Low-voltage arm capacitor and capacitive voltage divider with same

Abstract

The invention provides a low-voltage arm capacitor and a capacitive voltage divider with the same. The low-voltage arm capacitor comprises an upper polar plate and a lower polar plate which are parallel up and down and are arranged at intervals; the two coaxial conductive cylinder groups are arranged between the upper pole plate and the lower pole plate in a mutually staggered manner to form a nested coaxial cylinder structure distributed at equal intervals, a dielectric layer is arranged in a gap between the lower pole plate and the upper pole plate between the two coaxial conductive cylinder groups, and a central conductive column is arranged in the coaxial cylinder structure; the insulating supporting piece is arranged between the upper polar plate and the lower polar plate; the input end connecting piece is electrically connected with the upper polar plate; the grounding end of the output terminal is electrically connected with the lower pole plate, and the connecting wire is electrically connected with the other end of the central conductive column. According to the invention, a coaxial design is adopted, a pure coaxial capacitance loop is formed by the coaxial design and a high-voltage coaxial capacitor of a standard capacitive voltage divider, and the stability is good; the coaxial structure can reduce the self-inductance of the low-voltage arm, so that the low-voltage arm is more effective in measuring high-frequency voltage signals.

Description

Technical Field

[0001] The present invention relates to the technical field of capacitive voltage dividers, and in particular to a low-voltage arm capacitor and a capacitive voltage divider having the low-voltage arm capacitor. Background Art

[0002] With the rapid development of new power systems, the demand for reliable and high-performance voltage sensors is increasing. In this context, capacitive voltage dividers based on standard capacitors have become a technology that has attracted much attention. This type of capacitive voltage divider has excellent wide-band voltage measurement performance. Usually, the high-voltage arm of the capacitive voltage divider uses a coaxial capacitor based on compressed gas, while the low-voltage arm is placed outside the compressed gas capacitor, with a coaxial structure composed of chip capacitors connected in parallel to form a printed circuit board (PCB), which is then connected in series with the internal coaxial capacitor.

[0003] However, there is a challenge in the existing design, that is, the capacitor of the low voltage arm uses a chip capacitor, which makes its performance not comparable to that of a standard capacitor. This problem directly affects the performance of the capacitive voltage divider and limits its broadband voltage measurement capability. Summary of the invention

[0004] In view of this, the present invention proposes a low-voltage arm capacitor and a capacitive voltage divider having the low-voltage arm capacitor, aiming to solve the problem that the existing low-voltage arm capacitor uses a chip capacitor, resulting in large self-inductance and high inductance, which interferes with and affects the signal.

[0005] On the one hand, the present invention proposes a low-voltage arm capacitor, which includes: an upper electrode plate and a lower electrode plate which are arranged in parallel and spaced apart from each other, the lower electrode plate being used for grounding; two groups of coaxial conductive tube groups, the two groups of coaxial conductive tube groups are arranged alternately between the upper electrode plate and the lower electrode plate to form a stacked coaxial tube structure with equal spacing, the gap between the two groups of coaxial conductive tube groups is provided with a dielectric layer between the lower electrode plate and the upper electrode plate, the two groups of coaxial conductive tube groups are electrically connected to the upper electrode plate and the lower electrode plate respectively, and a central conductive column is provided inside the coaxial tube structure, one end of which is connected to the inner surface of the coaxial tube structure. The upper electrode plate is electrically connected; an insulating support member is arranged between the upper electrode plate and the lower electrode plate, and the insulating support member is sleeved on the outside of the two groups of coaxial conductive tube groups to form a sealed cavity between the upper electrode plate and the lower electrode plate; an input terminal connector, the input terminal connector is electrically connected to the upper electrode plate and is used to connect the high-voltage arm of the voltage divider to input voltage to the upper electrode plate; an output terminal, the ground terminal of the output terminal is electrically connected to the lower electrode plate, and the connecting wire of the output terminal is electrically connected to the other end of the central conductive column to obtain the voltage difference between the upper electrode plate and the lower electrode plate.

[0006] Furthermore, in the above-mentioned low-voltage arm capacitor, the connection end of one group of the coaxial conductive tube groups is connected to the upper electrode plate, and a gap is provided between the free end of the coaxial conductive tube group and the lower electrode plate; the connection end of another group of the coaxial conductive tube groups is connected to the lower electrode plate, and a gap is provided between the free end of the coaxial conductive tube group and the upper electrode plate.

[0007] Furthermore, in the above-mentioned low-voltage arm capacitor, the input end connector includes: a connecting flange for mounting on the upper plate; a connecting screw, the connecting end of which is connected to the connecting flange, and the connecting screw is used to connect the high-voltage arm of the voltage divider.

[0008] Furthermore, in the above-mentioned low-voltage arm capacitor, the coaxial conductive tube group includes a plurality of conductive tubes which are sequentially sleeved from the inside to the outside and arranged at intervals.

[0009] Furthermore, in the above-mentioned low-voltage arm capacitor, the outer wall of the insulating support is flush with the outer walls of the upper electrode plate and the lower electrode plate, and the three form a cylindrical structure; the two ends of the insulating support are respectively detachably connected to the upper electrode plate and the lower electrode plate.

[0010] Furthermore, in the above-mentioned low-voltage arm capacitor, the input terminal connector is installed on the upper plate, and the output terminal is installed on the lower plate.

[0011] Furthermore, in the above-mentioned low-voltage arm capacitor, the upper electrode plate and the lower electrode plate are disc structures, and the upper electrode plate, the lower electrode plate and the two groups of coaxial conductive tubes are all coaxially arranged.

[0012] Furthermore, in the above-mentioned low-voltage arm capacitor, the upper electrode plate, the lower electrode plate and the coaxial conductive tube group are all made of metal.

[0013] Furthermore, in the above-mentioned low-voltage arm capacitor, a grounding interface is provided on the lower electrode plate.

[0014] On the other hand, the present invention further provides a capacitive voltage divider having the above-mentioned low-voltage arm capacitor.

[0015] The low-voltage arm capacitor provided by the present invention adopts a coaxial design, and together with the high-voltage coaxial capacitor of the standard capacitor voltage divider, a pure coaxial capacitor loop is formed, which has good stability; the coaxial structure can reduce the self-inductance of the low-voltage arm, so it has a lower inductance, which makes the low-voltage arm more effective in measuring high-frequency voltage signals, because low inductance will not have too much impact on high-frequency signals; due to the characteristics of the coaxial structure, the electric field is distributed more evenly between the upper and lower plates, which helps to reduce the non-uniformity of the capacitor, improve its performance and stability, and solve the problem that the capacitor of the existing low-voltage arm adopts a patch capacitor, causing its self-inductance to be large and the inductance to interfere with and affect the signal. By replacing the traditional patch capacitor with the low-voltage arm capacitor, the high and low voltage capacitors of the entire capacitor voltage divider are all standard capacitors. Through this improvement, the performance of the capacitor voltage divider has been significantly improved, especially in the wideband voltage measurement, and more accurate and reliable measurement results have been obtained, which not only improves the performance of the capacitor voltage divider, that is, more accurate and reliable voltage measurement, but also provides reliable technical support for high-performance voltage measurement of the new power system, meeting the demand of the new power system for high-performance voltage sensors. The application of this technology will provide more accurate and reliable data for the monitoring and control of power systems, and promote the further development of power system technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings: Figure 1 A schematic diagram of the structure of a low-voltage arm capacitor provided by an embodiment of the present invention; Figure 2 A cross-sectional view of a low-voltage arm capacitor provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0017] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0018] Low voltage arm capacitor example: See also Figure 1 to Figure 2, which shows the preferred structure of the low-voltage arm capacitor provided by the embodiment of the present invention. As shown in the figure, the low-voltage arm capacitor includes: an upper plate 1, a lower plate 2, two sets of coaxial conductive tubes 3, a central conductive column 4, an insulating support 5, an input terminal connector 6 and an output terminal 7; wherein, The upper plate 1 and the lower plate 2 are arranged parallel to each other and spaced apart, and the lower plate 2 is used for grounding. Specifically, the upper plate 1 and the lower plate 2 are arranged parallel to each other and spaced apart, and both the upper plate 1 and the lower plate 2 can be metal discs as parallel conductive plates, which can collect charges, so that the upper plate 1 can carry positive charges and the lower plate 2 can carry opposite negative charges. Among them, the upper plate 1 and the lower plate 2 are both made of metal and can be a metal disc structure, that is, a disc structure and made of metal.

[0019] Two groups of coaxial conductive tube groups 3 are arranged alternately between the upper electrode plate 1 and the lower electrode plate 2 to form a stacked coaxial tube structure with equal spacing. The gap between the two groups of coaxial conductive tube groups 3 is located between the upper electrode plate 1 and the lower electrode plate 2. A dielectric layer 8 is provided between the two groups of coaxial conductive tube groups 3, and the two groups of coaxial conductive tube groups 3 are electrically connected to the upper electrode plate 1 and the lower electrode plate 2 respectively. A central conductive column 4 is provided inside the coaxial tube structure, one end of which is electrically connected to the upper electrode plate 1 for conductive connection, so that the central conductive column 4 and the upper electrode plate 1 are at the same potential.

[0020] Specifically, two groups of coaxial conductive tube groups 3 are arranged between the upper electrode plate 1 and the lower electrode plate 2 in an interlaced manner, and the upper electrode plate 1 and the lower electrode plate 2 are coaxially arranged in both groups of coaxial conductive tube groups 3. Each group of coaxial conductive tube groups 3 includes a plurality of conductive tubes which are sequentially sleeved and spaced from the inside to the outside, and each conductive tube is a metal thin-walled cylindrical structure, and each conductive tube is coaxially arranged with the central conductive column 4. From the inside to the outside, that is, from the central conductive column 4 to the outside, the central conductive column 4, the conductive tube of the first coaxial conductive tube group 3, the conductive tube of the second coaxial conductive tube group 3, the conductive tube of the first coaxial conductive tube group 3, the conductive tube of the second coaxial conductive tube group 3, ..., the outermost layer of the two groups of coaxial conductive tube groups 3 can be the conductive tube of the first coaxial conductive tube group 3, or the conductive tube of the second coaxial conductive tube group 3, which is not limited in this embodiment. In this embodiment, the central conductive column 4 and the second coaxial conductive tube group 3 can be electrically connected to the upper electrode plate 1, and the first coaxial conductive tube group 3 is connected to the lower electrode plate 2. That is to say, the central conductive column 4 and each conductive tube are radially spaced and electrically connected to the upper electrode plate 1 and the lower electrode plate 2 in an alternating manner.

[0021] In this embodiment, a dielectric layer is provided between the central conductive column 4 and each conductive cylinder, that is, a dielectric layer is provided between the central conductive column 4 and the conductive cylinder of its outer layer and any two adjacent conductive cylinders. The dielectric layer is placed between the upper electrode plate 1 and the lower electrode plate 2, and is mutually attached to the conductive cylinders of the upper electrode plate 1 and the lower electrode plate 2. The material of the dielectric layer can select the corresponding dielectric according to the required capacitance. The central conductive column 4 and each conductive cylinder are electrically connected to the upper and lower electrode plates respectively, and the upper and lower electrode plates are connected to the high voltage and the ground respectively. The central conductive column 4 and the conductive cylinder and the two adjacent conductive cylinders are respectively charged with positive and negative charges. Since the central conductive column 4 and the conductive cylinder and the two adjacent conductive cylinders are very close, the charges have a strong attraction to each other, so that the charges can be stored on the two central conductive columns 4 and the conductive cylinder and the two adjacent conductive cylinders, and are isolated by the dielectric layer. In this embodiment, the dielectric layer can be made of mica material, and of course other materials can also be used. There is no limitation on it in this embodiment. The two groups of coaxial conductive tube sets 3 have the same height, and the height of the central conductive column 4 is higher than the height of the coaxial conductive tube sets 3 .

[0022] The insulating support member 5 is arranged between the upper plate 1 and the lower plate 2, and the insulating support member 5 is sleeved on the outside of the two groups of coaxial conductive cylinder groups 3, so that a sealed cavity is formed between the upper plate 1 and the lower plate 2, so as to perform electrolysis in the sealed cavity. Specifically, the insulating support member 5 can be a thin-walled cylinder of an insulating material, the outer diameter of the cylinder is the same as the size of the upper and lower plates, and the height of the cylinder is adapted to the cylinder after the upper and lower plates and the dielectric layer are combined. In other words, the outer wall of the insulating support member 5 is flush with the outer wall of the upper plate 1 and the lower plate 2, and the three form a cylindrical structure. The two ends of the insulating support member 5 are detachably connected to the upper plate 1 and the lower plate 2, for example, the two ends of the insulating support member 5 are respectively connected to the upper plate 1 and the lower plate 2 by screws. Of course, it can also be connected in other ways. In this embodiment, the top and bottom of the insulating support member 5 are provided with threaded holes, which are fastened to the upper and lower plates by screws.

[0023] The input terminal connector 6 is electrically connected to the upper plate 1 and is used to connect the high voltage arm of the voltage divider to input voltage to the upper plate 1. Specifically, one end of the input terminal connector 6 (such as Figure 2 The bottom end shown in the figure) can be mounted on the top wall of the upper plate 1 (relative to the Figure 2 As for the position shown), and the other end of the input terminal connector 6 (as Figure 2 The top end shown in the figure can be connected to the high-voltage arm of the voltage divider used in conjunction with the input terminal 6 to input high voltage. The input terminal connector 6 can be coaxially arranged with the upper plate 1. The input terminal connector 6 can be fixedly mounted on the upper plate.

[0024] The shielding end 71 of the output terminal 7 is electrically connected to the lower electrode plate 2, and the signal end 72 of the output terminal 7 is electrically connected to the other end of the central conductive column 4 (such as Figure 2 The output terminal 7 is electrically connected to the bottom end of the upper plate 1 and the lower plate 2, and is used to obtain the voltage difference between the upper plate 1 and the lower plate 2, and output the voltage difference to obtain the voltage value at both ends of the capacitor. Specifically, the output terminal 7 can be a coaxial output terminal, which can be fixed to the bottom wall of the lower plate 2 by screws, and the shielding end of the output terminal 7, i.e., the ground, is electrically connected to the lower plate 2, and the signal end of the output terminal 7, i.e., the core, is electrically connected to the central conductive column 4 of the upper plate 1. Among them, the output terminal 7 can be fixedly mounted on the lower plate 2.

[0025] In this embodiment, the capacitance of the low voltage arm capacitor is determined by the spacing and length of the conductive tubes. Figure 2 The height, number and material of the dielectric layer shown are determined by the low-voltage arm capacitors of different sizes and capacitances that can be designed through simulation calculations, and can be flexibly selected based on the required capacitance and size of the device.

[0026] In this embodiment, if Figure 2 As shown, the top of the central conductive column 4 and the second coaxial conductive cylinder group 3 can be connected to the bottom wall of the upper plate 1, and the three can be an integrated structure to form an upper plate assembly, which can collect charges, and there is a gap between the bottom end of the second coaxial conductive cylinder group 3 and the lower plate 2; the bottom end of the first coaxial conductive cylinder group 3 can be connected to the top wall of the lower plate 2, and the two can be an integrated structure to form a lower plate assembly, which can collect charges, and there is a gap between the top end of the first coaxial conductive cylinder group 3 and the upper plate 1. Among them, when the upper plate assembly and the lower plate assembly are assembled, the conductive cylinders on the upper plate and the conductive cylinders on the lower plate cross each other to form an equidistant distribution.

[0027] In this embodiment, the central conductive column 4, the second coaxial conductive tube group 3 and the upper electrode plate 1 are arranged vertically and coaxially. The upper electrode plate 1 is provided with mounting through holes corresponding to the threaded holes on the top of the insulating support member 5, so as to realize the connection between the upper electrode plate 1 and the top of the insulating support member 5 by bolts. The top wall of the upper electrode plate 1 may also be provided with mounting threaded holes adapted to the input terminal connector 6, so that the input terminal connector 6 and the upper electrode plate 1 can be connected and fixed by bolts.

[0028] In this embodiment, the first coaxial conductive tube group 3 is arranged vertically and coaxially with the lower electrode plate 2. The lower electrode plate 2 is provided with mounting through holes corresponding to the threaded holes at the bottom of the insulating support member 5, so as to realize the connection between the lower electrode plate 2 and the bottom of the insulating support member 5 by bolts. The bottom wall of the lower electrode plate 2 may also be provided with mounting threaded holes adapted to the output terminal 7, so that the output terminal 7 and the lower electrode plate 2 can be connected and fixed by bolts. The lower electrode plate 2 is provided with a grounding interface for grounding, and the grounding interface can be a threaded interface or other interfaces. The lower electrode plate 2 is also provided with a clearance hole adapted to the central conductive column 4, so that the bottom end of the central conductive column 4 can extend to the clearance hole to realize the connection between the central conductive column 4 and the signal end of the output terminal 7.

[0029] Continue to see Figure 1 and Figure 2 The input terminal connector 6 includes: a connecting flange 61 and a connecting screw 62; wherein the connecting flange 61 is used to be installed on the upper plate 1; the connecting end of the connecting screw 62 is connected to the connecting flange 61, and the connecting screw 62 is used to connect the high-voltage arm of the voltage divider. Specifically, the input terminal connector 6 is a flange structure with a connecting screw 62, and the flange side is installed to the top wall of the upper plate 1 (relative to the upper plate 1) by screws. Figure 2 As for the position shown in the figure), the connecting screw 62 can be connected to the high-voltage arm of the matching voltage divider through a thread to input high voltage.

[0030] The low-voltage arm capacitor provided by the embodiment of the present invention is described in more detail below.

[0031] like Figure 1 and Figure 2As shown, the low-voltage arm capacitor is used as the low-voltage arm of a standard capacitive voltage divider, and the high-voltage arm of the standard capacitive voltage divider is a coaxial capacitor structure with a capacitance C1=10.23pF; the low-voltage arm capacitor includes an upper plate 1, a lower plate 2, two groups of coaxial conductive tubes 3, a central conductive column 4, an insulating support 5, an input terminal connector 6 and an output terminal 7. The upper plate 1 and the lower plate 2 can both be metal discs as parallel conductive plates, and the upper plate 1 and the lower plate 2 are parallel and spaced apart from each other. The two groups of coaxial conductive cylinder groups 3 can have 10 groups of coaxial thin-walled cylinders as conductive cylinders, and the 10 groups of coaxial thin-walled cylinders and the central conductive column 4 are all arranged between the upper electrode plate 1 and the lower electrode plate 2, from the inside to the outside, that is, from the central conductive column 4 to the outside, they are the central conductive column 4, the first coaxial thin-walled cylinder, the second coaxial thin-walled cylinder, ..., the tenth coaxial thin-walled cylinder, wherein the top ends of the central conductive column 4, the second coaxial thin-walled cylinder, the fourth coaxial thin-walled cylinder, the sixth coaxial thin-walled cylinder, the eighth coaxial thin-walled cylinder and the tenth coaxial thin-walled cylinder are connected to the bottom wall of the upper electrode plate 1, and the bottom ends of the first coaxial thin-walled cylinder, the third coaxial thin-walled cylinder, the fifth coaxial thin-walled cylinder, the seventh coaxial thin-walled cylinder and the ninth coaxial thin-walled cylinder are connected to the top wall of the lower electrode plate 1. The effective length of each coaxial thin-walled cylinder is 80mm, and the spacing between the thin-walled cylinders is 2mm. A dielectric layer is provided between the central conductive column 4 and the first coaxial thin-walled cylinder and between two adjacent coaxial thin-walled cylinders. The dielectric layer is made of mica, and its calculated capacitance is C2=8.38nF. The insulating support 5 is a thin-walled cylinder made of insulating material. The outer diameter of the cylinder is the same as the size of the upper and lower plates. The height of the cylinder is adapted to the cylinder after the upper and lower plates and the dielectric layer are combined. Its two ends are fixedly mounted on the upper and lower plates by screws. The input terminal connector 6 is mounted on the top wall of the upper plate 1 by screws. The top of the input terminal connector 6 can be connected to the high-voltage arm of the voltage divider used in conjunction with the input terminal connector 6, and high voltage can be input, that is, the low-voltage arm is connected to the low-voltage electrode of the standard capacitor voltage divider through the input terminal connector 6, and the low-voltage arm is grounded through the grounding terminal of the lower plate of the standard capacitor type low-voltage arm. Output terminal 7 is a coaxial output terminal, which is a BNC female socket, wherein the pin core of the BNC female socket is connected to the upper plate, and the outer layer of the BNC female socket is connected to the lower plate, wherein the voltage difference between the pin core and the outer layer of the BNC female socket is the voltage drop on the standard capacitor in the low-voltage arm. The low-voltage arm capacitor and the high-voltage arm are combined to form a capacitive voltage divider, that is, as a standard capacitive voltage divider, the high-voltage end of the standard capacitive voltage divider is connected to the voltage generator, and the outer shell is grounded. Start the voltage source, and the test voltage is applied to the circuit in series with the high-voltage arm and the low-voltage arm. The voltage value output through the low-voltage arm signal output interface is: ; The output interface of the low voltage arm is connected to the data acquisition unit through a cable. The voltage value displayed by the data acquisition unit is read and the voltage value is multiplied by the scale factor of the standard capacitive voltage divider to obtain the voltage value of the test voltage.

[0032] In summary, the low-voltage arm capacitor provided in this embodiment adopts a coaxial design, and together with the high-voltage coaxial capacitor of the standard capacitor voltage divider, it forms a pure coaxial capacitor loop, which has good stability; the coaxial structure can reduce the self-inductance of the low-voltage arm, so it has a lower inductance, which makes the low-voltage arm more effective in measuring high-frequency voltage signals, because low inductance does not have much impact on high-frequency signals; due to the characteristics of the coaxial structure, the electric field is distributed more evenly between the upper and lower plates, which helps to reduce the non-uniformity of the capacitor, improve its performance and stability, and solve the problem that the capacitor of the existing low-voltage arm uses a patch capacitor, which causes its self-inductance to be large and the inductance to interfere with and affect the signal. By replacing the traditional patch capacitor with the low-voltage arm capacitor, the high and low voltage capacitors of the entire capacitor voltage divider are all standard capacitors. Through this improvement, the performance of the capacitor voltage divider has been significantly improved, especially in the wideband voltage measurement, and more accurate and reliable measurement results have been obtained, which not only improves the performance of the capacitor voltage divider, that is, more accurate and reliable voltage measurement, but also provides reliable technical support for high-performance voltage measurement of new power systems, meeting the needs of new power systems for high-performance voltage sensors. The application of this technology will provide more accurate and reliable data for the monitoring and control of power systems, and promote the further development of power system technology.

[0033] Capacitor voltage divider example: This embodiment also proposes a capacitive voltage divider, on which the above-mentioned low-voltage arm capacitor is provided. The specific implementation process of the low-voltage arm capacitor can be found in the above description, and will not be repeated in this embodiment.

[0034] Since the low-voltage arm capacitor has the above-mentioned effects, the capacitive voltage divider having the low-voltage arm capacitor also has corresponding effects.

[0035] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0036] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A low voltage arm capacitor, characterized in that: include: An upper electrode plate and a lower electrode plate which are arranged parallel to each other and spaced apart from each other, wherein the lower electrode plate is used for grounding; Two groups of coaxial conductive cylinder groups, the two groups of coaxial conductive cylinder groups are staggered and arranged between the upper electrode plate and the lower electrode plate to form a stacked coaxial cylinder structure with equal spacing distribution, the gap between the two groups of coaxial conductive cylinder groups is located between the lower electrode plate and the upper electrode plate, and a dielectric layer is provided, the two groups of coaxial conductive cylinder groups are electrically connected to the upper electrode plate and the lower electrode plate respectively, and a central conductive column is provided inside the coaxial cylinder structure, one end of which is electrically connected to the upper electrode plate; An insulating support member is disposed between the upper electrode plate and the lower electrode plate, and the insulating support member is sleeved outside the two groups of coaxial conductive tube groups to form a sealed cavity between the upper electrode plate and the lower electrode plate; An input terminal connector, the input terminal connector is electrically connected to the upper plate and is used to connect the high voltage arm of the voltage divider to input voltage to the upper plate; An output terminal, wherein the grounding end of the output terminal is electrically connected to the lower electrode plate, and the connecting wire of the output terminal is electrically connected to the other end of the central conductive column, for obtaining the voltage difference between the upper electrode plate and the lower electrode plate.

2. The low voltage arm capacitor according to claim 1, characterized in that: The connecting end of one group of the coaxial conductive tube groups is connected to the upper electrode plate, and there is a gap between the free end of the coaxial conductive tube group and the lower electrode plate; The connecting end of another group of the coaxial conductive tube groups is connected to the lower electrode plate, and a gap is provided between the free end of the coaxial conductive tube group and the upper electrode plate.

3. The low voltage arm capacitor according to claim 1 or 2, characterized in that: The input terminal connector comprises: A connecting flange, used for mounting on the upper plate; A connecting screw, a connecting end of which is connected to the connecting flange, and the connecting screw is used to connect the high-voltage arm of the voltage divider.

4. The low voltage arm capacitor according to claim 1 or 2, characterized in that: The coaxial conductive tube set comprises a plurality of conductive tubes which are sequentially sleeved from the inside to the outside and arranged at intervals.

5. The low voltage arm capacitor according to claim 1 or 2, characterized in that: The outer wall of the insulating support is flush with the outer walls of the upper plate and the lower plate, and the three form a cylindrical structure; Two ends of the insulating support are detachably connected to the upper electrode plate and the lower electrode plate respectively.

6. The low voltage arm capacitor according to claim 1 or 2, characterized in that: The input terminal connector is mounted on the upper plate, and the output terminal is mounted on the lower plate.

7. The low voltage arm capacitor according to claim 1 or 2, characterized in that: The upper electrode plate and the lower electrode plate are disc structures, and the upper electrode plate, the lower electrode plate and the two groups of coaxial conductive tube groups are all coaxially arranged.

8. The low voltage arm capacitor according to claim 1 or 2, characterized in that: The upper electrode plate, the lower electrode plate and the coaxial conductive tube set are all made of metal.

9. The low voltage arm capacitor according to claim 1 or 2, characterized in that: A grounding interface is provided on the lower electrode plate.

10. A capacitive voltage divider, characterized in that: A low-voltage arm capacitor as claimed in any one of claims 1 to 9 is provided.

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