Fault threshold dynamic adjustment method capable of being used in field of fault diagnosis

Abstract

The invention relates to the field of circuit fault diagnosis, and discloses a fault threshold value dynamic adjustment method capable of being used in the field of fault diagnosis, and the method comprises the steps: obtaining a real-time current data sample of a distribution line; determining a preset frequency scale factor according to a preset frequency component proportion in the real-time current data sample; determining a fault threshold scaling factor of the real-time current data sample based on a preset frequency scaling factor; and adjusting a preset fault threshold according to the fault threshold scaling factor to obtain an electrical fault threshold of the distribution line. The preset frequency scale factor is determined according to the preset frequency component, the fault threshold telescopic factor of the distribution line is further determined, and the electrical fault threshold is determined according to the preset fault threshold and the fault threshold telescopic factor, so that the fault threshold can be dynamically adjusted according to the change of the preset frequency scale factor; false report or missing report caused by a fixed fault threshold value is avoided, and the accuracy and reliability of fault detection are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit fault diagnosis, and in particular to a fault threshold dynamic adjustment method that can be used in the field of fault diagnosis. Background Art

[0002] Due to factors such as line damage, aging, and loose connections in the power distribution system, fault arcs may be triggered, causing local high temperatures, which can easily lead to electrical fires or even explosions. The center temperature of the arc can be as high as 5000K to 15000K, and once a breakdown point occurs, it will occur frequently. Therefore, fire accidents caused by electrical fires are generally more serious, and it is of great significance to avoid electrical fires as much as possible.

[0003] In order to ensure the safe operation of the power system, the scientific and industrial communities have developed a large number of electrical fault protection devices based on fault diagnosis technology, and with the continuous improvement of microprocessor performance, various electrical fault detection algorithms have been transplanted into them. The large-scale application of such electrical fault protection devices has greatly reduced the risk of electrical fires, but the specific value of the fault diagnosis threshold has become a difficult problem. If the fault diagnosis threshold is set too low, it can be more sensitive to the detection of electrical faults, but it is also prone to false alarms; if the fault diagnosis threshold is set too high, it can effectively reduce the problem of false operation of the electrical fault protection device, but it will cause missed detection of electrical faults.

[0004] The above contents are only used to assist in understanding the technical solution of the present invention and do not constitute an admission that the above contents are prior art. Summary of the invention

[0005] The main purpose of the present invention is to provide a method for dynamically adjusting a fault threshold that can be used in the field of fault diagnosis, aiming to solve the technical problem in the prior art of difficulty in setting the size of the fault threshold in different power usage scenarios.

[0006] To achieve the above object, the present invention provides a method for dynamically adjusting a fault threshold value that can be used in the field of fault diagnosis. The method comprises the following steps:

[0007] Obtain real-time current data samples of distribution lines;

[0008] Determining a preset frequency proportional factor according to the proportion of the preset frequency component in the real-time current data sample;

[0009] determining a fault threshold scaling factor for the real-time current data sample based on the preset frequency scaling factor;

[0010] The preset fault threshold is adjusted according to the fault threshold scaling factor to obtain the electrical fault threshold of the distribution line.

[0011] Optionally, the step of determining the frequency proportional factor according to the proportion of the preset frequency component in the real-time current data sample includes:

[0012] Performing a micro Fourier transform on the real-time current data sample to obtain a preset frequency component of the real-time current data sample;

[0013] The proportion of the preset frequency component in the real-time current data sample is determined to obtain a preset frequency proportional factor.

[0014] Optionally, the step of determining a fault threshold scaling factor of the real-time current data sample based on the preset frequency scaling factor comprises:

[0015] Obtaining a target form of the fault threshold scaling factor;

[0016] When the target form is an exponential form, a fault threshold scaling factor in the exponential form is constructed based on the preset frequency scaling factor.

[0017] Optionally, the step of adjusting a preset fault threshold according to the fault threshold scaling factor to obtain an electrical fault threshold of the distribution line includes:

[0018] The fault threshold scaling factor is multiplied by a preset fault threshold, and the result of the operation is used as the electrical fault threshold of the distribution line.

[0019] Optionally, the step of obtaining a real-time current data sample of a distribution line includes:

[0020] Collect current signals of distribution lines;

[0021] The current signal is sampled according to a preset sampling frequency to obtain real-time current data samples.

[0022] Optionally, the step of sampling the current signal according to a preset sampling frequency to obtain a real-time current data sample includes:

[0023] Sampling the current signal according to a preset sampling frequency to obtain a current signal sequence to be processed;

[0024] A subsequence of a preset length is extracted from the current signal sequence to obtain a real-time current data sample.

[0025] Optionally, after the step of adjusting the preset fault threshold according to the fault threshold scaling factor, the method further includes:

[0026] The electrical fault threshold is called to perform electrical fault diagnosis on the power distribution line.

[0027] The present invention obtains real-time current data samples of a distribution line; determines a preset frequency proportional factor according to the proportion of preset frequency components in the real-time current data samples; determines a fault threshold scaling factor of the real-time current data samples based on the preset frequency proportional factor; and adjusts the preset fault threshold according to the fault threshold scaling factor to obtain an electrical fault threshold of the distribution line. Since the preset frequency proportional factor is determined according to the preset frequency component, and then the fault threshold scaling factor of the distribution line is determined, and the electrical fault threshold is determined according to the preset fault threshold and the fault threshold scaling factor, the fault threshold can be dynamically adjusted according to the change of the preset frequency proportional factor, thereby avoiding false alarms or missed alarms caused by fixed fault thresholds, and improving the accuracy and reliability of fault detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a flowchart diagram of a first embodiment of a method for dynamically adjusting a fault threshold value that can be used in the field of fault diagnosis according to the present invention;

[0029] Figure 2 It is a flow chart of a second embodiment of a method for dynamically adjusting a fault threshold value that can be used in the field of fault diagnosis according to the present invention;

[0030] Figure 3 It is a flow chart of a third embodiment of a method for dynamically adjusting a fault threshold value that can be used in the field of fault diagnosis according to the present invention;

[0031] Figure 4 The present invention is a flowchart of an application scenario of the method for dynamically adjusting a fault threshold value that can be used in the field of fault diagnosis.

[0032] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0033] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0034] The embodiment of the present invention provides a method for dynamically adjusting a fault threshold value that can be used in the field of fault diagnosis. Figure 1 , Figure 1 It is a flow chart of the first embodiment of the method for dynamically adjusting a fault threshold value that can be used in the field of fault diagnosis according to the present invention.

[0035] In this embodiment, the method for dynamically adjusting the fault threshold value that can be used in the field of fault diagnosis includes the following steps:

[0036] Step S10: Acquire real-time current data samples of the distribution line.

[0037] It should be noted that the execution subject of the method of this embodiment can be a terminal device with data processing and program running functions, such as a computer, a server, etc., or an electronic device with the same or similar functions, such as a fault threshold dynamic adjustment device used in the field of fault diagnosis. The following takes the fault threshold dynamic adjustment device (hereinafter referred to as the adjustment device) as an example to illustrate this embodiment and the following embodiments.

[0038] It is understandable that a data acquisition device for current data acquisition may be provided in the distribution line. The data acquisition device may be connected to the adjustment device and transmit the collected current signal of the distribution line to the adjustment device, so that the adjustment device may process the collected real-time current signal to determine the real-time current data sample.

[0039] It should be understood that by processing real-time current data samples, dynamic adjustment of the fault threshold of the distribution line can be achieved, so that the threshold of the distribution line can accurately adapt to changing conditions, provide more accurate fault detection and protection, avoid false alarms or missed alarms due to fixed fault thresholds, and improve the accuracy and reliability of fault detection.

[0040] In a specific implementation, the adjustment device obtains real-time current data samples of the distribution line, and adjusts the fault threshold of the distribution line according to the real-time current data samples, so that the fault threshold of the distribution line can be dynamically adjusted according to the collected real-time current data samples, so that the threshold of the distribution line can accurately adapt to changing conditions, provide more accurate fault detection and protection, avoid false alarms or missed alarms due to fixed fault thresholds, and improve the accuracy and reliability of fault detection.

[0041] Step S20: determining a preset frequency proportional factor according to the proportion of the preset frequency component in the real-time current data sample.

[0042] It is understandable that the collected real-time current data may contain different frequency components due to the influence of the connected load characteristics and environmental interference.

[0043] It should be understood that the current signal collected from the circuit may include frequency components of different frequencies such as fundamental frequency component, harmonic component, noise component, etc. The above-mentioned preset frequency component is also a frequency component in the current signal, such as fundamental frequency component, low-order harmonic component, etc.

[0044] It should be noted that changes in the circuit may cause changes in the circuit or voltage waveform and changes in the impedance of the circuit. These changes may cause harmonic components or other frequency responses to be introduced into the collected current signal, thereby causing the proportion of the preset frequency component in the circuit to change.

[0045] In other words, the proportion of the preset frequency component in the circuit signal can reflect the change of the distribution line to a certain extent. Therefore, the preset frequency proportional factor is determined according to the proportion of the preset frequency component in the real-time current data sample, and the fault threshold of the distribution line can be adjusted by processing the preset frequency proportional factor.

[0046] In one implementation manner, the embodiment of the present invention uses the fundamental frequency component as the preset frequency component of the present invention, and this embodiment and the following embodiments are described in detail.

[0047] It is understood that the fundamental frequency component refers to the basic frequency component in the current or voltage signal, and the fundamental frequency component is the basic frequency in the power system. Generally, the frequency of the fundamental frequency component of the circuit system can be 50 Hz or 60 Hz. The embodiments of the present invention take the fundamental frequency component of 50 Hz as an example to describe the embodiments of the present invention in detail.

[0048] It should be noted that in order to determine the frequency components in the real-time current data sample, it is necessary to perform a micro Fourier transform on the real-time current signal to obtain the frequency components contained in the real-time current data sample, and determine the proportion of the fundamental frequency component in these frequency components. Specifically, the step of determining the frequency proportional factor according to the proportion of the preset frequency component in the real-time current data sample includes:

[0049] Performing a micro Fourier transform on the real-time current data sample to obtain a preset frequency component of the real-time current data sample;

[0050] The proportion of a preset frequency component in the real-time current data sample is determined to obtain a preset frequency proportional factor.

[0051] It should be noted that the calculation method of the above base frequency proportional factor is as follows:

[0052]

[0053] Wherein, a is the real-time current data sample, β is the fundamental frequency proportional factor, y is the sine signal sequence with the same length as a and contains a complete cycle, y1 is the cosine signal sequence with the same length as a and contains a complete cycle, and rms(a) represents the effective value of the real-time current data sample a.

[0054] It should be noted that the embodiment of the present invention uses micro Fourier transform to perform fixed-point calculation on the preset frequency component. Compared with using the complete Fourier transform, the solution of the embodiment of the present invention can better save computing resources.

[0055] In a specific implementation, a micro Fourier transform is performed on the real-time current data sample to obtain the fundamental frequency component of the real-time current data sample; the proportion of the fundamental frequency component in the real-time current data sample is determined to obtain the fundamental frequency proportional factor. Since the fundamental frequency proportional factor of the real-time current data sample reflects the current change of the distribution line according to the change characteristics of the current signal, the dynamic adjustment of the fault threshold of the distribution line can be achieved.

[0056] Step S30: determining a fault threshold scaling factor of the real-time current data sample based on the preset frequency scaling factor.

[0057] It should be noted that the fault threshold scaling factor is also a proportional factor used to adjust the fault threshold. The actual operating conditions of the distribution line can be determined according to the preset frequency proportional factor of the distribution line, and then the fault threshold scaling factor of the distribution line can be determined, thereby realizing dynamic adjustment of the fault threshold of the distribution line.

[0058] It needs to be explained that, according to the fault threshold scaling factor, when the preset frequency component accounts for a relatively small proportion, the amplification factor of the fault threshold is larger; when the preset frequency component accounts for a large proportion, the amplification factor of the fault threshold is smaller, thereby ensuring the sensitivity of the fault diagnosis algorithm while taking into account the anti-interference ability of the diagnosis algorithm.

[0059] In a specific implementation, the adjustment device determines the fault threshold scaling factor of the real-time circuit data sample based on a preset frequency scaling factor, so that the fault threshold can be dynamically adjusted according to the change of the preset frequency scaling factor, avoiding false alarms or missed alarms due to a fixed fault threshold, and improving the accuracy and reliability of fault detection.

[0060] Step S40: adjusting the preset fault threshold according to the fault threshold scaling factor to obtain the electrical fault threshold of the distribution line.

[0061] It should be noted that when the preset frequency proportional factor and the fault threshold scaling factor are determined, a new electrical fault threshold can be determined based on the preset fault threshold and the fault threshold scaling factor, thereby achieving dynamic adjustment of the electrical fault threshold of the distribution line.

[0062] It can be understood that the above-mentioned preset fault threshold, that is, the set initial threshold, can determine the fault threshold scaling factor that changes in real time in the distribution line based on the real-time detection data in the distribution line, so that the electrical fault threshold of the distribution line can be changed according to the real-time detection data, thereby realizing adaptive adjustment of the electrical fault threshold.

[0063] The fault threshold dynamic adjustment method of the present invention is easy to identify, and only needs to add steps for calculating the fault threshold expansion factor and adjusting the fault threshold on the basis of the original fault diagnosis algorithm, without adding additional hardware requirements to the original system. In addition, in one embodiment of the present invention, the fundamental frequency component is used as the preset frequency component, and the proportion of the fundamental frequency component can reflect the health status of the low-voltage AC system to a certain extent. Combining it with the original fault threshold can greatly improve the sensitivity of the original fault diagnosis algorithm while ensuring the reliability of the original algorithm, and can successfully solve the problem that the false alarm rate and the missed alarm rate of the existing electrical fault protection device cannot be reduced at the same time.

[0064] It is understandable that when the electrical fault threshold of the distribution line is determined, the electrical fault threshold can be called to complete the electrical fault diagnosis of the distribution system. That is, the preset fault threshold is adjusted according to the fault threshold scaling factor to obtain the electrical fault threshold of the distribution line. After the step, it also includes: calling the electrical fault threshold to perform electrical fault diagnosis on the distribution line.

[0065] The embodiment of the present invention obtains the real-time current data sample of the distribution line; determines the preset frequency proportional factor according to the proportion of the preset frequency component in the real-time current data sample; determines the fault threshold scaling factor of the real-time current data sample based on the preset frequency proportional factor; and adjusts the preset fault threshold according to the fault threshold scaling factor to obtain the electrical fault threshold of the distribution line. Since the preset frequency proportional factor is determined according to the preset frequency component, and then the fault threshold scaling factor of the distribution line is determined, and the electrical fault threshold is determined according to the preset fault threshold and the fault threshold scaling factor, the fault threshold can be dynamically adjusted according to the change of the preset frequency proportional factor, thereby avoiding false alarms or missed alarms caused by fixed fault thresholds, and improving the accuracy and reliability of fault detection.

[0066] refer to Figure 2 , Figure 2 It is a flow chart of the second embodiment of the method for dynamically adjusting a fault threshold value which can be used in the field of fault diagnosis according to the present invention.

[0067] Based on the above first embodiment, in this embodiment, the step of determining the fault threshold scaling factor of the real-time current data sample based on the preset frequency scaling factor includes:

[0068] Step S31: obtaining a target form of the fault threshold scaling factor;

[0069] Step S32: when the target form is an exponential form, constructing a fault threshold scaling factor in the exponential form based on the preset frequency scaling factor.

[0070] It should be noted that the target form of the fault threshold scaling factor may be an exponential form, a polynomial form, a linear form, etc. The embodiment of the present invention is not limited to this and may be selected according to the circuit in a specific application.

[0071] In one implementation, the target form of the fault threshold scaling factor of the embodiment of the present invention is an exponential form. Specifically, when the target form of the fault threshold scaling factor is an exponential form, the fault threshold scaling factor in exponential form can be constructed based on a preset proportional factor, and the construction method can be shown in the following formula:

[0072] γ=a (1-α*β)

[0073] Wherein, γ is a fault threshold scaling factor in exponential form, a can be a natural logarithm e, and α can be a value close to 1, such as 0.9, 1.1, 1.2, etc. The value in the embodiment of the present invention is 1.2.

[0074] It should be noted that the embodiment of the present invention combines the characteristics that when the electrical fault of the power system is more severe, the smaller the proportion of the preset frequency component, the greater the electrical fault characteristics; and the smaller the preset frequency proportional factor, the faster the electrical fault characteristics change, to construct a fault threshold scaling factor in the form of an exponential; through the above-mentioned form of fault threshold scaling factor, it can be ensured that when the proportion of the preset frequency component is large, the magnification of the fault threshold of the distribution line is small; and when the proportion of the frequency component is small, the magnification of the fault threshold is large. By dynamically adjusting the electrical fault threshold through the preset frequency proportional factor and the fault threshold scaling factor, the sensitivity of the fault diagnosis algorithm can be guaranteed, and the anti-interference ability of the fault diagnosis algorithm can be taken into account, avoiding false alarms or missed alarms caused by fixed fault thresholds.

[0075] In one embodiment of the present invention, in order to determine the electrical fault threshold, the step of determining the electrical fault threshold of the distribution line according to the preset frequency proportional factor and the fault threshold scaling factor includes:

[0076] The fault threshold scaling factor is multiplied by a preset fault threshold, and the result of the operation is used as the electrical fault threshold of the distribution line.

[0077] It can be understood that by multiplying the fault threshold scaling factor by the preset fault threshold, an adaptive electrical fault threshold with real-time dynamic adjustment properties is obtained, so that the electrical fault threshold of the distribution system can be changed according to the operating conditions of the distribution line, thereby improving the accuracy of fault detection and reducing the missed detection rate of fault detection.

[0078] The embodiment of the present invention obtains the target form of the fault threshold scaling factor; when the target form is an exponential form, an exponential fault threshold scaling factor is constructed based on a preset frequency proportional factor. Since the exponential fault threshold scaling factor is constructed based on the preset frequency proportional factor, the more severe the electrical fault of the power system, the smaller the proportion of the preset frequency component, and the larger the electrical fault feature; and the smaller the preset frequency proportional factor, the faster the electrical fault feature changes, the sensitivity of the fault diagnosis algorithm can be guaranteed, and the anti-interference ability of the fault diagnosis algorithm can be taken into account, avoiding false alarms or missed alarms caused by fixed fault thresholds.

[0079] Based on the above embodiments, in order to obtain real-time current data samples, a third embodiment of the method of the present invention is proposed, referring to Figure 3 , Figure 3 It is a flow chart of a third embodiment of a method for dynamically adjusting a fault threshold value that can be used in the field of fault diagnosis according to the present invention.

[0080] In this embodiment, the step of obtaining the real-time current data sample of the distribution line includes:

[0081] Step S110: collecting current signals of distribution lines;

[0082] Step S120: sampling the current signal according to a preset sampling frequency to obtain real-time current data samples.

[0083] It should be noted that the diagnosis of electrical faults may be determined in seconds, such as 1s, 0.2s, 0.5s, etc., or in milliseconds, such as 50ms, 20ms, etc., and the embodiments of the present invention are not limited to this.

[0084] In one implementation, the embodiment of the present invention performs electrical fault diagnosis in seconds, collects the current signal of the distribution line every second through a data acquisition device, and determines the electrical fault threshold corresponding to the distribution line by analyzing the collected current signal.

[0085] It should be noted that when performing fault arc detection, the sampling rate of the distribution line can be between tens of kHz and hundreds of kHz. In order to better illustrate the embodiments of the present invention, the sampling rate of the current signal is set to 100kHz, that is, the preset sampling frequency in the embodiments of the present invention is 100kHz, and the corresponding current signal sequence length x(n) is 100000.

[0086] Furthermore, in order to reduce the amount of computation in the embodiment of the present invention, random sampling can be performed from the above current signal sequence. Specifically, the adjustment device can randomly extract a subsequence a(n) with a length of 2000 from the current signal sequence x(n), thereby obtaining a real-time current data sample. Specifically, the step of sampling the current signal according to a preset sampling frequency to obtain a real-time current data sample includes:

[0087] Step S121: sampling the current signal according to a preset sampling frequency to obtain a current signal sequence to be processed;

[0088] Step S122: extracting a subsequence of a preset length from the current signal sequence to obtain a real-time current data sample.

[0089] It should be noted that, in order to determine the frequency component of a current signal, the real-time current data sample obtained by sampling contains at least one complete cycle of the frequency. For a sampling rate of 100kHz, the signal length of a complete cycle of the base frequency component 50Hz component signal is exactly 2000. In addition, when the computing resources of the electrical protection device are relatively abundant, it is also possible to select signals with more cycle lengths as the real-time current data samples obtained by sampling, and the embodiment of the present invention is not limited to this.

[0090] The embodiment of the present invention collects the current signal of the distribution line; samples the current signal according to a preset sampling frequency to obtain a current signal sequence to be processed; extracts a subsequence of a preset length from the current signal sequence to obtain a real-time current data sample. Since the current signal sequence is obtained by sampling from the sampled current signal, and a subsequence of a preset length is extracted therefrom to obtain the real-time current data sample, the amount of calculation is reduced and the efficiency of data processing is improved.

[0091] like Figure 4 As shown, Figure 4 The present invention is a flowchart of an application scenario of the method for dynamically adjusting a fault threshold value that can be used in the field of fault diagnosis.

[0092] Reference Figure 4 The adjustment device can collect the current signal of the distribution line and sample the current signal according to the preset sampling frequency to obtain the real-time current data sample. The proportional factor β is obtained by performing micro Fourier transform on the real-time current data sample and then calculating the proportion of the 50Hz power frequency component in the total signal in the real-time data sample.

[0093] Furthermore, an exponential fault threshold scaling factor γ is constructed based on the proportional factor β, and the fault threshold scaling factor is multiplied by the preset fault threshold to obtain an electrical fault threshold with real-time dynamic adjustment properties. By calling the electrical fault threshold, electrical fault diagnosis can be performed.

[0094] The present invention evaluates the proportion of the 50Hz power frequency component by sampling and calculating the current signal of the distribution line to be processed to complete the prior analysis of the health status of the current signal to be processed; then, a fault threshold expansion factor with an exponential form is constructed according to the proportion of the 50Hz power frequency component and the correlation between the proportion of the 50Hz power frequency component and the electrical fault; further, the fault threshold expansion factor is multiplied by the fault threshold selected by the fault diagnosis algorithm to obtain an adaptive electrical fault threshold with real-time dynamic adjustment properties as the basis for fault identification of the electrical fault diagnosis algorithm. Compared with the traditional electrical fault diagnosis method based on fault threshold, the present invention has the following beneficial technical effects: the method is simple to implement, and the basic calculation of the fault threshold expansion factor can be completed only by sampling and calculating the current signal of the distribution line to be processed, with low computational complexity and less computational effort.

[0095] At the same time, the fault threshold scaling factor in exponential form is constructed based on the proportion of the 50Hz power frequency component in the total signal. It combines the prior information of the correlation between the severity of the electrical fault in the electrical system and the proportion of the 50Hz power frequency component in the total signal, and takes into account the a posteriori calculation of the impact of the electrical fault evolution on the selected fault characteristics. The construction method is more scientific, and it also enables the present invention to better solve the industry problem of both false fault reporting and missed fault reporting in electrical fault early warning technology, and achieves the application effect of greatly improving the detection sensitivity of the electrical fault detection method without increasing the false alarm rate of the product.

[0096] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or system including the element.

[0097] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0098] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as a read-only memory / random access memory, a magnetic disk, or an optical disk), and includes a number of instructions for a terminal device (which can be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to execute the methods described in each embodiment of the present invention.

[0099] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for dynamically adjusting a fault threshold value that can be used in the field of fault diagnosis, characterized in that: The method comprises: Obtain real-time current data samples of distribution lines; Determining a preset frequency proportional factor according to the proportion of the preset frequency component in the real-time current data sample; determining a fault threshold scaling factor for the real-time current data sample based on the preset frequency scaling factor; The preset fault threshold is adjusted according to the fault threshold scaling factor to obtain the electrical fault threshold of the distribution line.

2. The method for dynamically adjusting fault thresholds that can be used in the field of fault diagnosis as claimed in claim 1, characterized in that: The step of determining the frequency proportional factor according to the proportion of the preset frequency component in the real-time current data sample comprises: Performing a micro Fourier transform on the real-time current data sample to obtain a preset frequency component of the real-time current data sample; The proportion of the preset frequency component in the real-time current data sample is determined to obtain a preset frequency proportional factor.

3. The method for dynamically adjusting fault thresholds applicable to the field of fault diagnosis as claimed in claim 1, characterized in that: The step of determining the fault threshold scaling factor of the real-time current data sample based on the preset frequency scaling factor comprises: Obtaining a target form of the fault threshold scaling factor; When the target form is an exponential form, a fault threshold scaling factor in the exponential form is constructed based on the preset frequency scaling factor.

4. The method for dynamically adjusting fault thresholds applicable to the field of fault diagnosis as claimed in claim 1, characterized in that: The step of adjusting the preset fault threshold according to the fault threshold scaling factor to obtain the electrical fault threshold of the distribution line includes: The fault threshold scaling factor is multiplied by a preset fault threshold, and the result of the operation is used as the electrical fault threshold of the distribution line.

5. The method for dynamically adjusting fault thresholds applicable to the field of fault diagnosis as claimed in claim 1, characterized in that: The step of obtaining the real-time current data sample of the distribution line includes: Collect current signals of distribution lines; The current signal is sampled according to a preset sampling frequency to obtain real-time current data samples.

6. The method for dynamically adjusting fault thresholds applicable to the field of fault diagnosis as claimed in claim 5, characterized in that: The step of sampling the current signal according to a preset sampling frequency to obtain a real-time current data sample comprises: Sampling the current signal according to a preset sampling frequency to obtain a current signal sequence to be processed; A subsequence of a preset length is extracted from the current signal sequence to obtain a real-time current data sample.

7. The method for dynamically adjusting fault thresholds applicable to the field of fault diagnosis according to any one of claims 1 to 6, characterized in that: After the step of adjusting the preset fault threshold according to the fault threshold scaling factor, the method further includes: The electrical fault threshold is called to perform electrical fault diagnosis on the power distribution line.

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