CN112285456A - Potential-based ground grid uncertainty measuring method - Google Patents

Abstract

The application discloses a potential-based ground grid uncertainty measuring method, which comprises the steps of obtaining a potential on a ground surface circle which takes a current as a circle center and takes 10 meters as a radius; calculating an average value of the potential on the surface circle at a radius of 10 meters; calculating the average of the sum of the absolute values of the potential and average differences over a surface circle at a radius of 10 meters; and according to the average condition of the sum of the absolute values of the potential and the average value difference, the estimation that the measurement result is uncertain due to the current pole addressing in the reverse short-distance measurement of the grounding resistance of the grounding network is realized.

Description

Potential-based ground grid uncertainty measuring method

Technical Field

The invention relates to the field of power transmission and transformation, in particular to a potential-based ground grid uncertainty measuring method.

Background

The traditional method for measuring the grounding resistance of the grounding network at present comprises the wire paying-off time which accounts for about 90% of the total workload of the whole grounding network resistance measurement, and the reverse short-distance measuring method of the grounding resistance of the grounding network can reduce the workload of arrangement of current lines and potential lines by more than 50%. However, the potential distribution and equivalent characteristics of the current electrode region in the ground grid grounding resistance reverse-pushing short-distance measurement based on the dual-electrode potential distribution curve formed by the ground grid and the current electrode have a large influence on the measurement result, and an effective evaluation method for the measurement result is absent at present.

Disclosure of Invention

In order to solve the technical problem, the invention provides a potential-based ground network uncertainty measuring method which is used for reverse short-distance measurement of ground network ground resistance.

The technical scheme of the invention is as follows:

a potential-based earth screen uncertainty measurement method comprises the following steps:

s1, acquiring electric potentials V1, V2 at points of 3.14m arc length on a ground surface circle which takes a current as a center and takes 10 m as a radius;

s2, calculating an average of the potentials V1, V2,. on the watch circle at a radius of 10 meters;

s3, calculating the mean value of the sum of the absolute values of the differences from the mean value of the potentials V1, V2,. on the watch circle at a radius of 10 m;

s4, according to the potential V1, V2.

Further, in S1, there are 20 potential points in total.

Further, in S2, the calculation process of the average value is as follows:

further, in S3, the calculation process of the average value is as follows:

ΔV_{total mean of}＝(|V₁-V_Average|+|V₂-V_Average|+...+|V₂₀-V_Average|)。

Further, in S4, the uncertainty of the reverse short-distance measurement value of the earth ground resistance caused by the soil structure near the current pole is approximately α;

when alpha < 1% indicates that the current pole is reasonably selected, otherwise, the position of the current pole is replaced.

Compared with the prior art, the invention has the following beneficial effects:

the invention can judge whether the selection of the current pole is reasonable, when alpha is less than 1 percent, the site selection of the current pole is reasonable, otherwise, the position of the current pole is changed, and the execution reliability of the standard grounding grid grounding resistance short distance measurement method is improved.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a flow chart of a method of the present invention;

FIG. 2 is a schematic view of a surface circle with a current pole as the center and a radius of 10 meters;

fig. 3 shows the surface potential distribution obtained in the example.

Detailed Description

The technical solutions in the embodiments will be described clearly and completely with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the examples without making any creative effort, shall fall within the protection scope of the present invention.

Unless otherwise defined, technical or scientific terms used in the embodiments of the present application should have the ordinary meaning as understood by those having ordinary skill in the art. The use of "first," "second," and similar terms in the present embodiments does not denote any order, quantity, or importance, but rather the terms are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. "mounted," "connected," and "coupled" are to be construed broadly and may, for example, be fixedly coupled, detachably coupled, or integrally coupled; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. "Upper," "lower," "left," "right," "lateral," "vertical," and the like are used solely in relation to the orientation of the components in the figures, and these directional terms are relative terms that are used for descriptive and clarity purposes and that can vary accordingly depending on the orientation in which the components in the figures are placed.

As shown in fig. 1, the embodiment of the present invention is put into a potential-based uncertainty measurement method for measuring the ground resistance of a ground network in a reverse short distance manner, and includes the following steps:

s1, acquiring electric potentials V1, V2 at points of 3.14m arc length on a ground surface circle which takes a current as a center and takes 10 m as a radius; as shown in fig. 2, the present embodiment has 20 dot potentials in total.

S2, calculating an average value of the potentials V1, V2,. on a ground surface circle with a current pole as a center and a radius of 10 m:

s3, calculating the average value of the sum of the absolute values of the differences from the average value on the earth surface circle with the current pole as the center and the radius of 10 m, when the radius is 10 m, the electric potentials V1, V2,. on the earth surface circle with the current pole as the center:

ΔV_{total mean of}＝(|V₁-V_Average|+|V₂-V_Average|+...+|V₂₀-V_Average|)；

S4, according to the potential V1, V2, the average value condition of the sum of the absolute values of the difference between the average value and the average value is used for realizing the estimation that the measurement result is uncertain due to the current pole addressing in the reverse short-distance measurement of the grounding resistance of the grounding grid:

the uncertainty of the reverse short-distance measurement value of the grounding resistance of the ground network caused by the soil structure near the current pole is approximately alpha;

when alpha < 1% indicates that the current pole is reasonably selected, otherwise, the position of the current pole is replaced.

According to the technical scheme, in the embodiment of the application, the electric potentials V1, V2 at 3.14m points on the ground surface circle which takes the current as the center of the circle and takes 10 meters as the radius are obtained; calculating an average of the potentials V1, V2.. on the watch circle at a radius of 10 meters; calculating an average of the sum of the absolute values of the differences from the average of the potentials V1, V2,. on the surface circle at a radius of 10 m; the evaluation of uncertainty of measurement results caused by current pole addressing in reverse short-distance measurement of the grounding resistance of the grounding grid is realized according to the average condition of the sum of the absolute values of the potential V1, V2.

Fig. 3 shows the surface potential distribution of a certain ground grid, wherein the middle black line circle is a surface circle with a current pole center and a radius of 10 meters, and the potential V1, V2,. at 3.14m points of arc length is calculated as the average value of the potentials V1, V2,. the mean value:

the uncertainty caused by the soil is calculated

Because alpha is less than 1 percent, the current pole address is reasonable.

Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

It will be understood that the present application is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the application is limited only by the appended claims.

Claims (5)

1. A potential-based earth screen uncertainty measurement method is characterized by comprising the following steps: the method comprises the following steps:

s1, acquiring electric potentials V1, V2 at points of 3.14m arc length on a ground surface circle which takes a current as a center and takes 10 m as a radius;

s2, calculating an average of the potentials V1, V2,. on the watch circle at a radius of 10 meters;

s3, calculating the mean value of the sum of the absolute values of the differences from the mean value of the potentials V1, V2,. on the watch circle at a radius of 10 m;

s4, according to the potential V1, V2.

2. The method of claim 1, wherein: in S1, there are 20 potential points in total.

3. The method of claim 2, wherein: in S2, the average value is calculated as follows:

4. the method of claim 1, wherein: in S3, the average value is calculated as follows:

ΔV_{total mean of}＝(|V₁-V_Average|+|V₂-V_Average|+...+|V₂₀-V_Average|)。

5. The method of claim 1, wherein: in S4, the uncertainty of the reverse short-distance measurement value of the earth network grounding resistance caused by the soil structure near the current pole is approximate to alpha;

when alpha < 1% indicates that the current pole is reasonably selected, otherwise, the position of the current pole is replaced.

Images