CN110261740A - A method and device for ultraviolet imaging discharge detection - Google Patents

Abstract

The invention discloses an ultraviolet imaging discharge detection method and device, comprising: performing a discharge detection experiment on a discharge experiment model under different experimental parameter conditions; collecting current signals and ultraviolet images during the discharge detection experiment; Processing the signal to obtain the quantization parameter of the electrical signal; processing the ultraviolet image to obtain the quantization parameter of the image; analyzing and processing the quantization parameter of the electrical signal and the quantization parameter of the image to obtain the quantization parameter of the electrical signal and the quantization parameter of the image relationship between parameters. The invention can realize the ultraviolet imaging discharge detection, and can carry out quantitative analysis by using the established quantitative relationship between the electrical signal quantization parameter and the image quantization parameter.

Description

A method and device for ultraviolet imaging discharge detection

technical field

The invention relates to the technical field of discharge detection, in particular to an ultraviolet imaging discharge detection method and device.

Background technique

Under the action of long-term electric field, mechanical stress and environmental factors, the high-voltage electrical equipment running on the site may have insulation aging, deterioration, damage, cracking, loosening and other accidents; at the same time, electrical equipment is designed, manufactured, installed, operated and maintained If any link is not handled properly, it may cause equipment defects, resulting in local electric field concentration and the formation of corona discharge. The above defects pose a huge threat to the safe operation of power transmission and transformation equipment. According to the characteristics of ultraviolet light signal radiation accompanied by discharge, in recent years, power systems at home and abroad have begun to use ultraviolet imagers for discharge detection of electrical equipment.

In recent years, ultraviolet imaging technology has been initially applied in the field of power system, which provides a new idea for real-time detection of power system, and further promotes the research and development of ultraviolet imaging technology. Based on the currently published research materials, relevant research is mainly based on applied research, qualitative research and model research, which are mainly used to judge the presence or absence of discharge and locate discharge, but cannot conduct quantitative analysis on discharge.

Contents of the invention

In view of this, the object of the present invention is to provide a method and device for detecting discharge by ultraviolet imaging, which can detect and quantitatively analyze discharge.

Based on the above-mentioned purpose, the present invention provides a kind of ultraviolet imaging discharge detection method, comprising:

Under different experimental parameter conditions, the discharge detection experiment is carried out on the discharge experimental model;

During the discharge detection experiment, collect current signals and ultraviolet images;

Processing the current signal to obtain quantization parameters of the electrical signal;

Processing the ultraviolet image to obtain image quantization parameters;

Analyzing and processing the electrical signal quantization parameter and the image quantization parameter to obtain a correlation between the electrical signal quantization parameter and the image quantization parameter.

Optionally, the discharge experiment module is a rod-plate gap discharge simulation model, and the experimental parameters include ambient temperature, humidity, distance between rods and plates, gain of an ultraviolet imager, and observation distance.

Optionally, collect the current signal at the rod electrode end of the rod-plate gap discharge simulation model, and process the current signal to obtain the quantized parameter of the electrical signal, the quantized parameter of the electrical signal includes the peak value of the current signal, the current signal Average value, effective value of current signal, number of current pulses, discharge capacity.

Optionally, processing the ultraviolet image includes: preprocessing the ultraviolet image to obtain a binarized ultraviolet image; performing mathematical morphology filtering on the binarized ultraviolet image to obtain filtered ultraviolet image; performing denoising processing on the filtered ultraviolet image to obtain a denoised ultraviolet image; and extracting the image quantization parameter based on the denoised ultraviolet image.

Optionally, the image quantization parameters include the number of photons, spot area, region boundary perimeter, long axis and short axis; the spot area is the number of pixels contained in the denoised ultraviolet image; the The perimeter of the area boundary is the sum of the number of continuous pixels on the boundary point of the ultraviolet image after the denoising; Two points, the straight line where the line segment with the largest distance between the two points is located, and the minor axis is the straight line where the line segment with the smallest distance between the two points is located.

The embodiment of the present invention also provides an ultraviolet imaging discharge detection device, including:

The current measurement unit is used to collect current signals during the discharge detection experiment;

A signal processing module, configured to process the current signal to obtain quantization parameters of the electric signal;

The ultraviolet imaging module is used to collect ultraviolet images during the discharge detection experiment;

An image processing module, configured to process the ultraviolet image to obtain image quantization parameters;

The data processing module is configured to perform analysis and processing according to the corresponding electrical signal quantization parameters and image quantization parameters under different experimental parameter conditions, so as to obtain the correlation between the electrical signal quantization parameters and the image quantization parameters.

Optionally, the experimental parameters include ambient temperature, humidity, distance between rods and plates, gain and observation distance of the ultraviolet imaging module.

Optionally, the current measurement unit collects the current signal at the rod electrode end of the rod-plate gap discharge simulation model, and the signal processing module processes the current signal to obtain the quantization parameter of the electrical signal, and the quantization of the electrical signal The parameters include current signal peak value, current signal average value, current signal effective value, current pulse number, and discharge capacity.

Optionally, the processing of the ultraviolet image by the image processing module includes: preprocessing the ultraviolet image to obtain a binarized ultraviolet image; performing mathematical morphology filtering on the binarized ultraviolet image to obtain filtering the processed ultraviolet image; performing denoising processing on the filtered ultraviolet image to obtain a denoised ultraviolet image; and extracting the image quantization parameter based on the denoised ultraviolet image.

Optionally, the image quantization parameters include the number of photons, spot area, region boundary perimeter, long axis and short axis; the spot area is the number of pixels contained in the denoised ultraviolet image; the The perimeter of the area boundary is the sum of the number of continuous pixels on the boundary point of the ultraviolet image after the denoising; Two points, the straight line where the line segment with the largest distance between the two points is located, and the minor axis is the straight line where the line segment with the smallest distance between the two points is located.

As can be seen from the above, the ultraviolet imaging discharge detection method and device provided by the present invention process the current signal and the ultraviolet image by collecting the current signal and the ultraviolet image of the discharge experimental model under different experimental parameter conditions, and obtain the electric current signal and the ultraviolet image. The signal quantization parameter and the image quantization parameter perform regression analysis on the electrical signal quantization parameter and the image quantization parameter, and establish the correlation between the electrical signal quantization parameter and the image quantization parameter. The invention can realize the ultraviolet imaging discharge detection, and can carry out quantitative analysis by using the established quantitative relationship between the electric signal quantization parameter and the image quantization parameter.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is the schematic flow chart of the method of the embodiment of the present invention;

Fig. 2 is the structural representation of the discharge experiment model of the embodiment of the present invention;

FIG. 3 is a schematic diagram of image quantization parameters according to an embodiment of the present invention;

Fig. 4 is a block diagram of the device structure of the embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be described in further detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

It should be noted that all expressions using "first" and "second" in the embodiments of the present invention are to distinguish two entities with the same name but different parameters or parameters that are not the same, see "first" and "second" It is only for the convenience of expression, and should not be construed as a limitation on the embodiments of the present invention, which will not be described one by one in the subsequent embodiments.

Fig. 1 is a schematic flow chart of the method of the embodiment of the present invention. As shown in the figure, the ultraviolet imaging discharge detection method provided by the embodiment of the present invention includes:

S10: Under different experimental parameter conditions, conduct a discharge detection experiment on the discharge experimental model;

Factors that affect the discharge process include temperature and humidity, and factors that affect the sensitivity of discharge detection include the gain of the ultraviolet imager and the observation distance. In the embodiment of the present invention, the experimental parameter setting range of the discharge detection experiment is as follows:

parameter temperature/℃ Relative humidity/% gain Observation distance/m area of research -20～50 30～100 Set between min and max 3～120

Fig. 2 is a schematic structural diagram of a discharge experiment model of an embodiment of the present invention. As shown in the figure, the discharge experiment model of the embodiment of the present invention adopts a rod-plate gap discharge simulation model, and the rod-plate gap discharge simulation model is placed in an environment with adjustable temperature and humidity. By adjusting the temperature and humidity, the temperature of the ultraviolet imager is adjusted. Gain, adjust the observation distance between the ultraviolet imager and the rod-plate gap discharge simulation model, and conduct discharge detection experiments on the rod-plate gap discharge simulation model.

S11: During the discharge detection experiment, collect the current signal;

S12: Process the current signal to obtain quantization parameters of the electrical signal;

A voltage is applied to the rod electrode terminal of the rod-plate gap discharge simulation model, and the discharge detection experiment is carried out. Several main gap distances such as rod-plate gap 10 cm, 30 cm, 50 cm and 100 cm can be selected, and the discharge intensity can be controlled by applying different voltages to the rod electrode terminals. When a specific voltage is applied, the current signal is collected and processed to obtain the electrical signal quantization parameters corresponding to the specific voltage.

A current measurement unit for collecting current signals is arranged at the end of the rod electrode. The current measurement unit includes a shielded case and a current detection resistor in the shielded case, a data acquisition card, and an optical module. The current measurement unit is connected in series in the high-voltage side loop. The detection resistor detects the current signal, and transmits it to the optical module through the data acquisition card. The optical module converts the current signal into an optical signal and then transmits it to the optical transceiver on the ground through the optical fiber. The signal is processed to obtain electrical signal quantization parameters. The electrical signal quantification parameters include parameters such as current signal peak value, current signal average value, current signal effective value, current pulse number, discharge capacity and other parameters, wherein the discharge capacity is calculated and processed by integrating the current signal.

S13: During the discharge detection experiment, use the ultraviolet imager to collect ultraviolet images;

S14: Process the ultraviolet image to obtain image quantization parameters;

During the discharge detection experiment, under different experimental parameter conditions, when a specific voltage is applied, the ultraviolet imager is used to record video, and each frame of image is extracted from the video as an ultraviolet image, and the ultraviolet image is processed to obtain image quantification parameters, image Treatment methods include:

S140: Preprocessing the ultraviolet image to obtain a binary ultraviolet image;

include:

1) Carry out grayscale processing to the colored ultraviolet image to generate a grayscale ultraviolet image; the grayscale transformation formula is:

Y＝0.299R+0.587G+0.114B (1)

Among them, R is the value of the red component, G is the value of the green component, and B is the value of the blue component.

2) Binarize the gray-scale ultraviolet image to generate a binary ultraviolet image; after performing histogram statistical analysis on a large number of gray-scale ultraviolet images, there is an obvious trough near the gray-scale value of 220. Therefore, the gray-scale ultraviolet image is selected The threshold value is 220, that is, the pixel value of the grayscale ultraviolet image with a pixel value greater than 220 takes the value of 255, and the pixel value of less than 220 takes the value of 0.

S141: Perform mathematical morphology filter processing on the binarized ultraviolet image to obtain a filtered ultraviolet image;

In the embodiment of the present invention, an opening operation and a closing operation are used to filter the binarized ultraviolet image.

S142: For the filtered ultraviolet image, use the small area elimination algorithm to eliminate the noise area, and obtain the denoised ultraviolet image;

There are still some isolated interference points in the filtered ultraviolet image, and the small area elimination algorithm is used to remove the interference points. The algorithm includes: detecting each connected area of the filtered ultraviolet image, and obtaining the boundary information of each connected area; Obtain the area of each connected region through the boundary information; set the area threshold, compare the area of each connected region with the area threshold, keep the connected regions greater than or equal to the area threshold, and remove the connected regions smaller than the area threshold as noise.

S143: Extract image quantization parameters based on the denoised ultraviolet image.

FIG. 3 is a schematic diagram of image quantization parameters according to an embodiment of the present invention. As shown in the figure, image quantification parameters include photon number, spot area, area boundary perimeter, long axis and short axis, wherein, the number of photons can be directly output by the ultraviolet imager; the spot area is the discharge spot area (ultraviolet after denoising The number of pixels contained in the image 30); the perimeter of the area boundary is the sum of the number of continuous pixels on the boundary points of the discharge spot area. The long axis is the straight line where the line segment with the largest distance between the two points passes through the centroid point of the discharge photoelectric area and the boundary of the discharge spot area, and the short axis is the straight line where the line segment with the smallest distance between the two points is located.

S15: Analyze and process the electrical signal quantization parameter and the image quantization parameter, and establish a relationship between the electrical signal quantization parameter and the image quantization parameter.

Under different experimental parameter conditions, different voltages are applied to obtain corresponding electrical signal quantization parameters and image quantization parameters. Specifically, under the conditions of different ambient temperature, humidity, different gain of the ultraviolet imager, different observation distances between the ultraviolet imager and the experimental model, different rod-plate spacing, and different applied voltage conditions, the current measurement unit is used to collect current signals , use the ultraviolet imager to collect ultraviolet images, process the current signal to obtain the electrical signal quantization parameters, and process the ultraviolet images to obtain the image quantization parameters; after that, establish the relationship between different experimental parameters and the corresponding electrical signal quantization parameters and image quantization parameters relationship.

For the electrical signal quantization parameters and image quantization parameters under different experimental parameter conditions, a regression analysis method is used to obtain the quantization relationship between the electrical signal quantization parameters and the image quantization parameters. Regression analysis methods can use linear regression, least squares method, neural network algorithm, support vector machine, kernel regression method and other methods.

Fig. 4 is a block diagram of the device structure of the embodiment of the present invention. As shown in the figure, the ultraviolet imaging detection device provided by the embodiment of the present invention includes:

The current measurement unit is used to collect current signals during the discharge detection experiment;

The signal processing module is used to process the current signal to obtain the quantization parameter of the electric signal;

The ultraviolet imaging module is used to collect ultraviolet images during the discharge detection experiment;

The image processing module is used to process the ultraviolet image to obtain image quantization parameters;

The data processing module is used to perform regression analysis according to the corresponding electrical signal quantization parameters and image quantization parameters under different experimental parameter conditions, so as to obtain the correlation between the electrical signal quantization parameters and the image quantization parameters.

In the embodiment of the present invention, the experimental model adopts the rod-plate gap discharge simulation model, and the rod-plate gap discharge simulation model is placed in an environment with adjustable temperature and humidity. By adjusting the temperature and humidity, the gain of the ultraviolet imager is adjusted, and the ultraviolet imaging is adjusted. The observation distance between the instrument and the rod-plate gap discharge simulation model is used to conduct discharge detection experiments on the rod-plate gap discharge simulation model.

A voltage is applied to the rod electrode terminal of the rod-plate gap discharge simulation model, and the discharge detection experiment is carried out. When a specific voltage is applied, the current signal is collected and processed to obtain the electrical signal quantization parameters corresponding to the specific voltage. The current measurement unit includes a shielded case and a current detection resistor in the shielded case, a data acquisition card, and an optical module. The current measurement unit is connected in series in the high-voltage side circuit. The current detection resistor detects the current signal and transmits it to the optical module through the data acquisition card. The optical module converts the current signal into an optical signal and transmits it to the optical transceiver on the ground through the optical fiber. The optical transceiver converts the received optical signal into an electrical signal, and the signal processing module processes the electrical signal to obtain the quantization parameter of the electrical signal. The electrical signal quantification parameters include parameters such as current signal peak value, current signal average value, current signal effective value, current pulse number, discharge capacity and other parameters, wherein the discharge capacity is calculated and processed by integrating the current signal.

During the discharge detection experiment, under different experimental parameter conditions, when a specific voltage is applied, the UV imaging module is used to record video, and each frame of image is extracted from the video as a UV image, and the image processing module is used to process the UV image to obtain an image Quantify the parameters, and the image processing method includes: preprocessing the ultraviolet image to obtain a binary ultraviolet image; performing mathematical morphology filtering on the binary ultraviolet image to obtain a filtered ultraviolet image; , use the small area elimination algorithm to eliminate the noise area, and obtain the denoised ultraviolet image; based on the denoised ultraviolet image, extract the image quantization parameters. In the embodiment of the present invention, the image quantization parameters include the number of photons, the area of the light spot, the perimeter of the area boundary, the long axis and the short axis, wherein the number of photons can be directly output by the ultraviolet imager; the area of the light spot is the area of the discharge light spot (after denoising) The number of pixels contained in the ultraviolet image 30); the perimeter of the area boundary is the sum of the number of continuous pixels on the boundary points of the discharge spot area. The long axis is the straight line where the line segment with the largest distance between the two points passes through the centroid point of the discharge photoelectric area and the boundary of the discharge spot area, and the short axis is the straight line where the line segment with the smallest distance between the two points is located.

The data processing module obtains the quantitative relationship between the electrical signal quantization parameter and the image quantization parameter by using a regression analysis method according to the electrical signal quantization parameter and the image quantization parameter under different experimental parameter conditions. Regression analysis methods can use linear regression, least squares method, neural network algorithm, support vector machine, kernel regression method and other methods.

The apparatuses in the foregoing embodiments are used to implement the corresponding methods in the foregoing embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

Those of ordinary skill in the art should understand that: the discussion of any of the above embodiments is exemplary only, and is not intended to imply that the scope of the present disclosure (including claims) is limited to these examples; under the idea of the present invention, the above embodiments or Combinations between technical features in different embodiments are also possible, steps may be carried out in any order, and there are many other variations of the different aspects of the invention as described above, which are not presented in detail for the sake of brevity.

In addition, well-known power/ground connections to integrated circuit (IC) chips and other components may or may not be shown in the provided figures, for simplicity of illustration and discussion, and so as not to obscure the present invention. . Furthermore, devices may be shown in block diagram form in order to avoid obscuring the invention, and this also takes into account the fact that details regarding the implementation of these block diagram devices are highly dependent on the platform on which the invention is to be implemented (i.e. , these details should be well within the understanding of those skilled in the art). Where specific details (eg, circuits) have been set forth to describe example embodiments of the invention, it will be apparent to those skilled in the art that other embodiments may be implemented without or with variations from these specific details. Implement the present invention down. Accordingly, these descriptions should be regarded as illustrative rather than restrictive.

Although the invention has been described in conjunction with specific embodiments of the invention, many alternatives, modifications and variations of those embodiments will be apparent to those of ordinary skill in the art from the foregoing description. For example, other memory architectures such as dynamic RAM (DRAM) may use the discussed embodiments.

Embodiments of the present invention are intended to embrace all such alterations, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent replacements, improvements, etc. within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. An ultraviolet imaging discharge detection method, characterized in that, comprising: Under different experimental parameter conditions, the discharge detection experiment is carried out on the discharge experimental model; During the discharge detection experiment, collect current signals and ultraviolet images; Processing the current signal to obtain quantization parameters of the electrical signal; Processing the ultraviolet image to obtain image quantization parameters; Analyzing and processing the electrical signal quantization parameter and the image quantization parameter to obtain a correlation between the electrical signal quantization parameter and the image quantization parameter. 2. The method according to claim 1, wherein the discharge experiment module is a rod-plate gap discharge simulation model, and the experimental parameters include ambient temperature, humidity, rod-plate spacing, the gain and observation of the ultraviolet imager distance. 3. method according to claim 2, is characterized in that, collects the current signal of the rod electrode end of described rod-plate gap discharge simulation model, described current signal is processed and obtains described electrical signal quantization parameter, described The electrical signal quantification parameters include the peak value of the current signal, the average value of the current signal, the effective value of the current signal, the number of current pulses, and the discharge capacity. 4. The method according to claim 1, wherein processing the ultraviolet image comprises: performing preprocessing on the ultraviolet image to obtain a binarized ultraviolet image; performing mathematical processing on the binarized ultraviolet image Morphological filtering processing to obtain a filtered ultraviolet image; performing denoising processing on the filtered ultraviolet image to obtain a denoised ultraviolet image; extracting the image quantification based on the denoised ultraviolet image parameter. 5. The method according to claim 4, wherein the image quantization parameters include number of photons, spot area, area boundary perimeter, long axis and short axis; the spot area is the denoised ultraviolet The number of pixels contained in the image; the perimeter of the region boundary is the sum of the number of continuous pixels on the boundary points of the ultraviolet image after the denoising; the long axis is the The centroid point of the ultraviolet image, two points intersecting with its boundary, the straight line where the line segment with the largest distance between the two points is located, and the short axis is the straight line where the line segment with the smallest distance between the two points is located. 6. An ultraviolet imaging discharge detection device, characterized in that, comprising: The current measurement unit is used to collect current signals during the discharge detection experiment; A signal processing module, configured to process the current signal to obtain quantization parameters of the electric signal; The ultraviolet imaging module is used to collect ultraviolet images during the discharge detection experiment; An image processing module, configured to process the ultraviolet image to obtain image quantization parameters; The data processing module is configured to perform analysis and processing according to the corresponding electrical signal quantization parameters and image quantization parameters under different experimental parameter conditions, so as to obtain the correlation between the electrical signal quantization parameters and the image quantization parameters. 7. The device according to claim 6, wherein the experimental parameters include ambient temperature, humidity, distance between rods and plates, gain and observation distance of the ultraviolet imaging module. 8. The device according to claim 6, wherein the current measuring unit collects the current signal at the rod electrode end of the rod-plate gap discharge simulation model, and the signal processing module processes the current signal to obtain the The electrical signal quantization parameter includes the peak value of the current signal, the average value of the current signal, the effective value of the current signal, the number of current pulses, and the discharge capacity. 9. The device according to claim 6, wherein the processing of the ultraviolet image by the image processing module comprises: preprocessing the ultraviolet image to obtain a binary ultraviolet image; Performing mathematical morphology filtering on the ultraviolet image to obtain a filtered ultraviolet image; denoising the filtered ultraviolet image to obtain a denoised ultraviolet image; based on the denoised ultraviolet image, The image quantization parameter is extracted. 10. The device according to claim 9, wherein the image quantization parameters include the number of photons, spot area, area boundary perimeter, long axis and short axis; the spot area is the denoised ultraviolet The number of pixels contained in the image; the perimeter of the region boundary is the sum of the number of continuous pixels on the boundary points of the ultraviolet image after the denoising; the long axis is the The centroid point of the ultraviolet image, two points intersecting with its boundary, the straight line where the line segment with the largest distance between the two points is located, and the short axis is the straight line where the line segment with the smallest distance between the two points is located.