RU2768200C1 - Double sensor of electric field strength vector components - Google Patents

Abstract

FIELD: measuring technology.

SUBSTANCE: invention relates to the field of measuring technology and can be used to measure the components of the electric field strength vector. The sensor for measuring the electric field strength contains a conducting sphere, on the surface of which sensitive electrodes isolated from each other and from the sphere are diametrically opposed, made in the form of eight congruent spherical triangles bounded by three mutually perpendicular planes, the intersection point of which coincides with the center of the sphere. The sensor also contains six sensitive elements made in the form of spherical segments with angular dimensions θ₀≤45°, located in pairs on diametrically opposite parts of the sphere along three coordinate axes passing along the lines of intersection of three mutually perpendicular planes dividing the sphere into eight congruent triangles.

EFFECT: improving the accuracy of measuring the intensity of non-uniform electric fields in a wide spatial range of measurements.

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Description

The invention relates to the field of measuring technology and can be used to measure the components of the electric field strength vector in a wide spatial range with increased accuracy.

Known sensor implemented in the method of measuring the electric field strength, [Patent RU No. 2388003, MKI G01R 29/12, G01R 29/08], containing an electrically conductive spherical housing with three pairs of electrically conductive sensitive elements, in pairs and symmetrically located relative to the surface of the sensor on its coordinate axes passing through the center of the spherical body, while the sensitive elements and the sensor body are isolated from each other.

The advantage of the sensor is that it is made double, since diametrically opposite pairs of sensitive elements in the form of spherical segments are located along each coordinate axis of the sensor. The components of the electric field strength vector are judged by the difference in charges between opposite pairs of sensing elements. The use of a sensor in a differential connection leads to an increase in the accuracy of measurements, due to a decrease in common-mode components, i.e. external electrical interference.

The disadvantage of the sensor is that its sensitive elements are in the form of a spherical segment, the angular size of which, to prevent their overlap, is θ ₀ ≤45°. A sensor with such angular dimensions of sensitive elements in an inhomogeneous field has a positive error. As a result, the value of the electric field strength will be overestimated.

The closest is the sensor for measuring the electric field strength [AS. 1689884 USSR, MKI G01R 29/12 Device for measuring electric field intensity / Puchkov G.G., Sokolov A.G. - No. 4724939/21; Appl. 07/26/89; Published 07.11.91, Bull. No. 41.], containing a conducting sphere, on the surface of which sensitive electrodes isolated from each other and from the sphere are diametrically opposed, made in the form of eight congruent spherical triangles bounded by three mutually perpendicular planes, the intersection point of which coincides with the center of the sphere. Sensing electrodes combine two groups of sensing elements forming two hemispheres and measure electric current between each pair of formed sensing elements. Consistently forming from the sensor electrodes sensitive elements in the form of hemispheres separated by the YOZ, XOZ and XOY coordinate planes, the components E _X, E _Y and E _Z of the electric field strength vector E are measured.

The prototype sensor is made as a double sensor and has the same advantages as the analogue sensor.

The disadvantage of the sensor is that its sensitive elements, formed from eight congruent triangles, are in the form of hemispheres, the angular size of which is θ ₀ =90°. A sensor with such angular dimensions of sensitive elements in an inhomogeneous field has a negative error. As a result, the value of the electric field strength will be underestimated.

A common disadvantage of the known sensors is the low accuracy in measuring non-uniform electric fields and the limited spatial range of measurement to the field source - several linear dimensions of the sensor.

The objective of the invention is to improve the accuracy of measuring the intensity of non-uniform electric fields, expanding the spatial range of measurement and functionality.

The task is achieved by the fact that in a known sensor for measuring the electric field strength, containing a conductive sphere, on the surface of which sensitive electrodes isolated from each other and from the sphere are diametrically opposed, made in the form of eight congruent spherical triangles bounded by three mutually perpendicular planes, the intersection point which coincides with the center of the sphere, according to the claimed technical solution, six sensitive elements are introduced, made in the form of spherical segments with angular dimensions θ ₀ ≤45°, located in pairs on diametrically opposite parts of the sphere along three coordinate axes passing along the lines of intersection of three mutually perpendicular planes, dividing the sphere into eight congruent triangles.

The present invention is illustrated by drawings, where in Fig. 1 shows a dual double sensor of the components of the electric field strength vector, located in an electric field; in fig. 2 shows the decomposition of a dual sensor into its constituent sensors with the selection of their sensitive electrodes (2-9) and elements (10-15); in fig. 3 and FIG. 4 shows the shape and angular dimensions of sensitive electrodes (2-9) and sensitive elements (10-15), respectively; in fig. 5 shows graphs of errors from the inhomogeneity of the electric field for sensors implemented by analog and prototype and the proposed dual sensor, depending on the spatial measurement range a=R/d (R is the radius of the sensor body 1, d is the distance from the center of the sensor body 1 to the field source) .

The basis of the dual sensor is a conductive sphere 1 coated by sputtering with a thin layer of dielectric (Fig. 1). On the surface of the spherical dielectric layer, eight conductive sensitive electrodes (2-9) are applied, made in the form of congruent equilateral spherical triangles (Fig. 3). Sensing electrodes 6-9 in FIG. 1 and FIG. 2 are not visible. Sensitive electrodes 6-9 are covered with a thin dielectric layer, on the surface of which six sensitive elements (10-15) are applied, made in the form of spherical segments (Fig. 4). The sensing element 12 in FIG. 1 and FIG. 2 is not visible. Thus, the dual sensor is a layered structure in the form of a sphere. Since the conductive parts of the sensor, such as a sphere, sensitive electrodes and elements, are isolated from each other by a thin layer of dielectric and have a small thickness due to deposition, the entire ply structure of the sensor can be considered a continuous conductive spherical surface, and each conductive part of the sensor in an electric field will have almost the same electrical potential. In addition, to ensure an equal potential of all parts of the sensor, its sensitive electrodes and elements must be connected to measuring devices with a low-resistance input. As devices with a low-resistance input, current meters, current integrators (charge amplifiers) can be used. Preference should be given to current integrators, because its output voltage does not depend on the frequency of the field and is proportional to the charges induced on the sensitive elements of the sensor. The conductive sphere 1 can be the middle point of the sensor for the measuring circuit.

The sensor works as follows.

When a dual sensor is introduced into an electric field, electric charges are induced on the conductive electrodes 2-9 of the first sensor and 10-15 of the second sensor, the magnitude of which is proportional to the measured electric field strength E. Forming from electrodes 2-9 opposite pairs of groups of sensitive elements in the form of hemispheres, consisting of four sensitive electrodes: along the X axis - 2, 3, 4, 5 and 6, 7, 8, 9; along the Y axis - 3, 4, 7, 8 and 2, 5, 6, 9; along the Z axis - 2, 3, 6, 7 and 4, 5, 8, 9, separated by the coordinate planes YOZ, XOZ and XOY, the first sensor measures the difference in charges between electrically connected pairs of composite sensing elements proportional to the components E _x1 , E _y1 and E _z1 , and at the same time the second sensor measures the charge difference between the sensitive elements along the X axis - 10 and 12, along the Y axis - 11 and 14, along the Z axis - 13 and 15, proportional to the components E _x2 , E _y2 and E _z2 . According to the measured components of the electric field strength vector, the first and second sensors that are part of the dual sensor determine the modules of the electric field strength, simultaneously measured at one point

;first sensor

;

,second sensor

,

определяют напряженность измеряемого электрического поля.and then according to the formula

determine the intensity of the measured electric field.

и

.The use of a dual sensor improves the accuracy of measuring inhomogeneous electric fields. The increase in accuracy is achieved by the fact that in an inhomogeneous field the measured values of the intensity E ₁ and E ₂ contain opposite in sign relative errors from the inhomogeneity of the field, respectively equal to

And

.

Taking into account the errors, we can write

и

,

And

,

where E is the strength of the initial electric field.

The intensity of the measured field is determined by the formula

,

,

- погрешность измерения, вызванная неоднородностью поля.where

- measurement error caused by field inhomogeneity.

Thus, we obtain the values of the electric field strength with an error δ two times smaller than the difference between the error modules δ ₁ and δ ₂ .

The error reduction is confirmed by FIG. 5, where, as examples, graphs of the error from the inhomogeneity of the electric field of a point charge depending on the relative distance a=R/d (where R is the radius of the sensor sphere, d is the distance from the center of the sensor sphere to the field source) for the analogue δ ₁ , prototype δ ₂ and the claimed device δ.

The plotting of error graphs δ ₁ , δ ₂ and δ is based on the well-known expression for calculating the error from the inhomogeneity of the field of sensors of a spherical shape [Biryukov S.V. Calculation and measurement of electric field strength in electrical installations of super- and ultra-high voltage / S.V. Biryukov, F.G. Kaidanov, R.A. Katz, E.S. Kolechinsky, V.Ya. Lozhnikov, N.S. Smekalova, M.D. Stolyarov // The impact of high voltage electrical installations on the environment: Translations of the reports of the International Conference on Large Electrical Systems (SIGRE-86) (Energy abroad) / Ed. Yu.P. Shkarina. - M.: Energoatomizdat, 1988. - S. 6-13].

,

,

where a=R/d is the spatial measurement range, R is the radius of the sensor sphere, d is the distance from the center of the sensor sphere to the field source, θ ₀ is the angular size of the sensor's sensing element. For the first and second sensors included in the dual sensor, the angular dimensions of the sensitive elements are respectively equal to θ ₀ =90° and θ ₀ ≤45°

From the graphs of Fig. 5 it follows that the proposed dual sensor allows not only to significantly reduce the measurement error of inhomogeneous electric fields (see the graph for the claimed sensor), but also to expand the spatial measurement range. The graph of the error for the claimed dual sensor shows that the measurement error of the sensor is not more than +5% at distances from the field source, commensurate with the radius of the sensor body, i.e. with full spatial measurement range 0≤a≤1 (d=R). While for the analogue and the prototype with the same error, the spatial measurement ranges are respectively equal to 0≤a≤0.24 (d≈4R) and 0≤a≤0.3 (d≈3R).

The proposed tension sensor consists of two independent double sensors, united by one design solution, and is a dual sensor. This feature of the sensor allows you to expand its functionality. For example, you can use each of the sensors separately or simultaneously. The simultaneous use of a dual sensor is discussed in the example above. Because of its versatility, the dual probe can be used as single, dual, and triaxial, as well as single, double, and dual.

Thus, the use of a dual sensor makes it possible to achieve a significant increase in the accuracy of measuring the intensity of inhomogeneous electric fields in a wide spatial measurement range in comparison with known sensors and to expand the functionality of the dual sensor itself.

Claims (1)

A sensor for measuring the electric field strength, containing a conducting sphere, on the surface of which sensitive electrodes isolated from each other and from the sphere are diametrically opposed, made in the form of eight congruent spherical triangles bounded by three mutually perpendicular planes, the intersection point of which coincides with the center of the sphere, differing by the fact that six sensitive elements are introduced into it, made in the form of spherical segments with angular dimensions θ ₀ ≤45°, located in pairs on diametrically opposite parts of the sphere along three coordinate axes passing along the lines of intersection of three mutually perpendicular planes dividing the sphere into eight congruent triangles.

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