Zero-value insulator automatic discrimination method based on spark gap

Abstract

A zero-value insulator automatic discrimination method based on a spark gap relates to the technical field of electric power system insulators, light and temperature criteria are used as auxiliary criteria, and the two discrimination results pass through an OR gate and then are output together with a discrimination result of a current detection unit through an AND gate to serve as a final discrimination result. Three discharge detection methods with different principles are adopted to automatically identify the discharge process of the spark gap so as to judge whether the insulator is a zero value or not, so that the judgment accuracy can reach 100%, the possibility of misjudgment is avoided, the accuracy of the result is ensured, the zero-value insulator is automatically judged and recorded, errors possibly generated by manual judgment are avoided, and the working efficiency is improved. And the detection intelligence is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power system insulators, in particular to a zero-value insulator automatic discrimination method based on spark gap. BACKGROUND

[0002] Overhead transmission lines are the basic components of power systems, and insulators are the most widely used insulating devices in transmission lines, which bear the mechanical connection between the tower and the transmission line and the electrical insulation between the transmission line and the tower. However, during long-term operation, insulators will experience mechanical and electrical loads and temperature changes, leading to degradation such as reduced insulation resistance and surface cracking, which may result in insulator flashover or even string drop, posing a great risk. According to the requirements of operation and maintenance, porcelain insulators should be tested once every three years after being put into operation, and then the detection period should be set according to the measured degradation rate and operating experience, generally 3-5 years, and the longest should not exceed 10 years.

[0003] According to the line standard DL / T 626-2024 "Detection Regulation for Deteriorated Suspension Insulators", the zero-value detection methods include high-voltage impulse detection, spark gap method, and dry power frequency withstand voltage test. The spark gap method is the only method that can detect the zero value of insulators under live conditions, and has been widely used in power systems. This method requires workers to detect live on the tower, and uses a spark gap tester to contact the steel cap of the insulator. If the gap setting voltage is exceeded, a spark discharge will occur, accompanied by a discharge sound, indicating that the insulator is qualified. Otherwise, it is a zero value.

[0004] The spark gap method mainly relies on the hearing and vision of the workers to determine whether a spark is generated. Considering the complex and variable weather conditions in the field, such as wind speed, humidity, temperature, air pressure, and solar radiation, which can affect the discharge characteristics, and the noise interference in the environment, the discharge sound of the remote insulator may not be heard, resulting in a high misjudgment rate. The existing technology only amplifies the sound and light signals of the spark discharge, improving the audibility and visibility of the discharge phenomenon, but these methods still rely on manual judgment and may still have misjudgments. SUMMARY

[0005] The present application overcomes the shortcomings of the above technology and provides a zero-value insulator automatic discrimination method based on spark gap to improve the detection efficiency and accuracy of zero-value insulators.

[0006] The technical solution adopted by the present application to overcome the technical problems is: A zero-value insulator automatic discrimination method based on spark gap, comprising: S1. Construct a self-identifying spark gap zero detection device. The self-identifying spark gap zero detection device is equipped with two contact electrodes, a current detection unit, a zero value discrimination and recording device, an ultraviolet arc probe, and a temperature probe. Each contact electrode has a spark electrode horizontally arranged at its lower end, and the two spark electrodes are arranged opposite to each other. S2. During spark electrode discharge, the discharge current of the spark electrode is detected by the current detection unit, and the current rise rate is calculated based on the discharge current. ; S3. Based on the rate of rise of current A criterion for current detection is established. When the current is abnormal, the current detection unit outputs a high-level signal to the zero-value discrimination and recording device, and when the current is normal, the current detection unit outputs a low-level signal to the zero-value discrimination and recording device. S4. During discharge, the frequency and wavelength of the light are detected by an ultraviolet arc probe at the spark electrode. The ultraviolet light content is calculated based on the frequency and wavelength of the light. ; S5. Based on ultraviolet light content Construct arc light detection criteria to determine whether light anomalies occur; S6. During discharge, the temperature rise per unit time at the spark electrode is detected by a temperature probe. ; S7. Based on the temperature rise per unit time Establish a temperature rise detection criterion to determine whether an abnormal temperature has occurred; S8. The zero-value discrimination and recording device determines whether a discharge has occurred in the spark gap based on the high or low level sent by the current detection unit, whether there is an optical abnormality, and whether there is a temperature abnormality.

[0007] Furthermore, the aforementioned self-identifying spark gap zero detection device consists of a support plate and two contact electrodes fixed on the support plate. A spark electrode is horizontally installed at the lower end of the contact electrode via a fixing device. The two spark electrodes are arranged opposite to each other. A current detection unit, a zero-value discrimination and recording device, an ultraviolet arc light probe, and a temperature probe are installed inside the support plate. One spark electrode is connected to the zero-value discrimination and recording device via the current detection unit. The ultraviolet arc light probe and the temperature probe are both connected to the zero-value discrimination and recording device.

[0008] Furthermore, the aforementioned fixing device is a nut, and the spark electrode is fixed to the lower end of the contact electrode by the nut.

[0009] Furthermore, step S2 includes the following steps: S2-1. The current detection unit uses time intervals... Detect the peak current during spark electrode discharge to obtain Sampled current ,in For the first One sampled current, , , For spark electrodes in The average time required for the current to decay from its peak value to zero during the first discharge; S2-2. Through formula The current rise rate was calculated. In the formula, For the first One sampled current, .

[0010] Furthermore, the criterion for current detection in step S3 is: When the current detection criteria are met, the current is determined to be abnormal, and the current detection unit outputs a high-level signal to the zero-value discrimination and recording device. When the current detection criteria are not met, the current is determined to be normal, and the current detection unit outputs a low-level signal to the zero-value discrimination and recording device.

[0011] Furthermore, step S4 includes the following steps: S4-1. The frequency of the light is detected by an ultraviolet arc light probe during the discharge of the spark electrode. and ultraviolet wavelength Through formula The incident light power density was calculated. In the formula, Let be Planck's constant. The photosensitive area of ​​the ultraviolet arc light probe; S4-2. Through formula The ultraviolet light content was calculated. In the formula This is the circuit breaking current.

[0012] Furthermore, the arc detection criterion in step S5 is: When the arc light detection criterion is met, it is determined to be an abnormal light condition; when the arc light detection criterion is not met, it is determined to be a normal light condition.

[0013] Furthermore, in step S6, the temperature probe detects the air temperature at the spark electrode during discharge at 100ms intervals, and the absolute value of the difference between two adjacent air temperature values ​​is the temperature rise per unit time. .

[0014] Furthermore, the criteria for temperature rise detection are: When the temperature rise detection criteria are met, the temperature is determined to be abnormal; when the temperature rise detection criteria are not met, the temperature is determined to be normal.

[0015] Furthermore, in step S8, when the zero-value discrimination and recording device receives a high-level signal sent by the current detection unit, it determines that the spark gap has discharged. When the zero-value discrimination and recording device receives a low-level signal sent by the current detection unit and an optical abnormality or a temperature abnormality occurs, it determines that the spark gap has discharged. When the zero-value discrimination and recording device receives a low-level signal sent by the current detection unit and no optical abnormality or temperature abnormality occurs, it determines that the spark gap has not discharged.

[0016] The beneficial effects of this invention are as follows: Light and temperature criteria are used as auxiliary criteria. The results of these two criteria are ORed together with the results of the current detection unit and ANDed together to output the final result. By employing three discharge detection methods based on different principles, the discharge process of the spark gap is automatically identified, thereby determining whether the insulator is at zero value. This achieves 100% accuracy, avoids the possibility of misjudgment, ensures the accuracy of the results, and automatically identifies and records zero-value insulators, avoiding errors that may occur with manual judgment and improving the intelligence of the detection process. Attached Figure Description

[0017] Figure 1 This is a structural diagram of the self-identifying spark gap zero-detection device of the present invention; Figure 2 This is a circuit diagram of the present invention; In the diagram, 1. Contact electrode; 2. Nut; 3. Current detection unit; 4. Zero value discrimination and recording device; 5. Ultraviolet arc probe; 6. Temperature probe; 7. Support plate; 8. Spark electrode. Detailed Implementation

[0018] The following is in conjunction with the appendix Figure 1 Appendix Figure 2 The present invention will be further described below.

[0019] An automatic identification method for zero-value insulators based on spark gaps includes: S1. Construct a self-identifying spark gap zero detection device. The self-identifying spark gap zero detection device is equipped with two contact electrodes 1, a current detection unit 3, a zero value discrimination and recording device 4, an ultraviolet arc light probe 5, and a temperature probe 6. A spark electrode 8 is horizontally arranged at the lower end of each contact electrode 1, and the two spark electrodes 8 are arranged opposite each other.

[0020] S2. When the spark electrode 8 discharges, the discharge current of the spark electrode 8 is detected by the current detection unit 3, and the current rise rate is calculated based on the discharge current. .

[0021] S3. Based on the rate of rise of current A criterion for current detection is established. When the current is abnormal, the current detection unit 3 outputs a high-level signal to the zero-value discrimination and recording device 4. When the current is normal, the current detection unit 3 outputs a low-level signal to the zero-value discrimination and recording device 4.

[0022] S4. During discharge, the spark electrode 8 detects the frequency and wavelength of the light through the ultraviolet arc probe 5, and calculates the ultraviolet light content based on the frequency and wavelength of the light. .

[0023] S5. Based on ultraviolet light content Construct arc light detection criteria to determine whether light anomalies occur.

[0024] S6. During discharge, the temperature rise per unit time at the spark electrode 8 is detected by the temperature probe 6. .

[0025] S7. Based on the temperature rise per unit time Establish a temperature rise detection criterion to determine whether an abnormal temperature has occurred.

[0026] S8. The zero-value discrimination and recording device 4 determines whether a discharge has occurred in the spark gap based on the high or low level sent by the current detection unit 3, whether there is an optical abnormality, and whether there is a temperature abnormality.

[0027] This invention uses the loop current as the main criterion for spark gap discharge. This is because the distance of the spark gap is 0.4-0.6mm, and the circuit where the current transformer is located is an open circuit. If the gap is not broken down, the loop current will always be 0A. In addition, the current detection unit takes into account both the magnitude and duration of the current, which can effectively eliminate the influence of the induced current from the strong electromagnetic field.

[0028] In one embodiment of the present invention, the above-mentioned self-identifying spark gap zero detection device consists of a support plate 7 and two contact electrodes 1 fixed on the support plate 7. A spark electrode 8 is horizontally installed at the lower end of the contact electrode 1 through a fixing device. The two spark electrodes 8 are arranged opposite to each other. A current detection unit 3, a zero value discrimination and recording device 4, an ultraviolet arc light probe 5, and a temperature probe 6 are installed inside the support plate 7. One spark electrode 8 is connected to the zero value discrimination and recording device 4 through the current detection unit 3. The ultraviolet arc light probe 5 and the temperature probe 6 are both connected to the zero value discrimination and recording device 4.

[0029] In one embodiment of the present invention, the fixing device is a nut 2, and the spark electrode 8 is fixed to the lower end of the contact electrode 1 by the nut 2.

[0030] In one embodiment of the present invention, step S2 includes the following steps: S2-1. The current detection unit 3 is used at time intervals. The peak current during discharge at spark electrode 8 is detected to obtain... Sampled current ,in For the first One sampled current, , , For spark electrode 8 in The average time required for the current to decay from its peak value to zero during the first discharge; S2-2. Through formula The current rise rate was calculated. In the formula, For the first One sampled current, .

[0031] In one embodiment of the present invention, the criterion for current detection in step S3 is: When the current detection criteria are met, the current is determined to be abnormal, and the current detection unit 3 outputs a high-level signal (i.e., sends 1) to the zero-value discrimination and recording device 4. When the current detection criteria are not met, the current is determined to be normal, and the current detection unit 3 outputs a low-level signal (i.e., sends 0) to the zero-value discrimination and recording device 4. Experimental comparisons revealed that the maximum rise rate of the normal current is 1.08, which is lower than the rise rate under arc conditions. Under normal conditions, the rise rate at the same position in each cycle remains essentially constant, while under arc conditions, it varies and fluctuates significantly. The difference can be found by calculating the rise rates at the first three points, so the rise rates at other points are not calculated.

[0032] After the spark gap is broken down, the generation of the electric arc is accompanied by intense light. Analysis of the arc light spectrum reveals that the energy accumulation of the arc light occurs in the 300-450nm ultraviolet band and the 450-800nm ​​visible light band, with over 80% of the arc light being ultraviolet light. Therefore, using a specialized ultraviolet arc light probe can avoid misjudgments caused by visible light in the environment. Thus, in one embodiment of the present invention, step S4 includes the following steps: S4-1. During discharge, the frequency of light is detected by the ultraviolet arc light probe 5 through the spark electrode 8. and ultraviolet wavelength Through formula The incident light power density was calculated. In the formula, Let be Planck's constant. , The photosensitive area of ​​the ultraviolet arc light probe 5 is given in units of... .

[0033] S4-2. Through formula The ultraviolet light content was calculated. In the formula This is the breaking current. Ultraviolet wavelength. The unit is .

[0034] In one embodiment of the present invention, the arc detection criterion in step S5 is: When the arc light detection criterion is met, it is determined to be an abnormal light condition; when the arc light detection criterion is not met, it is determined to be a normal light condition.

[0035] In one embodiment of the present invention, in step S6, the temperature probe 6 detects the air temperature at the spark electrode 8 during discharge at 100ms intervals, and the absolute value of the difference between two adjacent air temperature values ​​is the temperature rise per unit time. .

[0036] In one embodiment of the present invention, the temperature rise detection criterion is: When the temperature rise detection criteria are met, the temperature is determined to be abnormal; when the temperature rise detection criteria are not met, the temperature is determined to be normal.

[0037] In one embodiment of the present invention, in step S8, when the zero-value discrimination and recording device 4 receives a high-level signal sent by the current detection unit 3, it is determined that the spark gap has discharged, i.e., the porcelain insulator is qualified. When the zero-value discrimination and recording device 4 receives a low-level signal sent by the current detection unit 3 and an optical abnormality or a temperature abnormality occurs, it is determined that the spark gap has discharged. When the zero-value discrimination and recording device 4 receives a low-level signal sent by the current detection unit 3 and no optical abnormality or temperature abnormality occurs, it is determined that the spark gap has not discharged, i.e., the porcelain insulator is zero-value and needs to be tested and repaired. The optical and temperature criteria are used as auxiliary criteria. The discrimination results of these two criteria are passed through an OR gate, and then combined with the discrimination result of the current detection unit through an AND gate to output the final discrimination result.

[0038] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An automatic identification method for zero-value insulators based on spark gaps, characterized in that, include: S1. Construct a self-identifying spark gap zero detection device. The self-identifying spark gap zero detection device is equipped with two contact electrodes (1), a current detection unit (3), a zero value discrimination and recording device (4), an ultraviolet arc light probe (5), and a temperature probe (6). Each contact electrode (1) has a spark electrode (8) horizontally arranged at its lower end, and the two spark electrodes (8) are arranged opposite to each other. S2. When the spark electrode (8) discharges, the discharge current of the spark electrode (8) is detected by the current detection unit (3), and the current rise rate is calculated based on the discharge current. ; S3. Based on the rate of rise of current The current detection criteria are constructed. When the current is abnormal, the current detection unit (3) outputs a high-level signal to the zero-value discrimination and recording device (4). When the current is normal, the current detection unit (3) outputs a low-level signal to the zero-value discrimination and recording device (4). S4. During discharge, the spark electrode (8) detects the frequency and wavelength of light through the ultraviolet arc probe (5), and calculates the ultraviolet light content based on the frequency and wavelength of the light. ; S5. Based on ultraviolet light content Construct arc light detection criteria to determine whether light anomalies occur; S6. During discharge, the temperature rise per unit time at the spark electrode (8) is detected by the temperature probe (6). ; S7. Based on the temperature rise per unit time Establish a temperature rise detection criterion to determine whether an abnormal temperature has occurred; S8. Zero value discrimination and recording device (4) determines whether the spark gap has discharged based on the high or low level sent by the current detection unit (3), whether there is light abnormality, and whether there is temperature abnormality.

2. The automatic identification method for zero-value insulators based on spark gap according to claim 1, characterized in that: The self-identifying spark gap zero detection device consists of a support plate (7) and two contact electrodes (1) fixed on the support plate (7). A spark electrode (8) is horizontally installed at the lower end of the contact electrode (1) through a fixing device. The two spark electrodes (8) are arranged opposite to each other. A current detection unit (3), a zero value discrimination and recording device (4), an ultraviolet arc light probe (5), and a temperature probe (6) are installed inside the support plate (7). One spark electrode (8) is connected to the zero value discrimination and recording device (4) through the current detection unit (3). The ultraviolet arc light probe (5) and the temperature probe (6) are both connected to the zero value discrimination and recording device (4).

3. The automatic identification method for zero-value insulators based on spark gaps according to claim 1, characterized in that: The fixing device is a nut (2), and the spark electrode (8) is fixed to the lower end of the contact electrode (1) by the nut (2).

4. The automatic identification method for zero-value insulators based on spark gaps according to claim 1, characterized in that, Step S2 includes the following steps: S2-1. Through the current detection unit (3) at time intervals The peak current during discharge at the spark electrode (8) is detected to obtain... Sampled current ,in For the first One sampled current, , , For spark electrode (8) in The average time required for the current to decay from its peak value to zero during the first discharge; S2-2. Through formula The current rise rate was calculated. In the formula, For the first One sampled current, .

5. The automatic identification method for zero-value insulators based on spark gap according to claim 4, characterized in that: The criterion for current detection in step S3 is: When the current detection criteria are met, the current is determined to be abnormal, and the current detection unit (3) outputs a high-level signal to the zero-value discrimination and recording device (4). When the current detection criteria are not met, the current is determined to be normal, and the current detection unit (3) outputs a low-level signal to the zero-value discrimination and recording device (4).

6. The automatic identification method for zero-value insulators based on spark gap according to claim 1, characterized in that, Step S4 includes the following steps: S4-1. The frequency of light is detected by the ultraviolet arc probe (5) during discharge using the spark electrode (8). and ultraviolet wavelength Through formula The incident light power density was calculated. In the formula, Let be Planck's constant. The photosensitive area of ​​the ultraviolet arc light probe (5); S4-2. Through formula The ultraviolet light content was calculated. In the formula This is the circuit breaking current.

7. The automatic identification method for zero-value insulators based on spark gaps according to claim 6, characterized in that: The arc detection criterion in step S5 is: When the arc light detection criterion is met, it is determined to be an abnormal light condition; when the arc light detection criterion is not met, it is determined to be a normal light condition.

8. The automatic identification method for zero-value insulators based on spark gap according to claim 1, characterized in that: In step S6, the temperature probe (6) detects the air temperature at the spark electrode (8) during discharge at 100ms intervals. The absolute value of the difference between two adjacent air temperature values ​​is the temperature rise per unit time. .

9. The automatic identification method for zero-value insulators based on spark gaps according to claim 8, characterized in that: The criteria for temperature rise detection are: When the temperature rise detection criteria are met, the temperature is determined to be abnormal; when the temperature rise detection criteria are not met, the temperature is determined to be normal.

10. The automatic identification method for zero-value insulators based on spark gap according to claim 1, characterized in that: In step S8, when the zero-value discrimination and recording device (4) receives a high-level signal sent by the current detection unit (3), it is determined that the spark gap has discharged. When the zero-value discrimination and recording device (4) receives a low-level signal sent by the current detection unit (3) and there is an optical abnormality or a temperature abnormality, it is determined that the spark gap has discharged. When the zero-value discrimination and recording device (4) receives a low-level signal sent by the current detection unit (3) and there is no optical abnormality or no temperature abnormality, it is determined that the spark gap has not discharged.

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