Method for detecting algae attachment condition on surface of insulator

Abstract

According to the method for detecting the algae attachment condition on the surface of the insulator, sensitive and accurate recognition of algae attachment is achieved by combining ultraviolet irradiation and image processing technologies. The method comprises the following steps: irradiating the surface of a to-be-detected insulator by using an ultraviolet light source to excite algae to generate fluorescence; capturing a fluorescence signal by using a high-sensitivity camera to form a fluorescence sequence; the method comprises the following steps: selecting a corresponding characteristic fluorescence function according to pollution conditions of the surface of the insulator, such as algae types and dust density, and establishing the function based on laboratory and field test data to describe a quantitative relationship among fluorescence characteristics, algae cell density and dust density; the fluorescence image is analyzed through an image processing technology, the algae cell density of the algae on the surface of the insulator is calculated, and therefore the algae attachment distribution condition is reversely deduced. According to the method, the detection accuracy is improved, the dependence on weather and light conditions is reduced, the requirements of equipment investment and professional operation are reduced, and reliable technical support is provided for stable operation of a power system.

Description

Technical Field

[0001] The invention relates to the technical field of power equipment detection, and in particular to a method for detecting algae attachment on the surface of an insulator. Background Art

[0002] In high-voltage power transmission systems, insulators are very important external insulation equipment. They play a dual role of electrical insulation and mechanical support. The safety of insulators largely determines the stable operation of the power system. Pollution flashover is one of the most common accidents in power systems. Configuring insulation levels and operation and maintenance frequencies according to regional characteristics is an effective means to prevent pollution flashover accidents. However, with the continuous improvement of the ecological environment, the significant increase in green space coverage, and the gradual increase in the number of organisms around high-voltage transmission lines, a new type of pollution, algae, has appeared on the surface of transmission line insulators in the humid and hot southern regions of my country. Different from traditional pollution, the growth and attachment of algae pollution on the surface of insulators may affect the electrical properties, hydrophobic properties, and physical and chemical properties of insulators. Therefore, effective detection of the growth and attachment of algae on the surface of insulators is of great significance for the reasonable configuration of insulation levels and types, targeted operation and maintenance cleaning, and ensuring the safe and stable operation of power systems.

[0003] At present, the detection methods for algae on the surface of insulators mainly include visual inspection, infrared thermal imager inspection, and ultrasonic inspection. However, the existing detection methods have problems such as poor detection effect, high equipment investment, and high demand for professional operation.

[0004] Disadvantages of existing methods:

[0005] 1) Visual inspection: Observe with the naked eye whether there are green or brown deposits on the surface of the transmission line. The advantage of visual inspection is that it is simple and intuitive, but the disadvantage is that it is restricted and affected by natural conditions such as weather and light, and has uncertainty.

[0006] 2) Infrared thermal imager detection: Infrared thermal imager detection uses infrared thermal imagers to detect the temperature difference on the line surface to determine whether there is algae contamination. Its advantages are fast and accurate, but its disadvantages are that the equipment cost of infrared thermal imagers is relatively high and the investment is relatively large.

[0007] 3) Ultrasonic testing: Ultrasonic testing detects whether there is algae contamination on the surface of the transmission line through changes in ultrasonic reflection signals. Ultrasonic testing can achieve non-contact detection, but it requires professional technicians to operate.

[0008] It should be noted that the information disclosed in the above background technology section is only used for understanding the background of the present application, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the invention

[0009] The main purpose of the present invention is to overcome the defects existing in the above-mentioned background technology and provide a method for detecting the algae attachment on the surface of an insulator.

[0010] To achieve the above object, the present invention adopts the following technical solutions:

[0011] A method for detecting algae attachment on an insulator surface, comprising:

[0012] S1, obtaining a fluorescence sequence of the surface of the insulator to be tested under ultraviolet light irradiation;

[0013] S2. Obtaining pollution conditions, wherein the pollution conditions include the type of algae attached to the surface of the insulator to be tested and the dust density on the surface of the insulator;

[0014] S3, selecting a corresponding characteristic fluorescence function according to the pollution condition; the characteristic fluorescence function is a function model established by observing and recording the fluorescence response of algae on the surface of the insulator under ultraviolet light irradiation for specific algae cell density and ash density through laboratory artificial experiments and field tests under different pollution conditions, and is used to describe the quantitative relationship between the fluorescence characteristics and the algae species, algae cell density, and ash density;

[0015] S4. Inferring the attachment distribution of algae on the surface of the insulator to be tested based on the fluorescence sequence and the characteristic fluorescence function.

[0016] Further:

[0017] In step S1, a fluorescence sequence of the surface of the insulator to be tested under ultraviolet light irradiation is obtained, including:

[0018] Use ultraviolet light source to irradiate the surface of the insulator to be tested;

[0019] Use a camera to capture the fluorescence signal produced by algae on the surface of the insulator under ultraviolet light excitation;

[0020] The fluorescence signal is recorded to form a fluorescence sequence.

[0021] In step S4, the algae attachment condition is inferred based on the fluorescence sequence and the characteristic fluorescence function, including:

[0022] Analyze fluorescence images using image processing techniques;

[0023] According to the intensity of the fluorescence signal, the algae cell density of the algae on the surface of the insulator is calculated by using the characteristic fluorescence function.

[0024] The image processing specifically includes: dividing the image into a number of 1cm*1cm small squares, each small square being used as a sampling pixel point, performing image analysis, and applying filtering, edge detection and recognition techniques to quantify the fluorescence signal.

[0025] The characteristic fluorescence function is:

[0026] I=K·D algae +I0

[0027] Where I is the fluorescence intensity reflected from the insulator surface, K is the proportionality coefficient, which is affected by the type of algae and the wavelength of ultraviolet light. algae is the algae cell density, I0 is the initial fluorescence intensity, and is affected by the NSDD of the insulator surface.

[0028] The algae is Chlorella vulgaris, and when the gray density NSDD of the insulator surface is 0, the characteristic fluorescence function is:

[0029]

[0030] Where I is the fluorescence intensity reflected from the insulator surface, D is the algae cell density,

[0031] The algae is Chlorella vulgaris, and the ash density NSDD of the insulator surface is 1, 2, 3, and 4 mg / cm 2 When , the characteristic fluorescence function is:

[0032]

[0033] The wavelength of the ultraviolet light source is 400nm and the power is 100mW.

[0034] The present invention has the following beneficial effects:

[0035] The present invention provides a method for detecting algae attachment on the surface of an insulator by combining ultraviolet irradiation and image processing technology, which can effectively improve the sensitivity and accuracy of detection. By using ultraviolet light of a specific wavelength to excite chlorophyll a in algae on the surface of the insulator to generate fluorescence signals, and using a high-sensitivity camera to capture these signals, the present invention can sensitively identify and quantitatively analyze the algae attachment. In addition, the application of image processing technology makes the analysis of fluorescence signals more accurate, and can accurately identify and analyze the distribution of algae. This method not only improves the accuracy of detection, but also can realize real-time monitoring, providing a reliable decision-making basis for the stable operation of the power system. Compared with traditional visual detection, infrared thermal imager detection and ultrasonic detection methods, the present invention avoids the limitations of weather and light conditions, high equipment costs and the need for professional operation, and realizes a detection scheme with higher cost-effectiveness, simpler operation and better effect, which helps operation and maintenance personnel to promptly discover and deal with the problem of algae attachment on the surface of the insulator, and provides reliable technical support for the stable operation of the power system.

[0036] In a preferred embodiment, the surface density (NSDD) of the insulator for the specific algae Chlorella is 0, 1, 2, 3, 4 mg / cm 2The fluorescence response characteristics at different times are fitted and corresponding nonlinear characteristic fluorescence functions are established. Using these functional relationship curves, the fluorescence response can accurately reflect the changes in algae cell density under different gray density conditions, thereby improving the accuracy of detection. The different characteristic fluorescence functions established by the present invention for different gray density conditions make the detection method have good adaptability and can be applied to detection under a variety of different environmental conditions. Therefore, it not only improves the accuracy and sensitivity of algae detection on the surface of insulators, but also has good adaptability and ease of operation.

[0037] Other beneficial effects of the embodiments of the present invention will be further described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The figure is a general flow chart of the method for detecting the algae attachment condition on the surface of an insulator of the present invention. DETAILED DESCRIPTION

[0039] The following is a detailed description of the embodiments of the present invention. It should be emphasized that the following description is only exemplary and is not intended to limit the scope and application of the present invention.

[0040] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0041] See also Figure 1 The embodiment of the present invention provides a method for detecting algae attachment on the surface of an insulator, comprising:

[0042] S1, obtaining a fluorescence sequence of the surface of the insulator to be tested under ultraviolet light irradiation;

[0043] S2. Obtaining pollution conditions, wherein the pollution conditions include the type of algae attached to the surface of the insulator to be tested and the dust density on the surface of the insulator;

[0044] S3, selecting a corresponding characteristic fluorescence function according to the pollution condition; the characteristic fluorescence function is a function model established by observing and recording the fluorescence response of algae on the surface of the insulator under ultraviolet light irradiation for specific algae cell density and ash density through laboratory artificial experiments and field tests under different pollution conditions, and is used to describe the quantitative relationship between the fluorescence characteristics and the algae species, algae cell density, and ash density;

[0045] S4. Inferring the attachment distribution of algae on the surface of the insulator to be tested based on the fluorescence sequence and the characteristic fluorescence function.

[0046] The method of the present invention effectively combines ultraviolet light irradiation and image processing technology, uses the fluorescence characteristics of ultraviolet light to improve the detection sensitivity of algae, and accurately identifies and analyzes the distribution of algae through image processing technology. This method not only improves the accuracy of algae detection on the surface of insulators, but also enables real-time monitoring and provides a reliable decision-making basis, thereby ensuring the stability and safety of the power system.

[0047] Specifically, in step S1, obtaining a fluorescence sequence of the surface of the insulator to be tested under ultraviolet light irradiation includes: using an ultraviolet light source to irradiate the surface of the insulator to be tested; using a camera to capture the fluorescence signal generated by algae on the surface of the insulator under ultraviolet light excitation; and recording the fluorescence signal to form a fluorescence sequence. In a preferred embodiment, the ultraviolet light source has a wavelength of 400nm and a power of 100mW.

[0048] In step S4, the algae attachment condition is inferred according to the fluorescence sequence and the characteristic fluorescence function, including: analyzing the fluorescence image by using image processing technology; and calculating the algae cell density of the algae on the surface of the insulator by using the characteristic fluorescence function according to the intensity of the fluorescence signal. The image processing specifically includes: dividing the image into a number of 1cm*1cm small squares, each small square being a sampling pixel point, performing image analysis, and applying filtering, edge detection and recognition technology to quantify the fluorescence signal.

[0049] In some embodiments, the characteristic fluorescence function is:

[0050] I=K·D algae +I0

[0051] Where I is the fluorescence intensity reflected from the insulator surface, K is the proportionality coefficient, which is affected by the type of algae and the wavelength of ultraviolet light. algae is the algae cell density, I0 is the initial fluorescence intensity, and is affected by the NSDD of the insulator surface.

[0052] In a preferred embodiment, the algae is Chlorella vulgaris, and the surface density NSDD of the insulator is 0, 1, 2, 3, 4 mg / cm 2 When , the characteristic fluorescence functions are:

[0053]

[0054] Where I is the fluorescence intensity reflected from the insulator surface, and D is the algae cell density.

[0055] The present invention uses ultraviolet light irradiation combined with image processing technology to detect the algae attachment on the surface of the insulator. The method first uses ultraviolet light of a specific wavelength to excite chlorophyll a in the algae on the surface of the insulator to generate a fluorescence signal, and then uses a high-sensitivity camera to capture these fluorescence signals and record them to form a fluorescence sequence. Next, according to the pollution conditions of the surface of the insulator to be tested, including the algae species and gray density, the corresponding characteristic fluorescence function is selected. These characteristic fluorescence functions are based on laboratory artificial experiments and field tests. For the algae cell density and gray density under different pollution conditions, the fluorescence response of the algae on the surface of the insulator under ultraviolet light is observed and recorded, and the function model is established to describe the quantitative relationship between the fluorescence characteristics and the algae species, algae cell density, and gray density. Finally, by analyzing the fluorescence sequence and the characteristic fluorescence function, the algae attachment distribution on the surface of the insulator is inferred. The main technical advantages of this method are its high sensitivity and accuracy, which can effectively improve the reliability of detection, reduce dependence on weather and light conditions, and reduce equipment investment and the need for professional operation. The present invention not only improves the accuracy of detection, but also can realize real-time monitoring, provide a reliable decision-making basis for the stable operation of the power system, and ensure the stability and safety of the power system.

[0056] In a preferred embodiment, for the specific algae of Chlorella vulgaris, the inventors selected the insulator surface ash density (NSDD) of 0, 1, 2, 3, 4 mg / cm through careful design and a large number of experimental verifications. 2 The fluorescence response characteristics at different times were used to establish the corresponding characteristic fluorescence functions. Using these functional relationship curves, the fluorescence response can accurately reflect the changes in algae cell density under different gray density conditions, thereby improving the accuracy of detection. Through experiments, the inventors determined the nonlinear relationship curve between fluorescence intensity and algae cell density under different gray density conditions, so that the detection method has a high sensitivity to algae attachment of different densities. In addition, considering the diversity of gray density on the surface of insulators in practical applications, the inventors established different characteristic fluorescence functions for different gray density conditions, which makes the detection method have good adaptability and can be applied to detection under a variety of different environmental conditions. Therefore, this method not only improves the accuracy and sensitivity of algae detection on the surface of insulators, but also has good adaptability and ease of operation.

[0057] The specific embodiments of the present invention are further described below.

[0058] The present invention proposes a method for identifying the algae attachment on the surface of an insulator more sensitively and accurately than the traditional method. The main principle is that the chlorophyll a contained in the algae on the surface of the insulator will generate a fluorescence signal under the irradiation of ultraviolet light of a specific wavelength, and the algae attachment on the surface of the insulator is calculated by capturing and processing the fluorescence signal. The specific scheme is to irradiate the surface of the insulator with ultraviolet light of a specific wavelength, and the chlorophyll a contained in the algae on the surface of the insulator will generate a specific fluorescence signal under the excitation of ultraviolet light. The fluorescence signal is captured by a high-sensitivity camera, and then these signals are analyzed by image processing technology to detect and evaluate the existence and distribution of algae.

[0059] Selection of ultraviolet light source: Expose the surface of the insulator to an ultraviolet light source. Ultraviolet light can excite the unique fluorescence signal on the surface of algae, so that the algae show obvious fluorescence characteristics under ultraviolet light. Chlorophyll has a strong absorption peak at 440nm. It is preferred to select visible near-ultraviolet light with a wavelength of 400nm, which is convenient for operators to debug the optical path and avoid ultraviolet light from causing damage to the operator's eyes. The irradiation intensity of the ultraviolet light source should not be too small, resulting in the chlorophyll excitation fluorescence intensity being too small to be easy to observe, and it should not be too large to cause damage to the insulator itself. Preferably, the ultraviolet light source used in this scheme has a wavelength of 400nm and a power of 100mW.

[0060] Fluorescence excitation and capture: UV light irradiates algae and causes them to emit fluorescence at a wavelength of about 690nm. Use a highly sensitive camera to capture these fluorescence signals.

[0061] Image processing: First, based on the fluorescence characteristics of algae on the surface of insulators, quantitatively study the functional relationship between the fluorescence characteristics of algae on the surface of insulators and the density of algae cells and gray density, and finally obtain the fluorescence characteristic function of algae on the surface of insulators by verification and correction using on-site insulators. Secondly, use a highly sensitive camera to capture the fluorescence signal (divide the image into several 1cm*1cm small squares (unit area), and each small square is used as a sampling pixel point), and finally use image processing software to perform data analysis, and apply filtering, edge detection and recognition technology to quantify the fluorescence signal.

[0062] Data analysis and reporting: The distribution of algae on the insulator surface is analyzed through image processing results and the algae fluorescence characteristic function on the insulator surface. The analysis results are output as visual reports or alarms so that maintenance personnel can perform follow-up processing based on the reports, such as cleaning or replacing insulators.

[0063] The specific implementation process includes the following steps:

[0064] 1) Selection of UV light source: The wavelength and intensity of the light source are crucial to ensure that the algae chlorophyll excites fluorescence for easy capture and analysis.

[0065] 2) Capturing excited fluorescence: The capture effect directly determines the accuracy of the original data of the image processing algorithm. It is necessary to capture the fluorescence excited by the algae on the surface of the insulator after irradiation with ultraviolet light as accurately as possible.

[0066] 3) Image processing: After the fluorescence image is obtained, it needs to be preprocessed, including cropping and filtering. Then the image reconstruction output is achieved through image segmentation, image opening, parameter calculation, etc.

[0067] 4) Establishment of characteristic fluorescence function: Establish characteristic function of fluorescence characteristics and algae species, algae cell density and ash density on the insulator surface. The characteristic function can accurately reflect the distribution of algae on the insulator surface through fluorescence characteristics. The fluorescence intensity is related to the algae species, algae cell density and ash density on the insulator surface, which can be expressed as

[0068] I=f(D,K,NSDD)

[0069] Specifically, the fluorescence intensity is usually positively correlated with the surface density of the algae, while the presence of ash mainly leads to the attenuation of reflected fluorescence and the increase of background noise. In general, the fluorescence intensity can be approximated to be linearly related to the surface density of the algae:

[0070] I=K·D algae +I0

[0071] Where I is the reflected fluorescence intensity, K is the proportionality coefficient, which depends on factors such as the type of algae, the wavelength of ultraviolet light, and the sensitivity of the measuring instrument. algae is the algae cell density, I0 is the initial fluorescence intensity, and it mainly depends on the insulator surface gray density NSDD, ambient light, and equipment noise.

[0072] However, if the algae density is very different, the difference in fluorescence intensity may be too obvious, which will lead to a large dynamic range in actual detection, thus affecting accurate detection, especially in the face of diverse algae density scenarios. For this reason, the present invention uses a nonlinear fitting method to establish a characteristic fluorescence function. The fitting data of the characteristic fluorescence function is obtained through laboratory artificial experiments, and the characteristic fluorescence function model constructed by nonlinear fitting is verified through field tests. The specific steps include:

[0073] The relationship between fluorescence intensity and algae cell density was obtained: when the gray density NSDD was 0, the algae cell density (Chlorella) on the surface of the artificially painted insulator was 0, 0.5×10 3 cells / cm 2 , 0.5×10 4 cells / cm 2 , 0.5×10 5 cells / cm 2 , 0.5×106 cells / cm 2 , 0.5×10 7 cells / cm 2 , 1.0×10 7 cells / cm 2 , 0.5×10 8 cells / cm 2 , 0.5×10 9 cells / cm 2 , 1.0×10 9 cells / cm 2 , 0.5×10 10 cells / cm 2 The algae species was Chlorella vulgaris, and each case was repeated 3 times. A preset ultraviolet light source was used for irradiation and a high-sensitivity camera was used for acquisition. A relationship curve between the fluorescence intensity value and the algae cell density was obtained.

[0074]

[0075] The relationship between fluorescence intensity and algae density under different ash densities was obtained: kaolin was used to simulate ash content, and the ash density on the insulator surface was set to 0, 0.5, 1, 1.5, 2, 3, and 4 mg / cm 2 After the kaolin is dried, the algae solution is inverted on the surface of the kaolin. The algae species is Chlorella vulgaris, and the algae cell density is set in the same way as in step (a), and each case is repeated 3 times. After the algae solution on the silicone rubber surface is dried, it is irradiated with a preset ultraviolet light source and captured using a high-sensitivity camera. The relationship curve between the fluorescence intensity value and the gray density is obtained.

[0076]

[0077] The above content is a further detailed description of the present invention in combination with specific / preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, it can also make several substitutions or modifications to these described embodiments, and these substitutions or modifications should be regarded as belonging to the protection scope of the present invention. In the description of this specification, the description of the reference terms "an embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily target the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In the absence of mutual contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. A method for detecting algae attachment on the surface of an insulator, characterized in that: include: S1, obtaining a fluorescence sequence of the surface of the insulator to be tested under ultraviolet light irradiation; S2. Obtaining pollution conditions, wherein the pollution conditions include the type of algae attached to the surface of the insulator to be tested and the dust density on the surface of the insulator; S3, selecting a corresponding characteristic fluorescence function according to the contamination condition; The characteristic fluorescence function is a function model established by observing and recording the fluorescence response of algae on the surface of the insulator under ultraviolet light irradiation for specific algae cell density and ash density through laboratory artificial experiments and field tests under different pollution conditions, and is used to describe the quantitative relationship between the fluorescence characteristics and the algae species, algae cell density, and ash density; S4. Inferring the attachment distribution of algae on the surface of the insulator to be tested based on the fluorescence sequence and the characteristic fluorescence function.

2. The method according to claim 1, characterized in that In step S1, a fluorescence sequence of the surface of the insulator to be tested under ultraviolet light irradiation is obtained, including: Use ultraviolet light source to irradiate the surface of the insulator to be tested; Use a camera to capture the fluorescence signal produced by algae on the surface of the insulator under ultraviolet light excitation; The fluorescence signal is recorded to form a fluorescence sequence.

3. The method according to any one of claims 1 to 2, characterized in that: In step S4, the algae attachment condition is inferred based on the fluorescence sequence and the characteristic fluorescence function, including: Analyze fluorescence images using image processing techniques; According to the intensity of the fluorescence signal, the algae cell density of the algae on the insulator surface is calculated by using the characteristic fluorescence function.

4. The method according to claim 3, characterized in that The image processing specifically includes: dividing the image into a number of 1cm*1cm small squares, each small square being used as a sampling pixel point, performing image analysis, and applying filtering, edge detection and recognition techniques to quantify the fluorescence signal.

5. The method according to any one of claims 1 to 4, characterized in that: The characteristic fluorescence function is: I=K·D algae +I0 Where I is the fluorescence intensity reflected from the insulator surface, K is the proportionality coefficient, which is affected by the type of algae and the wavelength of ultraviolet light. algae is the algae cell density, I0 is the initial fluorescence intensity, and is affected by the NSDD of the insulator surface.

6. The method according to any one of claims 1 to 4, characterized in that: The algae is Chlorella vulgaris, and when the gray density NSDD of the insulator surface is 0, the characteristic fluorescence function is: Where I is the fluorescence intensity reflected from the insulator surface, and D is the algae cell density.

7. The method according to any one of claims 1 to 4, characterized in that: The algae is Chlorella vulgaris, and the ash density NSDD of the insulator surface is 1, 2, 3, and 4 mg / cm 2 When , the characteristic fluorescence function is:

8. The method according to any one of claims 1 to 7, characterized in that The wavelength of the ultraviolet light source is 400nm and the power is 100mW.

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