Fault judgment method and device, readable storage medium and electronic equipment

Abstract

The application discloses a fault judgment method and device, a readable storage medium and an electronic device. The fault judgment method comprises the following steps: on the basis of sampling data of a current transient quantity, a single-point change quantity, a cumulative change quantity and a moving range of the sampling data of the current transient quantity are calculated, wherein the sampling data is obtained by high-pass filtering and high-frequency sampling processing on the current transient quantity in a power system; it is determined that the single-point change quantity is greater than a first threshold value, or the cumulative change quantity is greater than a second threshold value; it is determined that the moving range before a preset time of the single-point change quantity or the cumulative change quantity is less than a third threshold value; and it is judged that a fault occurs.

Description

Technical Field

[0001] This application relates to the field of power system relay protection, and more specifically, to a fault diagnosis method and apparatus, a readable storage medium, and an electronic device. Background Technology

[0002] A "transient state" refers to the transition process when a circuit changes its state from a stable state under certain conditions (such as a fault in the power grid circuit) and enters another stable state through a transition process.

[0003] "Transient quantity" refers to a data reference quantity that changes during a transient process, such as current transient quantity and voltage transient quantity.

[0004] When a fault occurs in the power system, the voltage in the power grid changes significantly, causing fluctuations and redistribution of energy in energy storage components such as inductors and capacitors in the power grid, which in turn generates a large number of high-frequency transient quantities.

[0005] The method of fault diagnosis in power grid systems based on high-frequency transient quantities has the advantages of high sensitivity and fast start-up speed. Rapidly determining whether a fault has occurred in the power grid is an important basis and fundamental condition for implementing traveling wave ranging and transient quantity protection, and is of great significance to the safe operation of the power system.

[0006] Fault detection methods based on high-frequency transients rely on fault detection algorithms for transient components (such as current transients and / or voltage transients). When a transient component satisfies a certain preset fault detection algorithm, a fault is detected in the power grid.

[0007] However, the inventors of this application have discovered the following problems with the current fault diagnosis algorithm.

[0008] 1. When a power grid fault occurs, the change value and amplitude of transient quantities are related to multiple factors such as the fault condition and the power grid architecture. Fault judgment algorithms need to consider both cases where the transient quantity changes rapidly or slowly. Currently, wavelet transform algorithms or fault judgment algorithms that use a single change quantity as a criterion have certain limitations.

[0009] 2. Current fault diagnosis algorithms cannot effectively distinguish between interference and fault transients. When subjected to interference from other factors, they may misdiagnose faults and have poor anti-interference capabilities.

[0010] 3. Current fault diagnosis algorithms do not assess the stationarity of transient quantities before a fault, which can easily lead to misjudgments. Summary of the Invention

[0011] According to a first aspect of this application, a fault diagnosis method is provided. The method includes calculating, based on sampled data of a current transient quantity, the single-point change, the cumulative change, and the moving range of the sampled current transient quantity, wherein the sampled data is obtained by high-pass filtering and high-frequency sampling of the current transient quantity in the power system; determining that the single-point change is greater than a first threshold, or the cumulative change is greater than a second threshold; determining that the moving range before a preset time of the single-point change or the cumulative change is less than a third threshold; and determining that a fault has occurred.

[0012] For example, in some embodiments of the first aspect of this disclosure, the sampling data includes transient current values, and the formula for calculating the single-point change is: ΔI p (k)=|I(k)-I(k-ΔT p )|, where ΔI p (k) represents the single-point change in the transient current value at point k; I(k) represents the transient current value at point k; I(k-ΔT) p ) is the k-ΔT p The transient current value at the point; ΔT p The step size is used to calculate the change at a single point; where k is a non-zero natural number.

[0013] For example, in some embodiments of the first aspect of this disclosure, the formula for calculating the cumulative change is: Where, ΔI i (k) represents the cumulative change in the transient current value at point k; I(j) represents the transient current value at point j; L is the data window length for calculating the cumulative change; ΔT i The step size is used to calculate the cumulative change, where j is a non-zero natural number.

[0014] For example, in some embodiments of the first aspect of this disclosure, the moving range is the difference between the maximum value and the minimum value of the current transient quantity within a preset time window; the formula for calculating the moving range is:

[0015] I pp (k)=max{I(k-N+1),…,I(k-1),I(k)}-min{I(k-N+1),…,I(k-1),I(k)}

[0016] Among them, I pp (k) represents the moving range of the transient current value at point k; N is the time window length for calculating the moving range.

[0017] For example, in some embodiments of the first aspect of this disclosure, it is determined that the single-point change is greater than a first threshold, or the cumulative change is greater than a second threshold; the determining equation for determining that the moving range before a preset time of the single-point change or the cumulative change is less than a third threshold is:

[0018] or

[0019] Where, ΔI set_p The first threshold; ΔI set_i The second threshold; I set_pp The third threshold is Δk, which is the preset time. The first and second thresholds are floating thresholds, and the third threshold is a fixed threshold.

[0020] For example, in some embodiments of the first aspect of this disclosure, the formula for calculating the first threshold is: ΔI set_p =D set_p +aI pp (k-Δk), where D set_p Δk is the preset value; a is the preset coefficient; Δk is the preset time length, I pp (k-Δk) represents the moving range before the preset time; the formula for calculating the second threshold is: ΔI set_i =D set_i +bI pp (k-Δk), where D set_i b is the preset value; Δk is the preset coefficient; I is the preset time length. pp (k-Δk) represents the moving range before the preset time.

[0021] For example, in some embodiments of the first aspect of this disclosure, the cutoff frequency of the high-pass filter is greater than or equal to 1 kHz.

[0022] For example, in some embodiments of the first aspect of this disclosure, the sampling frequency of high-frequency sampling is greater than 10 kHz.

[0023] According to a second aspect of this disclosure, a fault diagnosis device is provided, comprising: a data acquisition unit for performing high-pass filtering and high-frequency sampling on a current transient quantity at the fault diagnosis device to obtain sampled data of the current transient quantity; a processing unit for receiving the sampled data and, based on the sampled data, calculating the single-point change, cumulative change, and moving range of the sampled data of the current transient quantity; and a judgment unit for judging the magnitude of the single-point change and a first threshold, judging the magnitude of the cumulative change and a second threshold, and judging the magnitude of the moving range before a preset time of the single-point change or cumulative change and a third threshold; if the judgment unit judges that the single-point change is greater than the first threshold, or judges that the cumulative change is greater than the second threshold, and the moving range before the preset time of the single-point change or cumulative change is less than the third threshold, the judgment unit judges that a fault has occurred.

[0024] According to a third aspect of this disclosure, a non-volatile computer-readable storage medium is provided having a computer program stored thereon, the computer program causing a fault diagnosis device to perform the method described above.

[0025] According to a fourth aspect of this disclosure, a fault diagnosis electronic device is provided, comprising: one or more processors; a storage device for storing one or more programs; wherein when the one or more programs are executed by the one or more processors, the one or more processors perform the method described above.

[0026] This application provides a technical solution that, when the current transient quantity changes rapidly, determines the magnitude of a single-point change and a first threshold. When the current transient quantity changes slowly, it determines the magnitude of a cumulative change and a second threshold. When the single-point change or cumulative change meets certain conditions, it further compares the moving range of the current transient quantity with a third threshold, and judges the stability of the transient quantity before a preset time before the fault occurs based on the moving range.

[0027] The technical solution provided in this application can address different changes in transient quantities when a fault occurs, and uses the stability of the transient quantities before a preset time before the fault occurs as a reference quantity to make fault judgments on the power grid from multiple perspectives, which can effectively improve the reliability of fault judgment criteria. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 A flowchart 1000 showing a fault determination method according to an example embodiment of this application is provided.

[0030] Figure 2 Figure 2000 illustrates a data sampling process according to an example embodiment of this application;

[0031] Figure 3 This diagram illustrates a fault determination logic diagram 3000 according to an example embodiment of this application.

[0032] Figure 4 A schematic diagram 4000 of a fault determination device according to an example embodiment of this application is shown.

[0033] Figure label:

[0034] Fault diagnosis device 1; data acquisition unit 10; processing unit 30; judgment unit 50. Detailed Implementation

[0035] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this application will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted.

[0036] The described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a full understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced without one or more of these specific details, or other methods, components, materials, devices, etc. In these cases, well-known structures, methods, devices, implementations, materials, or operations will not be shown or described in detail.

[0037] 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 includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0038] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, rather than to describe a specific order.

[0039] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0040] According to one aspect of this application, a fault diagnosis method is provided. Figure 1 A flowchart 1000 illustrates a fault determination method according to an example embodiment of this application.

[0041] See Figure 1 Method 1000 includes steps S110 to S170.

[0042] In step S110, the fault diagnosis device calculates the single-point change, cumulative change, and moving range of the current transient quantity based on the sampled data. The sampled data of the current transient quantity is obtained by performing high-pass filtering and high-frequency sampling processing on the current transient quantity in the power system.

[0043] According to the example embodiment, transient current quantities in the power system are collected as sampling data.

[0044] For example, high-pass filtering and high-frequency sampling are performed on the transient current to obtain the sampled data of the transient current.

[0045] Figure 2 Figure 2000 illustrates a data sampling process according to an example embodiment of this application.

[0046] See Figure 2 Data sampling includes high-pass filtering and high-frequency sampling of transient current quantities in the power system. The following section combines... Figure 2 To describe Figure 1 Step S110 in the process.

[0047] For example, see Figure 1 and Figure 2 In step S110, the original analog value I′(t) of the current transient quantity is acquired. A high-pass filter is then applied to the original analog value I′(t) of the current transient quantity to obtain the analog value I(t) of the current transient quantity.

[0048] High-pass filtering is a filtering method that allows high-frequency signals to pass through normally, while blocking low-frequency signals below a set threshold.

[0049] According to the example embodiment, the analog raw value I′(t) of the current transient quantity connected to the fault judgment device is generally collected by a current transformer. The current value collected by the current transformer is the secondary current, which, in addition to the required current transient quantity, also contains some power frequency quantity and noise.

[0050] The frequency of power frequency quantities is generally 50Hz or 60Hz, while the frequency of transient quantities is much higher than that of power frequency quantities. Therefore, the original analog value I′(t) of the acquired current transient quantity needs to be high-pass filtered to remove impurities such as power frequency quantities and low-frequency noise, so as to reduce the interference of power frequency quantities and noise on the fault diagnosis algorithm.

[0051] See Figure 1 and Figure 2 In step S110, the data sampling process also includes performing high-frequency sampling on the analog value I(t) of the current transient quantity obtained after high-pass filtering to obtain the sampled data, namely the current transient quantity value I(k).

[0052] High-frequency sampling refers to collecting data values ​​that are higher than a preset frequency value from the sampled data.

[0053] Optionally, according to the example embodiment, the sampling frequency of high-frequency sampling is not less than 10kHz.

[0054] See Figure 1 In step S110, based on the sampling data of the current transient quantity, the single-point change, cumulative change, and moving range of the sampling data of the current transient quantity are calculated.

[0055] Optionally, the sampling data of the current transient quantity is the current transient quantity value I(k).

[0056] Optionally, in step S110, the formula for calculating the single-point change is:

[0057] ΔI p (k)=|I(k)-I(k-ΔT p )|

[0058] Where, ΔI p (k) represents the single-point change in the transient current value at point k; I(k) represents the transient current value at point k; I(k-ΔT) p ) is the k-ΔT p The transient current value at the point; ΔT p The step size is used to calculate the change at a single point; where k is a non-zero natural number.

[0059] According to the example embodiment, when the current transient quantity changes rapidly, the single-point change represents the change from point k to point k-ΔT. p The process of change of the transient current at a point.

[0060] The step size for calculating the change at a single point is determined based on actual needs. For example, ΔT p The value of can typically be 4.

[0061] Optionally, in step S110, the formula for calculating the cumulative change is:

[0062]

[0063] Where, ΔI i (k) represents the cumulative change in the transient current value at point k; I(j) represents the transient current value at point j; L is the data window length for calculating the cumulative change; ΔT i The step size is used to calculate the cumulative change, where j is a non-zero natural number.

[0064] According to the example embodiment, when the change in current transient quantity is small or slow, the cumulative change represents the cumulative change in current transient quantity calculated within a certain data window length L.

[0065] For example, the data window length L for calculating the cumulative change of current transient quantity can be taken as the number of sampling points corresponding to 100µs, and the step size ΔT for calculating the cumulative change of current transient quantity can be taken as... i The number of sampling points corresponding to 200us can be selected.

[0066] Optionally, in step S110, the range of the current transient quantity is the difference between the maximum value and the minimum value of the current transient quantity within a preset time window.

[0067] According to the example embodiment, the formula for calculating the moving range is:

[0068] I pp (k)=max{I(k-N+1),…,I(k-1),I(k)}-min{I(k-N+1),…,I(k-1),I(k)}

[0069] Among them, I pp (k) represents the moving range of the transient current value at point k; N is the time window length for calculating the moving range.

[0070] The time window length N for calculating the moving range should be greater than the maximum variation period of the random noise. The specific value of N depends on the conditions of the selected hardware facilities.

[0071] Through the above examples, when the current transient quantity changes rapidly, the single-point change represents the change process of the current transient quantity. When the change amplitude of the current transient quantity is small or the change is slow, the cumulative change represents the change process of the current transient quantity over a certain time window.

[0072] The moving range calculation is used to calculate the difference between the maximum and minimum values ​​of the transient current within a certain preset time window. This difference is used to incorporate the stability of the transient quantity within a specific time before the fault occurs into the reference value, so as to characterize the stability of the transient quantity before the fault.

[0073] In step S130, the fault determination device determines that the single-point change is greater than the first threshold, or the cumulative change is greater than the second threshold.

[0074] According to the example embodiment, in step S130, the magnitude of the single-point change is determined to be the same as that of the first threshold.

[0075] For example, the change at a single point ΔI p (k) represents the transient current value at any point k, and the first threshold is ΔI. set_p .

[0076] Determine the change ΔI at a single pointp (k) and the first threshold ΔI set_p The first equation for determining size is:

[0077] ΔI p (k)>ΔI set_p

[0078] Optionally, the first threshold ΔI set_p The first threshold ΔI is a floating threshold that varies with the moving range before a preset time. set_p The calculation formula is as follows:

[0079] ΔI set_p =D set_p +aI pp (k-Δk)

[0080] Among them, D set_p Δk is the preset value; a is the preset coefficient; Δk is the preset time length, I pp (k-Δk) represents the moving range before the preset time.

[0081] According to the example embodiment, in step S130, the magnitude of the cumulative change and the second threshold are also determined.

[0082] For example, the cumulative change ΔI i (k) represents the cumulative change at any point k, and the second threshold is ΔI. set_i .

[0083] Determine the cumulative change ΔI i (k) and the second threshold ΔI set_i The second equation for determining size is:

[0084] ΔI i (k)>ΔI set_i

[0085] Optionally, the second threshold ΔI set_i This is a floating threshold. The second threshold ΔI set_i The second threshold ΔI changes with the range of movement before a preset time. set_i The calculation formula is as follows:

[0086] ΔI set_i =D set_i +bI pp (k-Δk)

[0087] Among them, D set_i b is the preset value; Δk is the preset coefficient; I is the preset time length. pp (k-Δk) represents the moving range before the preset time.

[0088] According to the example embodiment, if it is determined in step S130 that the first judgment equation or the second judgment equation is satisfied, then proceed to step S150.

[0089] In step S150, it is determined that the moving range before a preset time for the single-point change or the cumulative change is less than the third threshold.

[0090] According to the example embodiment, in step S150, when the single-point change is greater than the first threshold or the cumulative change is greater than the second threshold, the magnitude of the moving range before the preset time of the single-point change or cumulative change that satisfies the first judgment equation or the second judgment equation is determined to be the same as the third threshold.

[0091] For example, I pp(k-△k) The third threshold is I, representing the range of movement before a preset time. set_pp .

[0092] △k is the interval step size corresponding to the preset time. The setting of △k needs to take into account factors such as the rate of change of the transient quantity and the magnitude of the change of the transient quantity. The value of △k needs to be set according to the specific actual situation.

[0093] In step S150, the moving range I is determined. pp (k) and the third threshold I set_pp The third equation for determining size is:

[0094] I pp(k-△k) <I set_pp

[0095] According to the example embodiment, the third threshold I set_pp Fixed threshold. Third threshold I set_pp The third threshold I is set based on the actual noise level of the fault diagnosis device; the higher the noise, the higher the threshold I. set_pp The larger the value, the better.

[0096] In the above embodiment, in step S150, the fault determination device determines the magnitude of the movement range before a preset time and the third threshold. When the movement range before the preset time is less than the third threshold, the process proceeds to step S170.

[0097] In step S170, it is determined that a fault has occurred.

[0098] For example, in step S170, when the single-point change or cumulative change satisfies the first judgment equation or the second judgment equation, and the moving range before the preset time satisfies the third judgment equation, the fault judgment device determines that a fault has occurred and executes the corresponding action (e.g., executing wave ranging or starting the transient quantity protection algorithm).

[0099] For example, Figure 3 A fault judgment logic diagram 3000 according to an example embodiment of this application is shown.

[0100] See Figure 3 The fault determination algorithm equation is as follows:

[0101] satisfy

[0102]

[0103] Or satisfy

[0104]

[0105] Through the above example embodiments, the technical solution of this application determines the magnitude of a single-point change and a first threshold when the current transient quantity changes rapidly, and determines the magnitude of a cumulative change and a second threshold when the current transient quantity changes slowly.

[0106] When the single-point change or cumulative change meets certain conditions, the moving range of the current transient quantity is compared with the third threshold, and the stability of the transient quantity before the preset time of the fault is judged based on the moving range.

[0107] The technical solution provided in this application can address the changes in transient quantities when different faults occur, and use the stability of transient quantities before a preset time of fault occurrence as a reference quantity to make fault judgments on the power grid from multiple perspectives, which can effectively improve the reliability of fault judgment criteria.

[0108] According to another aspect of this application, a fault diagnosis device is also provided. Figure 3 A schematic diagram 3000 of a fault determination device according to an example embodiment of this application is shown.

[0109] See Figure 3 The fault diagnosis device 1 includes a data acquisition unit 10, a processing unit 30, and a judgment unit 50.

[0110] According to the example embodiment, the data acquisition unit 10 performs high-pass filtering and high-frequency sampling processing on the current transient quantity connected to the fault judgment device 1 to obtain the acquired data.

[0111] The process of acquiring transient current data has been described in detail above and will not be repeated here.

[0112] The processing unit 30 receives the sampled data and, based on the sampled data, calculates the single-point change, cumulative change, and moving range of the sampled data of the transient current.

[0113] According to an example embodiment, the fault determination device 1 includes the fault determination method as described above.

[0114] The above fault diagnosis method has described in detail the process of obtaining single-point change, cumulative change and moving variance and the calculation formula, so it will not be elaborated on again.

[0115] The judgment unit 50 judges the magnitude of the single-point change and the first threshold, the magnitude of the cumulative change and the second threshold, and the magnitude of the moving range before a preset time of the single-point change or the cumulative change and the third threshold.

[0116] When the judgment result is that the single-point change at any point k is greater than the first threshold, or the cumulative change at any point k is greater than the second threshold, and the moving range before the preset time of the single-point change or the cumulative change is less than the third threshold, the judgment unit 50 judges that a power grid fault has occurred in the power system.

[0117] Through the above example embodiments, the technical solution of this application determines the magnitude of a single-point change and a first threshold when the current transient quantity changes rapidly, and determines the magnitude of a cumulative change and a second threshold when the current transient quantity changes slowly.

[0118] When the single-point change or cumulative change meets certain conditions, the moving range of the current transient quantity is compared with the third threshold, and the stability of the transient quantity before the preset time of the fault is judged based on the moving range.

[0119] The technical solution provided in this application can address different changes in transient quantities when a fault occurs, and uses the stability of the transient quantities before a preset time before the fault occurs as a reference quantity to make fault judgments on the power grid from multiple perspectives, which can effectively improve the reliability of fault judgment criteria.

[0120] According to another aspect of this application, a non-volatile computer-readable storage medium is also provided, on which a computer program is stored, the computer program being able to implement the fault diagnosis method described above.

[0121] According to another aspect of this application, an electronic device for fault diagnosis is also provided, comprising: one or more processors; and a storage device for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors are enabled to implement the fault diagnosis method described above.

[0122] Finally, it should be noted that the above description is merely a preferred embodiment of this application and is not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions of the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A fault diagnosis method, characterized in that, include: Based on the sampling data of the current transient quantity, the single-point change, cumulative change and moving range of the sampling data of the current transient quantity are calculated, wherein the sampling data is obtained by high-pass filtering and high-frequency sampling processing of the current transient quantity in the power system. Determine that the single-point change is greater than a first threshold, or the cumulative change is greater than a second threshold; Determine that the moving range before a preset time of the single-point change or the cumulative change is less than a third threshold. Determine if a fault has occurred; The sampled data includes transient current values, and the formula for calculating the single-point change is: in, For the first The single-point change in the transient current value at a point; For the first The transient current value at the point; For the first The transient current value at the point; The step size for calculating the single-point change; where k is a non-zero natural number; The formula for calculating the cumulative change is: in, For the first The cumulative change in the transient current value at a point; For the first The transient current value at the point; The data window length for calculating the cumulative change; The step size for calculating the cumulative change, where j is a non-zero natural number; The moving range is the difference between the maximum value and the minimum value of the transient current value within a preset time window; The formula for calculating the moving range is: in, For the first The range of the transient current value at a point; The time window length for calculating the moving range.

2. The method according to claim 1, characterized in that, The equation for determining that the single-point change is greater than a first threshold, or the cumulative change is greater than a second threshold, and that the moving range before a preset time of the single-point change or the cumulative change is less than a third threshold, is as follows: or in, The first threshold; The second threshold; The third threshold; The preset time is defined as follows: the first threshold and the second threshold are floating thresholds, and the third threshold is a fixed threshold.

3. The method according to claim 2, characterized in that, The formula for calculating the first threshold is: in, This is a preset value; These are preset coefficients; For the preset time length, The range of movement before the preset time; The formula for calculating the second threshold is: in, This is a preset value; These are preset coefficients; For the preset time length, The range of movement before the preset time.

4. The method according to claim 1, characterized in that, The cutoff frequency of the high-pass filter is greater than or equal to 1 kHz.

5. The method according to claim 1, characterized in that, The sampling frequency of the high-frequency sampling is greater than 10kHz.

6. A fault diagnosis device, characterized in that, include: The data acquisition unit performs high-pass filtering and high-frequency sampling on the current transient quantity at the fault judgment device to obtain the sampling data of the current transient quantity; The processing unit receives the sampled data and, based on the sampled data, calculates the single-point change, cumulative change, and moving range of the sampled data of the transient current quantity. The judgment unit determines the magnitude of the single-point change and the first threshold, the magnitude of the cumulative change and the second threshold, and the magnitude of the moving range before a preset time of the single-point change or the cumulative change and the third threshold. If the judgment unit determines that the single-point change is greater than the first threshold, or determines that the cumulative change is greater than the second threshold, and the movement range before the preset time of the single-point change or the cumulative change is less than the third threshold, the judgment unit determines that a fault has occurred. The sampled data includes transient current values, and the formula for calculating the single-point change is: in, For the first The single-point change in the transient current value at a point; For the first The transient current value at the point; For the first The transient current value at the point; The step size for calculating the single-point change; where k is a non-zero natural number; The formula for calculating the cumulative change is: in, For the first The cumulative change in the transient current value at a point; For the first The transient current value at the point; The data window length for calculating the cumulative change; The step size for calculating the cumulative change, where j is a non-zero natural number; The moving range is the difference between the maximum value and the minimum value of the transient current value within a preset time window; The formula for calculating the moving range is: in, For the first The range of the transient current value at a point; The time window length for calculating the moving range.

7. A non-volatile computer-readable storage medium having a computer program stored thereon, characterized in that, The computer program enables the fault diagnosis device to implement the method described in any one of claims 1 to 5.

8. A fault diagnosis electronic device, characterized in that, include: One or more processors; Storage device for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the method as described in any one of claims 1 to 5.

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