Non-intrusive electrical equipment temperature measurement method and system

Abstract

The invention belongs to the technical field of intelligent equipment, and discloses a non-intrusive electrical equipment temperature measurement method, which comprises the following steps of: preparing a temperature sensing adhesive tape and a standard colored tape, reasonably arranging cameras around measured electrical equipment, connecting the cameras with a data processing system, and transmitting shot data to the data processing system; the method comprises the following steps: acquiring standard image data under different environment light conditions, analyzing and processing the image, preliminarily determining a temperature interval, accurately processing the temperature interval by applying an interpolation algorithm, acquiring a temperature measurement value, displaying and storing in real time, and automatically alarming. The method can be widely applied to various electrical devices in a power system, and provides powerful guarantee for safe and stable operation of the electrical devices. The temperature of detected objects in different places can be monitored in real time, and zero-contact, high-precision, fast-response, low-cost and low-energy-consumption detection is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrical equipment monitoring, and in particular relates to a non-invasive electrical equipment temperature measurement method and system. Background Art

[0002] Temperature monitoring is crucial during the operation of electrical equipment. Excessive temperature may indicate that the equipment has hidden faults such as overload, poor contact, and insulation aging. If it is not discovered and handled in time, it may cause equipment damage, power outages, and even fires.

[0003] Traditional temperature measurement methods have many defects. For example, the wireless chip temperature measurement method requires the installation of a chip at the location to be measured and transmits temperature data wirelessly. However, the chip may not work properly or even be damaged in a high temperature environment. Chip intrusion into the device will bring safety risks, and it is difficult to maintain by replacing the battery. In addition, the micro-power wireless chip temperature measurement method relies on a certain amount of load current to work. It cannot perform self-test when the device is not powered, and problems can only be discovered after the device is running. For the method based on optical fiber temperature measurement, optical fiber intrusion into the device is prone to insulation risks.

[0004] Therefore, there is an urgent need for a safe, reliable, high-precision and non-invasive temperature measurement method for electrical equipment. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a non-invasive temperature measurement method for electrical equipment to overcome the shortcomings of existing temperature measurement technology.

[0006] In order to achieve the above purpose, the present invention provides the following technical solutions: A non-invasive electrical equipment temperature measurement method comprises the following steps: Step 1: Prepare temperature sensitive tape and standard ribbon. The temperature sensitive tape and the standard color tape are pasted on the surface of the electrical equipment under test, and the pasting position is determined; the temperature sensitive tape can change color according to the temperature change, and its color has a clear corresponding relationship with the temperature, and the standard color tape has a known color; Step 2: Layout the camera, The cameras are reasonably arranged around the electrical equipment under test, connected to the data processing system, and the captured data are transmitted to the data processing system; Step 3: Obtain standard image data under different ambient lighting conditions. Set different ambient light conditions, and use a camera to shoot the temperature-sensitive tape and the standard color tape under each set of ambient light conditions to obtain standard image data; Step 4: Image analysis and processing to preliminarily determine the temperature range. The standard image data is transmitted to the data processing system, which analyzes and processes the image, extracts the color information from the images of the temperature-sensitive tape and the standard color tape, and preliminarily determines the temperature range of the surface of the electrical equipment under test by comparing the color of the temperature-sensitive tape with the color of the standard color tape and combining the corresponding relationship between the color of the temperature-sensitive tape and the temperature; Step 5: Use the interpolation algorithm to accurately process the temperature range and obtain the temperature measurement value. Based on the corresponding law between the color change and temperature of the temperature-sensitive tape under different ambient lighting conditions, interpolation calculation is performed within the initially determined temperature range to obtain a more accurate temperature measurement value; Step 6: Real-time display and storage, and automatic alarm; The obtained temperature measurement values ​​are displayed and stored in real time, and a temperature threshold is set. When the measured temperature exceeds the threshold, the data processing system automatically triggers an alarm to prompt relevant personnel to inspect and maintain the electrical equipment.

[0007] Furthermore, in step 1, the pasting position is determined based on the key heating parts of the equipment or the parts prone to temperature abnormalities. The determination of the pasting position ensures that the temperature-sensitive tape and the standard color ribbon can fully contact the surface of the equipment to accurately sense temperature changes without affecting the normal operation of the equipment. The temperature-sensitive color-changing layer (thermochromic pigment or other polymer material) in the temperature-sensitive tape can change its color according to temperature changes, realizing direct contact color change warning.

[0008] Furthermore, in step two, the lens parameters, shooting angle and shooting distance of the camera are adjusted and optimized to ensure that the areas where the temperature sensitive tape and the standard color tape are located can be clearly and completely captured, and the camera and the data processing system establish a stable data transmission connection to realize data transmission and processing.

[0009] Furthermore, in step three, a variety of different ambient lighting conditions are set, including different light intensities, light source colors, and lighting angles. Under each ambient lighting condition, the temperature sensitive tape and the standard color tape are photographed using a camera to obtain multiple sets of image data under different ambient lighting conditions.

[0010] Furthermore, in step four, the color information of the temperature sensitive tape and the standard color tape is extracted using the image recognition algorithm in the data processing system, the color information is determined by analyzing the RGB values ​​of the pixels in the image, and the color of the temperature sensitive tape is compared with the color of the standard color tape. If the color of the temperature sensitive tape is similar to a color in the standard color tape, the temperature range of the electrical equipment under test is preliminarily determined based on the temperature range corresponding to the color.

[0011] Furthermore, in step 4, the specific method of determining the color information by analyzing the RGB values ​​of pixels in the image is: S1, preprocessing the image data and performing filtering operations, such as median filtering to remove impulse noise; S2, pixel color statistics, counts the color value of each pixel, and records the red (R), green (G), and blue (B) values ​​of each pixel in the RGB color space, such as using the Pillow library in Python to achieve this; S3, calculating the average value of pixel colors as the image color information of this image at the temperature point; The formula for calculating the average RGB value is: where R, G, and B are the red, green, and blue values ​​of the pixel.

[0012]

[0013] The alarm in step six includes the system alerting the operation and maintenance personnel through sound, pop-up window, text message, etc.

[0014] The present invention also discloses a system for implementing the method, including a temperature sensitive tape, a standard color tape, a camera, and a data processing system. The data processing system is connected to the camera, and the camera transmits color information of the temperature sensitive tape and the standard color tape on the electrical equipment under test to the data processing system, and the data processing system performs analysis and processing.

[0015] Beneficial effects: The present invention provides a non-invasive electrical equipment temperature measurement method, which can realize non-invasive and accurate measurement of the temperature of electrical equipment. The non-invasive sticking of temperature-sensitive tape and standard color tape avoids physical damage to the equipment and safety risks. The shooting and analysis under different ambient lighting and the application of interpolation algorithms effectively improve the accuracy and resolution of temperature measurement, and can timely and accurately monitor the temperature changes of electrical equipment, providing strong guarantees for the safe and stable operation of electrical equipment. Real-time temperature monitoring of detection objects in different places is realized, realizing zero-contact, high-precision, fast-response, low-cost, and low-energy detection.

[0016] 1. Low cost, point-to-point detection is adopted, and temperature-sensitive tapes and cameras are set according to actual needs to achieve point-to-point detection, without the need for large-scale detection equipment, and low cost. For example, point-to-point monitoring can be performed on the heat-prone parts of key equipment, which can not only meet the needs of temperature monitoring, but also save costs.

[0017] 2. Non-contact temperature measurement avoids physical damage to the equipment and safety risks. And the use of the place is not limited, no specific testing site and environmental requirements are required, whether in a small space, high temperature and high pressure environment or a place with extremely high cleanliness requirements, the equipment is widely used.

[0018] 3. High detection accuracy and fast response speed. Accurately matching temperature information with color information, shooting and analysis under different ambient lighting conditions, and the application of interpolation algorithms effectively improve the accuracy and resolution of temperature measurement. At the same time, it can capture temperature changes in a timely manner, providing reliable protection for real-time temperature monitoring.

[0019] 4. Low energy consumption. The camera and processing system are both low-energy monitoring equipment. There is no need to use large equipment. They are easy to install and disassemble, have strong applicability, and do not require a large amount of electricity supply and a complex heat dissipation system. Therefore, the present invention can also play a role in energy-constrained environments, such as field monitoring, portable detection, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the pasting position of the temperature sensitive tape and the standard color ribbon of the present invention.

[0021] Figure 2 It is a system architecture diagram of the present invention. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. Example

[0023] like Figure 1-2 A non-invasive electrical equipment temperature measurement method is shown, comprising the following steps: Step 1 According to the type, structure and heating characteristics of the electrical equipment under test, select the appropriate temperature-sensitive tape and standard color tape, and the pasting position is determined according to the key heating parts of the equipment or the parts prone to temperature abnormalities. For example, for high-voltage switchgear, the temperature-sensitive tape and standard color tape can be pasted on the contacts, busbar connection parts, etc. During the pasting process, ensure that the surface is clean and flat so that the temperature-sensitive tape and standard color tape can fit closely to the surface of the equipment to ensure the accuracy of temperature conduction. The temperature-sensitive tape can change color according to temperature changes, and its color has a clear correspondence with temperature. The standard color tape has a known color.

[0024] Step 2 The cameras are reasonably arranged around the electrical equipment under test, connected to the data processing system, and the shooting data is transmitted to the data processing system; when installing the camera, the lens parameters, shooting angle and shooting distance of the camera are adjusted and optimized according to the installation environment of the equipment and the position of the temperature-sensitive tape and the standard color tape, and the installation position and angle of the camera are determined. For example, in the substation, the camera is installed at a suitable position above the front of the switch cabinet, and the focal length, aperture and other parameters are adjusted to make the shooting picture clear and accurately capture the color changes of the temperature-sensitive tape and the standard color tape. The camera is connected to the data processing system by wire or wireless means to ensure the timeliness and stability of data transmission.

[0025] Step 3 Set different ambient lighting conditions, including different light intensities, light source colors, and light angles. Under each set of ambient lighting conditions, use a camera to shoot the temperature-sensitive tape and the standard color tape to obtain standard image data. When setting ambient lighting conditions, use adjustable lighting equipment, such as dimming desk lamps, color light strips, etc. Adjust gradually from low light intensity to high light intensity, change the light source color, such as white, red, blue, etc., and adjust the light angle to illuminate from different directions, such as horizontal and vertical, and take multiple images under each condition.

[0026] Step 4 The standard image data is transmitted to the data processing system, which analyzes and processes the image, extracts the color information from the images of the temperature sensitive tape and the standard color tape, and preliminarily determines the temperature range of the surface of the electrical equipment under test by comparing the color of the temperature sensitive tape with the color of the standard color tape and combining the corresponding relationship between the temperature sensitive tape color and temperature.

[0027] After receiving the image, the data processing system uses the image recognition algorithm to extract the color information of the temperature sensitive tape and the standard color tape. For example, the color is determined by analyzing the RGB value of the pixel in the image. The color of the temperature sensitive tape is compared with the color of the standard color tape. If the color of the temperature sensitive tape is similar to a color in the standard color tape, the temperature range of the device is preliminarily determined based on the temperature range corresponding to the color.

[0028] Step 5 The temperature range is precisely processed using an interpolation algorithm to obtain temperature measurement values. Based on the correspondence between the color change of the temperature-sensitive tape under different ambient lighting conditions and the temperature, interpolation calculations are performed within the preliminarily determined temperature range to obtain more accurate temperature measurement values.

[0029] For example, the color of the temperature-sensitive tape is similar to the color corresponding to 50 - 55°C in the standard color tape, and the device temperature is preliminarily determined to be in this range. Then, using the interpolation algorithm, assume that the relationship between the color change and temperature of the temperature-sensitive tape under white light is the function T1(x) (x is the color feature value), under red light it is T2 (x), and under blue light it is T3 (x). When the color feature value of the temperature-sensitive tape is x0 under a certain mixed light, and the color corresponds to a temperature range of T1 (a) - T1(b) under white light, T2 (c) - T2 (d) under red light, and T3 (e) - T3 (f) under blue light, the precise temperature value T is obtained by interpolating these relationships.

[0030] Step 6 The measured temperature value is displayed in real time on the monitoring screen, and the temperature change trend is displayed in the form of numbers, curves, etc. Set the temperature threshold, such as 80℃ for the transformer. When the measured temperature exceeds the threshold, the system will alarm the operation and maintenance personnel through sound, pop-up window, SMS, etc., so that timely measures can be taken, such as checking equipment, adjusting load, etc., to ensure the safe operation of electrical equipment.

[0031] In this embodiment, the specific method of determining the color information by analyzing the RGB values ​​of pixels in the image in step 4 is: S1, preprocessing the image data and performing filtering operations, such as median filtering to remove impulse noise; S2, pixel color statistics, traverses each pixel, counts its color value, and records the red (R), green (G), and blue (B) values ​​of each pixel in the RGB color space, such as using the Pillow library in Python to implement it.

[0032] S3, calculating the average value of pixel colors as the image color information of this image at the temperature point; The formula for calculating the average RGB value is:

[0033] Among them, R, G, B are the red, green, and blue values ​​of the pixel.

[0034] Of course, the main color information can be obtained by calculating the average value of the pixel color. For example, in the RGB color space, the average value of the R (red), G (green), and G (blue) channel values ​​of all pixels in the area is calculated to obtain an RGB value representing the color at the temperature point. The RGB color space can also be converted to the HSV (hue, saturation, value) color space, which is more convenient for analyzing the color hue and expressing the color information by extracting the HSV value. Among them, the method of converting RGB values ​​into HSV values ​​is: the color space of the image can be converted from RGB to HSV (Hue - Hue, Saturation- Saturation, Value - Brightness) or other color spaces such as Lab. For example, in the HSV color space, hue (H) more intuitively represents the color category, which may be more convenient for the extraction and analysis of color information. In the HSV color space, the average value of hue (H), saturation (S), and value (V) can also be calculated to represent color information.

[0035] like Figure 1As shown, the present invention also discloses a system for implementing the method, including a temperature sensitive tape, a standard color tape, a camera, and a data processing system. The data processing system is connected to the camera, and the camera transmits color information of the temperature sensitive tape and the standard color tape on the electrical equipment under test to the data processing system, and the data processing system performs analysis and processing.

[0036] The present invention can be widely applied to various electrical equipment in power systems, such as transformers, circuit breakers, contactors, etc., and can also be applied to electrical equipment such as motors and frequency converters in industrial production. It has broad application prospects and significant practical value.

[0037] The above are only preferred technical solutions of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements without departing from the principles of the present invention. These improvements should also be regarded as the protection scope of the present invention.

Claims

1. A non-invasive electrical equipment temperature measurement method, characterized in that: The following steps are involved: Step 1: Prepare temperature sensitive tape and standard ribbon. The temperature sensitive tape and the standard color tape are pasted on the surface of the electrical equipment under test, and the pasting position is determined; Step 2: Layout the camera, The cameras are reasonably arranged around the electrical equipment under test, connected to the data processing system, and the captured data are transmitted to the data processing system; Step 3: Obtain standard image data under different ambient lighting conditions. Set different ambient light conditions, and use a camera to shoot the temperature-sensitive tape and the standard color tape under each set of ambient light conditions to obtain standard image data; Step 4: Image analysis and processing to preliminarily determine the temperature range. The standard image data is transmitted to the data processing system, which analyzes and processes the image, extracts the color information from the images of the temperature-sensitive tape and the standard color tape, and preliminarily determines the temperature range of the surface of the electrical equipment under test by comparing the color of the temperature-sensitive tape with the color of the standard color tape and combining the corresponding relationship between the color of the temperature-sensitive tape and the temperature; Step 5: Use the interpolation algorithm to accurately process the temperature range and obtain the temperature measurement value. Based on the corresponding law between the color change and temperature of the temperature-sensitive tape under different ambient lighting conditions, interpolation calculation is performed within the initially determined temperature range to obtain a more accurate temperature measurement value; Step 6: Real-time display and storage, and automatic alarm; The obtained temperature measurement values ​​are displayed and stored in real time, and a temperature threshold is set. When the measured temperature exceeds the threshold, the data processing system automatically triggers an alarm to prompt relevant personnel to inspect and maintain the electrical equipment.

2. The method according to claim 1, characterized in that: In step 1, the pasting position is determined according to the key heating parts of the equipment or the parts prone to temperature abnormalities.

3. The method according to claim 1 or 2, characterized in that: In step 2, the lens parameters, shooting angle and shooting distance of the camera are adjusted and optimized.

4. The method according to claim 3, characterized in that: In step three, a variety of different ambient lighting conditions are set, including different light intensities, light source colors, and lighting angles. Under each ambient lighting condition, the temperature sensitive tape and the standard color tape are photographed using a camera to obtain multiple sets of image data under different ambient lighting conditions.

5. The method according to claim 1, characterized in that: In step 4, the color information of the temperature sensitive tape and the standard color tape is extracted by using the image recognition algorithm in the data processing system. The color information is determined by analyzing the RGB values ​​of the pixels in the image. The color of the temperature sensitive tape is compared with the color of the standard color tape. If the color of the temperature sensitive tape is similar to a color in the standard color tape, the temperature range of the electrical equipment under test is preliminarily determined based on the temperature range corresponding to the color.

6. The method according to claim 5, characterized in that: In step 4, the specific method of determining color information by analyzing the RGB values ​​of pixels in the image is: S1, preprocessing the image data and performing filtering operations; S2, pixel color statistics, counts the color value of each pixel, and records the red (R), green (G), and blue (B) values ​​of each pixel in the RGB color space; S3, calculating the average value of pixel colors as the image color information of this image at the temperature point; The formula for calculating the average RGB value is: ， Among them, R, G, B are the red, green, and blue values ​​of the pixel.

7. A non-invasive electrical equipment temperature measurement system, characterized in that: It includes a temperature-sensitive tape, a standard color tape, a camera, and a data processing system. The data processing system is connected to the camera. The camera transmits the color information of the temperature-sensitive tape and the standard color tape on the electrical equipment to the data processing system, and the data processing system performs analysis and processing.

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