A diagnostic method and device for a vehicle battery protection switch and a storage medium

Abstract

The application provides a diagnosis method and device of an on-board battery protection switch and a storage medium. The on-board battery is located between a voltage transformation module and a battery load. A first end of the protection switch is connected to a voltage end of the voltage transformation module. A second end of the protection switch is connected to a voltage end of the on-board battery. The diagnosis method comprises the following steps: disconnecting the protection switch; controlling the voltage transformation module to output a first characteristic voltage with a changing amplitude within a first diagnosis time window; determining a maximum value and a minimum value of a second voltage at the second end of the protection switch within the first diagnosis time window; and judging whether the protection switch has a disconnection fault according to a first difference between the maximum value and the minimum value. Through the execution of the steps, the diagnosis method can accurately diagnose whether the on-board battery protection switch has a disconnection fault when the on-board battery is powered on, and reduce the diagnosis cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of vehicle-mounted batteries, and in particular to a diagnosis method for a vehicle-mounted battery protection switch, a device for a vehicle-mounted battery protection switch, and a microcontroller readable storage medium. BACKGROUND

[0002] With the increasing emphasis on environmental protection and the consideration of battery life, lead-acid batteries are being replaced by other new types of vehicle-mounted batteries such as lithium batteries, sodium batteries, etc. due to their greater pollution and shorter life.

[0003] New vehicle-mounted batteries (e.g. lithium batteries) are designed to have a protection switch for the purpose of protecting themselves from overcurrent. The opening and closing functions of the protection switch need to be diagnosed every time the vehicle is powered on to troubleshoot faults in the protection switch itself.

[0004] The prior art mainly provides a direct current voltage to the protection switch and measures the voltage difference across the protection switch when it is in the closed or open state to troubleshoot the opening and closing faults of the protection switch. If the measured voltage difference is about 0V, it is considered that the protection switch is actually closed. Conversely, if the measured voltage difference is large, it is considered that the protection switch is actually open.

[0005] However, this existing diagnosis method is only suitable for components that do not have their own electromotive force, but not for devices that have their own electromotive force. Because when the vehicle is powered on, the DC / DC converter module at the front end needs to work in constant voltage mode to ensure that other battery loads can work normally when the protection switch of the vehicle-mounted battery is in the open state. At this time, the voltage difference across the vehicle-mounted battery will become less obvious under the action of the electromotive force of the vehicle-mounted battery itself, resulting in the system misdiagnosing the protection switch as closed, determining that it has an opening fault, issuing a false alarm, and ultimately causing the vehicle to fail to power on.

[0006] In order to overcome the above-mentioned defects of the prior art, there is an urgent need in the art for a diagnosis technology for a vehicle-mounted battery protection switch for multiplexing existing hardware to accurately diagnose the opening fault of the protection switch when the vehicle-mounted battery is powered on and reducing the diagnosis cost. SUMMARY

[0007] The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

[0008] In order to overcome the above-mentioned defects of the prior art, the application provides a diagnosis method of a vehicle-mounted battery protection switch, a diagnosis device of the vehicle-mounted battery protection switch, and a microcontroller readable storage medium, which can adapt to the diagnosis needs of devices with self-induced electromotive force, accurately diagnose the disconnection fault of the protection switch by multiplexing the existing hardware when the vehicle-mounted battery is powered on, and reduce the diagnosis cost.

[0009] Specifically, in the diagnosis method of the vehicle-mounted battery protection switch provided in the first aspect of the application, the vehicle-mounted battery is located between a voltage conversion module and a battery load. A first end of the protection switch is connected to a voltage end of the voltage conversion module. A second end of the protection switch is connected to a voltage end of the vehicle-mounted battery. The diagnosis method comprises the following steps: disconnecting the protection switch; controlling the voltage conversion module to output a first characteristic voltage with a varying amplitude within a first diagnosis time window; determining a maximum value and a minimum value of a second voltage at the second end of the protection switch within the first diagnosis time window; and determining whether the protection switch has a disconnection fault according to a first difference between the maximum value and the minimum value.

[0010] Preferably, in an embodiment of the application, the step of determining the maximum value and the minimum value of the second voltage at the second end of the protection switch within the first diagnosis time window comprises: measuring the second voltage in real time within the first diagnosis time window to cache a plurality of voltage measurement values; and determining the maximum value and the minimum value of the second voltage within the first diagnosis time window from the plurality of voltage measurement values.

[0011] Preferably, in an embodiment of the application, the step of determining the maximum value and the minimum value of the second voltage at the second end of the protection switch within the first diagnosis time window comprises: assigning an initial value of the second voltage to a first variable and a second variable in response to the protection switch being disconnected; measuring the second voltage in real time within the first diagnosis time window; updating the value of the first variable according to a real-time measurement value of the second voltage in response to the real-time measurement value being greater than a current value of the first variable; updating the value of the second variable according to the real-time measurement value of the second voltage in response to the real-time measurement value being less than a current value of the second variable; and determining the maximum value of the second voltage within the first diagnosis time window according to the current value of the first variable and determining the minimum value of the second voltage within the first diagnosis time window according to the current value of the second variable in response to the first diagnosis time window being closed.

[0012] Preferably, in an embodiment of the present application, the step of determining whether the protection switch has the opening fault according to the first difference between the maximum voltage value and the minimum voltage value comprises: determining whether the first difference is greater than a preset first voltage difference threshold; determining that the protection switch has the opening fault in response to a determination result that the first difference is greater than the first voltage difference threshold; and determining that the protection switch does not have the opening fault in response to a determination result that the first difference is less than or equal to the first voltage difference threshold.

[0013] Preferably, in an embodiment of the present application, the diagnostic method further comprises the following steps: closing the protection switch; controlling the variable voltage module to output a second characteristic voltage with a varying amplitude within a second diagnostic time window; measuring a first voltage of the first terminal of the protection switch and a second voltage of the second terminal of the protection switch within the second diagnostic time window in real time; and determining whether the protection switch has a closing fault according to a second difference between the first voltage and the second voltage measured simultaneously.

[0014] Preferably, in an embodiment of the present application, the step of determining whether the protection switch has the closing fault according to the second difference between the first voltage and the second voltage measured simultaneously comprises: measuring and buffering a plurality of first measurement values of the first voltage and corresponding measurement time points and a plurality of second measurement values of the second voltage and corresponding measurement time points within the second diagnostic time window; calculating the second difference between the first voltage and the second voltage at a plurality of measurement time points according to the plurality of first measurement values and the plurality of second measurement values in response to the second diagnostic time window being closed; determining that the protection switch has the closing fault in response to a determination result that any of the second differences at the measurement time points is greater than a preset second voltage difference threshold; and determining that the protection switch does not have the closing fault in response to a determination result that each of the second differences at the measurement time points is less than or equal to the second voltage difference threshold.

[0015] Preferably, in an embodiment of the present application, the step of determining whether the protection switch has the closing fault according to the second difference between the first voltage and the second voltage measured simultaneously comprises: simultaneously measuring the first voltage and the second voltage within the second diagnostic time window and calculating the second difference between the first voltage and the second voltage in real time; in response to the result that the second difference is less than or equal to the second voltage difference threshold, performing again the steps of measuring the first voltage and the second voltage and calculating the second difference in real time; in response to the result that the second difference is greater than the preset second voltage difference threshold, outputting in real time the result that the protection switch has the closing fault; and in response to the result that the second diagnostic time window is closed and the result that the protection switch has the closing fault is not outputted, determining that the protection switch does not have the closing fault.

[0016] Preferably, in an embodiment of the present application, before controlling the voltage transformation module to output the first characteristic voltage and / or the second characteristic voltage, the diagnostic method further comprises the step of: determining the first characteristic voltage and / or the second characteristic voltage according to the maximum working voltage and the minimum working voltage allowed by the battery load.

[0017] Optionally, in an embodiment of the present application, the waveform of the first characteristic voltage and / or the second characteristic voltage is selected from one or more combinations of the following: step wave, ramp wave, acceleration wave, square wave, sine wave, pulse wave.

[0018] In addition, the diagnostic device for the vehicle-mounted battery protection switch provided by the second aspect of the present application comprises: a first voltage probe connected to a first end of the protection switch for collecting a first voltage of the first end; a second voltage probe connected to a second end of the protection switch for collecting a second voltage of the second end; a memory having microcontroller instructions stored thereon; and a processor communicatively connected to the first voltage probe, the second voltage probe and the memory and configured to execute the microcontroller instructions stored on the memory to implement the diagnostic method for the vehicle-mounted battery protection switch provided by any one of the above embodiments.

[0019] In addition, the microcontroller readable storage medium provided by the second aspect of the present application has microcontroller instructions stored thereon. When the microcontroller instructions are executed by a processor, the diagnostic method for the vehicle-mounted battery protection switch provided by any one of the above embodiments is implemented. BRIEF DESCRIPTION OF DRAWINGS

[0020] The above features and advantages of the present application will be better understood by reading the detailed description of the embodiments of the present application in conjunction with the drawings, in which:

[0021] Figure 1 A circuit schematic diagram of a vehicle battery system according to some embodiments of the present application is shown.

[0022] Figure 2 A flowchart diagram of diagnosing an open fault of a protection switch according to some embodiments of the present application is shown.

[0023] Figure 3 A waveform diagram of a feature voltage according to some embodiments of the present application is shown.

[0024] Figure 4 A comparative diagram of a protection switch timing, a feature voltage, a first voltage and a second voltage according to some embodiments of the present application is shown.

[0025] Figure 5 A flowchart diagram of diagnosing a close fault of a protection switch according to some embodiments of the present application is shown. DETAILED DESCRIPTION

[0026] The specific embodiments of the present application will be described in the following detailed description with reference to the accompanying drawings, in which:

[0027] In the description of the present application, it is necessary to note that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "linking" should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through intermediate medium, can be internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0028] In addition, "upper", "lower", "left", "right", "top", "bottom", "horizontal", "vertical" used in the following description and shown in the related drawings should be understood as the orientation shown in the section and the related drawings. The relative terms are only for the convenience of description, and do not mean that the device described thereby should be manufactured or operated in a specific orientation, and therefore should not be understood as a limitation of the present application.

[0029] It can be understood that although the terms "first", "second", "third" and the like are used herein to describe various components, regions, layers and / or parts, these components, regions, layers and / or parts should not be limited by these terms, and these terms are only used to distinguish different components, regions, layers and / or parts. Therefore, the first components, regions, layers and / or parts discussed below can be referred to as the second components, regions, layers and / or parts without departing from some embodiments of the present application.

[0030] As described above, the new vehicle-mounted battery (for example: lithium battery) will have a protection switch for its own overcurrent protection. The disconnection and closure functions of the protection switch need to be diagnosed every time the vehicle is powered on to check the fault of the protection switch itself. In the prior art, the DC / DC conversion module needs to work in constant voltage mode to ensure that other battery loads can work normally when the protection switch of the vehicle-mounted battery is in the open state. However, at this time, the voltage difference between the two ends of the protection switch will become not obvious under the action of the electromotive force of the vehicle-mounted battery itself, thereby causing the system to misdiagnose the protection switch as a closed state and resulting in vehicle power-on failure.

[0031] In order to overcome the above-mentioned defects existing in the prior art, the present application provides a diagnosis method for a vehicle-mounted battery protection switch, a diagnosis device for a vehicle-mounted battery protection switch, and a microcontroller readable storage medium, which can adapt to the characteristics that the DC / DC must be in working state when the vehicle-mounted battery is powered on, and reuse the existing hardware to accurately diagnose the disconnection fault of the protection switch when the vehicle-mounted battery is powered on, and reduce the diagnosis cost.

[0032] In some non-limiting embodiments, the above-mentioned diagnosis method for a vehicle-mounted battery protection switch provided by the first aspect of the present application can be implemented by the above-mentioned diagnosis device for a vehicle-mounted battery protection switch provided by the second aspect of the present application. Specifically, the diagnosis device can be configured with a first voltage probe, a second voltage probe, a memory and a processor. The memory includes but is not limited to the above-mentioned microcontroller readable storage medium provided by the third aspect of the present application, and the microcontroller instructions are stored thereon. The processor is connected to the memory and is configured to execute the microcontroller instructions stored on the memory to implement the diagnosis method for a vehicle-mounted battery protection switch provided by the first aspect of the present application.

[0033] The working principle of the diagnostic device for the vehicle battery protection switch will be described below in combination with some embodiments of diagnostic methods for the vehicle battery protection switch. Those skilled in the art can understand that the embodiments of the diagnostic methods for the vehicle battery protection switch are only some non-limiting embodiments provided by the present application, which are intended to clearly demonstrate the main concept of the present application and provide some specific schemes for facilitating the public to implement, rather than to limit the overall function or overall working mode of the diagnostic device for the vehicle battery protection switch. Similarly, the diagnostic device for the vehicle battery protection switch is also only a non-limiting embodiment provided by the present application, which does not limit the execution subject and execution mode of each step in the diagnostic methods for the vehicle battery protection switch.

[0034] First of all, please refer to Figure 1 , Figure 1 The circuit schematic diagram of the vehicle battery system provided according to some embodiments of the present application is shown.

[0035] As Figure 1 shown, in some embodiments of the present application, the vehicle battery 11 can be a direct-current auxiliary battery configured in a vehicle, including but not limited to 12V lithium battery, 24V lithium battery, sodium battery, and various voltage levels and various energy storage principles of vehicle high-performance battery. The vehicle battery 11 can be configured between the voltage conversion module 12 and the battery load 13, charged by the power battery 20 of the vehicle via the voltage conversion module 12, and powers the battery load 13 at the back end. The first end of the protection switch S1 is connected to the voltage end (for example: positive electrode) of the voltage conversion module 13, and the second end is connected to the voltage end (for example: positive electrode) of the vehicle battery 11. The first voltage probe and the second voltage probe of the diagnostic device can be connected to the first end and the second end of the protection switch S1 respectively, to collect the first voltage V1 of the first end and the second voltage V2 of the second end, and to perform fault diagnosis of the protection switch S1 according to the first voltage V1 and the second voltage V2.

[0036] Please refer to Figure 2 , Figure 2 The flowchart of diagnosing the disconnection fault of the protection switch provided according to some embodiments of the present application is shown.

[0037] As Figure 2 shown, in the process of diagnosing whether the protection switch S1 has a disconnection fault, the diagnostic device can first send a disconnection command to the protection switch S1 to disconnect the protection switch S1, and then control the voltage conversion module 12 to output a first characteristic voltage with a magnitude change within a first diagnosis time window T1. Here, the first characteristic voltage can be selected from one or a combination of more than one of various common waveforms such as step wave, ramp wave, acceleration wave, square wave, sine wave, and pulse wave.

[0038] Further, in order to avoid affecting the normal work of the battery load 13 during the power-on process of the vehicle, the technician can also determine the maximum amplitude and minimum amplitude of the first characteristic voltage according to the maximum working voltage and the minimum working voltage allowed by the battery load 13 before the control transformer module 12 outputs the first characteristic voltage, so as to obtain the first characteristic voltage with amplitude variation.

[0039] For details, please refer to Figure 3 , Figure 3 The waveform diagram of the characteristic voltage provided according to some embodiments of the present application is shown. In Figure 3 In the embodiment shown, the first characteristic voltage can first decrease from 14V to 9V based on the minimum working voltage Umin of the battery load 13, then increase from 9V to 16V based on the maximum working voltage Umax of the battery load 13, and finally return from 16V to 14V. In this way, the first characteristic voltage neither affects the normal work of the battery load 13 nor has a large enough amplitude variation, thereby increasing the accuracy of the disconnection fault diagnosis result.

[0040] As Figure 2 shown, after outputting the first characteristic voltage, the diagnosis device can determine the maximum value and the minimum value of the second voltage V2 of the second end of the protection switch within the first diagnosis time window, and determine whether the protection switch has a disconnection fault according to the first difference between the maximum value and the minimum value.

[0041] Specifically, in the process of determining the maximum value and the minimum value of the second voltage V2 within the first diagnosis time window T1, the diagnosis device can first measure the second voltage V2 in real time within the first diagnosis time window T1 and store it in the microcontroller (MCU) buffer area of the battery management system (BMS) of the vehicle-mounted battery 11 to buffer multiple voltage measurement values. Then, in response to the first diagnosis time window T1 being closed, the diagnosis device can freeze the buffered data in the MCU buffer area of the BMS of the vehicle-mounted battery 11, and from the multiple voltage measurement values, statistically determine the maximum value max(V2) and the minimum value min(V2) of the second voltage V2 within the first diagnosis time window T1.

[0042] Optionally, in some other embodiments, in the process of determining the maximum and minimum values of the second voltage V2 within the first diagnostic time window T1, the diagnostic device can also implement this function by other algorithms. For example, in response to the protection switch being turned off, the diagnostic device can assign the initial value of the second voltage V2 to the first variable V2Max and the second variable V2Min, and measure the second voltage V2 in real time within the first diagnostic time window T1. Then, in response to the real-time measurement value of the second voltage V2 being greater than the current value of the first variable V2Max, the diagnostic device can update the value of the first variable V2Max according to the real-time measurement value. Alternatively, in response to the real-time measurement value of the second voltage V2 being less than the current value of the second variable V2Min, the diagnostic device can update the value of the second variable V2Min according to the real-time measurement value. Alternatively, in response to the real-time measurement value of the second voltage V2 being neither greater than the current value of the first variable V2Max nor less than the current value of the second variable V2Min, the first variable V2Max and the second variable V2Min remain unchanged. Then, in response to the first diagnostic time window T1 being closed, the diagnostic device can stop updating the first variable V2Max and the second variable V2Min, determine the maximum value max(V2) of the second voltage V2 within the first diagnostic time window T1 according to the current value of the first variable V2Max, and determine the minimum value min(V2) of the second voltage V2 within the first diagnostic time window T1 according to the current value of the second variable V2Min.

[0043] After determining the maximum value max(V2) and the minimum value min(V2) of the second voltage V2 within the first diagnostic time window T1, the diagnostic device can calculate the first difference D1 between the maximum value max(V2) and the minimum value min(V2) of the second voltage V2 within the first diagnostic time window T1.

[0044] Please refer to Figure 4 , Figure 4 The comparative diagram of the protection switch timing, the characteristic voltage, the first voltage and the second voltage provided according to some embodiments of the present application is shown.

[0045] As Figure 4 shown, after calculating the first difference D1 between the maximum value max(V2) and the minimum value min(V2) of the second voltage V2 within the first diagnostic time window T1, the diagnostic device can determine whether the first difference D1 is greater than a preset first pressure difference threshold D1 th . In response to the determination result that the first difference D1 is greater than the first pressure difference threshold D1 th , the diagnostic device can determine that the protection switch S1 has a disconnection fault. Conversely, in response to the determination result that the first difference D1 is less than or equal to the first pressure difference threshold D1 th , the diagnostic device can determine that the protection switch S1 does not have a disconnection fault.

[0046] Thus, by performing the step of diagnosing whether the protection switch has an open fault, the application can adapt to the feature that the DC / DC must be in working state when the vehicle battery 11 is powered on, accurately diagnose the open fault of the protection switch S1 by reusing the existing hardware when the vehicle battery 11 is powered on, and reduce the diagnosis cost. Figure 2

[0047] Please further refer to Figure 5 , Figure 5 Fig. 2 shows a flowchart of diagnosing the closed fault of the protection switch according to some embodiments of the application.

[0048] As shown in Figure 4 and Figure 5 , in the process of diagnosing whether the protection switch has a closed fault, the diagnosis device can first send a closing command to the protection switch S1 to close the protection switch S1, and then control the voltage transformation module 12 to output a second characteristic voltage with a variable amplitude within a second diagnosis time window T2. Here, the second characteristic voltage can be selected from one or a combination of multiple ones of various common waveforms such as a step wave, a ramp wave, an accelerating wave, a square wave, a sine wave, and a pulse wave.

[0049] Further, in order to avoid affecting the normal work of the battery load 13 during the power-on of the vehicle, the skilled person can also determine the maximum amplitude and the minimum amplitude of the second characteristic voltage in advance according to the maximum working voltage and the minimum working voltage allowed by the battery load 13 to obtain the second characteristic voltage with a variable amplitude before controlling the voltage transformation module 12 to output the second characteristic voltage. Here, the amplitude of the second characteristic voltage needs to be large enough to increase the accuracy of the diagnosis result, and cannot be too large to avoid affecting the normal work of the battery load 13. As shown in Figure 3 , the amplitude of the second characteristic voltage should be designed to be between the maximum working voltage Umax and the minimum working voltage Umin allowed by the battery load 13 to avoid causing the battery load 13 to work abnormally and to avoid the problem of vehicle power failure.

[0050] It should be noted that although the first characteristic voltage and the second characteristic voltage are illustrated as the same waveform in this article, it can be understood that the skilled person in the art can also use characteristic voltages with different waveforms based on the above-mentioned concept provided by the application to achieve the effect of diagnosing the open fault and the closed fault, respectively.

[0051] Please continue to refer to Figure 4 and Figure 5 ​After outputting the second characteristic voltage, the diagnostic device can measure the first voltage V1 of the first end of the protection switch S1 within the second diagnostic time window T2 and the second voltage V2 of the second end of the protection switch S1 within the second diagnostic time window T2 in real time. Then, the diagnostic device can further determine whether the protection switch has a closing fault according to the second difference D2 between the simultaneously measured first voltage V1 and second voltage V2.

[0052] Specifically, in the process of determining whether the protection switch S1 has a closing fault, the diagnostic device can first measure a plurality of first measurement values of the first voltage V1 and their corresponding measurement time points and a plurality of second measurement values of the second voltage V2 and their corresponding measurement time points within the second diagnostic time window T2, and store them in the MCU cache area of the battery management system (BMS) of the vehicle-mounted battery 11. Then, in response to the second diagnostic time window T2 being closed, the diagnostic device can calculate the second difference D2 between the first voltage V1 and the second voltage V2 at the plurality of measurement time points according to the plurality of first measurement values and the plurality of second measurement values cached in the MCU cache area of the battery management system (BMS) of the vehicle-mounted battery 11. In response to the second difference D2 at any measurement time point being greater than the preset second pressure difference threshold D2 th , the diagnostic device can determine that the protection switch S1 has the closing fault. Conversely, in response to the second difference D2 at each measurement time point being less than or equal to the second pressure difference threshold D2 th , the diagnostic device can determine that the protection switch S1 does not have the closing fault.

[0053] Further, in some embodiments, the diagnostic device can also calculate the second difference D2 in real time to determine whether the protection switch has a closing fault in real time, thereby improving the diagnosis efficiency of the closing fault. Specifically, the diagnostic device can measure the first voltage V1 and the second voltage V2 simultaneously within the second diagnostic time window T2 and calculate the second difference D2 between the first voltage V1 and the second voltage V2 in real time. In response to the second difference D2 being less than or equal to the second pressure difference threshold D2 th , the diagnostic device can continue to cyclically perform the steps of measuring the first voltage V1 and the second voltage V2 and calculating the second difference D2 in real time. Conversely, in response to the second difference D2 being greater than the preset second pressure difference threshold D2 th , the diagnostic device can output the result that the protection switch S1 has a closing fault in real time. Then, in response to the second diagnostic time window T2 being closed and the result that the protection switch S1 has a closing fault not being output, the diagnostic device can determine that the protection switch S1 does not have a closing fault.

[0054] In this way, by performing Figure 5The step of diagnosing whether the protection switch has a closing fault, the present application can reuse the existing hardware to accurately diagnose the closing fault of the protection switch S1 when the vehicle battery 11 is powered on, and reduce the diagnosis cost.

[0055] In summary, by outputting the characteristic voltage with amplitude change to the protection switch S1, the above-mentioned diagnosis method, device and storage medium of the vehicle battery protection switch provided by the present application can adapt to the feature that the voltage conversion module 12 needs to work in constant voltage mode when the vehicle is powered on, thereby reusing the existing hardware to accurately diagnose the opening fault and closing fault of the protection switch when the vehicle battery is powered on, and reducing the diagnosis cost.

[0056] Although the above-described methods are illustrated and described as a series of acts for simplicity, it will be appreciated and understood that the methods are not limited by the order of acts, as some acts can, in accordance with one or more embodiments, occur simultaneously or in different order than shown and described herein, or can occur with other acts not expressly shown and described herein.

[0057] Those skilled in the art will understand that information, signals, and data can be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that can be referenced throughout the above description can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0058] Those skilled in the art will further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein can be implemented as electronic hardware, microcontroller software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans can implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

[0059] The foregoing description of the disclosure has been presented for purposes of illustration and description. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A diagnostic method for an on-board battery protection switch, wherein, The vehicle battery is located between the transformer module and the battery load. The first terminal of the protection switch is connected to the voltage terminal of the transformer module, and the second terminal of the protection switch is connected to the voltage terminal of the vehicle battery. The diagnostic method includes the following steps: Disconnect the protection switch; The transformer module is controlled to output a first characteristic voltage with amplitude variation within the first diagnostic time window; Determine the maximum and minimum values ​​of the second voltage at the second terminal of the protection switch within the first diagnostic time window; and Based on the first difference between the maximum value and the minimum value, it is determined whether the protection switch has a disconnection fault.

2. The diagnostic method as described in claim 1, characterized in that, The step of determining the maximum and minimum values ​​of the second voltage at the second terminal of the protection switch within the first diagnostic time window includes: The second voltage is measured in real time within the first diagnostic time window to cache multiple voltage measurements; and The maximum and minimum values ​​of the second voltage within the first diagnostic time window are determined from the plurality of voltage measurements.

3. The diagnostic method as described in claim 1, characterized in that, The step of determining the maximum and minimum values ​​of the second voltage at the second terminal of the protection switch within the first diagnostic time window includes: In response to the protection switch being opened, the initial value of the second voltage is assigned to the first variable and the second variable; The second voltage is measured in real time within the first diagnostic time window; In response to the real-time measurement value of the second voltage being greater than the current value of the first variable, the value of the first variable is updated according to the real-time measurement value; In response to the real-time measured value of the second voltage being less than the current value of the second variable, the value of the second variable is updated based on the real-time measured value; and In response to the first diagnostic time window being closed, the maximum value of the second voltage within the first diagnostic time window is determined based on the current value of the first variable, and the minimum value of the second voltage within the first diagnostic time window is determined based on the current value of the second variable.

4. The diagnostic method as described in claim 1, characterized in that, The step of determining whether the protection switch has a disconnection fault based on the first difference between the maximum value and the minimum value includes: Determine whether the first difference is greater than a preset first differential pressure threshold; In response to the determination that the first difference is greater than the first differential pressure threshold, it is determined that the protective switch has the disconnection fault; and In response to the determination result that the first difference is less than or equal to the first differential pressure threshold, it is determined that the protection switch does not have the disconnection fault.

5. The diagnostic method as described in claim 1, characterized in that, The diagnostic method further includes the following steps: Close the protection switch; The transformer module is controlled to output a second characteristic voltage with amplitude variation within the second diagnostic time window; The first voltage at the first terminal of the protection switch and the second voltage at the second terminal of the protection switch within the second diagnostic time window are measured in real time. Based on the second difference between the first voltage and the second voltage measured simultaneously, it is determined whether the protection switch has a closing fault.

6. The diagnostic method as described in claim 5, characterized in that, The step of determining whether the protection switch has a closing fault based on the second difference between the simultaneously measured first voltage and second voltage includes: Within the second diagnostic time window, multiple first measurement values ​​of the first voltage and their corresponding measurement times, as well as multiple second measurement values ​​of the second voltage and their corresponding measurement times, are measured and cached respectively. In response to the second diagnostic time window being closed, a second difference between the first voltage and the second voltage at each of the plurality of measurement times is calculated based on the plurality of first measurement values ​​and the plurality of second measurement values. In response to a determination that the second difference at any of the measurement moments is greater than a preset second differential pressure threshold, it is determined that the protective switch has a closing fault; and In response to the determination that the second difference at each of the measurement times is less than or equal to the second differential pressure threshold, it is determined that the protection switch does not have the closing fault.

7. The diagnostic method as described in claim 5, characterized in that, The step of determining whether the protection switch has a closing fault based on the second difference between the simultaneously measured first voltage and second voltage includes: Within the second diagnostic time window, the first voltage and the second voltage are measured simultaneously, and the second difference between the first voltage and the second voltage is calculated in real time. In response to the judgment result that the second difference is less than or equal to the preset second differential pressure threshold, the steps of measuring the first voltage and the second voltage are performed again, and the step of calculating the second difference in real time is performed. In response to the judgment that the second difference is greater than the second differential pressure threshold, the result that the protective switch has a closing fault is output in real time; and In response to the second diagnostic time window being closed and no result being output indicating that the protection switch has the closing fault, it is determined that the protection switch does not have the closing fault.

8. The diagnostic method as described in claim 5, characterized in that, Before controlling the transformer module to output the first characteristic voltage and / or the second characteristic voltage, the diagnostic method further includes the following steps: The first characteristic voltage and / or the second characteristic voltage are determined based on the highest and lowest operating voltages allowed by the battery load.

9. The diagnostic method as described in claim 8, characterized in that, The waveforms of the first characteristic voltage and / or the second characteristic voltage are selected from one or more of the following combinations: step wave, ramp wave, acceleration wave, square wave, sine wave, and pulse wave.

10. A diagnostic device for a vehicle battery protection switch, characterized in that, include: A first voltage probe is connected to the first terminal of the protection switch and is used to collect the first voltage at the first terminal. The second voltage probe is connected to the second terminal of the protection switch and is used to collect the second voltage at the second terminal. The memory stores the microcontroller instructions. as well as The processor is communicatively connected to the first voltage probe, the second voltage probe, and the memory, and is configured to execute microcontroller instructions stored in the memory to implement the diagnostic method for the vehicle battery protection switch as described in any one of claims 1 to 9.

11. A microcontroller-readable storage medium storing microcontroller instructions thereon, characterized in that, When the microcontroller instructions are executed by the processor, the diagnostic method for the vehicle battery protection switch as described in any one of claims 1 to 9 is implemented.

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