Polishing method for improving surface flashover performance of three-post insulator

Abstract

The invention relates to the field of surface modification of insulating materials, in particular to a polishing method for improving surface flashover performance of a three-post insulator. Cleaning the surface of the post insulator, and measuring the potential, the surface conductivity and the roughness of each area of the post insulator; gradient grinding is sequentially carried out from the high-voltage end to the grounding end. Through the polishing method for improving the surface flashover performance of the three-post insulator, the modification efficiency and the modification result of the large three-post insulator can be improved.

Description

Technical Field

[0001] The invention relates to the field of surface modification of insulating materials, in particular to a polishing method for improving the surface flashover performance of a three-pillar insulator. Background Art

[0002] Three-pillar insulators are widely used as a good choice to solve the problem of power transmission in power stations due to their high reliability and strong transmission capacity. However, three-pillar insulators are inevitably subjected to complex electrical, thermal, mechanical and other coupling stresses when operating for a long time under high voltage and high power environment. The insulation deteriorates or even fails under the induction of local defects. Therefore, the surface modification of three-pillar insulators is of great significance.

[0003] At present, the main methods for surface modification of insulators are thin film deposition, surface coating and traditional uniform sandpaper polishing, etc. However, these methods are inefficient and have poor modification results for relatively complex large three-pillar insulators. Summary of the invention

[0004] In view of the above problems or problems existing in the prior art, the present invention is proposed.

[0005] Therefore, the purpose of the present invention is to provide a grinding method for improving the surface flashover performance of a three-pillar insulator, which can solve the problems of low modification efficiency and poor modification results of existing large three-pillar insulators.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a grinding method for improving the surface flashover performance of three-pillar insulators, which includes dividing the longitudinal equidistant annular areas into blocks; cleaning the surface of the post insulator, measuring the potential, surface conductivity and roughness of each area of ​​the post insulator; and performing gradient grinding from the high-voltage end to the grounding end.

[0007] As a preferred solution of the grinding method for improving the surface flashover performance of three-pillar insulators according to the present invention, the longitudinal equidistant annular area division includes:

[0008] Each single-pillar insulator of the three-pillar insulator is equally divided into 10 annular areas. The formula for the length of the annular width and the area formula for the longitudinally equidistant annular area are as follows:

[0009]

[0010] S n =2πR n d n

[0011] d n is the width of the nth region from the high voltage end to the ground end;

[0012] L is the total length of the single-post insulator;

[0013] S n is the area of ​​the nth region from the high voltage end to the ground end;

[0014] R n is the average radius of the nth area from the high voltage end to the ground end.

[0015] As a preferred solution of the polishing method for improving the surface flashover performance of three-pillar insulators described in the present invention, the measuring of the potential of each area of ​​the pillar insulator includes: applying a voltage of 1000V DC to the surface of the single-pillar insulator before modification, using an electrostatic potential probe, and performing 10 measurements at room temperature and constant indoor humidity to obtain the average potential of the area.

[0016] As a preferred solution of the polishing method for improving the surface flashover performance of three-pillar insulators according to the present invention, wherein: the measuring of the surface conductivity of the pillar insulators comprises:

[0017] The applied voltage was 1000 V DC, the recording step was 3 min, and 10 measurements were performed at constant room temperature and humidity. The average value was taken and the conductivity σ was calculated using the following formula s , the formula is as follows

[0018]

[0019] Where D1 and D2 are the diameters of the measuring electrode and the guard electrode, V a and I a are the applied DC voltage and measured current, respectively.

[0020] As a preferred solution of the polishing method for improving the surface flashover performance of three-pillar insulators described in the present invention, the measuring of the surface roughness of the post insulator includes: the surface roughness of the post insulator before modification, and its roughness is characterized by Ra (arithmetic mean surface roughness) and root mean square surface roughness (Rrms).

[0021] As a preferred solution of the grinding method for improving the surface flashover performance of three-pillar insulators described in the present invention, the gradient grinding from the high-voltage end to the grounding end includes: from the high-voltage end to the grounding end, grinding with different strengths and degrees according to different potentials and conductivity to form a gradient roughness.

[0022] As a preferred solution of the polishing method for improving the surface flashover performance of three-pillar insulators described in the present invention, wherein: the cleaning of the surface of the pillar insulator includes: wiping with 75% anhydrous ethanol and naturally air-drying for 10 minutes.

[0023] As a preferred solution of the polishing method for improving the surface flashover performance of three-post insulators described in the present invention, the measuring of the potential, surface conductivity and roughness of each area of ​​the post insulator includes: keeping the temperature and humidity of the environment in which the post insulator is located unchanged.

[0024] As a preferred solution of the polishing method for improving the surface flashover performance of three-pillar insulators described in the present invention, the polishing method for improving the surface flashover performance of three-pillar insulators also includes: judging whether all the modified single-pillar insulators have been completely modified.

[0025] As a preferred solution of the polishing method for improving the surface flashover performance of three-pillar insulators described in the present invention, the polishing method for improving the surface flashover performance of three-pillar insulators also includes: performing a flashover performance test and comparison between the modified three-pillar insulator and the unmodified three-pillar insulator.

[0026] The beneficial effects of the present invention are as follows: the grinding method for improving the surface flashover performance of a three-pillar insulator described in the present invention can improve the modification efficiency and modification results of large three-pillar insulators. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0028] Figure 1 The overall structural diagram of the grinding method for improving the surface flashover performance of three-pillar insulators;

[0029] Figure 2 Cross-sectional view of the grinding method for improving the surface flashover performance of three-pillar insulators. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0031] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0032] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0033] Example 1

[0034] Reference Figures 1-2 , which is the first embodiment of the present invention, provides a grinding method for improving the surface flashover performance of three-pillar insulators, specifically including dividing the longitudinal equidistant annular areas into blocks; cleaning the surface of the post insulator, measuring the potential, surface conductivity and roughness of each area of ​​the post insulator; and performing gradient grinding from the high-voltage end to the grounding end.

[0035] Furthermore, the longitudinal equidistant annular area segmentation includes equidistantly dividing each single-pillar insulator of the three-pillar insulator into 10 annular areas.

[0036] Furthermore, measuring the potential of each area of ​​the post insulator includes: applying a voltage of 1000V DC on the surface of the single post insulator before modification, using an electrostatic potential probe, performing 10 measurements at constant room temperature and indoor humidity, and obtaining an average potential value of the area.

[0037] Preferably, measuring the surface conductivity of the post insulator includes: applying a voltage of 1000 V DC, recording a step length of 3 min, performing 10 measurements at constant room temperature and indoor humidity, taking an average value, and calculating the conductivity using the following formula.

[0038] In this embodiment, the present invention provides a grinding method for improving the surface flashover performance of a three-pillar insulator. The single-pillar insulator of the three-pillar insulator is longitudinally divided into equidistant annular blocks, and the conductivity and roughness of each area are tested. Different degrees of gradient grinding are performed based on the different conductivity between the high-voltage section and the grounding end and the different roughness of each annular block, thereby obtaining a gradient roughness distribution.

[0039] Example 2

[0040] Reference Figures 1-2 , which is the second embodiment of the present invention, and this embodiment is based on the previous embodiment.

[0041] Specifically, firstly, a three-pillar insulator in any GIL transmission pipeline is obtained, wiped with 75% anhydrous ethanol, and naturally air-dried for 10 minutes.

[0042] Furthermore, the three-pillar insulator has three single pillars in total, and it is determined whether the number of modified single pillar insulators is 3 (i.e., whether all modifications have been completed). If the number of modified single pillar insulators is not 3, enter Figure 1 "Divide any unmodified single-pillar insulator into longitudinal equidistant annular regions" step; if the number of modified single-pillar insulators is 3, enter Figure 1 The step of "Comparison of flashover performance test with unmodified three-pillar insulators" is as follows.

[0043] Furthermore, since the modified single-pillar insulator is not 3, any unmodified single-pillar insulator is selected and the length L of 2-6 single-pillar insulators is measured, thereby obtaining the ring width At the same time, the area S of the longitudinal equidistant annular region is obtained. n =2πR n d n .

[0044] Furthermore, after obtaining the annular width and the area of ​​the longitudinally equidistant annular region, the conductivity test and roughness test of each block area from n1 to n10 are performed. In this embodiment, a polishing method for improving the surface flashover performance of a three-pillar insulator is described. The surface conductivity of the pillar insulator before modification is 1000V DC applied to the n1 area, the recording step length is 3min, and 10 measurements are performed at room temperature and indoor humidity. The average value is taken to obtain the conductivity of the n1 area. The conductivity of all n1 to n10 is obtained by analogy. At the same time, the surface roughness is measured at 10 different positions in any area from n1 to n10, and the average value is used as the actual roughness value, so as to obtain the roughness of all n1 to n10 for comparison after modification; when testing the point, the voltage applied is 1000V DC, and an electrostatic potential probe is used to perform 10 measurements at room temperature and indoor humidity to obtain the average value of the area. The simulated data example is shown in Table 1.

[0045] Table 1

[0046]

[0047] Furthermore, it can be seen from Table 1 that the potential range increases from n10 to n1, indicating that the degree of charge accumulation will also increase, so the three-pillar insulator is not suitable for uniform grinding. Therefore, the new annular profile grinder of the present invention is used to grind n10 to n1. The grinding intensity increases step by step, so that the magnitude gradient of the roughness increases step by step.

[0048] Preferably, after all modifications, the flashover performance test is compared with that of the unmodified three-pillar insulator. A high voltage DC power supply is connected to the high voltage end, and the ground end is grounded until a flashover occurs. The flashover voltage is recorded ten times using an oscilloscope and the average value is taken.

[0049] It should be understood that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but for those of ordinary skill having the benefit of this disclosure, the development effort will be a routine task of design, fabrication, and production without undue experimentation.

[0050] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A grinding method for improving the surface flashover performance of a three-pillar insulator, characterized in that: include, Divide the longitudinal equidistant annular area into blocks; Clean the surface of the post insulator and measure the potential, surface conductivity and roughness of each area of ​​the post insulator; Gradient grinding is performed from the high voltage end to the ground end.

2. The grinding method for improving the surface flashover performance of a three-pillar insulator according to claim 1 is characterized in that: The longitudinal equidistant annular area segmentation comprises: Each single-pillar insulator of the three-pillar insulator is equally divided into 10 annular areas. The formula for the length of the annular width and the area formula for the longitudinally equidistant annular area are as follows: S n =2πR n d n d n is the width of the nth region from the high voltage end to the ground end; L is the total length of the single-post insulator; S n is the area of ​​the nth region from the high voltage end to the ground end; R n is the average radius of the nth area from the high voltage end to the ground end.

3. The grinding method for improving the surface flashover performance of a three-pillar insulator according to claim 2 is characterized in that: The method of measuring the potential of each area of ​​the post insulator comprises: Before modification, a voltage of 1000 V DC was applied to the surface of the single-pillar insulator. Using an electrostatic potential probe, 10 measurements were performed at constant room temperature and indoor humidity to obtain the average potential value of the area.

4. The grinding method for improving the surface flashover performance of a three-pillar insulator according to claim 3 is characterized in that: The measuring of the surface conductivity of the post insulator comprises: The applied voltage was 1000 V DC, the recording step was 3 min, and 10 measurements were performed at constant room temperature and humidity. The average value was taken and the conductivity σ was calculated using the following formula s , the formula is as follows Where D1 and D2 are the diameters of the measuring electrode and the guard electrode, V a and I a are the applied DC voltage and measured current, respectively.

5. The grinding method for improving the surface flashover performance of a three-pillar insulator according to claim 4 is characterized in that: The measuring of the surface roughness of the post insulator comprises: The surface roughness of the post insulator before modification is characterized by Ra (arithmetic average surface roughness) and root mean square surface roughness (Rrms).

6. The grinding method for improving the surface flashover performance of a three-pillar insulator according to claim 5 is characterized in that: The step of performing gradient polishing from the high voltage end to the ground end in sequence includes: From the high-voltage end to the ground end, different strengths and degrees of grinding are performed according to the different potentials and conductivity to form a gradient roughness.

7. The grinding method for improving the surface flashover performance of a three-pillar insulator according to claim 6 is characterized in that: The cleaning of the surface of the post insulator comprises: Wipe with 75% anhydrous ethanol and air dry for 10 minutes.

8. The grinding method for improving the surface flashover performance of a three-pillar insulator according to claim 7 is characterized in that: The measuring of the potential, surface conductivity and roughness of each area of ​​the post insulator includes: Keep the temperature and humidity of the environment where the post insulator is located constant.

9. The grinding method for improving the surface flashover performance of a three-pillar insulator according to claim 8, characterized in that: The polishing method for improving the surface flashover performance of the three-pillar insulator also includes: Determine whether all the modified single-pillar insulators have been modified.

10. The grinding method for improving the surface flashover performance of a three-pillar insulator according to claim 9, characterized in that: The polishing method for improving the surface flashover performance of the three-pillar insulator also includes: The flashover performance of the modified three-pillar insulator was tested and compared with that of the unmodified three-pillar insulator.

Images