Electric arc light energy level analysis method and device based on polarization and harmonic waves

Abstract

The invention relates to the field of power fault detection, in particular to an electric arc light energy level analysis method and device based on polarization and harmonic waves. Comprising the following steps: S1, acquiring a polarization angle change rate and harmonic characteristics of arc light; s2, establishing an arc energy level evaluation model, and inputting the polarization angle change rate of the arc light and the harmonic characteristics into the arc energy level evaluation model to obtain an arc energy level index; s3, the arc energy level index is judged, when the arc energy level index is larger than a set threshold value, it is judged that an arc fault occurs, the arc fault is reported, and when the arc energy level index is smaller than the set threshold value, the step S1 is executed again. According to the method, arc fault detection is realized by comprehensively analyzing the polarization characteristics and harmonic characteristics of arc light, the arc fault detection accuracy is remarkably improved by combining the polarization characteristics and the harmonic characteristics, both low-energy arcs and high-energy arcs can be accurately identified, and the risks of missing report and false report are effectively reduced.

Description

Technical Field

[0001] The present invention relates to the field of power fault detection, and particularly to a method and device for analyzing the energy level of arc light based on polarization and harmonic waves. Background Art

[0002] An arc is a gas discharge phenomenon. When an electric current passes through some insulating media (such as air), instantaneous sparks will be generated. The generation of an arc stems from the electron emission from the surface of the contact metal and the ionization of gas atoms or molecules in the gap. The arc has the characteristics of high temperature and high heat, and its temperature can reach 3000°C - 4000°C, accompanied by the splashing of molten metal, which is extremely likely to ignite the line insulation layer and surrounding combustibles, thus triggering a fire. Therefore, in the power system, arc fault detection and identification are key issues to ensure the safe operation of the system.

[0003] Arc faults, especially in medium and low voltage distribution systems, have a relatively high occurrence probability, and their harm cannot be underestimated. Traditional arc detection technologies have many limitations. 1. Insufficient detection sensitivity: The existing technologies have limited detection capabilities for low-energy arcs (such as micro-arcs), and it is difficult to meet the requirements of high-precision monitoring. Although low-energy arcs have low energy, the harm they cause cannot be ignored. Especially in medium and low voltage distribution systems, micro-arcs may lead to a decline in the insulation performance of equipment and trigger more serious faults. 2. Lack of classification ability: Most of the existing methods can only judge whether an arc exists and cannot distinguish the types of arcs (such as short-circuit type and non-short-circuit type). Different types of arc faults have different impacts on the power system. Accurately distinguishing the types of arcs is crucial for taking targeted protection measures. 3. Weak anti-interference ability: The existing technologies are easily affected by factors such as ambient light and electromagnetic interference, resulting in false alarms or missed alarms. In the complex power system environment, ambient light and electromagnetic interference are inevitable, and weak anti-interference ability will seriously affect the reliability of the detection results. 4. Slow response speed: Some technologies rely on complex signal processing algorithms, resulting in a long response time and unable to meet the requirements of real-time monitoring. When an arc fault occurs, a quick response is the key to preventing the expansion of the fault. A slow response speed may lead to the further deterioration of the fault. Summary of the Invention

[0004] In view of the problems mentioned in the existing technology, the present invention proposes a method and device for analyzing the energy level of arc light based on polarization and harmonic waves, and realizes the accurate assessment of the arc energy level by comprehensively analyzing the change rate of the polarization angle and the harmonic components of the arc light.

[0005] To achieve the above object, the present invention adopts the following technical solutions: The present invention proposes a method for analyzing the energy level of arc light based on polarization and harmonic waves, including the following steps: S1. Obtain the change rate of the polarization angle and the harmonic characteristics of the arc light; S2. Establish an arc energy level evaluation model, input the polarization angle change rate and harmonic characteristics of the arc light into the arc energy level evaluation model, and obtain the arc energy level index; S3. Judge the arc energy level index. When the arc energy level index is greater than the set threshold, it is determined that an arc fault has occurred and the arc fault is reported. When the arc energy level index is less than the set threshold, return to S1.

[0006] As a further improvement of the present invention, the expression of the polarization angle change rate of the arc light in S1 is as follows:

[0007] In the formula: is the polarization angle change rate; is the polarization angle; is the time; is the differential of; is the differential of.

[0008] As a further improvement of the present invention, specifically obtaining the harmonic characteristics is: collecting the current signal of the arc and extracting the harmonic information in the current signal. The expression is as follows:

[0009] In the formula: is the fundamental angular frequency; n is the harmonic order; is the amplitude of the nth harmonic; is the phase of the nth harmonic; is the current signal of the arc light.

[0010] As a further improvement of the present invention, the calculation formula for calculating the arc energy level index is as follows:

[0011] In the formula: , are the weight coefficients; N is the highest harmonic order considered; is the arc energy level index.

[0012] As a further improvement of the present invention, the specific process of S3 is: setting a dynamic threshold for the arc energy level. When the arc energy level index exceeds the threshold, it is determined as an arc fault. The expression of the dynamic threshold of the arc energy level is as follows:

[0013] In the formula, k is the safety factor; m is the number of historical data samples; E i is the arc energy level index of the i-th sample; is the dynamic threshold.

[0014] An arc light energy level analysis device based on polarization and harmonics, implemented by the method as described above, includes: A polarization light detection unit for detecting the polarization angle of the arc light; A harmonic detection unit for collecting the arc current signal and extracting harmonic information; A data processing and analysis unit for performing fusion analysis on the data collected by the polarization light detection unit and the harmonic detection unit to achieve arc energy level evaluation; An alarm display unit for sending an alarm signal when the arc energy level reaches the set threshold and for displaying the arc energy level and related parameters in real time.

[0015] As a further improvement of the present invention, the polarization light detection unit includes a polarizer, a photoelectric converter, and a signal amplifier.

[0016] As a further improvement of the present invention, the harmonic detection unit includes a current transformer, a signal acquisition module, and a fast Fourier transform analysis module.

[0017] As a further improvement of the present invention, the alarm display unit includes an audible and visual alarm and a display screen.

[0018] As a further improvement of the present invention, the data processing and analysis unit includes a microprocessor for loading an arc energy level evaluation model.

[0019] The present invention has achieved the following technical effects compared with the prior art: The present invention realizes arc fault detection by comprehensively analyzing the polarization characteristics and harmonic characteristics of arc light. The polarization characteristics can reveal the vibration mode of arc light in a specific direction, while the harmonic characteristics reflect the proportion of different frequency components in the arc current. The combination of the two significantly improves the accuracy of arc fault detection, and both low-energy arcs (such as weak arcs caused by poor contact or slight wear) and high-energy arcs (such as strong arcs caused by severe short circuits) can be accurately identified, effectively reducing the risks of missed alarms and false alarms.

[0020] The present invention can complete the evaluation of the arc energy level within an extremely short time (less than 5 milliseconds), which exceeds the traditional detection means. Once an arc fault occurs, the system can almost immediately respond, initiate corresponding protection measures, and effectively prevent the escalation of the fault, ensuring the safe and stable operation of the power grid.

[0021] The polarization light detection and harmonic detection technologies mentioned in the present invention have extremely strong anti-interference capabilities. The polarization light detection effectively eliminates environmental light interference by accurately measuring the polarization state of light; while the harmonic detection uses the unique frequency characteristics of the arc current to distinguish the arc signal from background noise, ensuring the accuracy and stability of the detection results.

[0022] In order to improve the pertinence and efficiency of fault handling, the present invention introduces a model based on the polarization characteristics and harmonic features of arc light, realizing intelligent classification of arc faults. By learning the features of a large number of arc fault samples, this model can automatically identify and distinguish different types of arc faults, not only improving the accuracy of fault identification but also providing strong support for fault handling. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic flow diagram of the method for analyzing the energy level of arc light based on polarization and harmonics of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] In the following text, only some exemplary embodiments are simply described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present invention. Therefore, the drawings and the description are considered to be exemplary in nature rather than restrictive.

[0025] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present invention.

[0026] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0027] In the present invention, unless otherwise clearly specified and defined, the terms "mounted", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection, or a communication connection; it can be directly connected, or indirectly connected through an intermediate medium, and can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may include direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is less than that of the second feature.

[0029] It should be understood that when used in this specification and the appended claims, the terms "comprises" and "comprising" indicate the presence of the described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or their combinations.

[0030] It should also be understood that the terms used in the specification of the present invention are merely for the purpose of describing particular embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly dictates otherwise, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0031] It should be further understood that the term "and / or" used in the specification of the present invention and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0032] Structural schematic diagrams according to the disclosed embodiments of the present invention are shown in the drawings. These figures are not drawn to scale, where for the purpose of clear expression, some details are enlarged and some details may be omitted. The shapes of various regions and layers shown in the figures and their relative sizes and positional relationships are merely exemplary, and in practice, there may be deviations due to manufacturing tolerances or technical limitations, and those skilled in the art can additionally design regions / layers with different shapes, sizes and relative positions according to actual needs.

[0033] The embodiments of the present invention will be described in detail below with reference to the drawings.

[0034] The present invention provides an arc light energy level analysis device based on polarization and harmonic waves, comprising a polarization light detection unit for detecting the polarization angle of arc light; a harmonic detection unit for collecting arc current signals and extracting harmonic information; a data processing and analysis unit for performing fusion analysis on the data collected by the polarization light detection unit and the harmonic detection unit to achieve arc energy level evaluation; An alarm display unit is used to send an alarm signal when the arc energy level reaches a set threshold value, and to display the arc energy level and related parameters in real time.

[0035] In the embodiment, the polarized light detection unit is composed of a polarizer, a photoelectric converter and a signal amplifier. Among them, the polarizer is specifically a high-precision polarizer, which can directly affect the accuracy of polarization angle measurement; the photoelectric converter is preferably a high-sensitivity photodiode, which can quickly respond to the change of the optical signal and improve the real-time performance of measurement. At the same time, it is applicable to the detection of polarized light with different wavelengths; the signal amplifier can amplify the electrical signal converted by the photodiode. Preferably, a low-noise amplifier is adopted, which can reduce the noise interference in the amplification process, improve the purity of the signal, and can process signals of different intensities at the same time to avoid signal distortion or saturation.

[0036] In the embodiment, the harmonic detection unit is composed of a current transformer, a signal acquisition module and a fast Fourier transform analysis module. Among them, the current transformer adopts a high-precision and wide-band transformer, which can measure the current signal more accurately, reduce the measurement error, improve the accuracy of harmonic detection, and can cover a wider frequency range, including the fundamental wave and each harmonic, so as to extract harmonic characteristics more comprehensively; the signal acquisition module adopts an analog-to-digital converter with a high sampling rate and high resolution, which can convert the current signal into a digital signal for subsequent digital signal processing. The high sampling rate can collect the current signal more frequently, so as to capture the change of harmonic components more accurately. The high resolution can provide more quantization levels, reduce the quantization error, and improve the accuracy of the digital signal; the fast Fourier transform analysis module is specifically a high-performance digital signal processor, which is used to execute the fast Fourier transform (FFT) algorithm to extract harmonic characteristics. Through the high performance of the digital signal processor, the time-domain signal is converted into a frequency-domain signal, which is convenient for subsequent analysis and processing. Through FFT analysis, each harmonic component in the current signal, including amplitude, phase and other information, can be extracted, providing an important basis for the subsequent process.

[0037] In the embodiment, the data processing and analysis unit specifically adopts a high-performance microprocessor, which can quickly process data, including the polarization data and harmonic data of the arc light, ensure the real-time performance, and at the same time provide high-precision floating-point operation and integer operation capabilities to ensure the accuracy of the analysis results.

[0038] In the embodiment, the alarm display unit is specifically an alarm and a display screen. The alarm can send an alarm signal when the arc energy level reaches the preset threshold value and display the arc energy level and related parameters through the display screen.

[0039] According to the device described above, as Figure 1 shown, the present invention proposes an arc light energy level analysis method based on polarization and harmonics, including the following steps: Step 1. During the propagation of the arc light, its polarization angle changes with the change of the arc energy level. The polarization angle of the arc light is measured in real time by a polarization light detection unit to obtain a polarization angle change curve, and the polarization angle change rate is calculated. The calculation formula is as follows:

[0040] In the formula: is the polarization angle change rate; is the polarization angle; is the time; is the differential component of; is the differential component of.

[0041] The arc current signal is collected by a harmonic detection unit, and the harmonic components in the current signal are extracted by using the fast Fourier transform analysis module in the harmonic detection unit, and the amplitudes of each harmonic are calculated , and the calculation formula is as follows:

[0042] In the formula: is the fundamental angular frequency; n is the harmonic order; is the amplitude of the nth harmonic; is the phase of the nth harmonic; is the current signal of the arc light.

[0043] Step 2. An arc energy level evaluation model based on the polarization angle change rate and the harmonic amplitude is established. The polarization angle change rate and the harmonic amplitude obtained in Step 1 are input into the arc energy level evaluation model to obtain an arc energy level index. The calculation formula is as follows:

[0044] In the formula: , are the weight coefficients; N is the highest harmonic order considered; is the arc energy level index.

[0045] Step 3. According to the operating conditions of the power system and the historical data of arc faults, a dynamic threshold of the arc energy level is set. When the arc energy level index exceeds the dynamic threshold , it is determined as an arc fault, and corresponding protection measures are taken according to the energy level. The setting formula of the dynamic threshold is:

[0046] Where k is the safety factor; m is the number of historical data samples; E i is the arc energy level index of the i-th sample; is the dynamic threshold.

[0047] The arc light energy level analysis method and device of the present invention are applied to the arc fault monitoring of the switchgear in a 110 kV substation. The substation has multiple switch cabinets responsible for distributing and controlling power supply. Arc faults may cause equipment damage and power outages, so accurate monitoring and energy level assessment of arc faults are crucial.

[0048] Installation and commissioning of the device Installation location: Install the arc light energy level analysis device in the bus chamber of the substation switchgear to ensure that the polarized light detection unit and the current transformer can accurately detect arc light and arc current signals.

[0049] Commissioning process: Commissioning of the polarized light detection unit: Calibrate the polarizer to ensure that its temperature resistance range is higher than the highest temperature that may be generated by arc light (exceeding 1000 °C), the light transmittance is not less than 95%, and the polarization efficiency is not less than 90%. Use a standard polarized light source for testing to verify that the sensitivity of the photoelectric converter is higher than 1 A / W, the response time is less than 10 ns, and the dark current is less than 1 nA.

[0050] Commissioning of the harmonic detection unit: Set the accuracy level of the high-precision current transformer to 0.2 level, and the frequency band width covers 0 - 5 kHz. Set the sampling frequency of the signal acquisition module to 100 kHz, the resolution of the analog-to-digital converter to 16 bits, the number of FFT points of the fast Fourier transform analysis module to 1024, and select the Hamming window as the window function.

[0051] Commissioning of the data processing and analysis unit: Set the main frequency of the high-performance microprocessor to 1 GHz, with 4 GB of memory and 16 GB of storage space. Load the arc energy level assessment model, set the initial weight coefficients w1 = 1.2, w2 = 0.8, and consider the highest harmonic order N = 5. Verify the accuracy and real-time performance of the model through simulated arc fault data.

[0052] Commissioning of the alarm and display unit: Set the sound intensity of the audible and visual alarm to 100 dB and the light intensity to 1000 cd. Under normal operating conditions, the display screen shows the arc energy level and related parameters in real time, without alarm signals.

[0053] Test data and analysis Test conditions: Arc types: Simulate three different types of arc faults: carbonization path discharge caused by poor contact of copper conductors, surface discharge caused by aging of insulating materials, and gap discharge caused by excessive gap between switch contacts.

[0054] Arc current: Set the arc current to 5 A, 10 A, and 15 A (rms) respectively.

[0055] Duration: The duration for each arc current is 500 ms.

[0056] Environmental conditions: Temperature 25 ± 5 °C, relative humidity ≤ 80%, no strong electromagnetic interference source.

[0057] Test data: Polarization angle change rate: Use the polarized light detection unit to measure the polarization angle change rate γ of the arc light in real time.

[0058] Harmonic characteristics: Collect the arc current signal through the harmonic detection unit, and use the fast Fourier transform analysis module to extract the amplitude An of each harmonic.

[0059] Data analysis: Carbonization path discharge caused by poor contact of copper conductor: When the arc current = 5 A: Time (ms): 0 - 50 50 - 100 100 - 200 200 - 300 300 - 500 Polarization angle change rate γ (rad / s): 0.02 0.03 0.04 0.03 0.02 Harmonic amplitude A1 (A): 1.0 1.2 1.5 1.3 1.1 Harmonic amplitude A2 (A): 0.5 0.6 0.7 0.6 0.5 Harmonic amplitude A3 (A): 0.3 0.3 0.4 0.3 0.3 Harmonic amplitude A4 (A): 0.2 0.2 0.2 0.2 0.2 Harmonic amplitude A5 (A): 0.1 0.1 0.1 0.1 0.1 Sum of harmonic components ∑A (A): 1.0 + 0.5 + 0.3 + 0.2 + 0.1 = 2.1 Arc energy level index E = 1.2×γ + 0.8×∑A = 1.2×0.02 + 0.8×2.1 = 0.0024 + 1.68 = 1.682 Dynamic threshold T = 6.0 Judgment result: E < T, no arc fault is detected.

[0060] Since the arc energy level index \(E = 1.682 < T = 6.0\), it is determined that there is no arc fault and the system is in normal operation.

[0061] When the arc current = 10 A: Time (ms): 0 - 50 50 - 100 100 - 200 200 - 300 300 - 500 Polarization angle change rate γ (rad / s): 0.04 0.06 0.08 0.07 0.05 Harmonic amplitude A1 (A): 2.0 2.5 3.0 2.7 2.3 Harmonic amplitude A2 (A): 1.0 1.2 1.5 1.3 1.1 Harmonic amplitude A3 (A): 0.6 0.7 0.8 0.7 0.6 Harmonic amplitude A4 (A): 0.4 0.4 0.5 0.4 0.4 Harmonic amplitude A5 (A): 0.2 0.2 0.3 0.2 0.2 Total harmonic component ∑A (A): 2.0 + 1.0 + 0.6 + 0.4 + 0.2 = 4.2 Arc energy level index E = 1.2×γ + 0.8×∑A = 1.2×0.04 + 0.8×4.2 = 0.0048 + 3.36 = 3.3648 Dynamic threshold T = 6.0 Judgment result: E < T, the arc energy level is relatively low, the system is in the early warning state, and the alarm and display unit makes the local indicator light flash.

[0062] Since the arc energy level index \(E = 3.3648 < T = 6.0\), it is determined that the arc energy level is relatively low, the system is in the early warning state, and the alarm and display unit makes the local indicator light flash.

[0063] When the arc current = 15A: Time (ms): 0 - 50 50 - 100 100 - 200 200 - 300 300 - 500 Polarization angle change rate γ (rad / s): 0.08 0.12 0.15 0.13 0.09 Harmonic amplitude A1 (A): 3.0 3.8 4.5 4.0 3.5 Harmonic amplitude A2 (A): 1.5 1.8 2.2 1.9 1.6 Harmonic amplitude A3 (A): 1.0 1.2 1.5 1.3 1.1 Harmonic amplitude A4 (A): 0.7 0.8 1.0 0.9 0.8 Harmonic amplitude A5 (A): 0.4 0.5 0.6 0.5 0.5 Total harmonic component ∑A(A): 3.0 + 1.5 + 1.0 + 0.7 + 0.4 = 6.6 Arc energy level index E = 1.2×γ + 0.8×∑A = 1.2×0.08 + 0.8×6.6 = 0.0096 + 5.28 = 5.2896 Dynamic threshold T = 6.0 Judgment result: E < T, the arc energy level is relatively high, the system is in the alarm state, the alarm and display unit issues a secondary alarm signal, and at the same time sends a warning signal to the monitoring center.

[0064] Since the arc energy level index \(E = 5.2896 < T = 6.0\), it is determined that the arc energy level is relatively high, the system is in the alarm state, the alarm and display unit issues a secondary alarm signal, and at the same time sends a warning signal to the monitoring center.

[0065] Performance verification Test method: Use a standard arc generator to generate arcs with known energy levels, record the detection results of the device, and compare them with the actual energy levels.

[0066] Test results: For arcs with arc energy level indexes between 0.1 and 10, the detection accuracy of the device reaches over 98%. In 100 tests, the arc energy levels were accurately identified 99 times, and there was a slight deviation once, but it was still within the acceptable range.

[0067] Specific test data are as follows: The actual energy level is 0.5, and the device detection result is 0.49 (deviation 0.01, accuracy rate 98%) The actual energy level is 2.0, and the device detection result is 2.03 (deviation 0.03, accuracy rate 98.5%) The actual energy level is 5.0, and the device detection result is 5.01 (deviation 0.01, accuracy rate 99%) The actual energy level is 8.0, and the device detection result is 8.02 (deviation 0.02, accuracy rate 99.5%) The actual energy level is 10.0, and the device detection result is 10.05 (deviation 0.05, accuracy rate 99.5%).

[0068] Response speed Test method: At the moment when the arc occurs, use a high-speed camera to record the response time of the device.

[0069] Test results: The average response time of the device is less than 5 milliseconds. In 100 tests, the response time was within 5 milliseconds in 98 cases, and in 2 cases, the response time was 5.5 milliseconds, which may be due to environmental interference or equipment aging. However, these two response times still meet the requirements of the power system for rapid response to arc faults.

[0070] Anti-interference ability Test method: Conduct arc fault simulation tests in an environment with strong electromagnetic interference (such as large motors running nearby or high-frequency equipment operating), and observe the operating status and detection results of the device.

[0071] Test results: The device operates stably in a strong electromagnetic interference environment without false alarms or missed alarms. In 100 tests, arc faults were accurately identified in 99 cases. In 1 case, due to extremely strong interference signals, there was a slight deviation in the detection results, but it was still within an acceptable range.

[0072] The specific test data is as follows: In an ambient light intensity of 3000 lx, the device operates stably without false alarms.

[0073] In the presence of 50 Hz power frequency interference, the device can still accurately identify arc faults, and the false alarm rate is 1%.

[0074] In the presence of high-frequency interference (such as 100 kHz - 1 MHz), the anti-interference ability of the device is outstanding, and the false alarm rate is 0.5%.

[0075] Based on the above test cases, the arc light energy level analysis method and device of the present invention have been successfully applied to the arc fault monitoring of switchgear in a 110 kV substation. During actual operation, the device successfully identified an arc fault caused by poor contact in the power distribution cabinet and issued a warning signal at the initial stage of the arc (0 - 50 ms), effectively preventing the further expansion of the fault. At the same time, the device accurately distinguished different types of arc faults, providing strong support for fault handling. The entire monitoring process does not require contact with live conductors, is safe and reliable, significantly improves the accuracy and response speed of arc fault detection, and effectively avoids equipment damage and power outages caused by arc faults. By real-time monitoring the arc energy level, it provides strong support for the operation and maintenance of the substation and has important practical application value in the power system.

[0076] The foregoing has shown and described the basic principles, main features and advantages of the present invention. For a person skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims concerned.

[0077] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment only contains an independent technical solution. This narrative manner of the specification is only for clarity. A person skilled in the art should regard the specification as a whole. The technical solutions in the various embodiments can also be appropriately combined to form other embodiments that can be understood by a person skilled in the art. The above content is only to illustrate the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the claims of the present invention.

Claims

1. An arc light energy level analysis method based on polarization and harmonic waves, characterized in that, Including the following steps: S1. Obtain the polarization angle change rate and harmonic characteristics of the arc light; S2. Establish an arc energy level evaluation model, input the polarization angle change rate and harmonic characteristics of the arc light into the arc energy level evaluation model to obtain the arc energy level index; S3. Judge the arc energy level index. When the arc energy level index is greater than the set threshold, it is determined that an arc fault has occurred and the arc fault is reported. When the arc energy level index is less than the set threshold, return to S1.

2. The method for analyzing the arc light energy level based on polarization and harmonic waves according to claim 1, wherein The expression of the polarization angle change rate of the arc light in S1 is as follows: In the formula: is the polarization angle change rate; is the polarization angle; is the time; is the differential component of; is the differential component of.

3. The method for analyzing the arc light energy level based on polarization and harmonic waves according to claim 1, wherein The specific method for obtaining the harmonic characteristics is: collect the current signal of the arc, extract the harmonic information in the current signal, and the expression is as follows: Wherein: is the fundamental angular frequency; n is the harmonic order; is the amplitude of the nth harmonic; is the phase of the nth harmonic; is the current signal of the arc light.

4. The method for analyzing the arc light energy level based on polarization and harmonic waves according to claim 1, characterized in that, The calculation formula for calculating the arc energy level index is as follows: In the formula: , are weighting coefficients; N is the highest harmonic order considered; is the arc energy level index.

5. The method for analyzing the arc light energy level based on polarization and harmonic waves according to claim 1, wherein The specific process of S3 is: set the dynamic threshold of the arc energy level. When the arc energy level index exceeds the threshold, it is judged as an arc fault. The expression of the dynamic threshold of the arc energy level is as follows: In the formula, k is the safety factor; m is the number of historical data samples; E i is the arc energy level index of the i-th sample; is the dynamic threshold value.

6. An arc light energy level analysis device based on polarization and harmonic waves, characterized in that, Implemented by the method according to any one of claims 1 to 5, including: A polarized light detection unit for detecting the polarization angle of the arc light; A harmonic detection unit for collecting the arc current signal and extracting harmonic information; A data processing and analysis unit for performing fusion analysis on the data collected by the polarized light detection unit and the harmonic detection unit to realize arc energy level evaluation; An alarm display unit for emitting an alarm signal when the arc energy level reaches the set threshold and displaying the arc energy level and related parameters in real time.

7. The arc light energy level analysis device based on polarization and harmonic waves according to claim 6, wherein The polarized light detection unit includes a polarizer, a photoelectric converter and a signal amplifier.

8. The arc light energy level analysis device based on polarization and harmonic waves according to claim 6, wherein The harmonic detection unit includes a current transformer, a signal acquisition module and a fast Fourier transform analysis module.

9. The arc light energy level analysis device based on polarization and harmonic waves according to claim 6, wherein The alarm display unit includes an audible and visual alarm and a display screen.

10. The arc light energy level analysis device based on polarization and harmonic waves according to claim 6, wherein, The data processing and analysis unit includes a microprocessor for loading the arc energy level evaluation model.

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