Local electric field measuring method and device based on field grinding type high-voltage direct-current electric field measuring instrument

Abstract

The invention discloses a local electric field measuring method and device based on a field grinding type high-voltage direct-current electric field measuring instrument, which can reduce the size of the instrument, reduce the distortion interference of the instrument to an electric field, accurately measure the intensity of a local direct-current electric field in a small area range, and accurately measure the local direct-current electric field according to the actual size of the measured area range. The specific number of shielding sensors is dynamically adjusted, so that accurate measurement of a specific target area is accurately achieved, when the shielding sensors are used for measuring a direct-current electric field, due to the fact that a metal plug board has the physical characteristic of shielding charges, when the metal plug board shields the sensors, generation of inductive charges is reduced, and the electric field cannot be effectively measured; the sensor which is not shielded by the metal plugboard accurately measures and records the charge induced by the surface of the sensor in detail according to the field grinding principle to obtain a measured value, finally, the calibration coefficient is combined, accurate measurement of the local electric field based on the field grinding type high-voltage direct-current electric field measuring instrument sold in the market is achieved, and the method can be widely applied to the field of high-voltage direct-current electric field measurement.

Description

Technical Field

[0001] The invention relates to a local electric field measuring method and a device based on a field mill type high voltage direct current electric field measuring instrument, belonging to the technical field of high voltage direct current electric field measurement. Background Art

[0002] The field mill type DC electric field tester is mainly used to measure the ground synthetic electric field strength under the UHV DC transmission line, and the field mill sensor plays a core role in this process. This sensor rotates at a constant speed through a rotating shutter (dynamic grinding plate), so that the exposed area of ​​the inductive electrode (static grinding plate) below shows periodic changes in the electric field E. When the static grinding plate is exposed to the electric field, in order to keep the ground potential unchanged, the corresponding charge will accumulate on the static grinding plate. On the contrary, when the static grinding plate is shielded by the rotating shutter, the accumulated charge will flow into the earth, forming a periodically changing current. The magnitude of this current reflects the strength of the electric field. The field mill type high-voltage DC electric field measuring instrument usually uses 6 sensors evenly distributed on the surface of the instrument, and the measured electric field value is the superposition value of each sensor. For measuring a large range of electric fields, such a layout ensures that the data evenly covers the measurement area, avoids local deviations, and ensures reliable results.

[0003] In order to more accurately measure the electric field generated by the transmission line itself and avoid the influence of local uneven ground and the introduction of measuring instruments on the spatial electric field, the field mill type high voltage DC electric field measuring instrument usually needs to be equipped with a 1m 2 Square metal grounding plate. During measurement, the field mill type high voltage DC electric field measuring instrument is placed on the grounding plate, and the grounding plate is placed on the ground. In this way, the existence of the grounding plate makes the metal shell on the surface of the instrument have a potential of 0, and maintains the same potential as the grounding plate and the ground, which also have a potential of 0, which greatly reduces the interference of the instrument on the measured electric field, effectively reduces the electric field distortion, creates a relatively uniform electric field environment, and ensures the measurement accuracy.

[0004] Existing field mill electric field testers have obvious limitations. On the one hand, due to the structural limitations of the dispersed distribution of sensors, they are usually only applicable to the measurement scenarios of large-space electric fields. Once applied to small-space electric field measurements, they are difficult to be effective and cannot obtain accurate data; on the other hand, the instrument is equipped with a grounding plate and has a large overall volume, which is not only inconvenient to carry and operate, but also in some measurement environments with strict space requirements. The large volume of the instrument itself will have a more significant distortion effect on the electric field, further restricting the measurement accuracy.

[0005] In summary, due to the large area of ​​the grounding plate, the field mill DC electric field tester equipped with the grounding plate on the market can only work in large-scale electric field scenarios. For those small-scale, localized DC electric field precision measurements, there are few devices and instruments designed and developed specifically for this purpose on the market at this stage. Summary of the invention

[0006] The present invention overcomes the shortcomings of the prior art and provides a local electric field measurement method and device based on a field mill type high voltage DC electric field measuring instrument, which reduces the volume of the instrument and reduces the distortion interference of the instrument on the electric field. It can achieve accurate measurement of the local DC electric field strength in a small area, fills the gap in the prior art, and expands the application boundary of the field mill type electric field tester.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is: a local electric field measurement method based on a field mill type high voltage direct current electric field measuring instrument is implemented according to the following steps: Step 1: Put the ring seat on the electric field tester, align the slide seat with the sensor, and after determining the position, use the first bolt to fix the ring seat on the electric field tester; Step 2: After determining the number of sensors required for local electric field measurement, insert the plug plate into the guide groove of the slide seat, or fix the baffle plate on the ring seat, so that the plug plate or baffle plate completely blocks the unnecessary sensors, and the electric field tester is grounded with a wire. Next, the conductive sheet at the rear end of the plug plate or baffle plate is fixed to the outer surface of the electric field tester with a first bolt. The sensors blocked by the grounded plug plate or baffle plate no longer induce charge, and therefore no longer measure the electric field at their corresponding positions. Finally, only the sensors that are not blocked record the electric field data. Step 3: Start the electric field tester to measure. After the electric field tester runs stably, an electric field measurement value can be obtained. , calculate the ratio W of the number of unblocked sensors to the total number of sensors, and use this electric field measurement value Divide by W to get the initial value of the electric field corresponding to the specific area of ​​the sensor ; Step 4: Get the initial value of the electric field Divide by the calibration coefficient K, calibrate the data, and then get the precise value E of the electric field in the specific area;

[0008] in: K: calibration factor; E: precise value of electric field; Furthermore, the calibration coefficient K is obtained by the following process: constructing a test environment in which the internal electric field is completely uniformly distributed, performing occlusion measurement on the sensor in the uniform electric field using steps 1 to 4, and accurately measuring the initial value of the electric field At the same time, the field strength value measured when the sensor is not blocked and in normal working condition is defined as the reference field strength value. Under this condition, the value of the calibration coefficient K is the initial value of the electric field With the reference field strength value The ratio of the two; .

[0009] The present invention discloses a local electric field measuring device based on a field mill type high voltage direct current electric field measuring instrument, comprising a ring seat, a slide seat, an insert plate, a first bolt and a conductive sheet, wherein the ring seat and the slide seat are both made of non-metallic materials, the ring seat is fitted on and fixed to the electric field tester through the first bolt, the slide seat corresponds to a sensor arrangement on the electric field tester, and the slide seat is fixedly arranged at the upper end of the ring seat, the insert plate is made of conductive material, the insert plate is movably arranged on the slide seat, the sensor is shielded by the insert plate and connected to the conductive sheet arranged on the outer surface of the electric field tester, and a wire for grounding is connected to the insert plate.

[0010] Furthermore, an inverted T-shaped guide groove is provided on the upper end surface of the slide seat, and the plug plate is movably inserted in the guide groove.

[0011] In particular, the present invention provides a local electric field measuring device based on a field mill-type high-voltage direct current electric field measuring instrument, comprising a ring seat, a baffle, a first bolt and a conductive sheet, wherein the ring seat is made of non-metallic material, the ring seat is mounted on and fixed to the electric field tester by a first bolt, the baffle is made of conductive material and is U-shaped, the baffle is fixed to the top of the ring seat by a second bolt, the baffle corresponds to a part of the sensor that can shield the electric field tester, the sensor is shielded by the baffle and connected to the conductive sheet arranged on the outer side of the electric field tester, and a wire for grounding is connected to the baffle.

[0012] Furthermore, the first bolt fixes the ring seat and the conductive sheet together on the outer side of the electric field tester.

[0013] Compared with the prior art, the present invention has the following beneficial effects: the present invention can dynamically adjust the specific number of occluded sensors according to the actual size of the measured area, so as to accurately achieve accurate measurement of a specific target area. When using an occluded sensor to measure a DC electric field, since the metal plug plate itself has the physical property of shielding charges, when the metal plug plate shields the sensor, the induced charge generation is reduced, and the electric field cannot be effectively measured. For sensors that are not blocked by the metal plug plate, the charges induced on their surfaces are accurately measured and recorded in detail based on the field grinding principle to obtain the measured values. Finally, combined with the calibration coefficient, accurate measurement of the local electric field based on a commercially available field grinding high-voltage DC electric field measuring instrument is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be further described below in conjunction with the accompanying drawings.

[0015] Figure 1 It is a front structural schematic diagram of the second embodiment of the present invention.

[0016] Figure 2 It is a schematic diagram of the top view of the structure of the second embodiment of the present invention.

[0017] Figure 3 It is a side view structural diagram of the second embodiment of the present invention.

[0018] Figure 4 It is a front structural schematic diagram of Example 3 in the present invention.

[0019] Figure 5 It is a schematic diagram of the top view of the structure of the third embodiment of the present invention.

[0020] Figure 6 is the initial field strength value at different distances in the present invention With the reference field strength value Schematic diagram of the curve.

[0021] In the figure: 1 is a ring seat, 2 is a sliding seat, 3 is an insert plate, 4 is a first bolt, 5 is a conductive sheet, 6 is an electric field tester, 7 is a guide groove, 8 is a second bolt, and 9 is a baffle. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with specific embodiments.

[0023] Embodiment 1

[0024] like Figure 1 to Figure 6 As shown, the local electric field measurement method based on the field mill type high voltage direct current electric field measuring instrument of the present invention is implemented according to the following steps: Step 1: Put the ring seat 1 on the electric field tester 6, align the slide seat 2 with the sensor, and after determining the position, fix the ring seat 1 on the electric field tester 6 with the first bolt 4; Step 2: After determining the number of sensors required for local electric field measurement, insert the plug plate 3 into the guide groove 7 of the slide seat 2, or fix the baffle 9 on the ring seat 1, so that the plug plate 3 or the baffle 9 completely blocks the unnecessary sensors, and the electric field tester 6 is grounded with a wire. Then, the conductive sheet 5 at the rear end of the plug plate 3 or the baffle 9 is fixed to the outer surface of the electric field tester 6 with the first bolt 4. The sensors blocked by the grounded plug plate 3 or the baffle 9 no longer induce charge, and therefore no longer measure the electric field at their corresponding positions. Finally, only the sensors that are not blocked record the electric field data. Step 3: Start the electric field tester 6 to measure. After the electric field tester 6 runs stably, an electric field measurement value can be obtained. , calculate the ratio W of the number of unblocked sensors to the total number of sensors, and use this electric field measurement value Divide by W to get the initial value of the electric field corresponding to the specific area of ​​the sensor ; The initial value of the electric field is The specific calculation process is as follows: 1. Get the initial electric field measurement: First, get the measurement of the unobstructed sensor .

[0025] 2. Calculate the initial value: The electric field measurement value Divide by the ratio W of the number of unblocked sensors to the total number of sensors to get the initial value of the electric field .

[0026] ; ; in: : The measurement value of the unobstructed sensor; : initial value of electric field; W: the ratio of the number of unblocked sensors to the total number of sensors; Step 4: Get the initial value of the electric field Divide by the calibration coefficient K, calibrate the data, and then get the precise value E of the electric field in the specific area;

[0027] in: K: calibration factor; E: precise value of electric field; In the technical implementation process of this embodiment, the calibration coefficient K is obtained through rigorous experiments. The specific steps are as follows: First, a large-scale test environment with a completely uniform electric field is constructed. Steps 1 to 4 are used to perform occlusion measurements on the sensor in a uniform electric field to accurately measure the initial value of the electric field. At the same time, the field strength value measured when the sensor is not blocked and in normal working condition is defined as the reference field strength value. Under this condition, the value of the calibration coefficient K is the initial value of the electric field With the reference field strength value The ratio of the two.

[0028]

[0029] In this embodiment, in order to achieve accurate measurement of the electric field strength in a smaller range, only one sensor is kept in working state by adjusting the shielding plate 3 or the baffle 9. The corresponding calibration coefficient when only one sensor is used for measurement under different distance conditions is By analogy, the corresponding calibration coefficient when using two sensors for measurement is ; The corresponding calibration coefficient when using 3 sensors for measurement is However, the purpose of the present invention is to improve the field mill DC electric field tester to achieve local measurement in the smallest space. Therefore, only the electric field calibration coefficient corresponding to the measurement using one sensor is used. Have a discussion.

[0030] Since the attachment device of the occlusion sensor can adopt different structures, the calibration factor is a range. Unlike the original instrument, which is mainly used for measurement scenarios where the power source is far away from the measured point (such as electric field measurement under the transmission line), after adding the adapter, the instrument is suitable for situations where the distance between the power source and the measured point is short. In order to more intuitively display this coefficient, the initial field strength values ​​at different distances are plotted. With the reference field strength value At the same time, the calibration coefficients at different distances H when the distance between the power supply and the measured point is short are listed in Tables 1 and 2 respectively. .

[0031] Table 1 Distance H and coefficients when measuring using case 1 The corresponding relationship

[0032] Table 2 Distance H and coefficients when using case 2 for measurement The corresponding relationship

[0033] In summary, when using a DC electric field tester for measurement, this additional device can dynamically adjust the specific number of occluded sensors according to the actual size of the measured area, so as to accurately achieve accurate measurement of specific target areas. When using an occluded sensor to measure the DC electric field, given that the metal plug plate itself has the physical property of shielding charges, when the metal plug plate shields the sensor, the induced charge is reduced and the electric field cannot be effectively measured. For sensors that are not blocked by the metal plug plate, the charges induced on their surfaces are accurately measured and recorded in detail based on the field grinding principle to obtain the measured value. Finally, combined with the calibration coefficient, accurate measurement of the local electric field based on the commercially available field grinding high-voltage DC electric field measuring instrument is achieved.

[0034] Embodiment 2

[0035] like Figure 1 to Figure 3As shown, the present invention is a local electric field measuring device based on a field mill type high voltage direct current electric field measuring instrument, comprising a ring seat 1, a slide seat 2, an insert plate 3, a first bolt 4 and a conductive sheet 5, the ring seat 1 and the slide seat 2 are both made of non-metallic materials, the ring seat 1 is set and fixed on the electric field tester 6 by the first bolt 4, the slide seat 2 corresponds to the sensor arrangement on the electric field tester 6, and the slide seat 2 is fixedly arranged at the upper end of the ring seat 1, and an inverted T-shaped guide groove 7 is arranged on the upper end surface of the slide seat 2, and the insert plate 3 is movably inserted in the guide groove 7. The insert plate 3 is made of conductive material, and the insert plate 3 is movably arranged on the slide seat 2, shielding the sensor through the insert plate 3 and connecting the conductive sheet 5 arranged on the outer surface of the electric field tester 6, the insert plate 3 is connected with a wire for grounding, and the first bolt 4 fixes the ring seat 1 and the conductive sheet 5 together on the outer surface of the electric field tester 6.

[0036] In this embodiment, the ring seat 1 is made of non-metallic material, and has 6 bolt holes symmetrically distributed around it, which are used to fix the ring seat 1 on the electric field tester 6. Six slide seats 2 are fixed on the ring seat 1 corresponding to the sensor positions. The slide seat 2 is divided into a head and a tail, and the head and tail materials are both non-metallic. The head is round, with a circular groove of the size of the sensor in the middle, which is located between the sensor and the fan, with a 0.1 cm gap above and below. A guide groove 7 is left at the tail for inserting the plug board 3. The plug board 3 is made of conductive metal such as aluminum and copper. It is used to be inserted into the guide groove 7 of the slide seat 2 to block the sensor, and there is a handle on it for plugging and unplugging the plug board 3. A small wire is welded at the tail of the plug board 3 as a conductive sheet 5, which is fixed to the surface of the electric field tester 6 with a first bolt 4.

[0037] Embodiment 3

[0038] like Figure 4-5 As shown, the present invention is a local electric field measuring device based on a field mill type high voltage direct current electric field measuring instrument, comprising a ring seat 1, a baffle 9, a first bolt 4 and a conductive sheet 5, wherein the ring seat 1 is made of non-metallic material, the ring seat 1 is fitted on and fixed to the electric field tester 6 by the first bolt 4, the baffle 9 is made of conductive material and is U-shaped, the baffle 9 is fixed to the top of the ring seat 1 by the second bolt 8, the baffle 9 corresponds to a part of the sensor that can shield the electric field tester 6, the baffle 9 shields the sensor and is connected to the conductive sheet 5 arranged on the outer side of the electric field tester 6, and the baffle 9 is connected to a wire for grounding. The first bolt 4 fixes the ring seat 1 and the conductive sheet 5 together on the outer side of the electric field tester 6.

[0039] In this embodiment, the ring seat 1 is made of non-metallic material, and has 6 bolt holes symmetrically distributed around it, which are used to fix the ring seat 1 on the electric field tester 6. The baffle 9 is made of conductive metal such as aluminum and copper, and has a U-shaped structure with a round head. It is located between the sensor and the fan, and has a 0.1 cm gap above and below to shield the 5 sensors. The baffle 9 is fixed to the ring seat 1 by the second bolt 8. A small wire is welded to the tail of the baffle 9 above each sensor as a conductive sheet 5, which is fixed to the surface of the electric field tester 6 by the first bolt 4.

[0040] The present invention is based on a field mill type high voltage direct current electric field measuring instrument, and has been innovatively designed to achieve local electric field measurement. First, the grounding plate configuration commonly used in traditional instruments is abandoned, and it is directly connected to the electric field tester 6 through a grounding wire, so that the metal plane on the surface of the electric field tester 6 and the charged body to be measured still form a small flat capacitor structure, which significantly reduces the volume of the electric field tester 6. Secondly, a metal grounding plug plate 3 or baffle 9 is introduced as a shielding element, which, on the one hand, achieves the purpose of selecting the number of sensors according to measurement needs, and on the other hand, the grounded metal plug plate 3 or baffle 9 effectively reduces the distortion effect of the electric field tester 6 on the surrounding electric field, thereby ensuring the accuracy of the electric field tester 6 in small-scale electric field measurement.

[0041] The present invention has made innovative designs for the measuring device: first, the traditional grounding plate setting is abandoned, and a grounding wire is used to connect the instrument to achieve its own miniaturized design. Second, the introduction of a metal grounding plug plate as a shielding component can significantly reduce the distortion interference of the instrument on the original electric field, reduce the mutual interference of the electric field between sensors, and construct a more uniform electric field. Third, at the measurement method level, the specific number of occluded sensors is dynamically adjusted according to the actual size of the measurement area, so as to accurately focus on the target measurement area. A complete calculation method from the initial measurement value to the corrected precise value is given. Fourth, the calibration coefficient of a single sensor measurement at different distances measured based on the precise value calculation rule of the dynamic occlusion sensor is given through experiments. The range is shown in Table 3.

[0042] Table 3 The coefficients at different distances H when using different structural attachments for measurement The value range of

[0043] On the whole, this device does not come into contact with the internal structure of the electrical equipment during the entire measurement process, and is easy to operate, sophisticated in design, and highly reliable.

[0044] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A local electric field measurement method based on a field mill type high voltage direct current electric field measuring instrument, characterized in that: Follow these steps to implement: Step 1: Put the ring seat (1) on the electric field tester (6), align the slide seat (2) with the sensor, and after determining the position, use the first bolt (4) to fix the ring seat (1) on the electric field tester (6); Step 2: After determining the number of sensors required for local electric field measurement, insert the plug plate (3) into the guide groove (7) of the slide seat (2), or fix the baffle (9) on the ring seat (1), so that the plug plate (3) or the baffle (9) completely blocks the unnecessary sensors, and the electric field tester (6) is grounded with a wire. Then, the conductive sheet (5) at the rear end of the plug plate (3) or the baffle (9) is fixed to the outer surface of the electric field tester (6) with a first bolt (4). The sensors blocked by the grounded plug plate (3) or the baffle (9) no longer induce charge, and therefore no longer measure the electric field at their corresponding positions. Finally, only the sensors that are not blocked record the electric field data. Step 3: Start the electric field tester (6) to measure. After the electric field tester (6) runs stably, an electric field measurement value can be obtained. , calculate the ratio W of the number of unblocked sensors to the total number of sensors, and use this electric field measurement value Divide by W to get the initial value of the electric field corresponding to the specific area of ​​the sensor ; Step 4: Get the initial value of the electric field Divide by the calibration coefficient K, calibrate the data, and then get the precise value E of the electric field in the specific area; 2. in: K: calibration factor; E: Exact value of the electric field.

3. The local electric field measurement method based on the field mill type high voltage direct current electric field measuring instrument according to claim 1 is characterized in that: The calibration coefficient K is obtained by the following process: constructing a test environment in which the internal electric field is completely uniformly distributed, performing occlusion measurement on the sensor in the uniform electric field using steps 1 to 4, and accurately measuring the initial value of the electric field At the same time, the field strength value measured when the sensor is not blocked and in normal working condition is defined as the reference field strength value. Under this condition, the value of the calibration coefficient K is the initial value of the electric field With the reference field strength value The ratio of the two; 。 4. The local electric field measuring device based on the field mill type high voltage direct current electric field measuring instrument according to claim 1 is characterized in that: The invention comprises a ring seat (1), a slide seat (2), an insert plate (3), a first bolt (4) and a conductive sheet (5), wherein the ring seat (1) and the slide seat (2) are both made of non-metallic materials, the ring seat (1) is mounted on and fixed to an electric field tester (6) by means of the first bolt (4), the slide seat (2) corresponds to a sensor arrangement on the electric field tester (6), and the slide seat (2) is fixedly arranged at the upper end of the ring seat (1), the insert plate (3) is made of conductive material, the insert plate (3) is movably arranged on the slide seat (2), shields the sensor through the insert plate (3) and is connected to a conductive sheet (5) arranged on the outer surface of the electric field tester (6), and a wire for grounding is connected to the insert plate (3).

5. The local electric field measuring device based on the field mill type high voltage direct current electric field measuring instrument according to claim 3 is characterized in that: An inverted T-shaped guide groove (7) is provided on the upper end surface of the slide seat (2), and the insert plate (3) is movably inserted into the guide groove (7).

6. The local electric field measuring device based on the field mill type high voltage direct current electric field measuring instrument according to claim 1 is characterized in that: The invention comprises a ring seat (1), a baffle (9), a first bolt (4) and a conductive sheet (5), wherein the ring seat (1) is made of a non-metallic material, the ring seat (1) is mounted on and fixed to an electric field tester (6) by means of a first bolt (4), the baffle (9) is made of a conductive material and is U-shaped, the baffle (9) is fixed to the top of the ring seat (1) by means of a second bolt (8), the baffle (9) corresponds to a part of a sensor that can shield the electric field tester (6), shields the sensor by means of the baffle (9) and is connected to a conductive sheet (5) arranged on the outer surface of the electric field tester (6), and a wire for grounding is connected to the baffle (9).

7. The local electric field measuring device based on the field mill type high voltage direct current electric field measuring instrument according to claim 3 or 5, characterized in that: The first bolts (4) fix the ring seat (1) and the conductive sheet (5) together on the outer side of the electric field tester (6).

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