An infrared temperature measurement method and system applicable to UHV voltage-induced heating equipment

Abstract

An infrared temperature measurement method and system applicable to UHV voltage-induced heating equipment disclosed by the present disclosure include: obtaining the surface temperature difference, ambient temperature, light intensity, and wind force of the equipment; obtaining the corrected surface temperature difference of the equipment through the surface temperature difference, ambient temperature, light intensity, wind force, and surface temperature difference correction model of the equipment; wherein, an ambient temperature correction term, a light intensity correction term, and a wind speed correction coefficient are added to the surface temperature difference correction model. Infrared temperature measurement can still be carried out in a timely manner when the environmental conditions are not ideal, and the true temperature difference after excluding the influence of environmental factors can be obtained, so as to accurately evaluate the operation status of the equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of high-voltage equipment condition detection, and particularly to an infrared temperature measurement method and system applicable to UHV voltage thermal equipment. Background Art

[0002] The statements in this part merely provide background technical information related to the present disclosure and do not necessarily constitute prior art.

[0003] 1000kV CVT, 1000kV GIS outgoing line bushing, and 1000kV lightning arrester are the main voltage thermal equipment in UHV substations. They are usually arranged side by side on the outgoing line side or main transformer side of the 1000kV equipment area, and play important roles such as voltage measurement, high-voltage insulation, and limiting overvoltage.

[0004] When diagnosing defects of UHV voltage thermal equipment in the prior art, a method of detecting the surface temperature difference of the equipment and then diagnosing the defects according to the surface temperature difference is often used. However, UHV voltage thermal equipment has the characteristics of small heat generation, low surface temperature rise, and the surface temperature is easily affected by external environmental factors. At the same time, when there are internal defects in the equipment, the surface temperature difference is small and the hot spot is not obvious. In order to accurately obtain the surface temperature difference of the equipment, infrared precise temperature measurement defect diagnosis needs to be carried out in an ideal environment. However, due to the influence of external environmental factors such as light and wind at the site, the temperature measurement is inaccurate, and thus the defects cannot be accurately diagnosed, leading to the further development of the defects. Summary of the Invention

[0005] In order to solve the above problems, the present disclosure proposes an infrared temperature measurement method and system applicable to UHV voltage thermal equipment. By considering environmental factors such as light intensity, wind force, and ambient temperature, the measured surface temperature difference data is corrected, and the corrected surface temperature difference obtained is the true temperature difference under ideal environmental conditions, so that the internal defects of UHV voltage thermal equipment can be accurately diagnosed according to the corrected surface temperature difference.

[0006] To achieve the above object, the present disclosure adopts the following technical solutions:

[0007] In a first aspect, an infrared temperature measurement method applicable to UHV voltage thermal equipment is proposed, including:

[0008] Obtain the surface temperature difference, ambient temperature, light intensity, and wind force of the equipment;

[0009] Obtain the corrected surface temperature difference of the equipment through the surface temperature difference, ambient temperature, light intensity, wind force of the equipment, and the surface temperature difference correction model;

[0010] Among them, an environmental temperature correction term, a light intensity correction term, and a wind speed correction coefficient are added to the surface temperature difference correction model.

[0011] In a second aspect, an infrared temperature measurement system applicable to UHV voltage-induced heating equipment is proposed, including:

[0012] A data acquisition module for acquiring the surface temperature difference, environmental temperature, light intensity, and wind force of the equipment;

[0013] A surface temperature difference correction module for obtaining the corrected surface temperature difference of the equipment through the surface temperature difference, environmental temperature, light intensity, wind force, and the surface temperature difference correction model of the equipment;

[0014] Among them, an environmental temperature correction term, a light intensity correction term, and a wind speed correction coefficient are added to the surface temperature difference correction model.

[0015] In a third aspect, an electronic device is proposed, including a memory, a processor, and computer instructions stored on the memory and running on the processor. When the computer instructions are run by the processor, the steps of an infrared temperature measurement method applicable to UHV voltage-induced heating equipment are completed.

[0016] In a fourth aspect, a computer-readable storage medium is proposed for storing computer instructions. When the computer instructions are executed by the processor, the steps of an infrared temperature measurement method applicable to UHV voltage-induced heating equipment are completed.

[0017] Compared with the prior art, the beneficial effects of the present disclosure are:

[0018] Through theoretical calculation and on-site infrared temperature measurement, this disclosure obtains the surface temperature difference data of voltage-induced heating equipment under different light intensities, ambient temperatures, and wind speeds. Then, regression analysis is used to obtain the variation law and correction model of the surface temperature difference. Thus, considering environmental factors such as light intensity, wind speed, and ambient temperature, the measured surface temperature difference data is corrected, and the corrected surface temperature difference obtained is the true temperature difference under ideal environmental conditions. Therefore, the internal defects of UHV voltage-induced heating equipment can be accurately diagnosed based on this corrected surface temperature difference. The infrared temperature measurement method proposed in this disclosure does not need to wait for ideal environmental conditions to carry out infrared temperature measurement. Even when the environmental conditions are not ideal, infrared temperature measurement can still be carried out in a timely manner to obtain the true temperature difference after excluding the influence of environmental factors, and accurately evaluate the operating status of the equipment. By combining theoretical calculation and on-site infrared temperature measurement, this disclosure conducts data statistics within a large range of three types of environmental factors: light intensity, ambient temperature, and wind speed, obtains the corresponding variation curves, covers various climate conditions, and has high applicability. By adding correction terms and correction coefficients, this disclosure proposes a measurement method for the surface temperature difference of voltage-induced heating equipment under the influence of different environmental factors, which is simple to calculate and convenient for on-site implementation. The advantages of additional aspects of the present invention will be partially given in the following description, partially will become obvious from the following description, or will be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The specification drawings forming a part of this application are used to provide a further understanding of this application. The schematic embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation of this application.

[0020] Figure 1 It is a flowchart of the method disclosed in Embodiment 1;

[0021] Figure 2 It is a graph showing the change of the surface temperature difference with the light intensity obtained in Embodiment 1;

[0022] Figure 3 It is a graph showing the change of the ambient temperature with the light intensity obtained in Embodiment 1;

[0023] Figure 4 It is a graph showing the change of the wind speed with the light intensity obtained in Embodiment 1;

[0024] Figure 5 It is a simulation model of the voltage-induced heating equipment disclosed in Embodiment 1;

[0025] Figure 6 It is the temperature field calculation process disclosed in Embodiment 1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The following further describes this disclosure in conjunction with the drawings and embodiments.

[0027] It should be noted that the following detailed description is illustrative and aims to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application pertains.

[0028] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0029] Example 1

[0030] In this embodiment, an infrared temperature measurement method applicable to UHV voltage-induced heating equipment is disclosed, including:

[0031] Obtain the surface temperature difference, ambient temperature, light intensity, and wind force of the equipment;

[0032] Obtain the corrected surface temperature difference of the equipment through the surface temperature difference of the equipment, ambient temperature, light intensity, wind force, and the surface temperature difference correction model;

[0033] Among them, an ambient temperature correction term, a light intensity correction term, and a wind speed correction coefficient are added to the surface temperature difference correction model.

[0034] Furthermore, the surface temperature difference correction model is:

[0035]

[0036] Among them, is the corrected surface temperature difference of the equipment, is the light intensity correction term, is the ambient temperature correction term, is the wind speed correction coefficient, T is the ambient temperature, E is the light intensity, v is the wind force, is the actually measured surface temperature difference.

[0037] Furthermore, the specific process of obtaining the surface temperature difference correction model is:

[0038] Obtain the change curves of the surface temperature difference of the equipment with respect to light intensity, ambient temperature, and wind speed respectively;

[0039] Fit the three change curves respectively to obtain the fitting curves of the surface temperature difference with respect to light intensity, ambient temperature, and wind speed respectively;

[0040] Obtain the light intensity correction term, the ambient temperature correction term, and the wind speed correction coefficient according to the fitting curve;

[0041] Construct a surface temperature difference correction model according to the light intensity correction term, the ambient temperature correction term, and the wind speed correction coefficient.

[0042] Furthermore, use the least squares method to fit the three change curves respectively.

[0043] Furthermore, use the correlation coefficient to evaluate the accuracy of curve fitting.

[0044] Furthermore, calculate the surface temperature difference of the device under different constraints of light intensity, ambient temperature, and wind speed;

[0045] Obtain the change curves of the surface temperature difference of the device with respect to the light intensity, ambient temperature, and wind speed respectively according to the surface temperature difference of the device under different constraints of light intensity, ambient temperature, and wind speed.

[0046] Furthermore, calculate the surface temperature difference of the device under different constraints of light intensity, ambient temperature, and wind speed by means of simulation analysis.

[0047] A detailed description is given to an infrared temperature measurement method applicable to UHV voltage-induced heating equipment disclosed in this embodiment.

[0048] 1000kV CVT, 1000kV GIS outgoing line bushing, and 1000kV lightning arrester are the main voltage-induced heating equipment in UHV substations. They are usually arranged side by side on the outgoing side or main transformer side of the 1000kV equipment area, and play important roles such as voltage measurement, high-voltage insulation, and limiting overvoltage.

[0049] When diagnosing defects of UHV voltage-induced heating equipment in the prior art, the method of detecting the surface temperature difference value of the equipment and then diagnosing defects according to the surface temperature difference is often used. However, UHV voltage-induced heating equipment has the characteristics of small heat generation, low surface temperature rise, and its surface temperature is easily affected by external environmental factors. At the same time, when there are internal defects in the equipment, the surface temperature difference is small and the hot spot is not obvious. In order to accurately obtain the surface temperature difference of the equipment, infrared precise temperature measurement defect diagnosis needs to be carried out in an ideal environment. However, due to the influence of external environmental factors such as light and wind at the site, the temperature measurement is inaccurate, and thus the defects cannot be accurately diagnosed, leading to the further development of the defects.

[0050] If waiting for suitable environmental conditions, the work efficiency will be reduced, and even the defects cannot be detected in time. Therefore, it is necessary to study the internal and external temperature distribution characteristics of UHV lightning arresters under the influence of external environmental factors. Therefore, it is necessary to study the correction method of infrared temperature measurement results under non-ideal environmental conditions.

[0051] The surface temperature difference value of UHV voltage thermal equipment is the basis for defect diagnosis. When environmental factors such as light intensity, ambient temperature, and wind speed change, the surface temperature difference changes accordingly. If theoretical calculations and on-site measurements can be combined to statistically analyze the variation law of the surface temperature difference, and then a correction method for the surface temperature difference when environmental factors change can be obtained in the form of regression analysis, infrared temperature measurement can be carried out in a timely manner when the environmental conditions are not ideal, and the operating conditions of UHV voltage thermal equipment can be accurately evaluated.

[0052] An infrared temperature measurement method for UHV voltage thermal equipment based on regression analysis disclosed in this embodiment obtains the surface temperature difference data of voltage thermal equipment under different light intensities, ambient temperatures, and wind speeds through theoretical calculations and on-site infrared temperature measurements. Then, regression analysis is used to obtain the variation law and correction model of the surface temperature difference, so that infrared temperature measurement can be carried out in a timely manner when the environmental conditions are not ideal, and the measured surface temperature difference can be corrected to the true temperature difference under ideal environmental conditions, and the internal defects of UHV voltage thermal equipment can be diagnosed accurately and in a timely manner.

[0053] An infrared temperature measurement method applicable to UHV voltage thermal equipment, as Figure 1 shown, includes:

[0054] S1: Obtain the surface temperature difference, ambient temperature, light intensity, and wind speed of the equipment.

[0055] S2: Obtain the corrected surface temperature difference of the equipment through the surface temperature difference, ambient temperature, light intensity, wind speed of the equipment, and the surface temperature difference correction model;

[0056] Among them, an ambient temperature correction term, a light intensity correction term, and a wind speed correction coefficient are added to the surface temperature difference correction model.

[0057] The specific process of obtaining the surface temperature difference correction model is as follows:

[0058] S21: Data statistics: When the light intensity is in the range of 0.001 lx (night) to 10,000 lx (sunny day), the ambient temperature is in the range of 0 °C to 40 °C, and the wind speed is in the range of 0 m / s to 9 m / s, a large number of theoretical calculations and on-site tests are carried out on the surface temperature difference of UHV voltage thermal equipment to obtain the change curve of the surface temperature difference with the light intensity, ambient temperature, and wind speed, as Figures 2 - 4 shown.

[0059] In specific implementation, a simulation analysis method is used to calculate the surface temperature difference of the equipment under different constraints of light intensity, ambient temperature, and wind speed, as Figure 6 shown, and the steps include:

[0060] S211: Use finite element simulation software to establish a three-dimensional temperature field simulation calculation model for UHV voltage-induced heating equipment. The model structure size is the same as the actual size of the equipment. The simulation model and the temperature field calculation process are as Figure 5 shown.

[0061] S212: Conduct electric field simulation and extract the voltage and current data of the equipment.

[0062] S213: Calculate the heating power of the internal heat source, that is, the loss power, according to the obtained voltage and current data.

[0063] The main heat source inside the 1000kV CVT is the dielectric loss heating. The dielectric loss power per unit volume P is

[0064] (1)

[0065] In the formula, f is the frequency, with the unit of Hz, e and are the relative permittivity and the tangent value of the dielectric loss angle respectively, dimensionless, and are known constants for each structural material. E is the electric field strength, with the unit of V / m.

[0066] The main heat source inside the 1000kV lightning arrester comes from the leakage current heating of the zinc oxide varistor and the dielectric loss power :

[0067] (2)

[0068] (3)

[0069] In the formula, R , C and tg d are the equivalent resistance, capacitance and dielectric loss tangent value of the zinc oxide varistor respectively. U and are the magnitude of the voltage of the power supply and the angular frequency respectively.

[0070] When the 1000kV GIS bushing operates normally, the main heat source is the eddy current loss of the conductor. The eddy current loss power per unit length of the conductor is only related to the real part of the AC impedance and the effective value I of the conductor current, and is

[0071] (4)

[0072] (5)

[0073] In the formula, a and b are the inner diameter and outer diameter of the hollow conductor respectively, R 0 is the DC resistance per unit length of the conductor, , is the angular frequency, and are the conductivity and permeability respectively, are the zero-order Bessel function of the first kind, the first-order Bessel function of the first kind, the zero-order Bessel function of the second kind, and the first-order Bessel function of the second kind respectively.

[0074] S214: Assign thermal parameters and boundary conditions to the simulation model.

[0075] In the simulation calculation model, the light intensity, ambient temperature, and wind speed affect the temperature distribution of the device by changing the form of the boundary conditions.

[0076] (1) Influence of light intensity

[0077] The spectral composition of sunlight is relatively fixed. It can be considered that the light intensity of sunlight E (unit: lx) is proportional to the radiation intensity I (unit: W / m 2 ), and the relationship between the two is

[0078] (6)

[0079] Apply the light radiation intensity to the surface of the device in the form of the second type of boundary condition, and conduct a simulation analysis on the surface temperature distribution of the voltage-induced heating device under different light intensities.

[0080] (2) Influence of ambient temperature

[0081] In the temperature field simulation calculation model, the ambient temperature affects the surface temperature of the device in the form of the third type of boundary condition (convective heat transfer boundary condition),

[0082] (7)

[0083] In the formula, l is the thermal conductivity of the surface material of the device, T a is the surface temperature of the device (temperature to be calculated), T is the ambient temperature, h is the convective heat transfer coefficient between the CVT and the air.

[0084] (3) Influence of wind speed

[0085] The wind speed also affects the surface temperature of the device in the form of the convective heat transfer boundary condition. The convective heat transfer coefficient h (W / m 2 ·°C) can be numerically approximated as being proportional to the wind speed v (m / s). The numerical relationship between the two is as follows:

[0086] (8)

[0087] Furthermore, by performing corresponding assignments through the convective heat transfer coefficient, the temperature distribution under different wind speed magnitudes can be simulated and calculated.

[0088] S215: Conduct a temperature field simulation to obtain the surface temperature difference of the device under the constraints of different light intensities, ambient temperatures, and wind speed magnitudes.

[0089] S22. Regression analysis: Use the least squares method to fit the known curve. Commonly used types of fitting curves include power functions, exponential functions, logarithmic functions, etc. Usually, the correlation coefficient R 2 is used to evaluate the accuracy of the fitting. R The closer 2 is to 1, the better the fitting effect. Through regression analysis, the present invention obtains three fitting curves of the surface temperature difference varying with the light intensity E , ambient temperature T , and wind speed magnitude v , and the correlation coefficient R 2 is

[0090] (9)

[0091] In the formula, is the actually measured surface temperature difference, is the corrected surface temperature difference of the device. Then, by introducing the light intensity correction term , ambient temperature correction term , and wind speed correction coefficient , the surface temperature difference correction model is further obtained as

[0092] (10)

[0093] Verify an infrared temperature measurement method for UHV voltage-induced heating equipment disclosed in this embodiment.

[0094] Under the five environmental conditions recorded in Table 1, infrared temperature measurement and measurement of light intensity, ambient temperature, and wind force were carried out on a partially damp lightning arrester. The measured surface temperature difference, as well as the values of light intensity, ambient temperature, and wind force, were substituted into the surface temperature difference correction model (10) to calculate the corrected surface temperature difference, which is the true surface temperature difference of the equipment. The results are shown in Table 2. It can be seen that the relative errors between the temperature difference correction values and the true temperature differences under ideal environmental conditions are all less than 10%, verifying the accuracy of the method disclosed in this embodiment.

[0095] Table 1 Actual environmental condition parameters

[0096]

[0097] Table 2 Temperature difference test and correction results for the local part of the lightning arrester

[0098]

[0099] In addition, infrared temperature measurement of UHV voltage-heat type equipment can be directly carried out in each season, various climates, and each time period of a day, and corrected by the method disclosed in this embodiment, which is beneficial to the mastery of the equipment operation status and the development of operation and maintenance. It has good practical application value and promotion value.

[0100] The infrared temperature measurement method proposed in this embodiment does not need to wait for ideal environmental conditions to carry out infrared temperature measurement. Infrared temperature measurement can still be carried out in a timely manner when the environmental conditions are not ideal, and the true temperature difference after excluding the influence of environmental factors can be obtained to accurately evaluate the equipment operation status. Through the combination of theoretical calculation and on-site infrared temperature measurement, data statistics are carried out within a large range of three environmental factors, namely light intensity, ambient temperature, and wind force, covering various climate conditions, and has high applicability. And this embodiment proposes an infrared temperature measurement method for voltage-heat type equipment under the influence of different environmental factors by adding correction terms and correction coefficients, which is simple to calculate and convenient for on-site implementation.

[0101] Embodiment 2

[0102] In this embodiment, an infrared temperature measurement system applicable to UHV voltage-heat type equipment is disclosed, including:

[0103] A data acquisition module for acquiring the surface temperature difference, ambient temperature, light intensity, and wind force of the equipment;

[0104] A surface temperature difference correction module for obtaining the corrected surface temperature difference of the equipment through the surface temperature difference, ambient temperature, light intensity, wind force of the equipment, and the surface temperature difference correction model;

[0105] Among them, an ambient temperature correction term, a light intensity correction term, and a wind speed correction coefficient are added to the surface temperature difference correction model.

[0106] Embodiment 3

[0107] In this embodiment, an electronic device is disclosed, which includes a memory, a processor, and computer instructions stored on the memory and running on the processor. When the computer instructions are run by the processor, the steps of an infrared temperature measurement method applicable to UHV voltage-induced heating type devices disclosed in Embodiment 1 are completed.

[0108] Embodiment 4

[0109] In this embodiment, a computer-readable storage medium is disclosed, which is used to store computer instructions. When the computer instructions are executed by the processor, the steps of an infrared temperature measurement method applicable to UHV voltage-induced heating type devices disclosed in Embodiment 1 are completed.

[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications or equivalent replacements can still be made to the specific implementation manners of the present invention. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. An infrared temperature measurement method applicable to UHV voltage-induced heating equipment, characterized in that, Including: Obtain the surface temperature difference, ambient temperature, light intensity, and wind force of the device; Obtain the corrected surface temperature difference of the device through the surface temperature difference of the device, ambient temperature, light intensity, wind force, and the surface temperature difference correction model; Among them, an ambient temperature correction term, a light intensity correction term, and a wind speed correction coefficient are added to the surface temperature difference correction model; The surface temperature difference correction model is: Among them, is the corrected temperature difference on the device surface, is the light intensity correction term, is the environmental temperature correction term, is the wind speed correction coefficient, T is the environmental temperature, E is the light intensity, v is the wind force magnitude, is the actually measured surface temperature difference.

2. The infrared temperature measurement method for UHV voltage-induced heating equipment according to claim 1, wherein The specific process of obtaining the surface temperature difference correction model is: Obtain the change curves of the surface temperature difference of the device with respect to light intensity, ambient temperature, and wind speed respectively; Fit the three change curves respectively to obtain the fitting curves of the surface temperature difference with respect to light intensity, ambient temperature, and wind speed respectively; Obtain the light intensity correction term, ambient temperature correction term, and wind speed correction coefficient according to the fitting curves; Construct the surface temperature difference correction model according to the light intensity correction term, ambient temperature correction term, and wind speed correction coefficient.

3. The infrared temperature measurement method for UHV voltage-induced heating equipment according to claim 2, characterized in that Use the least squares method to fit the three change curves respectively.

4. The infrared temperature measurement method for UHV voltage-induced heating equipment according to claim 2, characterized in that, Use the correlation coefficient to evaluate the accuracy of curve fitting.

5. The infrared temperature measurement method for UHV voltage-induced heating equipment according to claim 2, wherein Calculate the surface temperature difference of the device under the constraints of different light intensities, ambient temperatures, and wind speeds of the device; Obtain the change curves of the surface temperature difference of the device with respect to light intensity, ambient temperature, and wind speed respectively according to the surface temperature difference of the device under the constraints of different light intensities, ambient temperatures, and wind speeds of the device.

6. The infrared temperature measurement method for UHV voltage-induced heating equipment according to claim 5, characterized in that Calculate the surface temperature difference of the device under the constraints of different light intensities, ambient temperatures, and wind speeds of the device by means of simulation analysis.

7. An infrared temperature measurement system applicable to UHV voltage-induced heating equipment, which adopts an infrared temperature measurement method applicable to UHV voltage-induced heating equipment according to any one of claims 1-6, characterized in that, Including: A data acquisition module for obtaining the surface temperature difference, ambient temperature, light intensity, and wind force of the device; A surface temperature difference correction module for obtaining the corrected surface temperature difference of the device through the surface temperature difference of the device, ambient temperature, light intensity, wind force, and the surface temperature difference correction model; Among them, an ambient temperature correction term, a light intensity correction term, and a wind speed correction coefficient are added to the surface temperature difference correction model.

8. An electronic device, characterized in that, Including a memory, a processor, and computer instructions stored on the memory and running on the processor. When the computer instructions are run by the processor, the steps of an infrared temperature measurement method for UHV voltage-induced heating type devices described in any one of claims 1-6 are completed.

9. A computer-readable storage medium, characterized in that, For storing computer instructions, when the computer instructions are executed by the processor, the steps of an infrared temperature measurement method for UHV voltage-induced heating type devices described in any one of claims 1-6 are completed.

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