CN106199352A - The modification method of insulator contamination voltage under a kind of high conductivity mist - Google Patents

Abstract

The invention provides a method for correcting the pollution flashover voltage of insulators with high conductivity under fog. The method includes: measuring the actual equivalent salt density ρ _ESDD on the surface of the insulator; measuring the pollution flashover voltage U of the insulator according to the artificial pollution method insulator flashover test , further fitting the classic pollution flashover voltage function according to the shape and pollution degree of the insulator and the pollution flashover voltage measured by the test; according to the classic pollution flashover voltage function, the calculated equivalent salt density ρ _ESDD of the insulator under the corresponding fog water conductivity is deduced; According to the calculated equivalent salt density ρ _ESDD and the actual equivalent salt density ρ _ESDD , the additional salt density coefficient K is derived; according to the additional salt density coefficient K, the modified pollution flashover voltage function is obtained, and the pollution flashover voltage of the insulator is further predicted. The present invention introduces an additional salt density coefficient K, so that the original calculation formula can reflect the joint influence of fog water conductivity and insulator surface pollution on the insulator flashover voltage, making the calculated value more accurate and closer to reality.

Description

A Correction Method for Pollution Flashover Voltage of Insulators with High Conductivity in Fog

technical field

The invention relates to the technical field of voltage testing, in particular to a method for correcting pollution flashover voltage of insulators with high conductivity under fog.

Background technique

With the rapid development of my country's economy and the continuous acceleration of the industrialization process, a large amount of industrial waste has caused immeasurable damage to the environment. The exhaust gas emitted by the combustion of fossil fuels is particularly polluting to the atmosphere, which has made the smog situation worse in recent years. The Beijing-Tianjin-Hebei region, the Yangtze River Delta and the Pearl River Delta have experienced continuous smog weather. Power grid fog flashover accidents caused by smog have also seriously threatened the safe operation of the power system and people's production and life. In the power grid flashover accidents, insulator flashover accidents account for a relatively large proportion. Because the surface of the insulator is polluted or even wet, partial discharge occurs on the surface of the insulator and an arc is generated. The continuous development of the discharge will eventually lead to a flashover. Therefore, calculating the flashover voltage on the surface of the insulator, accurately grasping the voltage margin that the insulator can withstand, and fully considering the influence of environmental factors on the flashover voltage of the insulator are of great significance to preventing the flashover of the insulator, protecting the safe operation of the power system, and ensuring people's lives. Significance.

Contents of the invention

The purpose of this invention is to provide a method for correcting the pollution flashover voltage of insulators with high conductivity under fog, and introduce an additional salt density coefficient, so as to reflect the joint influence of fog water conductivity and insulator surface pollution on the insulator flashover voltage, so that the insulator The measurement result of pollution flashover voltage is more accurate.

The technical scheme provided by the invention is:

The method for correcting pollution flashover voltage of insulators under fog with high conductivity includes the following steps:

Step 1. Smear the insulator and obtain the actual equivalent salt density ρ _ESDD on the surface of the insulator;

Step 2. Measure the pollution flashover voltage U of the insulator according to the insulator flashover test of the artificial pollution method;

Step 3: Fitting the classic pollution flashover voltage function according to the shape and pollution degree of the insulator and the pollution flashover voltage measured by the test.

$\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; E.</span>}\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; D.</span>}\mathrm{<span\; class="notranslate">\; D.</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; ,</span>$

Where A is the coefficient related to the shape of the insulator and the degree of pollution, and a is the characteristic index that characterizes the influence of ρ _ESDD on the pollution flashover voltage;

Step 4. Measure the pollution flashover voltage U′ under the mist water conductivity, and substitute it into

${\mathrm{<span\; class="notranslate">\; u</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; E.</span>}\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; D.</span>}\mathrm{<span\; class="notranslate">\; D.</span>}}^{<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; ,</span>$

Obtain the calculated equivalent salt density ρ′ _ESDD of the insulator under the corresponding mist water conductivity;

Step 5. According to the calculated equivalent salt density ρ′ _ESDD and the actual equivalent salt density ρ _ESDD , deduce the additional salt density coefficient

Step 6. Calculating the corrected pollution flashover voltage function under the corresponding mist water conductivity:

U″=A×(K·ρ″ _ESDD ) ^-a , where ρ″ _ESDD is the actual equivalent salt density measurement value of the insulator surface.

Preferably, in step 1, according to the actual surface area of the insulator, the amount of diatomaceous earth and NaCl required for the corresponding configuration of the dirty solution is determined, and a dirty solution with a corresponding equivalent salt density ρ _ESDD is prepared, and evenly coated on the surface of the insulator. The equivalent salt density on the insulator surface after drying is ρ _ESDD .

The beneficial effects of the present invention are reflected in the following aspects: the present invention introduces an additional salt density coefficient K, so that the original calculation formula can reflect the joint influence of the mist water conductivity and the surface pollution of the insulator on the flashover voltage of the insulator, making the calculated value more accurate , which is closer to reality.

Description of drawings

Fig. 1 is a flow chart of the method for correcting the pollution flashover voltage of an insulator with high conductivity under fog according to the present invention.

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings, so that those skilled in the art can implement it with reference to the description.

The invention provides a method for correcting the pollution flashover voltage of an insulator with high conductivity under fog, which includes the following steps:

Step 1 S110: Obtain the actual equivalent salt density ρ _ESDD of the surface of the insulator.

In this step, according to the method of artificial pollution, before the insulator is smeared, the amount of diatomite and NaCl required for the corresponding configuration of the dirty solution is determined according to the actual surface area of the insulator, and the corresponding equivalent salt density ρ _ESDD is prepared. The dirty solution is evenly applied on the surface of the insulator, and the equivalent salt density on the surface of the insulator after drying is ρ _ESDD .

Step 2 S120: Measure the pollution flashover voltage U of the insulator according to the insulator flashover test of the artificial pollution method.

Step 3 S130: Fitting a classic pollution flashover voltage function according to the shape and pollution degree of the insulator and the pollution flashover voltage measured by the test.

In this step, the classic pollution flashover voltage calculation function model is Where A is a coefficient related to the shape of the insulator and the degree of pollution, and a is the characteristic index that characterizes the influence of ρ _ESDD on the pollution flashover voltage. The experimentally measured pollution flashover voltage U and the corresponding equivalent salt density ρ _{ESDD are} substituted into the calculation function model, and the classic pollution flashover voltage calculation formula is obtained according to the exponential polynomial fitting, that is, the values of A and a are obtained.

Step 4 S140: Calculate the equivalent salt density ρ′ _ESDD of the insulator under the corresponding fog water conductivity according to the classic pollution flashover voltage function.

In this step, since the classic calculation formula of pollution flashover voltage is based on clean fog, a is kept constant under the condition of clean fog, and the pollution flashover voltage under the corresponding conductivity of fog water is substituted into the classic calculation formula The calculated equivalent salt density ρ′ _ESDD under the corresponding mist water conductivity is obtained.

Step 5 S150: According to the calculated equivalent salt density ρ′ _ESDD and the actual equivalent salt density ρ _ESDD , the additional salt density coefficient K is derived, so that the additional salt density coefficient

Step 6 S160: After obtaining the additional salt density coefficient K, the corrected pollution flashover voltage function under the corresponding mist water conductivity is obtained as:

U″=A×(K·ρ″ _ESDD ) ^−a .

That is, after measuring the actual equivalent salt density measurement value ρ″ _ESDD on the surface of the insulator, the above formula can be used to obtain the corrected pollution flashover voltage U″ under the corresponding mist water conductivity.

According to the above formula, it can reflect the joint influence of fog water conductivity and insulator surface pollution on the flashover voltage of insulators, and can calculate the flashover voltage of insulators more accurately.

As shown in Table 1, the experimental data of pollution flashover voltage (kV) of three XP10-160 insulators under specific salt density and mist water conductivity.

Table 1

The coefficient A related to the shape of the insulator and the degree of pollution and the salt density index a are iteratively obtained from the experimental data of pollution flashover voltage by exponential polynomial fitting, and the classical calculation formula is fitted Table 2 shows the values of the constant A and the salt density characteristic index a under different mist water conductivity.

Table 2

For example, ρ _ESDD is 0.10 mg/cm ² , and when the mist water conductivity is 0.0018S/m as the benchmark, its U is 48.231kV, at this time a=0.3254, and when the mist water conductivity rises to 0.275S/m, Its U is reduced to 40.775kV, a=0.2932.

classic The formula is obtained under the test condition of clean fog. For the convenience of comparison with classical research results, under the conductivity of 0.0018S/m fog water, the characteristic index a=0.3254 of the influence of ρ _ESDD on pollution flashover voltage can be kept unchanged. case, according to The calculated value ρ′ ESDD is _0.1713 mg/cm ² , which shows the ratio of the calculated value to the actual value of the equivalent salt density That is, the correction coefficient K is 1.713.

Therefore, under the mist water conductivity of 0.0018S/m, the modified pollution flashover voltage function is:

U″=A×(1.713·ρ″ _ESDD ) ^−a .

Although embodiments of the present invention have been disclosed above, it is not limited to the applications set forth in the specification and examples. It can be fully applied to various fields suitable for the present invention. Additional modifications can readily be made by those skilled in the art. Therefore, the invention should not be limited to the specific details and examples shown and described herein, without departing from the general concept defined by the claims and their equivalents.

Claims (2)

1. A method for correcting the pollution flashover voltage of insulators under fog with high conductivity, is characterized in that, comprises the steps: Step 1. Smear the insulator and obtain the actual equivalent salt density ρ _ESDD on the surface of the insulator; Step 2. Measure the pollution flashover voltage U of the insulator according to the insulator flashover test of the artificial pollution method; Step 3: Fitting the classic pollution flashover voltage function according to the shape and pollution degree of the insulator and the pollution flashover voltage measured by the test. $\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; E.</span>}\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; D.</span>}\mathrm{<span\; class="notranslate">\; D.</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; ,</span>$ Where A is the coefficient related to the shape of the insulator and the degree of pollution, and a is the characteristic index that characterizes the influence of ρ _ESDD on the pollution flashover voltage; Step 4. Measure the pollution flashover voltage U′ under the mist water conductivity, and substitute it into ${\mathrm{<span\; class="notranslate">\; u</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; E.</span>}\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; D.</span>}\mathrm{<span\; class="notranslate">\; D.</span>}}^{<span\; class="notranslate">\; \&prime;</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; ,</span>$ Obtain the calculated equivalent salt density ρ′ _ESDD of the insulator under the corresponding mist water conductivity; Step 5. According to the calculated equivalent salt density ρ′ _ESDD and the actual equivalent salt density ρ _ESDD , deduce the additional salt density coefficient Step 6. Calculating the corrected pollution flashover voltage function under the corresponding mist water conductivity: U"=A×(K·ρ" _ESDD ) ^-a , where ρ" _ESDD is the actual equivalent salt density measurement value on the surface of the insulator. 2. The method for correcting the pollution flashover voltage of an insulator with high conductivity under fog according to claim 1, characterized in that, in step 1, the amount of diatomite and NaCl required when correspondingly configuring the dirty solution is determined according to the actual surface area of the insulator , and prepare a dirty solution with corresponding equivalent salt density ρ _ESDD , and evenly spread it on the surface of the insulator. After drying, the equivalent salt density of the insulator surface is ρ _ESDD .