range (such as less than the minimum voltage threshold or greater than the maximum voltage threshold), it is determined that the auxiliary voltage sampling is disconnected, wherein the above-mentioned preset threshold Cntr OpnThrd , the minimum voltage threshold and the maximum voltage threshold are not specified as constant thresholds, but can be set as dynamic thresholds considering other factors. Due to the loss of voltage information, the sensor current diagnosis function is lost, but it still has the basic current sampling function and only reports that the current sensor diagnosis function is invalid.

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

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

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

[0154] In the embodiment, a battery pack current sampling disconnection diagnosis device is also provided, which is used to implement the above embodiments and preferred embodiments, and will not be described again. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, implementation of hardware, or a combination of software and hardware, is also possible and is contemplated.

[0155] Figure 4 is a structural block diagram of the battery pack current sampling disconnection diagnosis device according to one embodiment of the present application, as shown in Figure 4As shown, the battery pack current sampling breakage diagnosis device 400 is exemplified, which comprises: an acquisition module 401, configured to acquire a first voltage of the battery pack at a first time 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 time is used to represent the time when the current sampling chip enters the preset state; a first determination module 402, configured to determine a size relationship between a second voltage of the battery pack at a second time and the first voltage to obtain a first determination result, wherein the second time is later than the first time; a second determination module 403, configured to determine a size relationship between a third voltage of the battery pack at a third time 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 time is later than the second time; and a diagnosis module 404, configured to diagnose the current sampling breakage of the battery pack based on a 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 represent the switching number of the voltage change direction of the battery pack.

[0156] Optionally, the acquisition module 401 is further configured 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 in response to the shunt current value being less than or equal to a preset shunt current value, determine that the current sampling chip enters the preset state.

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

[0158] Optionally, the second determination module 403 is further configured to determine a size relationship between the third voltage of the battery pack at the third time and the upper limit voltage value to obtain a first sub-determination result; and update the switching number in response to the first sub-determination result satisfying a second condition, wherein the second condition comprises: the upper limit voltage value is greater than the third voltage, a voltage difference between the upper limit voltage value and the third voltage is greater than or equal to a preset voltage difference, and a duration for which the voltage difference between the upper limit voltage value and the third voltage is greater than or equal to the preset voltage difference is greater than a preset time period.

[0159] Optionally, the second determination module 403 is further 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.

[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 the preset voltage difference, and the duration of the voltage difference between the first voltage and the second voltage is 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 downward; when the voltage change direction is in the downward stage, determine the lower limit voltage value of the battery pack.

[0162] Optionally, the first determining 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 size 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 is greater than or equal to the preset voltage difference is greater than the preset time period.

[0164] Optionally, the second determining 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 through 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] The embodiment of the present application also provides a computer readable storage medium, wherein the storage medium stores a computer program, and the computer program is configured to execute the steps in any one of the method embodiments when running on a computer or a processor.

[0168] Optionally, in the embodiment, the computer readable storage medium is configured to store the computer program for executing the following steps.

[0169] In step S10, in response to the current sampling chip entering a preset state, a first voltage of the battery pack at a first time 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 time is used to represent the time when the current sampling chip enters the preset state.

[0170] In step S11, a size relationship between a second voltage of the battery pack at a second time and the first voltage is determined, and a first determination result is obtained, wherein the second time is later than the first time.

[0171] In step S12, a size relationship between a third voltage of the battery pack at a third time and a target voltage value is determined, and a second determination result is obtained, wherein the target voltage value is determined based on the first determination result, and the third time is later than the second time.

[0172] In step S13, the current sampling wire break diagnosis of the battery pack is performed based on a switching number and a preset switching number threshold, and a diagnosis result is obtained, wherein the switching number is determined based on the second determination result, and the switching number is used to represent the switching number of the voltage change direction of the battery pack.

[0173] Optionally, in the embodiment, the computer readable storage medium can include but is not limited to a U disk, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk and various storage media that can store computer programs.

[0174] The embodiment of the present application also provides an electronic device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor is configured to execute the computer program to perform the steps in any one of the method embodiments.

[0175] Optionally, in the embodiment, the processor in the electronic device can be configured to execute the computer program to perform the following steps.

[0176] Step S10, in response to the current sampling chip entering a preset state, acquiring a first voltage of the battery pack at a first time 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 time is used to represent the time when the current sampling chip enters the preset state;

[0177] Step S11, determining the size relationship between a second voltage of the battery pack at a second time and the first voltage to obtain a first determination result, wherein the second time is later than the first time;

[0178] Step S12, determining the size relationship between a third voltage of the battery pack at a third time 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 time is later than the second time;

[0179] Step S13, performing current sampling disconnection diagnosis on the battery pack based on the number of switches and a preset number of switch thresholds to obtain a diagnosis result, wherein the number of switches is determined based on the second determination result, and the number of switches is used to represent the number of changes in the voltage change direction of the battery pack.

[0180] Embodiments of the present application also provide a computer program product comprising a computer program which, when executed by a processor, implements the steps in any of the above method embodiments.

[0181] Optionally, in the present embodiment, the computer program in the above computer program product can be set to execute the following steps when executed by the processor:

[0182] Step S10, in response to the current sampling chip entering a preset state, acquiring a first voltage of the battery pack at a first time 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 time is used to represent the time when the current sampling chip enters the preset state;

[0183] Step S11, determining the size relationship between a second voltage of the battery pack at a second time and the first voltage to obtain a first determination result, wherein the second time is later than the first time;

[0184] Step S12, determining the size relationship between a third voltage of the battery pack at a third time 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 time is later than the second time;

[0185] Step S13, performing current sampling disconnection diagnosis on the battery pack based on the number of switches and a preset number of switch thresholds to obtain a diagnosis result, wherein the number of switches is determined based on the second determination result, and the number of switches is used to represent the number of changes in the voltage change direction of the battery pack.

[0186] Optionally, the specific examples in the embodiments can refer to the examples described in the above embodiments and optional implementation manners, and the embodiments will not be described here again.

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

[0188] In the above embodiments of the application, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0189] In several embodiments provided in the present application, it should be understood that the disclosed technical contents can be implemented by other means. Among them, the above-mentioned device embodiments are only schematic, for example, the division of the units can be a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units or modules shown or discussed can be indirect coupling or communication connection through some interfaces, units or modules, which can be electrical or other forms.

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

[0191] In addition, each functional unit in each embodiment of the application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The above integrated unit can be realized in the form of hardware, or in the form of software functional unit.

[0192] The integrated unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application, essentially or in other words, the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, including a number of instructions to make a computer device (which can be a personal computer, a server or a network device, etc.) execute all or part of the steps of the methods described in various embodiments of the present application. The aforementioned storage medium includes: a U disk, a read-only memory (Read-Only Memory, ROM), a random access memory (Random Access Memory, RAM), a mobile hard disk, a magnetic disk or an optical disk, and various media that can store program codes.

[0193] The above only describes the preferred embodiments of the present application. It should be noted that, for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A battery pack current sampling open wire diagnostic method, characterized in that, The method comprises: in response to the current sampling chip entering a preset state, obtaining a first voltage of the battery pack at a first time 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 time represents the time when the current sampling chip enters the preset state; determining the size relationship between the second voltage of the battery pack at a second time and the first voltage to obtain a first determination result, wherein the second time is later than the first time; determining the size relationship between the third voltage of the battery pack at a third time 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 time is later than the second time; based on the switching number and the preset switching number threshold, the current sampling of the battery pack is diagnosed to obtain a diagnosis result, wherein the switching number is determined based on the second determination result, and the switching number represents the number of switching of the voltage change direction of the battery pack.

2. The method of claim 1, wherein, Before the method comprises: based on the first sampling channel in the current sampling chip, obtaining a first voltage of the battery pack at a first time in response to the current sampling chip entering a preset state, the method further comprises: obtaining a shunt voltage value of a shunt based on a second sampling channel in the current sampling chip; determining a shunt current value based on the shunt voltage value; 3. The method of claim 1, wherein, 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 the preset state. The target voltage value includes an upper limit voltage value, and before the method comprises: 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 comprises: 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 for which the voltage difference between the second voltage and the first voltage is greater than or equal to the preset voltage difference is greater than a preset time period; 4. The method of claim 3, wherein, in the rising stage of the voltage change direction, 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. The method further comprises: determining the size relationship between the third voltage of the battery pack at the third time and the upper limit voltage value to obtain a first sub-determination result; 5. The method of claim 4, wherein, in response to the first sub-determination result satisfying a second condition, updating the switching number, wherein the second condition comprises: 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 for which the voltage difference between the upper limit voltage value and the third voltage is greater than or equal to the preset voltage difference is greater than the preset time period. The method further comprises: determining that a voltage change direction of the battery pack is falling; determining a lower limit voltage value of the battery pack in a falling phase of the voltage change direction, wherein the lower limit voltage value is a minimum voltage value reached by the battery pack in the falling phase.

6. The method of claim 4, wherein, 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 continuously determining whether the first sub-determination result satisfies the second condition.

7. The method of claim 3, wherein, The target voltage value further comprises a lower limit voltage value, and the method further comprises: 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 comprises: the first voltage is greater than the second voltage, a voltage difference between the first voltage and the second voltage is greater than or equal to the preset voltage difference, and a duration for which the voltage difference between the first voltage and the second voltage is greater than or equal to the preset voltage difference is greater than the preset time period; determining that a voltage change direction of the battery pack is falling in response to the third determination result satisfying the third condition; determining the lower limit voltage value of the battery pack in a falling phase of the voltage change direction.

8. The method of claim 7, wherein, The method further comprises: in response to the third determination result not satisfying the third condition, continuing to determine the size relationship between the second voltage and the first voltage.

9. The method of claim 7, wherein, The determination of the size relationship between the third voltage of the battery pack at a third time and a target voltage value to obtain a second determination result comprises: determining the size relationship between the third voltage of the battery pack at the third time 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 frequency, wherein the fourth condition comprises: the third voltage is greater than the upper limit voltage value, a voltage difference between the third voltage and the upper limit voltage value is greater than or equal to the preset voltage difference, and a duration for which the voltage difference between the third voltage and the upper limit voltage value is greater than or equal to the preset voltage difference is greater than the preset time period.

10. The method of claim 9, wherein, The method further comprises: determining that a voltage change direction of the battery pack is falling; determining the upper limit voltage value of the battery pack in a rising phase of the voltage change direction.

11. A battery pack current sampling open wire diagnostic system, comprising: The battery pack current sampling broken line diagnosis system comprises: 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 comprises a first sampling channel, a second sampling channel and a calculation 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 processing circuit is used to convert the voltage value recorded by the second sampling channel into a current value and output, 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, the shunt is connected in parallel with a target resistor, and the battery pack current sampling broken line diagnosis system is used to execute the battery pack current sampling broken line diagnosis method in any one of claims 1 to 10.

12. A battery pack current sampling open wire diagnostic device, comprising: Comprise: An acquisition module is configured to acquire a first voltage of a battery pack at a first time based on a first sampling channel in a current sampling chip in response to the current sampling chip entering a preset state, wherein a current recorded by the current sampling chip in the preset state is less than a preset current threshold, and the first time is used to represent a time when the current sampling chip enters the preset state; A first determination module is configured to determine a size relationship between a second voltage of the battery pack at a second time and the first voltage to obtain a first determination result, wherein the second time is later than the first time; A second determination module is configured to determine a size relationship between a third voltage of the battery pack at a third time 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 time is later than the second time; A diagnosis module is configured to perform current sampling broken line diagnosis on the battery pack based on a 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 represent the number of times of switching of the voltage change direction of the battery pack.

13. A vehicle characterized by comprising: The vehicle is used to execute the battery pack current sampling broken line diagnosis method in any one of claims 1 to 10.

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 broken line diagnosis method 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, the electronic device characterized by, The memory stores a computer program, and the processor is configured to execute the battery pack current sampling broken line diagnosis method in any one of claims 1 to 10 by running the computer program.

16. A computer program product, characterised in that, Comprise a computer program, the computer program is executed by a processor to realize the battery pack current sampling broken line diagnosis method in any one of claims 1 to 10.

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