Vehicle insulation resistance detection method, vehicle and storage medium

Abstract

The embodiment of the invention provides a vehicle insulation resistance detection method, a vehicle and a storage medium, and the method comprises the steps: obtaining the sampling voltage data of an insulation detection circuit which is used for detecting the first insulation resistance between the positive electrode of a power battery of a target vehicle and a vehicle housing, the second insulation resistor is arranged between the negative electrode of the power battery and the vehicle shell; screening the sampled voltage data to obtain a data screening result; insulation detection is carried out based on the data screening result to obtain a detection result, and the detection result is used for determining a positive electrode insulation state and a negative electrode insulation state corresponding to the insulation detection circuit; and generating a vehicle maintenance instruction of the target vehicle by using the detection result. According to the invention, the technical problem of low performance detection efficiency and accuracy of the vehicle insulation resistor in the prior art is solved.

Description

Technical Field

[0001] This application relates to the field of battery management system testing technology, and more specifically, to a vehicle insulation resistance testing method, a vehicle, and a storage medium. Background Technology

[0002] Against the backdrop of the rapid development of the new energy vehicle industry, the monitoring and maintenance of the insulation performance of battery management systems and motor drive systems, as core components of electric vehicles, has become crucial. Accurate detection of insulation resistance not only ensures vehicle electrical safety but also effectively improves energy efficiency and prevents potential fire risks.

[0003] With the development of new energy vehicle technology, the complexity of vehicle electrical systems is increasing, and existing insulation resistance testing methods are often unable to adapt to this complex change, thus affecting the accuracy and reliability of insulation resistance testing.

[0004] There is currently no good solution to the above problems. Summary of the Invention

[0005] This application provides a method for detecting the insulation resistance of a vehicle, a vehicle, and a storage medium, to at least solve the technical problem of low efficiency and accuracy in the performance testing of vehicle insulation resistance in related technologies.

[0006] According to one aspect of the embodiments of this application, a method for detecting vehicle insulation resistance is provided, comprising: acquiring sampling voltage data of an insulation detection circuit, wherein the insulation detection circuit is used to detect a first insulation resistance between the positive terminal of a power battery of a target vehicle and the vehicle casing, and a second insulation resistance between the negative terminal of a power battery and the vehicle casing; performing filtering processing on the sampling voltage data to obtain data filtering results; performing insulation detection based on the data filtering results to obtain detection results, wherein the detection results are used to determine the positive and negative insulation states corresponding to the insulation detection circuit; and generating vehicle maintenance instructions for the target vehicle using the detection results.

[0007] Furthermore, the insulation detection circuit includes: a first switch, a second switch, and a bridge detection circuit. The first switch is used to control the connection state of the positive detection branch in the bridge detection circuit, and the second switch is used to control the connection state of the negative detection branch in the bridge detection circuit. Obtaining the sampling voltage data of the insulation detection circuit includes: obtaining the switch state information of the insulation detection circuit, wherein the switch state information includes: the closed state of the first switch and the closed state of the second switch; and obtaining the sampling voltage data based on the switch state data.

[0008] Furthermore, obtaining sampled voltage data based on switch state data includes: in response to the first switch being closed and the second switch being open, obtaining a first sampled voltage based on a preset sampling frequency; in response to the first switch being open and the second switch being closed, obtaining a second sampled voltage based on a preset sampling frequency; and determining sampled voltage data based on the first sampled voltage and the second sampled voltage.

[0009] Furthermore, the sampled voltage data is filtered to obtain the following results: the sampled voltage data is filtered using digital filtering to obtain the filtered results; the filtered results are then calibrated to obtain the final data selection results.

[0010] Furthermore, insulation testing is performed based on the data screening results, and the test results include: in response to the fact that the first sampling voltage and the second sampling voltage in the data screening results are both preset values, it is determined that the insulation state of the positive electrode and the insulation state of the negative electrode are both normal.

[0011] Furthermore, insulation testing is performed based on the data screening results, and the test results include: in response to the first sampling voltage in the data screening results being a preset value and the second sampling voltage being greater than the preset value, determining that the positive insulation state of the insulation detection circuit is an abnormal state and the negative insulation state is a normal state, and determining the first insulation resistance based on the first calculation model corresponding to the insulation detection circuit.

[0012] Furthermore, insulation detection is performed based on the data screening results, and the detection results include: in response to the first sampling voltage being greater than a preset value and the second sampling voltage being a preset value in the data screening results, the positive electrode insulation state corresponding to the insulation detection circuit is determined to be normal and the negative electrode insulation state is determined to be abnormal; and the second insulation resistance is determined based on the second calculation model corresponding to the insulation detection circuit.

[0013] Furthermore, insulation testing is performed based on the data screening results, and the test results include: in response to the fact that the first sampling voltage and the second sampling voltage in the data screening results are both greater than the preset values, it is determined that the positive electrode insulation state and the negative electrode insulation state are both abnormal states; and the first insulation resistance and the second insulation resistance are determined based on the third calculation model corresponding to the insulation detection circuit.

[0014] According to another aspect of the embodiments of this application, a vehicle insulation resistance detection device is also provided, comprising: an acquisition module for acquiring sampling voltage data of an insulation detection circuit, wherein the insulation detection circuit is used to detect a first insulation resistance between the positive terminal of the power battery of the target vehicle and the vehicle casing, and a second insulation resistance between the negative terminal of the power battery and the vehicle casing; a screening module for screening the sampling voltage data to obtain a data screening result; a detection module for performing insulation detection based on the data screening result to obtain a detection result, wherein the detection result is used to determine the positive and negative insulation states corresponding to the insulation detection circuit; and a generation module for generating vehicle maintenance instructions for the target vehicle using the detection result.

[0015] According to another aspect of the embodiments of this application, a vehicle is also provided, including: a memory storing an executable program; and a processor for running the program, wherein the program executes the methods in various embodiments of this application when it runs.

[0016] According to another aspect of the embodiments of this application, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored executable program, wherein, when the executable program is running, it controls the device where the computer-readable storage medium is located to perform the methods of various embodiments of this application.

[0017] According to another aspect of the embodiments of this application, a computer program product is also provided, including a computer program that, when executed by a processor, implements the methods of various embodiments of this application.

[0018] In this embodiment, sampling voltage data of an insulation detection circuit is first acquired. This insulation detection circuit detects the first insulation resistance between the positive terminal of the power battery and the vehicle casing, and the second insulation resistance between the negative terminal of the power battery and the vehicle casing. The sampling voltage data is then filtered to obtain a data filtering result. Insulation detection is performed based on the data filtering result to obtain a detection result, which is used to determine the positive and negative insulation states corresponding to the insulation detection circuit. Finally, vehicle maintenance instructions for the target vehicle are generated using the detection result. This achieves the goal of accurately measuring the insulation resistance of the vehicle's electrical system, thereby realizing early warning, effective prevention of safety risks, ensuring the electrical safety and reliability of new energy vehicles during use, and reducing electrical accidents caused by insulation faults. This solves the technical problem of low efficiency and accuracy in the performance testing of vehicle insulation resistance in related technologies. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0020] Figure 1 This is a flowchart of a vehicle insulation resistance detection method according to an embodiment of this application;

[0021] Figure 2 This is a schematic diagram of an optional balanced bridge structure according to an embodiment of this application;

[0022] Figure 3 This is a schematic diagram of an optional balanced bridge resistance method for insulation resistance detection according to an embodiment of this application.

[0023] Figure 4 This is a schematic diagram of an optional insulation resistance detection principle where both switch 1 and switch 2 are closed, according to an embodiment of this application.

[0024] Figure 5 This is a schematic diagram of an optional insulation resistance detection principle where switch 1 is closed and switch 2 is open, according to an embodiment of this application.

[0025] Figure 6 This is a schematic diagram of an optional insulation resistance detection principle with switch 1 open and switch 2 closed according to an embodiment of this application;

[0026] Figure 7 This is a hardware block diagram of an optional unbalanced bridge resistance method for insulation detection according to an embodiment of this application;

[0027] Figure 8 This is a schematic diagram of an optional software program design flow according to an embodiment of this application;

[0028] Figure 9 This is a schematic diagram of a vehicle insulation resistance detection device according to an embodiment of this application. Detailed Implementation

[0029] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0030] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0031] According to an embodiment of this application, an embodiment of a vehicle insulation resistance detection method is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0032] This method embodiment can be executed in an electronic device or similar computing device that includes memory and a processor. Taking operation on a computer terminal as an example, the computer terminal may include one or more processors (processors may include, but are not limited to, central processing units (CPUs), graphics processing units (GPUs), digital signal processing (DSP) chips, microcontroller units (MCUs), field-programmable gate arrays (FPGAs), neural network processors (NPUs), tensor processors (TPUs), artificial intelligence (AI) type processors, etc.) and memory for storing data. Optionally, the computer terminal may also include transmission devices, input / output devices, and display devices for communication functions. Those skilled in the art will understand that the above structural description is merely illustrative and does not limit the structure of the computer terminal. For example, the computer terminal may include more or fewer components than described above, or have a different configuration than described above.

[0033] The memory can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the vehicle insulation resistance detection method in this embodiment. The processor executes various functional applications and data processing by running the computer program stored in the memory, thereby realizing the aforementioned vehicle insulation resistance detection method. The memory may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory may further include memory remotely located relative to the processor, and these remote memories can be connected to the mobile terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0034] The transmission device is used to receive or send data via a network. Specific examples of the network described above may include a wireless network provided by the mobile terminal's communication provider. In one example, the transmission device includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission device may be a Radio Frequency (RF) module, used for wireless communication with the Internet.

[0035] Display devices can be, for example, touchscreen liquid crystal displays (LCDs) and touch displays (also referred to as "touchscreens" or "touch displays"). The LCD allows users to interact with the user interface of the mobile terminal. In some embodiments, the mobile terminal has a graphical user interface (GUI), which allows users to interact with the GUI through finger contact and / or gestures on a touch-sensitive surface. Optional human-computer interaction functions include: creating web pages, drawing, word processing, creating electronic documents, playing games, video conferencing, instant messaging, sending and receiving emails, call interfaces, playing digital video, playing digital music, and / or web browsing, etc. Executable instructions for performing the above human-computer interaction functions are configured / stored in one or more processor-executable computer program products or readable storage media.

[0036] This embodiment provides a method for detecting the insulation resistance of a vehicle. Figure 1 This is a flowchart of a vehicle insulation resistance detection method according to an embodiment of this application, such as... Figure 1 As shown, the method includes the following steps:

[0037] Step S10: Obtain the sampling voltage data of the insulation detection circuit, wherein the insulation detection circuit is used to detect the first insulation resistance between the positive terminal of the power battery of the target vehicle and the vehicle shell, and the second insulation resistance between the negative terminal of the power battery and the vehicle shell.

[0038] In this embodiment, the insulation detection circuit refers to a circuit system designed based on the unbalanced bridge resistance method, used to measure and evaluate the insulation state between the power battery and the vehicle casing.

[0039] Sampling voltage data refers to the voltage values ​​obtained by the insulation detection circuit from the bridge network under different switching states. The voltage values ​​reflect the current distribution in the bridge, and thus indirectly represent the resistance values ​​of the first insulation resistance (between the positive terminal and the casing) and the second insulation resistance (between the negative terminal and the casing).

[0040] In this application, the target vehicle refers to an electric vehicle equipped with a power battery system.

[0041] The power battery is the core energy storage unit of new energy vehicles, responsible for supplying power to the electric motor and other electrical equipment.

[0042] The vehicle shell refers to the metal frame, passenger compartment, and other non-power electronic components of a new energy vehicle, which are usually used as the reference ground or safety ground for the electrical system.

[0043] The first insulation resistance refers to the insulation resistance between the positive terminal of the power battery and the vehicle casing. The first insulation resistance is an important parameter for measuring the electrical safety of the positive terminal.

[0044] The second insulation resistance refers to the insulation resistance between the negative terminal of the power battery and the vehicle casing. The second insulation resistance is an important parameter for measuring the electrical safety of the negative terminal.

[0045] As can be seen, the embodiments of this application aim to obtain voltage data reflecting the insulation state between the positive and negative electrodes of the power battery and the vehicle casing, laying the foundation for further analysis and evaluation of the safety of the power battery system.

[0046] Step S12: Filter the sampled voltage data to obtain the data filtering results;

[0047] In this embodiment of the application, the data screening result refers to the valid and reliable sampled voltage dataset that meets the detection requirements and is retained after a series of data quality control and preprocessing steps.

[0048] The data filtering process involves checking and removing outliers from the sampled voltage data to eliminate any values ​​outside the normal range. Digital filtering algorithms (such as average filtering, median filtering, or adaptive filtering) are then used to remove random noise from the data, ensuring the purity and stability of the signal. Finally, the filtered data is integrated to obtain the final data filtering result.

[0049] As can be seen, through the above screening steps, the final data screening result is a clean, calibrated and verified set of sampled voltage data. The data screening result can be used for subsequent insulation resistance calculation and provides a data basis for accurately assessing the insulation status of the power battery system.

[0050] Step S14: Perform insulation testing based on the data filtering results to obtain the test results, wherein the test results are used to determine the positive and negative insulation states of the insulation testing circuit.

[0051] In this embodiment of the application, the detection result refers to the first insulation resistance value between the positive electrode of the power battery and the vehicle casing and the second insulation resistance value between the negative electrode and the vehicle casing, which are calculated by processing and analyzing the data screening results and using the unbalanced bridge resistance method.

[0052] The positive electrode insulation status reflects the insulation condition between the positive electrode of the power battery and the vehicle casing.

[0053] The negative electrode insulation status reflects the insulation condition between the negative electrode of the power battery and the vehicle casing.

[0054] Insulation testing is performed based on the data screening results. The test results can be understood as follows: the data screening results are analyzed using the calculation model of the unbalanced bridge resistance method, and the insulation resistance values ​​between the positive and negative electrodes of the power battery and the vehicle shell are calculated, including the first insulation resistance and the second insulation resistance.

[0055] It can be seen that by conducting insulation tests on the data screening results, the test results can not only directly reflect the actual insulation performance of the power battery system, but also improve the electrical safety of new energy vehicles.

[0056] Step S16: Generate vehicle maintenance instructions for the target vehicle using the detection results.

[0057] In this embodiment, the vehicle maintenance instruction refers to specific operational guidelines or suggestions generated based on insulation test results, aimed at maintaining and repairing insulation problems in the target vehicle's power battery system. Vehicle maintenance instructions are typically output by the battery management system or the vehicle's central control unit based on the analysis of test results, directly or indirectly guiding vehicle maintenance personnel to perform necessary maintenance work to ensure the safety and reliability of the vehicle's electrical system.

[0058] For example, generating vehicle maintenance instructions for the target vehicle based on the test results can be understood as follows: if the test results show that the insulation resistance is decreasing but has not yet reached the critical point, the maintenance instruction may suggest "insulation status monitoring" or "periodic retesting" to ensure that the problem is detected and dealt with in time before it deteriorates; when the test results show that the insulation status is good, the system may generate an instruction of "insulation status normal", which is not limited here.

[0059] It can be seen that, based on vehicle maintenance instructions, potential insulation problems in the power battery system can be prevented and resolved, ensuring the electrical safety and normal operation of the vehicle.

[0060] Through the above steps, the sampling voltage data of the insulation detection circuit is first obtained. This circuit detects the first insulation resistance between the positive terminal of the power battery and the vehicle casing, and the second insulation resistance between the negative terminal of the power battery and the vehicle casing. Next, the sampling voltage data is filtered to obtain the filtering results. Then, insulation detection is performed based on the filtering results to obtain the detection results, which are used to determine the positive and negative insulation states corresponding to the insulation detection circuit. Finally, the detection results are used to generate vehicle maintenance instructions for the target vehicle. This achieves the goal of accurately measuring the insulation resistance of the vehicle's electrical system, thereby enabling early warning, effective prevention of safety risks, ensuring the electrical safety and reliability of new energy vehicles during use, and reducing electrical accidents caused by insulation faults. This solves the technical problem of low efficiency and accuracy in the performance testing of vehicle insulation resistance in related technologies.

[0061] Furthermore, the insulation detection circuit includes: a first switch, a second switch, and a bridge detection circuit. The first switch is used to control the connection state of the positive detection branch in the bridge detection circuit, and the second switch is used to control the connection state of the negative detection branch in the bridge detection circuit. In step S10, acquiring the sampling voltage data of the insulation detection circuit includes the following execution steps:

[0062] Step S101: Obtain the switch status information of the insulation detection circuit, wherein the switch status information includes: the closed state of the first switch and the closed state of the second switch.

[0063] Step S102: Obtain sampled voltage data based on switch state data.

[0064] In this embodiment, the switch state information refers to the closure information of the first and second switches. A closed state indicates that the switch is on, allowing current to flow, thereby forming a specific current path in the bridge network and providing conditions for subsequent voltage measurement.

[0065] Obtaining the switch status information of the insulation detection circuit can be understood as follows: in the insulation resistance detection circuit of the unbalanced bridge resistance method, the first switch and the second switch are used to control the signal path. The control unit monitors the status (closed or open) of the first switch and the second switch and records it through the software program.

[0066] Obtaining sampled voltage data based on switch state data can be understood as collecting sampled voltage data based on the switch state information of the first and second switches. Specifically, an analog-to-digital converter is used to digitize the voltage formed in the bridge network to obtain a series of sampled voltage data, which is not limited here.

[0067] It can be seen that by separately acquiring the switching state information of the insulation detection circuit and the sampled voltage data based on the switching state information, the accuracy and completeness of data acquisition are ensured, providing high-quality raw data for subsequent signal processing, insulation calculation and state judgment.

[0068] Further, in step S102, acquiring the sampled voltage data based on the switch state data includes the following execution steps:

[0069] Step S1021: In response to the first switch being closed and the second switch being open, the first sampled voltage is obtained based on a preset sampling frequency;

[0070] Step S1022: In response to the first switch being open and the second switch being closed, the second sampling voltage is obtained based on a preset sampling frequency;

[0071] Step S1023: Determine the sampling voltage data based on the first sampling voltage and the second sampling voltage.

[0072] In this embodiment of the application, the preset sampling frequency refers to the rate at which the analog-to-digital converter samples the bridge output signal during the data acquisition process, usually expressed as the number of samples per second.

[0073] The first sampling voltage is obtained when the first switch is closed and the second switch is open, and is used to reflect the voltage distribution on both sides of the first insulation resistance between the positive terminal of the power battery and the vehicle casing.

[0074] The second sampling voltage is obtained when the first switch is open and the second switch is closed, and is used to reflect the voltage distribution on both sides of the second insulation resistance between the negative terminal of the power battery and the vehicle casing.

[0075] In response to the first switch closing and the second switch opening, obtaining the first sampled voltage based on a preset sampling frequency can be understood as follows: when the first switch in the circuit is detected to be closed and the second switch remains open, the unbalanced bridge circuit will generate current in a specific path. This current will flow through the first insulation resistance between the positive terminal of the power battery and the vehicle casing. At this time, based on a preset sampling frequency (such as several thousand or tens of thousands of times per second), the analog-to-digital converter will continuously measure the voltage on this path to obtain the first sampled voltage.

[0076] In response to the first switch being open and the second switch being closed, obtaining the second sampled voltage based on a preset sampling frequency can be understood as follows: when the first switch in the circuit is detected to be open and the second switch remains closed, the unbalanced bridge circuit will generate current in a specific path. This current will flow through the second insulation resistance between the negative terminal of the power battery and the vehicle casing. At this time, based on a preset sampling frequency (such as several thousand or tens of thousands of times per second), the analog-to-digital converter will continuously measure the voltage on this path to obtain the second sampled voltage.

[0077] Determining the sampled voltage data based on the first and second sampled voltages can be understood as integrating the first and second sampled voltages after they have been acquired to determine the complete sampled voltage dataset.

[0078] It can be seen that by controlling the switch state, sampling voltage data related to the insulation state of the power system can be obtained at a certain sampling frequency, providing necessary information for subsequent insulation resistance calculation and condition assessment.

[0079] Further, in step S12, the sampled voltage data is filtered to obtain the data filtering results, which includes the following steps:

[0080] Step S121: The sampled voltage data is filtered using a digital filtering method to obtain the filtering result;

[0081] Step S122: The filtering results are calibrated to obtain the data filtering results.

[0082] In this embodiment, digital filtering is a signal processing technique used to remove noise and interference signals from sampled voltage data while retaining useful signal components. Exemplarily, digital filters can be classified according to different needs and characteristics; common types include low-pass filters, high-pass filters, band-pass filters, and band-stop filters, and this is not a limitation.

[0083] The filtering result refers to the effective voltage signal that has been removed by digital filtering, thus removing most of the noise and interference, and is closer to the true insulation state of the resistor under test.

[0084] Calibration typically includes zero-point calibration and gain calibration. Zero-point calibration ensures that the output voltage is zero when there is no input; gain calibration adjusts the signal amplification factor to ensure that the signal maintains a consistent amplitude under different environments.

[0085] The sampling voltage data is filtered using digital filtering. The result can be understood as removing noise and irrelevant signals from the original sampling voltage data and retaining the signal components directly related to insulation resistance detection.

[0086] The calibration of the filtering results to obtain the data selection results can be understood as performing zero-point calibration and gain calibration on the filtering results, correcting the nonlinear errors of the system hardware and the influence of the environment, thereby obtaining the data selection results.

[0087] It can be seen that digital filtering and calibration together constitute the core process of sampling voltage data preprocessing. By purifying and correcting the data, the final data screening results provide an accurate data basis for the precise measurement of insulation resistance.

[0088] Further, in step S14, insulation testing is performed based on the data screening results, and the test results are obtained through the following steps:

[0089] Step S141: In response to the fact that the first sampling voltage and the second sampling voltage in the data filtering results are both preset values, it is determined that the positive electrode insulation state and the negative electrode insulation state are both normal.

[0090] In this embodiment of the application, the preset value is a voltage threshold, which is used to determine whether the insulation state between the positive and negative terminals in the circuit is normal.

[0091] The fact that the first and second sampling voltages in the data filtering results are both preset values ​​indicates that the insulation state of both the positive and negative electrodes is normal. This can be understood as follows: when the first and second sampling voltages in the data filtering results are both equal to the preset values, it indicates that the insulation state of the positive and negative electrodes of the power battery is normal, and the vehicle can continue to operate normally.

[0092] Further, in step S14, insulation testing is performed based on the data screening results, and the test results are obtained through the following steps:

[0093] Step S142: In response to the first sampling voltage in the data filtering result being a preset value and the second sampling voltage being greater than the preset value, the positive electrode insulation state corresponding to the insulation detection circuit is determined to be an abnormal state and the negative electrode insulation state is a normal state, and the first insulation resistance is determined based on the first calculation model corresponding to the insulation detection circuit.

[0094] In this embodiment of the application, the first calculation model is a mathematical formula used to calculate the insulation resistance (i.e., the first insulation resistance) between the positive electrode of the power battery and the vehicle casing, within the framework of the unbalanced bridge resistance method.

[0095] In response to the first sampling voltage in the data filtering results being a preset value and the second sampling voltage being greater than the preset value, it is determined that the positive electrode insulation state corresponding to the insulation detection circuit is an abnormal state and the negative electrode insulation state is a normal state. The determination of the first insulation resistance based on the first calculation model corresponding to the insulation detection circuit can be understood as follows: when the first sampling voltage is equal to the preset value and the second sampling voltage is greater than the preset value, it indicates that the positive electrode insulation state of the power battery is an abnormal state and the negative electrode insulation state of the power battery is a normal state. The first insulation resistance is calculated through the first calculation model.

[0096] Further, in step S14, insulation testing is performed based on the data screening results, and the test results are obtained through the following steps:

[0097] Step S143: In response to the first sampling voltage in the data filtering result being greater than a preset value and the second sampling voltage being a preset value, the positive electrode insulation state corresponding to the insulation detection circuit is determined to be normal and the negative electrode insulation state is determined to be abnormal. The second insulation resistance is determined based on the second calculation model corresponding to the insulation detection circuit.

[0098] In this embodiment of the application, the second calculation model is a mathematical model based on the unbalanced bridge resistance method, which is used to calculate the second insulation resistance between the negative electrode and the casing under a specific switching state.

[0099] In response to the first sampling voltage being greater than a preset value and the second sampling voltage being equal to a preset value in the data filtering results, the positive electrode insulation state corresponding to the insulation detection circuit is determined to be normal and the negative electrode insulation state to be abnormal. The determination of the second insulation resistance based on the second calculation model corresponding to the insulation detection circuit can be understood as follows: when the first sampling voltage is greater than a preset value and the second sampling voltage is equal to a preset value, it indicates that the negative electrode insulation state of the power battery is abnormal and the positive electrode insulation state of the power battery is normal. The second insulation resistance is then calculated using the second calculation model.

[0100] Further, in step S14, insulation testing is performed based on the data screening results, and the test results are obtained through the following steps:

[0101] Step S144: In response to the fact that the first sampling voltage and the second sampling voltage in the data filtering results are both greater than the preset values, it is determined that both the positive electrode insulation state and the negative electrode insulation state are abnormal states, and the first insulation resistance and the second insulation resistance are determined based on the third calculation model corresponding to the insulation detection circuit.

[0102] In this embodiment of the application, the third calculation model is used to calculate the first insulation resistance and the second insulation resistance when the insulation state of both the positive and negative electrodes of the power battery is abnormal.

[0103] In response to the fact that both the first and second sampling voltages in the data filtering results are greater than preset values, it is determined that both the positive and negative insulation states are abnormal. The first and second insulation resistances are determined based on the third calculation model corresponding to the insulation detection circuit. This can be understood as follows: when both the first and second sampling voltages are greater than preset values, the insulation states of both the positive and negative terminals of the power battery are abnormal. The first and second insulation resistances are calculated by the third calculation model.

[0104] As can be seen, by comparing the first sampling voltage and the second sampling voltage with preset values ​​through steps S141 to S144, the system can effectively monitor the insulation status of the positive and negative electrodes of the power battery and ensure the safe operation of the vehicle's electrical system.

[0105] The following is a specific embodiment provided in this application. Figure 2 This is a schematic diagram of an optional balanced bridge structure according to an embodiment of this application, as shown below. Figure 2 As shown, a balanced bridge is essentially a quadrilateral circuit structure consisting of four resistors R0, R1, and R2 and the resistor to be measured, Rx. Two opposite vertices (A and B) are connected to the power supply, while the other two vertices (C and D) are connected to the measuring instruments, commonly voltmeters or ammeters. In the insulation resistance detection system based on the unbalanced bridge resistance method, these four resistors R0, R1, R2, and the resistor to be measured, Rx, are composed of known standard resistors and the insulation resistance to be measured, respectively.

[0106] exist Figure 2 In the bridge circuit shown, the bridge consists of four resistors R0, R1, R2 and the resistor being measured, Rx. When the bridge reaches equilibrium, that is, the potentials at points C and D are equal. Based on Kirchhoff's laws, it can be deduced that... .

[0107] When the bridge circuit is unbalanced, a voltage difference will be generated across the measuring instrument. Using Kirchhoff's laws, the formula for the insulation resistance Rx of the bridge circuit in an unbalanced state can also be derived. Figure 3 This is a schematic diagram of an optional balanced bridge resistance method for insulation resistance detection according to an embodiment of this application, as shown below. Figure 3 As shown, in the practical application of insulation resistance testing in new energy vehicles, the traditional balance bridge schematic needs to be optimized. Taking the insulation resistance testing of the battery management system as an example, the key lies in accurately measuring the insulation resistance between the positive and negative terminals of the power battery and the vehicle casing.Figure 3 As shown, with the vehicle housing as the center of symmetry, two symmetrically distributed unbalanced bridge circuits are designed. The sampling voltages Up and Un are obtained by controlling the closing and opening of switches 1 and 2. Given that resistors R1=R4, R2=R3, and R1>R2, the insulation resistances RI1 and RI2 between the positive and negative terminals of the power battery and the vehicle housing can be measured using the calculation formula.

[0108] Specifically, there are generally four situations regarding the insulation resistance between the positive and negative electrodes of a new energy vehicle's power battery and the casing: both positive and negative electrodes have good insulation; the positive electrode has abnormal insulation, while the negative electrode has good insulation; the positive electrode has good insulation, while the negative electrode has abnormal insulation; and both positive and negative electrodes have abnormal insulation.

[0109] All four scenarios can be derived and calculated using the voltage sampling values ​​Up and Un of switches 1 and 2 under different closed states, combined with known parameters such as resistors R1 and R2, and relevant electrical formulas. The specific derivation process is as follows: When switches 1 and 2 are closed simultaneously, the voltage across R2 is defined as Up0 and the voltage across R3 as Un0; when switch 1 is closed and switch 2 is open, the voltage across R2 is defined as Up1 and the voltage across R3 as Un1; when switch 1 is open and switch 2 is closed, the voltage across R2 is defined as Up2 and the voltage across R3 as Un2.

[0110] Specifically, the battery voltage value is obtained directly through the vehicle's power battery management system. Alternatively, the power battery voltage value can be obtained through sampling and calculation using an unbalanced bridge circuit. . Figure 4 This is a schematic diagram of an optional insulation resistance detection principle where both switch 1 and switch 2 are closed, according to an embodiment of this application. Figure 4 As shown, the power battery voltage value is obtained by sampling and calculation using an unbalanced bridge circuit. This includes: simultaneously closing switches 1 and 2, and then, based on the principle of voltage division by resistance, obtaining:

[0111]

[0112]

[0113] Figure 5 This is a schematic diagram of an optional insulation resistance detection principle with switch 1 closed and switch 2 open, according to an embodiment of this application. Figure 5As shown, when switch 1 is closed and switch 2 is open, the voltage across R2 is Up1, and the voltage across R3 is Un1; since switch 2 is open, Un1 = 0V. When Up1 = 0V, the insulation resistance of the negative terminal (i.e., the second insulation resistance) RI2 is infinite, meaning the negative terminal insulation is good; when Up1 > 0V, according to the principle of voltage division, we can obtain:

[0114]

[0115] Figure 6 This is a schematic diagram of an optional insulation resistance detection principle with switch 1 open and switch 2 closed according to an embodiment of this application, such as... Figure 6 As shown, when switch 2 is closed and switch 1 is open, the voltage across R2 is Up2 and the voltage across R3 is Un2; since switch 1 is open, Up2 = 0V. When Un2 = 0V, the positive insulation resistance (i.e., the first insulation resistance) RI1 is infinite, meaning the positive insulation is good; when Un2 > 0V, according to the principle of voltage division, we can obtain:

[0116]

[0117] Assumption:

[0118]

[0119]

[0120]

[0121] When Up1=0V and Un2=0V, the insulation resistance values ​​RI1 and RI2 of the positive and negative terminals are both infinite, indicating that the insulation of the positive and negative terminals of the power battery is good.

[0122] When Up1=0V and Un2>0V, the negative terminal of the power battery has good insulation, while the positive terminal has abnormal insulation. At this time, the insulation resistance value RI2 of the negative terminal is infinite. Substituting into the formula... The positive electrode insulation resistance value can be obtained as follows: .

[0123] When Up1>0V and Un2=0V, the positive terminal of the power battery has good insulation, while the negative terminal has abnormal insulation. At this time, the positive terminal insulation resistance value RI1 is infinite. Substituting into the formula... The insulation resistance value of the negative electrode can be obtained. .

[0124] When Up1>0V and Un2>0V, the insulation of both the positive and negative terminals of the power battery is abnormal. (The formula is missing from the original text.) , By combining the equations, the insulation resistance value of the positive electrode can be obtained. The insulation resistance value of the negative electrode is .

[0125] Figure 7 This is a hardware block diagram of an optional unbalanced bridge resistance method for insulation detection according to an embodiment of this application, such as... Figure 7 As shown, an Inter-Integrated Circuit (IIC) is used to electrically isolate the insulation detection circuit from the microcontroller unit (MCU) of the main control section. This ensures that the insulation performance of the vehicle is not affected, while accurately measuring the insulation resistance and protecting the main control device. The isolation power supply circuit includes: ±5V power supply for positive and negative insulation resistance detection, which is generated by a general-purpose B0505S-1WR3 module and then -5V by a charge pump ME7660CS1G. The bridge resistor network consists of 1206 resistors with 1% accuracy (E96), and the switch is handled by a KAQY214STLD optical MOS device. A capacitor and a Zener diode are connected in parallel across the sampled resistor to reduce interference, improve sampling accuracy, and protect the sampling port. The signal amplification circuit uses two domestic 3Peak high-voltage operational amplifiers (TP2582-VR) to form two instrumentation amplifiers, used to acquire the voltage values ​​across the positive and negative sampling resistors of the unbalanced bridge. Analog-to-Digital Converter (ADC) acquisition circuit: The domestically produced MS1112 chip is used. This chip has a 16-bit high-precision resolution, which can accurately convert the analog signal output from the bridge into a digital signal, and also has the advantage of low power consumption. I2C isolators include: the domestically produced 3Peak I2C isolator TPT72617-SSO1R.

[0126] This application also provides a vehicle insulation resistance detection system, including: a data acquisition module: which accurately acquires the bridge output signal by configuring the relevant registers of the ADC; supports multi-channel synchronous acquisition, and can simultaneously acquire signals from multiple detection points; and has a real-time data verification function, which immediately triggers re-acquisition and records the abnormal information if data abnormality is detected. A signal processing module: which uses a digital filtering algorithm to denoise the acquired data. It also performs zero-point calibration and gain calibration on the signal to eliminate the influence of circuit component errors and environmental factors on the signal. An insulation resistance calculation module: which has a built-in unbalanced bridge resistance method calculation model and automatically selects an appropriate calculation formula based on the actual circuit structure and measurement conditions. A result processing and uploading module: which uploads the calculated insulation resistance value, and the host judges the insulation state and issues a response processing command.

[0127] Figure 8This is a schematic diagram of an optional software program design flow according to an embodiment of this application, such as... Figure 8 As shown, when the program starts, it first initializes and configures the microprocessor, ADC, and hardware devices, specifically setting the microprocessor's operating mode and initializing the ADC sampling frequency and resolution to ensure that each hardware module is in normal operating condition. Next, according to the preset sampling frequency, the ADC acquires the bridge output signal in real time and converts the acquired analog signal into a digital signal. This signal is then transmitted to the MCU via an IIC isolator, and the acquired digital signal is filtered in real time to eliminate noise interference. Based on the calculation results of the signal processing algorithm, the signal is calibrated and compensated to improve signal accuracy. The processed data is stored to provide a basis for subsequent insulation resistance calculations. Then, based on the selected calculation model and the processed data, combined with known standard resistance values, the insulation resistance value to be measured is calculated. Next, the calculation results are verified for accuracy and error analysis. If the error exceeds the allowable range, the signal processing and calculation are repeated. Finally, the calculated insulation resistance value is uploaded, and the host determines the positive and negative insulation status of the power battery, issuing response processing commands based on the insulation status.

[0128] Therefore, this application addresses the testing needs of power batteries for new energy vehicles by optimizing the traditional bridge design and deriving the insulation resistance calculation formula under different operating conditions. This achieves the technical effect of real-time monitoring of insulation resistance, ensuring electrical safety, and reducing power generation efficiency loss.

[0129] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, use and processing of the relevant data must comply with the relevant laws, regulations and standards of the relevant countries and regions, and corresponding operation entry points are provided for users to choose to authorize or refuse.

[0130] According to an embodiment of this application, a vehicle insulation resistance testing device is provided. It should be noted that the device can be used to perform the above-described vehicle insulation resistance testing method.

[0131] Figure 9 This is a schematic diagram of a vehicle insulation resistance detection device according to an embodiment of this application, as shown below. Figure 9As shown, the vehicle insulation resistance detection device 900 includes: an acquisition module 901, used to acquire sampling voltage data of an insulation detection circuit, wherein the insulation detection circuit is used to detect the first insulation resistance between the positive terminal of the power battery of the target vehicle and the vehicle casing, and the second insulation resistance between the negative terminal of the power battery and the vehicle casing; a screening module 902, used to screen the sampling voltage data to obtain data screening results; a detection module 903, used to perform insulation detection based on the data screening results to obtain detection results, wherein the detection results are used to determine the positive and negative insulation states corresponding to the insulation detection circuit; and a generation module 904, used to generate vehicle maintenance instructions for the target vehicle using the detection results.

[0132] It should be noted that the above modules can be implemented by software or hardware. For the latter, they can be implemented in the following ways, but are not limited to: all the above modules are located in the same processor; or, the above modules are located in different processors in any combination.

[0133] Embodiments of this application also provide a vehicle, including: a memory storing an executable program; and a processor for running the program, wherein the program executes the methods described in various embodiments of this application when it runs.

[0134] Optionally, in this embodiment, the processor can be configured to perform the following steps via a computer program:

[0135] Step S10: Obtain the sampling voltage data of the insulation detection circuit, wherein the insulation detection circuit is used to detect the first insulation resistance between the positive terminal of the power battery of the target vehicle and the vehicle shell, and the second insulation resistance between the negative terminal of the power battery and the vehicle shell.

[0136] Step S12: Filter the sampled voltage data to obtain the data filtering results;

[0137] Step S14: Perform insulation testing based on the data filtering results to obtain the test results, wherein the test results are used to determine the positive and negative insulation states of the insulation testing circuit.

[0138] Step S16: Generate vehicle maintenance instructions for the target vehicle using the detection results.

[0139] Embodiments of this application also provide a computer-readable storage medium including a stored executable program, wherein, when the executable program is running, it controls the device where the computer-readable storage medium is located to perform the methods of various embodiments of this application.

[0140] Optionally, in this embodiment, the storage medium may be configured to store a computer program for performing the following steps:

[0141] Step S10: Obtain the sampling voltage data of the insulation detection circuit, wherein the insulation detection circuit is used to detect the first insulation resistance between the positive terminal of the power battery of the target vehicle and the vehicle shell, and the second insulation resistance between the negative terminal of the power battery and the vehicle shell.

[0142] Step S12: Filter the sampled voltage data to obtain the data filtering results;

[0143] Step S14: Perform insulation testing based on the data filtering results to obtain the test results, wherein the test results are used to determine the positive and negative insulation states of the insulation testing circuit.

[0144] Step S16: Generate vehicle maintenance instructions for the target vehicle using the detection results.

[0145] Embodiments of this application also provide a computer program product, including a computer program that, when executed by a processor, implements the methods of various embodiments of this application.

[0146] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0147] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0148] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0149] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0150] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0151] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for detecting the insulation resistance of a vehicle, characterized in that, include: Acquire sampling voltage data of insulation detection circuit, wherein the insulation detection circuit is used to detect the first insulation resistance between the positive terminal of the power battery of the target vehicle and the vehicle shell, and the second insulation resistance between the negative terminal of the power battery and the vehicle shell. The sampled voltage data is filtered to obtain the data filtering results; Insulation testing is performed based on the data filtering results to obtain test results, wherein the test results are used to determine the positive and negative insulation states of the insulation testing circuit. The detection results are used to generate vehicle maintenance instructions for the target vehicle.

2. The method according to claim 1, characterized in that, The insulation detection circuit includes: a first switch, a second switch, and a bridge detection circuit. The first switch is used to control the connection state of the positive detection branch in the bridge detection circuit, and the second switch is used to control the connection state of the negative detection branch in the bridge detection circuit. Acquiring the sampling voltage data of the insulation detection circuit includes: Obtain the switch status information of the insulation detection circuit, wherein the switch status information includes: the closed state of the first switch and the closed state of the second switch; The sampled voltage data is obtained based on the switch state data.

3. The method according to claim 2, characterized in that, Obtaining the sampled voltage data based on the switch state data includes: In response to the first switch being closed and the second switch being open, a first sampled voltage is acquired based on a preset sampling frequency; In response to the first switch being open and the second switch being closed, a second sampling voltage is obtained based on the preset sampling frequency; The sampling voltage data is determined based on the first sampling voltage and the second sampling voltage.

4. The method according to claim 1, characterized in that, The sampled voltage data is filtered to obtain the following data filtering results: The sampled voltage data is filtered using a digital filtering method to obtain the filtering result. The filtering results are calibrated to obtain the data filtering results.

5. The method according to claim 3, characterized in that, Insulation testing is performed based on the data filtering results, and the test results include: Since both the first sampling voltage and the second sampling voltage in the data filtering results are preset values, it is determined that both the positive electrode insulation state and the negative electrode insulation state are normal.

6. The method according to claim 3, characterized in that, Insulation testing is performed based on the data filtering results, and the test results include: In response to the first sampling voltage being a preset value in the data filtering result, and the second sampling voltage being greater than the preset value, the positive electrode insulation state corresponding to the insulation detection circuit is determined to be an abnormal state, the negative electrode insulation state is determined to be a normal state, and the first insulation resistance is determined based on the first calculation model corresponding to the insulation detection circuit.

7. The method according to claim 3, characterized in that, Insulation testing is performed based on the data filtering results, and the test results include: In response to the first sampling voltage being greater than a preset value in the data filtering results, and the second sampling voltage being the preset value, the positive electrode insulation state corresponding to the insulation detection circuit is determined to be normal, the negative electrode insulation state is determined to be abnormal, and the second insulation resistance is determined based on the second calculation model corresponding to the insulation detection circuit.

8. The method according to claim 3, characterized in that, Insulation testing is performed based on the data filtering results, and the test results include: In response to the fact that both the first sampling voltage and the second sampling voltage in the data filtering results are greater than preset values, it is determined that both the positive electrode insulation state and the negative electrode insulation state are abnormal states, and the first insulation resistance and the second insulation resistance are determined based on the third calculation model corresponding to the insulation detection circuit.

9. A vehicle, characterized in that, include: Memory, which stores executable programs; A processor for running the program, wherein the program, when running, performs the method according to any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored executable program, wherein, when the executable program is executed, it controls the device on which the storage medium is located to perform the method according to any one of claims 1 to 8.

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