Arc spectrum identification method and apparatus

Abstract

The present invention relates to an arc spectrum identification method and device, and is related to the technical field of power system relay protection. The method employs Euclidean distance, minimizes the objective function, and utilizes the spectrum threshold truncation method to quickly find the essential spectrum of the arc, and then sends a signal to the protection control device, which can conveniently output an output alarm and trip signal. After adopting the present invention, the operation speed is fast, the installation and debugging are convenient, the scalability is high, the reliability is high, and the cost performance is high. An arc spectrum identification device corresponding to the arc spectrum identification method is developed, and especially by adding such a spectrum identification device to the existing switch cabinet, the operation of the existing switch cabinet is more reliable and safer.

Description

[Technical field]

[0001] The present invention relates to the technical field of power system relay protection, and in particular to an arc spectrum identification method and apparatus. [Background technology]

[0002] Faults are prone to serious accidents, such as fire accidents in cable trenches, switch cabinets, and even substations, due to long-term operation. The initial unstable contact between electricity and the medium, the unstable burning of the arc, the physical and chemical changes of the medium, and other causes cause the earth fault current, so that the arc fault has a certain degree of randomness, and the fault current has a nonlinear aberration, which has been widely recognized by researchers, and this aberration mainly comes from the impedance and the nonlinearity of the medium in the process of the arc burning.

[0003] DL / T 872-2016 《Technical Conditions for Single-Phase Ground Fault Routing Device for Small Current Grounding System》 stipulates: “The fault routing device should be able to accurately select the fault branch”. The neutral point through the arc canceling coil grounding mode needs to inject variable frequency and traveling wave signals, that is, it cannot be made into the nature of ground fault judgment. It is not easy to timely cut off the permanent single-phase ground fault line, and in the case of personal shock, it cannot be disconnected from the power supply in a timely manner. If the neutral point is grounded with a small resistance, the fault current is large, and the occurrence of intermittent arc lamp ground overvoltage can be suppressed. The feeder zero sequence protection works smoothly to trip the line, but the operation time is long (more than 3s), assuming that the fault line cannot be removed in a timely manner, the line will cause a great risk to personal safety. May 10, 2019, Power Supply Bureau of Southern Power Grid Company 10kV combined transformer (oil-filled) explosion fire, the action time of the line protection device is too slow, did not cut off the power supply in time, and finally caused two accidental deaths, the lesson is very tragic. In the needs of electrical fire and personal protection, arc protection technology has undergone rapid development, and GB / T 14598.302-2016《Arc Protection Device Technical Requirements》 proposes that the power distribution system arc protection device has an action time of within 20ms to eliminate the arc fault, and the arc protection logic has two methods: arc single judgment, arc and current double judgment, and the more widely used is double judgment, as shown in Figure 2, the action logic of the protection device is the arc lamp investigation and the current sensor multiple installation, the arc lamp sensor is installed on the bus side, the current sensor is installed at the entrance, and the exit signal takes the "AND" operation directly. Due to the existence of the limit value of the arc protection logic and the user arc protection, the exit trip signal is generally sent to the input circuit breaker, which expands the scope of the power outage and affects the reliability of the power supply.

[0004] The previous patent ZL201310038256.7, named: high-precision electrical signal measurement equipment device and method, mainly provides a compensation identification and control measurement method for electrical signals, and does not provide accurate identification of spectrum methods; the patent ZL201610945569.4, named: arc lamp protection device and its fault diagnosis method, also collects the corresponding voltage and current signals, and does not involve spectrum information, and additionally prepares an arc lamp fault diagnosis method. As shown in Figure 3, the sensor such as the spectrum detection sensor that collects the arc spectrum signal generally includes two parameters, x is the wavelength and y is the light intensity, corresponding to different spectral wavelengths of the arc, and x1...x n correspond to different arc intensities, y1…y n When an arc occurs, it is difficult to accurately determine the occurrence of an arc due to the interference of external light sources (sunlight, indoor lighting sources), and there is even a risk of misjudgment. Therefore, how to overcome the shortcomings of the existing technology is an urgent problem to be solved in the current field of power system relay protection technology. Summary of the Invention

[0005] The objective of the present invention is to provide an arc spectrum identification method and apparatus for solving the shortcomings of the prior art, to solve the problem of low reliability of the existing arc light spectrum identification method, to overcome the problem of inaccurate measurement of spectrum in the presence of optical interference sources, and to improve the detection accuracy of spectrum.

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] The arc spectrum identification method includes the following steps: Step (1): Measure the arc caused by the short circuit with an arc sensor, and obtain a numerical curve of the arc spectrum; Step (2): Sort the measured light intensity values ​​of the arc spectrum from largest to smallest, find the n wavelength spectrum measurement points with the highest light intensity, and classify the wavelengths of the n measurement points in order as x1, x2, ..., x n, the light intensity is y1, y2, ..., y n year, Step (3), calculating the Euclidean distance between the measurement points of the n wavelength spectra obtained in step (2); Step (4), corresponding to the case where S is the smallest y j D Until you find Minimize and iterate according to TIFF0007676663000001.tif10170, In the formula TIFF0007676663000002.tif29170, y j D denotes the light intensity value at D iterations, where y j D The initial value of is set to the maximum light intensity value among n wavelength spectrum measurement points, and then in each iteration, the light intensity value of any measurement point among n wavelength spectrum measurement points whose light intensity is greater than dc is taken, and cd i is the light intensity at the i-th target arc measurement point, TIFF0007676663000003.tif7170 is wavelength x among n wavelength spectrum measurement points i and x j is the Euclidean distance of, dc is the cutoff threshold of the spectral measurement point light intensity, TIFF0007676663000004.tif5170 is the conversion coefficient between the measurement point wavelength and the light intensity, D is the number of iterations, Step (5), the light intensity obtained in step (4) y j D is equal to or greater than the set light intensity threshold, it is determined that an arc short circuit has occurred, and if not, it is determined that an arc short circuit has not occurred.

[0008] Further, preferably, in step (2), the value of n is 20 times or more the number of light intensity measurement points of the cutoff threshold, and the wavelength interval between the different measurement points is the resolution of the light intensity measurement points.

[0009] Further, preferably, in step (3), the wavelengths of the n wavelength spectrum measurement points are sequentially designated as x1, x2, ..., x n , the light intensity is y1, y2, ..., y n year, The Euclidean distance d between these wavelength spectrum measurement points ij (x) is The file is TIFF0007676663000005.tif14170.

[0010] Further, preferably, in step (4), the range of the dc value is [dc minimum, dc maximum], where the dc maximum value is the arc spectrum maximum wavelength minus the minimum wavelength, and the minimum value is 2% to 10% of the dc maximum value.

[0011] Further, preferably, in step (4), dc is a value obtained by subtracting 20% ​​of the minimum wavelength from the maximum wavelength of the arc spectrum.

[0012] Additionally, the light intensity threshold is preferably equal to or greater than the maximum arc light intensity perceived by the human eye.

[0013] Further, preferably, the light intensity threshold is 5000 Lux to 10000 Lux in an indoor enclosed space, and 15000 Lux to 40000 Lux in an outdoor environment.

[0014] The present invention provides a simultaneous arc spectrum identification device, which is composed of an arc sensor and an identification system, the arc sensor measures an arc caused by a short circuit, obtains an arc spectrum, and transmits it to the identification system; The identification system comprises: The measured light intensity values ​​of the arc spectrum are sorted from largest to smallest, and the measurement points of the n wavelength spectrum with the highest light intensity are found. The wavelengths of the n measurement points are sequentially designated as x1, x2, ..., x n , the light intensity is y1, y2, ..., y n a first processing module configured to a second processing module configured to calculate Euclidean distances between measurement points of the obtained n wavelength spectra; Corresponds to the case where S is the smallest y j D Until you find a third processing module configured to minimize and iteratively calculate according to TIFF0007676663000006.tif10170; and In the formula TIFF0007676663000007.tif29170, y j D denotes the light intensity value at the Dth iteration, where y j D The initial value of is set to the maximum light intensity value among n wavelength spectrum measurement points, and then in each iteration, the light intensity value of any measurement point among n wavelength spectrum measurement points whose light intensity is greater than dc is taken, and cd i is the light intensity at the i-th arc measurement point, TIFF0007676663000008.tif7170 is the wavelength x of n wavelength spectrum measurement points. i and x j is the Euclidean distance of, dc is the cutoff threshold of the spectral measurement point light intensity, TIFF0007676663000009.tif5170 is the conversion coefficient between the measurement point wavelength and the light intensity. Light intensity obtained by processing in the third processing module y j D is equal to or greater than a set light intensity threshold, determine that an arc short circuit has occurred, and if not, determine that an arc short circuit has not occurred.

[0015] The present invention further provides an electronic device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, the program, when executed by the processor, performing the steps of the above arc spectrum identification method.

[0016] The present invention further provides a non-transitory computer readable storage medium having stored thereon a computer program which, when executed by a processor, performs the steps of the above arc spectrum identification method.

[0017] In step (1) of the present invention, an arc caused by a short circuit is measured by an arc sensor to obtain a numerical curve of an arc spectrum, and then an arc maximum spectral wavelength point and a minimum spectral wavelength point are obtained in the obtained numerical curve of the arc spectrum, and according to the measurement range of the arc spectrum sensor, the maximum spectral wavelength point is the upper limit value of the maximum measurement range of the arc spectrum sensor, and the minimum spectral wavelength point is the lower limit value of the minimum measurement range of the arc spectrum sensor.

[0018] In step (3) of the present invention, y i is the wavelength of the arc spectrum, and the exact output light intensity value y i It is.

[0019] In step (4) of the present invention, TIFF0007676663000010.tif5170 is a conversion coefficient between the measurement point wavelength and the light intensity, and its value is 5000 to 20000, and preferably 10000. In the present invention, the number of iterations D is not limited.

[0020] In step (5) of the present invention, the light intensity threshold is preferably 5000 Lux to 10000 Lux in an indoor closed space, and 15000 Lux to 40000 Lux in an outdoor environment. Due to the attenuation phenomenon of light intensity during the optical fiber transmission process, the preferred value used in the present invention has undergone normalization processing, and is equivalent to the optical fiber length of 1 m.

[0021] According to the method of the present invention, the measurement of the arc is not affected by external light source or interference source spectrum, and the characteristic wavelength of the arc and the corresponding light intensity are correctly identified and output.

[0022] In the present invention, when it is determined that an arc short circuit has occurred, a control signal is output to a higher-level monitoring and alarm system or device, and then an "alarm" or "trip" signal is displayed on the higher-level monitoring and alarm system or device, making it easier to manually determine the occurrence of the arc short circuit on the monitoring and alarm system or device, or convenient for directly cutting off the operating circuit of the circuit breaker.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The method of the present invention has accurate measurements, fast operating speed, high scalability, high reliability, and high cost performance. In particular, it can accurately identify characteristic wavelengths of the spectrum even in the case of interference sources such as fluorescent lights (200 nm to 1500 nm), improving the identification accuracy by 18% to 25%.

[0025] Under the condition that an arc protection device is added to an existing switch cabinet, the short circuit identification accuracy is higher than that of the traditional arc protection device, so that the operation of the existing switch cabinet is more reliable and safer. For example, in the case of an arc short circuit, the conversion factor between the wavelength of the arc measurement point and the light intensity is The classification accuracy of TIFF0007676663000011.tif5170 improved by 18% to 25%, especially TIFF0007676663000012.tif6170 was able to achieve a score of 10,000, and the recognition accuracy was steadily improved by 25%. [Brief description of the drawings]

[0026] [Figure 1] 2 is a flow chart of the arc spectrum identification method of the present invention. [Diagram 2] A conventional high-performance arc protection method is shown, where Td indicates a time relay, ≧1 takes logical OR, and & takes logical AND; [Diagram 3] A typical arc spectrum discrimination curve is shown. [Figure 4] FIG. 2 is a structural schematic diagram of the arc spectrum identification device of the present invention. [Diagram 5] 1 is a structural schematic diagram of an electronic device of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] The present invention will now be described in more detail with reference to the following examples.

[0028] Those skilled in the art should understand that the following examples are used only for the purpose of illustrating the present invention, and are not intended to limit the scope of the present invention. In the examples, if no specific techniques or conditions are shown, they are in accordance with the techniques or conditions or product specifications described in the literature in this field. If the materials or equipment used do not have the manufacturer's name, they are conventional products available for purchase.

[0029] When an arc fault occurs in a switchgear cabinet, most of them are diagnosed by double criteria (overcurrent signal and arc signal), or "multiple criteria", that is, by adding zero sequence current, zero sequence voltage, and low voltage signals. In the traditional switchgear cabinet, multiple high-voltage primary devices are assembled, and when a short circuit occurs, these devices will generate different zero sequence current, zero sequence voltage signals, and the zero sequence current, zero sequence voltage signal will not be generated, and then the short circuit fault will occur, and the zero sequence signal will also have a sudden change. In this condition, the first step is to freely combine various implementations of signals. 2, some partly for a little time, generally 0.2-2 frequency interval, this is mainly to consider single-phase or three-phase arc discharge short circuit, when the front phase or three-phase voltage, current jump, as neutral current, voltage signal, will be a sudden change, neutral current and voltage signal, according to different hardware conditions, when the neutral current transformer, neutral voltage transformer is installed, only need to take out directly from the secondary coil of the transformer, if the neutral current transformer, neutral voltage transformer is not installed, it is necessary to make software connection of voltage signal, current signal, that is, both ends may be connected together, as the neutral voltage signal, neutral current signal of the transformer. As shown in Figure 2, a single switch cabinet is regarded as a closed electromagnetic field, when an arc occurs, a short circuit event occurs, and it is easily affected by the electromagnetic field, so it is necessary to collect and judge zero sequence current, overcurrent signal, etc., and the electrical signal, in order to separate such floating signals, it is necessary to consume a huge amount of calculation, which increases the hardware cost, and may not be able to identify the accuracy, so the present invention puts forward a new arc spectrum identification method that can be applied to high-performance arc monitoring based on the traditional arc light monitoring method.

[0030] The arc spectrum signal collected by the sensor generally includes two parameters (e.g., the arc spectrum signal collected by the spectrum detection sensor, shown in Figure 3), where x is the wavelength and y is the light intensity, corresponding to different spectral wavelengths of the arc, and x1...x n correspond to different arc intensities, y1…y nWhen an arc occurs, it is difficult to accurately determine whether an arc has occurred due to the interference of external light sources (e.g., sunlight, indoor lighting sources), and there is even a risk of misjudgment. The present invention provides a method and device for accurately identifying the arc spectrum.

[0031] The arc spectrum identification method includes the following steps: Step (1): Measure the arc caused by the short circuit with an arc sensor, and obtain a numerical curve of the arc spectrum; Step (2): Sort the measured light intensity values ​​of the arc spectrum from largest to smallest, find the n wavelength spectrum measurement points with the highest light intensity, and classify the wavelengths of the n measurement points in order as x1, x2, ..., x n , the light intensity is y1, y2, ..., y n year, Step (3), calculating the Euclidean distance between the measurement points of the n wavelength spectra obtained in step (2); Step (4), corresponding to the case where S is the smallest y j D Until you find Minimize and iterate according to TIFF0007676663000013.tif10170, In the formula TIFF0007676663000014.tif29170, y j D denotes the light intensity value at D iterations, where y j D The initial value of is set to the maximum light intensity value among n wavelength spectrum measurement points, and then in each iteration, the light intensity value of any measurement point among n wavelength spectrum measurement points whose light intensity is greater than dc is taken, and cd i is the light intensity at the i-th target arc measurement point, TIFF0007676663000015.tif7170 is wavelength x among n wavelength spectrum measurement points i and x j is the Euclidean distance of, dc is the cutoff threshold of the spectral measurement point light intensity, TIFF0007676663000016.tif5170 is the conversion coefficient between the measurement point wavelength and the light intensity, D is the number of iterations, Step (5), the light intensity obtained in step (4) y j D is equal to or greater than the set light intensity threshold, it is determined that an arc short circuit has occurred, and if not, it is determined that an arc short circuit has not occurred.

[0032] In step (2), the value of n is equal to or greater than 20 times the number of light intensity measurement points that is the truncation threshold, and the wavelength interval between different measurement points is the resolution of the light intensity measurement points.

[0033] In step (3), the wavelengths of the n wavelength spectrum measurement points are sequentially designated as x1, x2, ..., x n , the light intensity is y1, y2, ..., y n year, The Euclidean distance d between these wavelength spectrum measurement points ij (x) is The file is TIFF0007676663000017.tif14170.

[0034] In step (4), the range of dc values ​​is [dc minimum, dc maximum], where dc maximum is the arc spectrum maximum wavelength minus the minimum wavelength, and the minimum is 2% to 10% of dc maximum.

[0035] In step (4), dc is the maximum wavelength minus 20% of the minimum wavelength in the arc spectrum.

[0036] The light intensity threshold is equal to or greater than the maximum arc light intensity perceived by the human eye.

[0037] The light intensity threshold is 5000 Lux to 10000 Lux in an indoor enclosed space, and 15000 Lux to 40000 Lux in an outdoor environment.

[0038] The spectrum range is very wide, spanning 15 orders of magnitude from 0.1 nm cosmic rays to 100 km near infrared, and such an iterative method is very time-consuming. Therefore, in this invention, the optical intensity cd of any wavelength is calculated. i By iterating through all the measurement points, the minimum of the objective function is always found, which becomes the characteristic wavelength of the arc spectrum, and the light intensity corresponding to the characteristic wavelength becomes the exact light intensity of the arc.

[0039] As shown in FIG. 4, the arc spectrum identification device is composed of an arc sensor 101 and an identification system. The arc sensor measures an arc caused by a short circuit, obtains an arc spectrum, and transmits it to the identification system. The identification system comprises: The measured light intensity values ​​of the arc spectrum are sorted from largest to smallest, and the measurement points of the n wavelength spectrum with the highest light intensity are found. The wavelengths of the n measurement points are sequentially designated as x1, x2, ..., x n , the light intensity is y1, y2, ..., y n a first processing module 102 configured to a second processing module 103 configured to calculate the Euclidean distance between the measurement points of the obtained n wavelength spectra; Corresponds to the case where S is the smallest y j D Until you find a third processing module 104 configured to iteratively minimize according to TIFF0007676663000018.tif10170; In the formula TIFF0007676663000019.tif29170, y j D denotes the light intensity value at the Dth iteration, where y j D The initial value of is set to the maximum light intensity value among n wavelength spectrum measurement points, and then in each iteration, the light intensity value of any measurement point among n wavelength spectrum measurement points whose light intensity is greater than dc is taken, and cd i is the light intensity at the i-th arc measurement point, TIFF0007676663000020.tif7170 is the wavelength x of n wavelength spectrum measurement points. i and x j is the Euclidean distance of, dc is the cutoff threshold of the spectral measurement point light intensity, TIFF0007676663000021.tif5170 is the conversion coefficient between the measurement point wavelength and the light intensity. Light intensity obtained by processing in the third processing module y j D is equal to or greater than the set light intensity threshold, determine that an arc short circuit has occurred, and if not, determine that an arc short circuit has not occurred.

[0040] The system provided by the embodiment of the present invention can be used to implement the embodiments of each of the above methods, and the specific flow and details can be referred to the above embodiments and will not be repeated here.

[0041] 5 is a structural schematic diagram of an electronic device provided by an embodiment of the present invention. Referring to FIG. 5, the electronic device includes a processor 201, a communications interface 202, a memory 203 and a communications bus 204, where the processor 201, the communications interface 202 and the memory 203 communicate with each other through the communications bus 204. The processor 201 calls the logic instructions in the memory 203 to execute the following method: Obtain the numerical curve of the arc spectrum, The measured light intensity values ​​of the arc spectrum are sorted from largest to smallest, and the measurement points of the n wavelength spectrum with the highest light intensity are found. The wavelengths of the n measurement points are sequentially designated as x1, x2, ..., x n , the light intensity is y1, y2, ..., y n year, Calculate the Euclidean distance between the measurement points of the n wavelength spectra obtained, Corresponds to the case where S is the smallest y jD Until you find Minimize and iterate according to TIFF0007676663000022.tif10170, In the formula TIFF0007676663000023.tif29170, y j D denotes the light intensity value at the Dth iteration, where y j D The initial value of is set to the maximum light intensity value among n wavelength spectrum measurement points, and then in each iteration, the light intensity value of any measurement point among n wavelength spectrum measurement points whose light intensity is greater than dc is taken, and cd i is the light intensity at the i-th arc measurement point, TIFF0007676663000024.tif7170 is the wavelength x of n wavelength spectrum measurement points. i and x j is the Euclidean distance of, dc is the cutoff threshold of the spectral measurement point light intensity, TIFF0007676663000025.tif5170 is the conversion coefficient between the measurement point wavelength and the light intensity, D is the number of iterations, Obtained light intensity y j D is equal to or greater than the set light intensity threshold, it is determined that an arc short circuit has occurred, and if not, it is determined that an arc short circuit has not occurred.

[0042] Also, the logic instructions in the memory 203 can be implemented in the form of a software functional unit and stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the technical solution of the present invention can be embodied in the form of a software product, and the computer software product is stored in a storage medium and includes a plurality of instructions that cause a computer device (such as a personal computer, a server, or a network device) to execute all or part of the steps of the method according to each embodiment of the present invention. The storage medium can be any medium capable of storing program code, such as a USB disk, a removable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0043] On the other hand, an embodiment of the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, the computer program being executed by a processor to implement the arc spectrum identification method provided in each of the above embodiments, for example including the following steps: Obtain the numerical curve of the arc spectrum, The measured light intensity values ​​of the arc spectrum are sorted from largest to smallest, and the measurement points of the n wavelength spectrum with the highest light intensity are found. The wavelengths of the n measurement points are sequentially designated as x1, x2, ..., x n , the light intensity is y1, y2, ..., y n year, Calculate the Euclidean distance between the measurement points of the n wavelength spectra obtained, Corresponds to the case where S is the smallest y j D Until you find Minimize and iterate according to TIFF0007676663000026.tif10170, In the formula TIFF0007676663000027.tif29170, y j Ddenotes the light intensity value at the Dth iteration, where y j D The initial value of is set to the maximum light intensity value among n wavelength spectrum measurement points, and then in each iteration, the light intensity value of any measurement point among n wavelength spectrum measurement points whose light intensity is greater than dc is taken, and cd i is the light intensity at the i-th arc measurement point, TIFF0007676663000028.tif7170 is the wavelength x of n wavelength spectrum measurement points. i and x j is the Euclidean distance of, dc is the cutoff threshold of the spectral measurement point light intensity, TIFF0007676663000029.tif5170 is the conversion coefficient between the measurement point wavelength and the light intensity. Obtained light intensity y j D is equal to or greater than the set light intensity threshold, it is determined that an arc short circuit has occurred, and if not, it is determined that an arc short circuit has not occurred.

[0044] The above-described embodiment of the device is merely illustrative, and the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, i.e., may be co-located or distributed across multiple network units. According to actual needs, some or all of the modules may be selected to achieve the purpose of the solution of the embodiment. Those skilled in the art can understand and implement it without creative work.

[0045] Through the above description of the embodiments, those skilled in the art can understand that each embodiment can be implemented by adding a general hard disk platform required for software, and can also be implemented by a hard disk. Based on this understanding, the above technical solution is essentially or the part that contributes to the existing technology is embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, ROM / RAM, magnetic disk, optical disk, etc., and includes a number of instructions that cause a computer device (such as a personal computer, a server, or a network device) to execute the above method of each embodiment or a part of the embodiment.

[0046] Application examples As shown in FIG. 3, a certain arc spectrum discrimination curve has a cutoff threshold of the light intensity of the spectrum measurement point of (15000-40000) Lux, which is 20000 Lux in this embodiment. There are 45 spectrum measurement points that are greater than the cutoff threshold. The maximum spectrum measurement wavelength is 820 nm, the minimum measurement wavelength is 200 nm, the spectrum wavelength measurement resolution is 2 nm, and the total number of measurement points is 310. TIFF0007676663000030.tif5170 is the conversion coefficient between the measurement point wavelength and the light intensity, and the value is 10000. According to the iteration rule with the smallest arc spectrum identification target function, find the characteristic wavelength of the arc spectrum of 426 nm, and the corresponding light intensity is 28400 Lux, which is greater than the light intensity threshold, and the light intensity threshold is 25000 Lux. At this time, it is proved that an arc short circuit has occurred, and therefore output the arc short circuit control signal. This light intensity threshold is generally different from that without interference when there is interference from an external light source, and when there is interference from an external light source, the light intensity threshold must be more than twice the light intensity threshold when there is no interference from an external light source. In addition, in order to determine whether a short circuit actually occurs, the light intensity threshold is related to the attenuation of the optical fiber, and must be calibrated according to the length of the optical fiber when installed and shipped.

[0047] At this time, if the characteristic wavelength of the arc spectrum and the corresponding light intensity are smaller than the light intensity threshold, it is proven that no arc short circuit has occurred, so the arc short circuit control signal is not output. That is, when the calculated target function is at a minimum, the corresponding y i If the light intensity is greater than or equal to the light intensity threshold, then it is proven that an arc short has occurred, and if the light intensity is less than the light intensity threshold, then it is proven that an arc short has not occurred.

[0048] The basic principles, main features and advantages of the present invention have been shown and described above. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and the above embodiments and the description in the specification are merely illustrative of the principles of the present invention, and that various modifications and improvements can be made to the present invention without departing from the spirit and scope of the present invention, and all such modifications and improvements are included within the scope of the present invention that is intended to be protected. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. (1) measuring an arc caused by a short circuit with an arc sensor and obtaining a numerical curve of an arc spectrum; The measured values ​​of the light intensity of the arc spectrum are sorted from largest to smallest, and the measurement points of the n wavelength spectrum with the highest light intensity are found. The wavelengths of the n measurement points are then sorted in order by x １ , x ２ , …, x ｎ The light intensity is then expressed as y １ , y ２ , …, y ｎ Step (2) of: A step (3) of calculating the Euclidean distance between the measurement points of the n wavelength spectra obtained in the step (2); until we find y j D corresponding to the case where S is the smallest. (4) performing an iterative calculation by minimizing according to In the formula, y ｊ Ｄ denotes the light intensity value at the Dth iteration, where y ｊ Ｄ The initial value of is set to the maximum value of the light intensity among the n wavelength spectrum measurement points, and then in each iteration, the light intensity value of any measurement point among the n wavelength spectrum measurement points whose light intensity is greater than dc is taken, and cd ｉ denotes the light intensity at the i-th arc measurement point, is the wavelength x among n wavelength spectrum measurement points ｉ and x ｊ where dc is the cutoff threshold of the light intensity of the spectrum measurement point, is a conversion coefficient between the measurement point wavelength and the light intensity, D is the number of iterations, and step (5) of determining that an arc short circuit has occurred if the light intensity y j D obtained in step (4) is equal to or greater than a set light intensity threshold, and determining that an arc short circuit has not occurred if not.

2. 2. The method for identifying an arc spectrum according to claim 1, wherein in step (2), n≧(the number of measurement points in the numerical curve of the arc spectrum whose light intensity is greater than the cutoff threshold)×20, and the wavelength interval of different measurement points is the resolution of the light intensity measurement points.

3. In step (3), the wavelengths of the n wavelength spectrum measurement points are sequentially set to x １ , x ２ , …, x ｎ The light intensity is then expressed as y １ , y ２ , …, y ｎ Then, The Euclidean distance d between these wavelength spectrum measurement points ｉｊ (x) is 2. The method of claim 1, wherein:

4. 2. The method of claim 1, wherein the light intensity threshold is equal to or greater than a maximum arc light intensity perceived by the human eye.

5. The method for identifying arc spectrum according to claim 1, wherein the light intensity threshold is 5000 Lux-10000 Lux in indoor enclosed space, and 15000 Lux-40000 Lux in outdoor environment.

6. an arc sensor and an identification system for measuring an arc caused by a short circuit, obtaining an arc spectrum, and transmitting the arc spectrum to the identification system; The identification system comprises: The measured values ​​of the light intensity of the arc spectrum are sorted from largest to smallest, and the measurement points of the n wavelength spectrum with the highest light intensity are found. The wavelengths of the n measurement points are then sorted in order by x １ , x ２ , …, x ｎ , the light intensity is expressed as y １ , y ２ , …, y ｎ a first processing module configured to a second processing module configured to calculate the Euclidean distance between the measurement points of the obtained n wavelength spectra; until we find y j D corresponding to the case where S is the smallest. a third processing module configured to iteratively minimize according to In the formula, y ｊ Ｄ denotes the light intensity value at the Dth iteration, where y ｊ Ｄ The initial value of is set to the maximum light intensity value among n wavelength spectrum measurement points, and then in each iteration, the light intensity value of any measurement point among n wavelength spectrum measurement points whose light intensity is greater than dc is taken, and cd ｉ is the light intensity at the i-th arc measurement point, is the wavelength x among n wavelength spectrum measurement points ｉ and x ｊ is the Euclidean distance of the spectral measurement point light intensity cutoff threshold, is the conversion coefficient between the measurement point wavelength and the light intensity, and an arc short circuit determination module configured to determine that an arc short circuit has occurred if the light intensity y j D obtained by the third processing module processing is equal to or greater than a set light intensity threshold, and to determine that an arc short circuit has not occurred if not.

7. 6. An electronic device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, the electronic device performing steps of the arc spectrum identification method according to any one of claims 1 to 5 when the processor executes the program.

8. A non-transitory computer readable storage medium having a computer program stored thereon, the computer program, when executed by a processor, performing steps of the arc spectrum identification method of any one of claims 1 to 5.

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