Method and device for evaluating aging state of silicone rubber composite insulator

Patent metadata

Field	Value
Publication number	US-12247971-B2
Application number	US-202117789534-A
Country	US
Kind code	B2
Filing date	Dec 10, 2021
Priority date	Dec 8, 2021
Publication date	Mar 11, 2025
Grant date	Mar 11, 2025

Abstract

A method for evaluating an aging state of a silicone rubber composite insulator includes: step 1: collecting samples from the silicone rubber composite insulator, and subjecting samples in a surface layer and a center layer successively to hydrophobicity, flexing resistance, hardness, color, and absorbance tests; step 2: determining relevant data of the samples in a natural evolution process according to the tests in step 1; step 3: subjecting the samples to thermo-oxidative aging; and after the thermo-oxidative aging is completed, subjecting the samples to a hardness test of artificial accelerated evolution, and calculating position coordinates (F 1 , F 2 ) of the samples in an aging space; and step 4: classifying the samples in advance and solving an aging state centroid of each classified population, calculating a minimum aging distance based on the position coordinates in step 3, and evaluating the aging state of the silicone rubber composite insulator.

First claim

The invention claimed is:

1. A method for evaluating an aging state of a silicone rubber composite insulator, comprising the following steps:
step 1: collecting samples from the silicone rubber composite insulator, subjecting samples in a surface layer successively to hydrophobicity, flexing resistance, hardness, color, and absorbance tests, and subjecting samples in a center layer successively to hardness, color, and absorbance tests;
step 2: determining an average static contact angle, a flexing resistance index, a hardness difference, a color difference, and an absorbance rise rate of the samples during a natural evolution process according to the tests in step 1;
step 3: subjecting the samples to thermo-oxidative aging; and after the thermo-oxidative aging is completed, subjecting the samples to a hardness test of artificial accelerated evolution, and calculating position coordinates (F 1 , F 2 ) of the samples in an aging space; and
step 4: classifying the samples in advance and solving an aging state centroid of each classified population, calculating a minimum aging distance based on the position coordinates in step 3, and evaluating the aging state of the silicone rubber composite insulator based on the minimum aging distance.

2. The method for evaluating an aging state of a silicone rubber composite insulator according to claim 1 , wherein
the step of collecting samples from the silicone rubber composite insulator comprises:
step 1.1: randomly collecting a whole umbrella skirt S zp of a second umbrella or a third umbrella of a high-voltage end from the silicone rubber composite insulator;
step 1.2: collecting samples A w , B w , C w , and D w respectively from four positions a, b, c, and d on an upper surface of the whole umbrella skirt S zp ; and
step 1.3: collecting samples A n , B n , C n , and D n respectively from four positions a, b, c, and d in a split layer of the whole umbrella skirt S zp ;
wherein a connecting line ab is perpendicular to a connecting line cd, and an intersection point of the two is located at a pivot of the whole umbrella skirt; and distances of the four points a, b, c, and d to the pivot of the whole umbrella skirt are equal.

3. The method for evaluating an aging state of a silicone rubber composite insulator according to claim 2 , wherein
the samples A w , B w , C w , and D w are each subjected to a hydrophobicity test, and static contact angles of surfaces of the samples are recorded as CAV A w , CAV B w , CAV C w , and CAV D w ; and
an average static contact angle ΔCAV=ΣCAV i w /4 of the samples is calculated based on the static contact angles of the surfaces of the samples, wherein i=A, B, C, or D.

4. The method for evaluating an aging state of a silicone rubber composite insulator according to claim 3 , wherein
the subjecting the samples to a flexing resistance test specifically comprises: folding an edge of the sample S zp at 180°, and determining a flexing resistance index C dz based on a crack state at a crease position;
wherein

C

d
⁢
z

=

{

0
,

There
⁢

are
⁢

cracks

≥

2
⁢

mm

1
,

There
⁢

are
⁢

cracks

≤

2
⁢

mm

2
,

There
⁢

is
⁢

no
⁢

crack

.

5. The method for evaluating an aging state of a silicone rubber composite insulator according to claim 4 , wherein
the subjecting the samples to a hardness test in step 1 further comprises:
subjecting the samples A w , B w , C w , D w , A n , B n , C n , and D n to a Shore hardness test to obtain Shore hardness values Shore iw and Shore in of a sample at each position, wherein i=A, B, C, or D;
calculating a Shore hardness difference Shore i =Shore iw −Shore in of a sample at each position; and
calculating a natural evolution difference ΔH shore =Σ(Shore iw −Shore in )/4 in Shore hardness of the samples at the four positions.

6. The method for evaluating an aging state of a silicone rubber composite insulator according to claim 5 , wherein
the subjecting the samples to a color test in step 1 further comprises:
subjecting the samples A w , B w , C w , D w , A n , B n , C n , and D n to a lightness test to obtain lightness values L iw and L in of a sample at each position in a color space L*a*b, wherein i=A, B, C, or D;
calculating a lightness difference L i =L iw −L in of a sample at each position; and
calculating a natural evolution difference ΔL=Σ(L iw −L in )/4 in lightness of the samples at the four positions.

7. The method for evaluating an aging state of a silicone rubber composite insulator according to claim 6 , wherein
the samples A w , B w , C w , D w , A n , B n , C n , and D n are subjected to an absorbance test, and absorbance ratios R iw and R in of a sample at each position are recorded, wherein i=A, B, C, or D;
an absorbance rise rate

IR
i

=

(

R

i
⁢

Assignees

• State Grid Hebei Electric Power Co Ltd Res Institute
• State Grid Corp China
• State Grid Hebei Energy Tech Service Co Ltd
• Hebei Silicon Valley Chemical Co Ltd
• Zibo Qianheng Automation Eng Co Ltd

Inventors

• Jia Boyan
• Liu Jie
• Xia Yanwei
• Pang Xianhai
• Zhao Yuhao
• Li Shilin
• Song Liqiang
• Liu Xiangxia

Classifications

• G01N21/31

  Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry {(G01N21/72 takes precedence)} · CPC title

• G01N3/40 Primary

  Investigating hardness or rebound hardness · CPC title

• G01N3/20

  by applying steady bending forces (G01N3/26, G01N3/28 take precedence) · CPC title

• G01N33/445 Primary

  Rubber · CPC title

• G01N2203/0076

  Hardness, compressibility or resistance to crushing · CPC title