Non-contact arc light monitoring method and monitoring device

Abstract

The invention discloses a non-contact arc light monitoring method and device, and belongs to the technical field of power system fault detection, and the method comprises the steps: S1, monitoring the magnetic field intensity of an arc generation region, and converting the magnetic field intensity into polarized light intensity components in x and y directions; collecting an ultraviolet light component and a near-infrared light component in the arc light, and respectively generating an ultraviolet light electric signal and a near-infrared light electric signal; s2, extracting and amplifying power frequency alternating current components of the ultraviolet light electric signal and the near-infrared light electric signal to obtain an ultraviolet light quantity value and an infrared light quantity value respectively; s3, in each monitoring period, calculating the spectral intensity ratio of the ultraviolet light to the infrared light based on the ultraviolet light quantity value and the infrared light quantity value; and when and only when the spectral intensity ratio of the ultraviolet light to the infrared light is greater than a spectral intensity ratio threshold value, calculating a deflection angle tangent value in the monitoring period, and performing arc classification according to the deflection angle tangent value and the y-direction polarized light intensity component. The method has the advantages of high sensitivity and high reliability.

Description

Technical Field

[0001] The present invention belongs to the technical field of power system fault detection, and in particular relates to a non-contact arc light monitoring method and a monitoring device. Background Art

[0002] Arc faults are common electrical faults in power systems, especially in low-voltage and medium-voltage distribution systems. Arc faults can cause equipment damage, fire, and even personal injury. Traditional arc detection technologies are mainly divided into the following categories, but all have certain limitations:

[0003] 1) Detection method based on current waveform

[0004] Technical principle: Arc fault is determined by detecting the high-frequency components or distortion characteristics of the current waveform.

[0005] Representative patent: CN112904228A proposes a method for arc analysis based on current harmonic components and their variation characteristics. This method has limitations: it requires direct circuit access, posing a safety hazard. It lacks sensitivity for detecting low-energy arcs (such as micro-arcs). It is susceptible to load fluctuations and harmonic interference, resulting in a high false alarm rate.

[0006] 2) Detection method based on ultraviolet light intensity

[0007] Technical Principle: Detection relies on the intensity of ultraviolet radiation generated by an arc. However, limitations include relying solely on a single UV intensity parameter, unable to distinguish arc types (e.g., short-circuit vs. non-short-circuit). It is susceptible to interference from ambient light (e.g., sunlight, lighting), especially outdoors or in strong sunlight. Its UV radiation detection capabilities are limited for low-energy arcs.

[0008] 3) Detection method based on magneto-optical effect

[0009] Technical principle: Utilize the Faraday magneto-optical effect to detect the arc by detecting the deflection of polarized light caused by the magnetic field around the arc.

[0010] Limitations: Relying solely on magnetic field strength, it cannot distinguish the energy level and type of arcs. Insufficient sensitivity for weak magnetic fields makes it difficult to identify low-energy arcs. Failure to integrate other physical quantities (such as spectral characteristics) leads to a high rate of misjudgment.

[0011] 4) Signal processing technology based on frequency-locked amplification

[0012] Technical principle: Specific frequency components (such as power frequency components) in the signal are extracted through frequency-locked amplification to improve the signal-to-noise ratio.

[0013] Limitations: The design is not optimized for arc characteristic frequencies, resulting in low signal extraction efficiency. Crosstalk between channels occurs when processing multi-channel signals. The amplification capability for weak signals is limited, making it difficult to detect low-energy arcs.

[0014] In summary, the existing technology has the following problems:

[0015] Insufficient detection sensitivity: Existing technologies have limited detection capabilities for low-energy arcs (such as micro-arcs), making it difficult to meet high-precision monitoring requirements.

[0016] Lack of classification capabilities: Most existing methods can only determine whether an arc exists, but cannot distinguish the arc type (such as short-circuit type and non-short-circuit type).

[0017] Weak anti-interference ability: easily affected by factors such as ambient light and electromagnetic interference, resulting in false alarms or missed alarms.

[0018] Slow response speed: Some technologies rely on complex signal processing algorithms, resulting in long response times and unable to meet real-time monitoring needs.

[0019] Therefore, it is necessary to propose a new arc light monitoring method and device to solve the above problems. Summary of the Invention

[0020] The present invention provides a non-contact arc light monitoring method and monitoring device, which overcome the deficiencies of the prior art, have the advantages of high sensitivity and high reliability, and realize non-contact measurement.

[0021] In order to achieve the above object, the present invention adopts the following technical solutions:

[0022] In a first aspect, the present invention provides a non-contact arc light monitoring method, comprising:

[0023] S1, using a magneto-optical polarization detection unit to monitor the magnetic field intensity in the arc generation area in real time, and converting the magnetic field intensity into mutually orthogonal x-direction polarized light intensity components and y-direction polarized light intensity components;

[0024] The ultraviolet light component and near-infrared light component in the arc light are synchronously collected through a dual-channel radiation light intensity detection unit to generate ultraviolet photoelectric signals and near-infrared photoelectric signals respectively;

[0025] S2. Inputting the ultraviolet photoelectric signal and the near-infrared photoelectric signal into a dual-channel frequency-locked amplification unit, extracting the power frequency AC components of the ultraviolet photoelectric signal and the near-infrared photoelectric signal and performing amplitude amplification to obtain ultraviolet light quantity values and infrared light quantity values, respectively;

[0026] S3. Set the monitoring period as mT, where m is an integer from 1 to 10 and T is a power frequency period; within each monitoring period, calculate the spectral intensity ratio of ultraviolet light to infrared light based on the ultraviolet light quantity value and the infrared light quantity value.

[0027] S4. When and only when the spectral intensity ratio r of ultraviolet light to infrared light is greater than the spectral intensity ratio threshold, calculate the tangent value tga of the deflection angle within this monitoring period, and perform arc classification based on the tangent value tga of the deflection angle and the y-direction polarized light intensity component; otherwise, jump to step S3 and adjust m.

[0028] Furthermore, in step S4, the method for adjusting m is as follows:

[0029] When the spectral intensity ratio r of ultraviolet light to infrared light is less than or equal to the spectral intensity ratio threshold within three consecutive monitoring periods, extend the monitoring period and take m = 10.

[0030] When the spectral intensity ratio r of ultraviolet light to infrared light is greater than the spectral intensity ratio threshold within any monitoring period, shorten the monitoring period to m = 1.

[0031] Furthermore, in step S3, the calculation formula for the spectral intensity ratio r of ultraviolet light to infrared light is: r = na / ua, where ua is the mean value of the ultraviolet light quantity value and na is the mean value of the infrared light quantity value.

[0032] Furthermore, in step S4, when performing arc classification according to the following rules:

[0033] If tga = 0 and PLy ≠ 0, it is determined as non-short-circuit type low-energy discharge.

[0034] If 0 < tga < 0.1 and PLy ≠ 0, it is determined as short-circuit high-resistance type arc discharge.

[0035] If tga ≥ 0.1 and PLy ≠ 0, it is determined as short-circuit low-resistance type arc discharge.

[0036] Furthermore, in step S4, when performing arc classification, when the y-direction polarized light intensity component PLy = 0, trigger the self-check program and perform the following operations:

[0037] SA1. Turn off the laser emission module and detect the background light intensity.

[0038] SA2. Determine the cause of the abnormality according to the background light intensity:

[0039] If the background light intensity > threshold I0, it is determined that there is noise in the ultraviolet channel.

[0040] If the background light intensity ≤ I0, it is determined that the magneto-optical sensor fails.

[0041] Furthermore, in step S4, the spectral intensity ratio threshold is 0.13.

[0042] In a second aspect, the present invention provides a non-contact arc monitoring device, comprising:

[0043] A magneto-optical polarization detection unit is used to monitor the magnetic field intensity in the arc generation area in real time and convert the magnetic field intensity into mutually orthogonal x-direction polarized light intensity components and y-direction polarized light intensity components;

[0044] The dual-channel radiation detection unit collects the ultraviolet and near-infrared components of the arc light and generates ultraviolet photoelectric signals and near-infrared photoelectric signals respectively;

[0045] The frequency-locked amplifier unit is used to extract the power frequency AC component of the ultraviolet photoelectric signal and the near-infrared photoelectric signal and amplify the amplitude to obtain the ultraviolet light quantity value and the infrared light quantity value respectively;

[0046] A signal processing mainboard is used to classify arcs based on the ultraviolet light quantity value, the infrared light quantity value, the x-direction polarized light intensity component, and the y-direction polarized light intensity component, obtain classification results, and dynamically adjust the monitoring period according to the spectral intensity ratio r within consecutive periods;

[0047] Multi-level alarm module, used to issue alarms based on classification results.

[0048] Furthermore, the magneto-optical polarization detection unit includes a Faraday crystal, a laser emitting module, a polarization splitter and a temperature compensation module. The laser emitted by the laser emitting module passes through the Faraday crystal. The polarization splitter is collimated and aligned with the Faraday crystal to detect the polarization component and input it into a dual-channel photodetector. The temperature compensation device is close to the photodetector and measures its surface temperature.

[0049] Furthermore, the multi-level alarm module sets up a three-level response mechanism:

[0050] Level 1 alarm: local indicator light flashes;

[0051] Secondary alarm: Send warning signal to monitoring center;

[0052] Level 3 alarm: Triggers the circuit breaker to trip and activates the fire linkage.

[0053] Furthermore, it also includes a power supply module for power supply, which supports POE power supply and lithium battery dual-mode power supply, and the standby power consumption is ≤2W.

[0054] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0055] This invention utilizes a multi-physics fusion detection method: a high-precision magneto-optical sensor captures the arc's magnetic field intensity in real time, while a dual-channel radiation light intensity detection unit simultaneously collects optical signals in the ultraviolet and near-infrared bands. Combining magneto-optical effects with spectral analysis, this multi-parameter fusion of magnetic field intensity, ultraviolet light, and near-infrared light improves detection accuracy and reliability. A dynamic threshold algorithm based on the spectral intensity ratio (R) and magneto-optical polarization ratio (TGA) is also proposed to enable intelligent classification of arc types. The use of optical and magnetic sensors eliminates the need for direct circuit access, improving safety and applicability.

[0056] Furthermore, the monitoring cycle is dynamically adjusted according to the measured data, which not only ensures a highly sensitive response to arc risks, but also significantly reduces the system's computing load and energy consumption during low-risk periods. This solves the contradiction between sensitivity and computing power / power consumption in traditional solutions, and achieves a balance between resource efficiency and safety performance.

[0057] This invention uses a non-contact detection solution, directly converting magnetic fields into optical signals through magneto-optical crystals, ensuring that the detection unit maintains a safe distance from the charged object. This design completely eliminates the contact measurement method of traditional current transformers, avoiding the safety risks associated with circuit connection while enhancing the monitoring device's suitability in complex electromagnetic environments and extreme temperature conditions.

[0058] Furthermore, the present invention adopts dual-channel frequency-locked amplification technology to optimize the power frequency characteristics and improve the signal extraction efficiency.

[0059] Through the above-mentioned manner, the present invention can effectively overcome the deficiencies of the prior art and provide a highly sensitive, highly reliable, non-contact arc light energy monitoring method and device. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 A flow chart of a non-contact arc monitoring method;

[0061] Figure 2 This is a structural diagram of a non-contact arc monitoring device. DETAILED DESCRIPTION

[0062] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0063] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0064] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be another element centered thereon. When an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be another element centered thereon at the same time. The terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc. used herein indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0065] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0066] A non-contact arc light monitoring method and monitoring device specifically relate to a non-contact arc light energy monitoring method and device based on magneto-optical effect and spectral analysis, which are suitable for arc fault monitoring and classification identification in power systems.

[0067] Example 1

[0068] This embodiment provides a non-contact arc monitoring method, proposes a dual-criteria fusion algorithm of the magneto-optical polarization ratio tga and the spectral intensity ratio r, and establishes a three-level discharge classification model.

[0069] Reference Figure 1 , this embodiment provides a non-contact arc light monitoring method, comprising the following steps:

[0070] (a) The magnetic field intensity in the arc generation area is monitored in real time by a magneto-optical polarization detection unit, and the Faraday magneto-optical effect is used to convert the magnetic field intensity into mutually orthogonal x-direction polarized light intensity components PLx and y-direction polarized light intensity components Ply;

[0071] (b) The ultraviolet light component and the near-infrared light component in the arc light are synchronously collected by the dual-channel radiation light intensity detection unit, and the ultraviolet photoelectric signal U(t) and the near-infrared photoelectric signal N(t) are respectively generated;

[0072] (c) The mutually orthogonal x-direction polarized light intensity component PLx and y-direction polarized light intensity component Ply obtained in step (a) and the ultraviolet photoelectric signal U(t) and the near-infrared photoelectric signal N(t) in step (b) are input into the dual-channel lock-in amplifier unit, the power frequency AC components of the ultraviolet photoelectric signal and the near-infrared photoelectric signal are extracted and amplitude amplified, and the ultraviolet light quantity value u and the infrared light quantity value n are respectively obtained;

[0073] (d) Set the monitoring period to mT, where T = 20ms is a power frequency period and m is an integer from 1 to 10; within each power frequency period T, calculate the mean value ua of the ultraviolet light quantity value u and the mean value na of the quantity value infrared light quantity value n, and calculate the spectral intensity ratio r = na / ua;

[0074] (e) Within a unit time period T, when and only when r > 0.13, calculate the tangent value of the deflection angle tga = PLx / Ply within the power frequency period T; according to the tangent value of the deflection angle tga and the y-direction polarized light intensity component, perform arc classification:

[0075] If tga = 0 and Ply ≠ 0, it is determined as non-short-circuit type low-energy discharge;

[0076] If 0 < tga < 0.1 and Ply ≠ 0, it is determined as short-circuit high-resistance type arc discharge;

[0077] If tga ≥ 0.1 and Ply ≠ 0, it is determined as short-circuit low-resistance type arc discharge.

[0078] Preferably, the monitoring period setting rule in step (d) is:

[0079] When r ≤ 0.13 within three consecutive T periods, automatically extend the monitoring period and take m = 10;

[0080] When r > 0.13 within any monitoring period, immediately shorten the monitoring period to m = 1.

[0081] Preferably, in the arc classification in step (e), when Ply = 0, trigger the self-check program and perform the following operations:

[0082] (i) Turn off the laser emission module and detect the background light intensity of the solar-blind phototube;

[0083] (ii) If the background light intensity > the threshold value I0, it is determined that there is noise in the ultraviolet channel, and the value range of I0 is 3 - 6dB;

[0084] (iii) If the background light intensity is ≤ I0, it is determined that the magneto-optical sensor is faulty.

[0085] Example 2

[0086] Reference Figure 2 , this embodiment provides a non-contact arc light monitoring device, including a magneto-optical polarization detection unit, a dual-channel radiation detection unit, a frequency-locked amplification unit, a signal processing mainboard, a multi-level alarm module and a power supply module.

[0087] Wherein, the magneto-optical polarization detection unit includes:

[0088] Faraday crystal (TGG material): used to convert magnetic field intensity into polarized optical signals, using Tb3Ga5O 12 The crystal has a size of 10×10×(10-20) mm and can respond to the magnetic field strength range of 10 -6 T to 10 -3 T;

[0089] Laser emission module: used to provide the basic light source for the Faraday crystal, outputting a linearly polarized laser source with a wavelength of 532±5nm and a power of 1-10mW;

[0090] Polarization splitting device: used for magneto-optical polarization analysis, including Wollaston prism and dual-channel photodetector, with splitting angle deviation ≤ 0.1°;

[0091] Temperature compensation module: used to monitor temperature to compensate for sensor temperature drift or temperature alarm, built-in PT100 temperature sensor, compensation coefficient β = 0.05% / °C.

[0092] The laser emission module provides laser light to pass through the Faraday crystal, the polarization splitter device aligns the laser light to the crystal, detects the polarization component and inputs it to the dual-channel photodetector, and the temperature compensation device measures the surface temperature of the photodetector close to the photodetector.

[0093] The dual-channel radiation detection unit includes an ultraviolet channel and a near-infrared channel.

[0094] The ultraviolet channel is used to collect the ultraviolet light component in the arc light and generate an ultraviolet photoelectric signal U(t), and the near-infrared channel is used to collect the near-infrared light component in the arc light and generate a near-infrared photoelectric signal N(t); the output ends of the ultraviolet channel and the near-infrared channel are both connected to the input end of the frequency-locked amplifier unit.

[0095] Among them, the detection band of the ultraviolet channel is 200-280nm, using a solar-blind photomultiplier tube with a cathode sensitivity of ≥40mA / W@254nm; the ultraviolet channel is equipped with a solar-blind bandpass filter,

[0096] The detection band of the near-infrared channel is 850-1700nm, using InGaAs photodiode with a response time of ≤10μs; the near-infrared channel is equipped with an infrared long-wave bandpass filter.

[0097] The frequency-locked amplifier unit adopts a dual-channel digital phase-locked amplifier with the following operating parameters: center frequency 50Hz±0.5Hz, Q value ≥100; dynamic range: 0.1μV-10V; channel isolation ≥80dB; using digital orthogonal demodulation algorithm, phase noise ≤-100dBc / Hz@1kHz offset.

[0098] Signal processing mainboard: used for data acquisition of signals from each unit, control of the power module, and issuance of multi-level alarm signals. It also dynamically adjusts the monitoring period based on the spectral intensity ratio r within consecutive periods. It integrates an FPGA chip and a 24-bit ADC, and the sampling rate can be configured to 1kHz-100kHz.

[0099] Multi-level alarm module: includes LED indicator light, relay output and RS485 communication interface.

[0100] Preferably, the alarm module sets a three-level response mechanism:

[0101] Level 1 alarm (tga<0.1): local indicator light flashes;

[0102] Level 2 alarm (0.1≤tga<0.3): Send warning signal to the monitoring center;

[0103] Level 3 alarm (tga ≥ 0.3): Triggers the circuit breaker to trip and activates the fire linkage.

[0104] Power module: used to provide power for the entire arc monitoring device, supports POE power supply and lithium battery dual-mode power supply, and the standby power consumption is ≤2W.

[0105] Magneto-optical polarization detection unit: connected to the non-contact arc monitoring device through an optical fiber bundle and connected to the host computer through internal communication. The housing of the magneto-optical polarization detection unit is μ-metal high magnetic permeability shielding material;

[0106] The installation structure of the magneto-optical polarization detection unit meets the following requirements:

[0107] The distance d between the end face of the magneto-optical polarization detection unit and the charged conductor satisfies: d = K·V / (B_max·√3), where K = a safety factor of 0.8-1.2;

[0108] The optical axis of the magneto-optical polarization detection unit forms an angle of 45±5° with the center of the target area to be measured;

[0109] Equipped with an adjustable magnetic shield, with a shielding effectiveness of ≥60dB@50Hz.

[0110] The application examples are as follows

[0111] 1. Application Scenario

[0112] Switchgear: 110kV circuit breaker;

[0113] Place the magneto-optical polarization detection unit and dual-channel radiation detection unit inside the busbar air chamber of the circuit breaker. Position them 150 mm from the busbar conductor, with the detection optical axes of the magneto-optical polarization detection unit and dual-channel radiation detection unit forming a 45° angle with the busbar conductor.

[0114] Environmental conditions: temperature 25±5℃, relative humidity ≤80%, no strong electromagnetic interference source;

[0115] 2. Specific parameters of the device

[0116] ①Magnetic optical polarization detection unit:

[0117] Laser wavelength: 532.5nm

[0118] Laser power: 5mW (Class II safety level)

[0119] Faraday crystal: Tb3Ga5O 12 , size 10×10×15mm

[0120] Polarization beam splitter: extinction ratio ≥1000:1

[0121] Photodetector: response time ≤ 10ns, dark current ≤ 1nA

[0122] ②Dual-channel radiation detection unit:

[0123] UV channel:

[0124] Sensor: Solar-blind photomultiplier tube R7154

[0125] Gain: 10 5 -10 6 A / W adjustable

[0126] Spectral range: 200-280nm

[0127] Minimum detectable power: 1pW

[0128] Near-infrared channel:

[0129] Sensor: InGaAs photodiode

[0130] Spectral range: 850-1700nm

[0131] Responsivity: 0.9A / W@1550nm

[0132] ③Frequency-locked amplifier unit:

[0133] Center frequency: 50.0Hz

[0134] Bandwidth: 1Hz

[0135] Dynamic range: 120dB

[0136] Equivalent input noise: ≤0.1nV / √Hz

[0137] 3. Test Cases

[0138] ①Test conditions:

[0139] Arc type: Carbonized path discharge caused by poor contact of copper conductor Arc current: 8.5A (effective value)

[0140] Duration: 200ms

[0141] ②The test data is shown in Table 1:

[0142] Table 1

[0143] Time (ms) PLx(V) PLy(V) U(t)(mV) N(t)(mV) u(mV) n(mV) r tga Judgment results 0-20 0.02 0.25 10.2 1.5 10.1 1.48 0.15 0.08 Short circuit high resistance type 20-40 0.05 0.30 12.5 1.8 12.3 1.75 0.14 0.17 Short circuit low resistance type 40-60 0.12 0.35 15.0 2.1 14.8 2.05 0.14 0.34 Short circuit low resistance type 60-80 0.08 0.28 11.8 1.7 11.6 1.65 0.14 0.29 Short circuit low resistance type 80-100 0.03 0.26 10.5 1.6 10.3 1.55 0.15 0.12 Short circuit high resistance type

[0144] ③Data analysis:

[0145] In the 0-20ms and 80-100ms periods, tga < 0.1, which is determined to be a short-circuit high-resistance discharge, corresponding to the arc initiation and extinction stages; in the 20-80ms period, tga ≥ 0.1, which is determined to be a short-circuit low-resistance discharge, corresponding to the arc stable burning stage;

[0146] The r value remained stable at 0.14-0.15 during the entire process, satisfying the trigger condition of r>0.13.

[0147] 4. Performance Verification

[0148] ①The sensitivity test results are shown in Table 2:

[0149] Table 2

[0150] Arc current (A) Detection success rate Response time (ms) 5 98.2％ 12.5 10 99.5％ 9.8 20 100％ 8.2

[0151] ②The anti-interference test results are shown in Table 3:

[0152] Table 3

[0153] Interference Source Interference intensity False alarm rate fluorescent lamp 3000lx 0％ Mobile phone signal 2W@900MHz 0％ welding machine 10m distance 0.1％

[0154] ③Classification accuracy:

[0155] Arc type Number of samples Accuracy Non-short circuit discharge 200 99.0％ Short circuit high resistance type 150 98.7％ Short circuit low resistance type 250 99.2％

[0156] 5. Implementation Effect

[0157] Successfully identifies arc faults caused by poor contact in distribution cabinets; issues early warning signals at the arc initiation stage (0-20ms); accurately distinguishes arc types, providing a decision-making basis for fault handling; the entire monitoring process requires no contact with live conductors, making it safe and reliable.

[0158] From the above results, it can be seen that the present invention has the following advantages:

[0159] Improved detection sensitivity: can identify arc current ≥5mA;

[0160] Classification accuracy: 98.7% in laboratory testing (IEC 62606 standard test samples);

[0161] Response time: ≤10ms (faster than the action time of conventional protection devices);

[0162] Anti-interference ability: It can maintain stable detection even at an ambient light intensity of 3000lx.

[0163] The detailed examples above fully demonstrate the technical feasibility and superior performance of the present invention, providing strong support for the practical application of the patent. This solution significantly improves the accuracy and reliability of arc detection through multi-physics fusion detection and intelligent threshold algorithms, and has outstanding industrial application value.

[0164] The term "consisting of" when describing a combination should include the identified elements, ingredients, components, or steps as well as other elements, ingredients, components, or steps that do not materially affect the basic novel characteristic of the combination. The use of the terms "comprising" or "including" to describe a combination of elements, ingredients, components, or steps herein also contemplates embodiments consisting essentially of these elements, ingredients, components, or steps. The use of the term "may" herein is intended to indicate that any of the attributes described as "may" be optional.

[0165] Multiple elements, ingredients, parts or steps can be provided by a single integrated element, ingredient, part or step. Alternatively, a single integrated element, ingredient, part or step can be divided into separate multiple elements, ingredients, parts or steps. The disclosure of "a" or "an" to describe an element, ingredient, part or step is not intended to exclude other elements, ingredients, parts or steps.

[0166] It should be understood that the above description is for illustrative purposes only and is not intended to be limiting. Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but rather with reference to the preceding claims and the full scope of equivalents to which such claims are entitled. For the purpose of completeness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein from the preceding claims is not a disclaimer of such subject matter, nor should it be considered that the applicants did not consider such subject matter to be part of the disclosed inventive subject matter.

Claims

1. A non-contact arc light monitoring method, characterized in that: Including: S1. The magnetic field intensity in the arc generation area is monitored in real time by a magneto-optical polarization detection unit, and the magnetic field intensity is converted into x-direction polarized light intensity components and y-direction polarized light intensity components that are orthogonal to each other; The ultraviolet light component and the near-infrared light component in the arc light are synchronously collected by a dual-channel radiation light intensity detection unit, and ultraviolet photoelectric signals and near-infrared photoelectric signals are respectively generated; S2. The ultraviolet photoelectric signal and the near-infrared photoelectric signal are input into a dual-channel frequency-locked amplifier unit, the power-frequency AC components of the ultraviolet photoelectric signal and the near-infrared photoelectric signal are extracted and amplitude-amplified, and ultraviolet light quantity values and infrared light quantity values are respectively obtained; S3. The monitoring period is set to mT, where m is an integer from 1 to 10 and T is a power-frequency period; within each monitoring period, the spectral intensity ratio of ultraviolet light and infrared light is calculated based on the ultraviolet light quantity value and the infrared light quantity value; S4. When and only when the spectral intensity ratio r of ultraviolet light and infrared light is greater than the spectral intensity ratio threshold, the tangent value tga of the deflection angle within this monitoring period is calculated, and arc classification is performed according to the tangent value tga of the deflection angle and the y-direction polarized light intensity component, otherwise, jump to step S3 and adjust m.

2. The non-contact arc light monitoring method according to claim 1, characterized in that: In the step S4, the method for adjusting m is as follows: When the spectral intensity ratio r of ultraviolet light and infrared light is less than or equal to the spectral intensity ratio threshold within three consecutive monitoring periods, the monitoring period is extended, and m = 10 is taken; When the spectral intensity ratio r of ultraviolet light and infrared light is greater than the spectral intensity ratio threshold within any monitoring period, the monitoring period is shortened to m = 1.

3. The non-contact arc light monitoring method according to claim 1, characterized in that: In the step S3, the calculation formula for the spectral intensity ratio r of ultraviolet light to infrared light is: r = na / ua, where ua is the mean value of the ultraviolet light quantity value and na is the mean value of the infrared light quantity value.

4. The non-contact arc light monitoring method according to claim 1, characterized in that: In the step S4, when performing arc classification according to the following rules: If tga = 0 and PLy ≠ 0, it is determined as non-short-circuit type low-energy discharge; If 0 < tga < 0.1 and PLy ≠ 0, it is determined as short-circuit high-resistance type arc discharge; If tga ≥ 0.1 and PLy ≠ 0, it is determined as short-circuit low-resistance type arc discharge.

5. The non-contact arc light monitoring method according to claim 1, characterized in that: In the step S4, when performing arc classification, when the y-direction polarized light intensity component PLy = 0, a self-check program is triggered and the following operations are performed: SA1. Turn off the laser emission module and detect the background light intensity; SA2. Determine the cause of the abnormality according to the background light intensity: If the background light intensity > threshold I0, it is determined that there is noise in the ultraviolet channel; If the background light intensity ≤ I0, it is determined that the magneto-optical sensor is faulty.

6. The non-contact arc light monitoring method according to claim 1, characterized in that: In the step S4, the spectral intensity ratio threshold is 0.

13.

7. A non-contact arc monitoring device, characterized in that: Including: A magneto-optical polarization detection unit for monitoring the magnetic field intensity in the arc generation area in real time and converting the magnetic field intensity into x-direction polarized light intensity components and y-direction polarized light intensity components that are orthogonal to each other; A dual-channel radiation detection unit for collecting the ultraviolet light component and the near-infrared light component in the arc light and respectively generating ultraviolet photoelectric signals and near-infrared photoelectric signals; A frequency-locked amplifier unit for extracting the power-frequency AC components of the ultraviolet photoelectric signal and the near-infrared photoelectric signal and performing amplitude amplification to respectively obtain ultraviolet light quantity values and infrared light quantity values; A signal processing mainboard is used to classify arcs based on the ultraviolet light quantity value, the infrared light quantity value, the x-direction polarized light intensity component, and the y-direction polarized light intensity component, obtain classification results, and dynamically adjust the monitoring period according to the spectral intensity ratio r within consecutive periods; Multi-level alarm module, used to issue alarms based on classification results.

8. The non-contact arc monitoring device according to claim 7, characterized in that: The magneto-optical polarization detection unit includes a Faraday crystal, a laser emission module, a polarization splitter and a temperature compensation module. The laser emitted by the laser emission module passes through the Faraday crystal. The polarization splitter is aligned with the Faraday crystal, detects the polarization component and inputs it into a dual-channel photodetector. The temperature compensation device is close to the photodetector and measures its surface temperature.

9. The non-contact arc monitoring device according to claim 7, characterized in that: The multi-level alarm module sets a three-level response mechanism: Level 1 alarm: local indicator light flashes; Secondary alarm: Send warning signal to monitoring center; Level 3 alarm: Triggers the circuit breaker to trip and activates the fire linkage.

10. The non-contact arc monitoring device according to claim 7, characterized in that: It also includes a power supply module for power supply, which supports POE power supply and lithium battery dual-mode power supply, and the standby power consumption is ≤2W.

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