A ring-shaped capacitive voltage sensor structure

Abstract

The present invention relates to the field of electronic components, and particularly to a parallel structure of high-voltage ceramic capacitor chips. The structure includes at least two ceramic capacitor chips; one end electrode of the ceramic capacitor chips is conductively fixedly connected, and the connection point is the high-voltage input end; the other end electrode is conductively fixedly connected to an external metal connector, and the external metal connector is the low-voltage output end; the ceramic capacitor chips are connected in parallel and are evenly distributed inside the external metal connector. The external metal connector plays a shielding role for the ceramic capacitor chips, enabling the ceramic capacitor chips to generate a uniformly distributed electric field when used in a high-voltage smart grid, thereby reducing the interference with the transmitted signal, and reducing the interference effect of the stray capacitance generated by the cables and other measuring devices connected to the ceramic capacitor chips on the ceramic capacitor chips, ensuring the stability of the voltage signal.

Description

Technical Field

[0001] The present invention relates to the field of electronic components, and particularly to a parallel structure of high-voltage ceramic capacitor chips. Background Art

[0002] Ceramic capacitor chips are generally in the form of flakes or cylinders. They are formed and sintered with ceramic materials as the dielectric, then conductive layers are coated on both ends, electrodes are set on the conductive layers, and then encapsulated with insulating resin. The electrodes, as the lead-out ends of the ceramic capacitor chips, are connected to the external circuit. High-voltage ceramic capacitor chips are generally used in the power industry and can play roles such as metering, measurement, voltage division, energy storage, etc. Currently, a kind of high-voltage ceramic capacitor chip used in high-voltage smart grids includes a ceramic capacitor chip. Conductive layers are coated on both ends of the ceramic capacitor chip. The conductive layers are generally formed by coating silver paste and then sintering. Electrodes are set at the central parts of the conductive layers. The electrode structure generally includes a circular base in contact with the conductive layer. Then, an insulating resin layer is cast outside the ceramic capacitor chip and the electrodes. After casting, only one end of the electrode connection part is exposed outside the insulating resin layer to facilitate connection with the external circuit. This type of ceramic capacitor chip is used in high-voltage smart grids and can be used as functions such as zero-sequence capacitor, phase-sequence capacitor, power-taking capacitor, etc. Currently, when the ceramic capacitor chip is used as a zero-sequence capacitor, one end of the capacitor is respectively connected in parallel to the three-phase high-voltage busbars, and the other end is installed at the zero-sequence measurement end of the distribution switch monitoring terminal (hereinafter referred to as "FTU"). When the power supply is normal, there is no voltage output from the capacitor. When a certain phase of the busbar has a ground short circuit, a voltage signal is output to the subsequent FTU terminal, and the fault location point is displayed on the computer screen while power-off protection is performed; when the ceramic capacitor chip is used as a phase-sequence capacitor, one end of the capacitor is respectively connected in parallel to the three-phase high-voltage busbars, and the other end is installed at the phase-sequence measurement end of the FTU terminal. When the power supply is normal, the low-voltage end of the capacitor outputs a voltage of about 1.732V to the FTU terminal. The terminal can accurately measure the voltage value of the high-voltage busbar through the detected extremely low voltage value and rated ratio operation; when the ceramic capacitor chip is used as a power-taking capacitor, one end of the capacitor is respectively connected in parallel to the three-phase high-voltage busbars, and the other end is connected to the high-voltage-side electronic device to provide power for it. Phase-sequence, zero-sequence capacitors or power-taking capacitors increase the capacitance value when connected in parallel and increase the breakdown voltage when connected in series. When the ceramic capacitor chip is used for the above purposes, its electrical performance is stable and it works reliably, but there are still some defects. During actual use, due to the uneven electric field distribution of this type of ceramic capacitor chip, the interference to the transmission signals of the smart grid is relatively large, which will cause the transmission signals to be distorted and cannot meet the accuracy requirements of the smart grid for transmission signals. The signals and power at the power output end are unstable; at the same time, because the capacitance of the ceramic capacitor chip used in the smart grid itself is very small, and the stray capacitance generated by the cables of the FTU terminal and other measuring devices is relatively large and extremely unstable, these stray capacitances seriously interfere with the ceramic capacitor chip, resulting in unstable characteristics of the ceramic capacitor chip. Therefore, how to make the electric field generated by the ceramic capacitor chip evenly distributed during use to reduce the interference to the transmitted signals, and reduce the interference effect of the stray capacitance generated by the connecting cables and other measuring devices on the ceramic capacitor chip has become an urgent technical problem to be solved. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to generate a uniformly distributed electric field when a ceramic capacitor chip is used in a high-voltage smart grid, thereby reducing the interference with the transmitted signal, and reducing the interference effect of the stray capacitance generated by the cable and other measuring devices connected to the ceramic capacitor chip on the ceramic capacitor chip.

[0004] To solve the above technical problem, the technical solution provided by the present invention is a ring-shaped capacitive voltage sensor structure, which includes at least two ceramic capacitor chips. One end electrode of the ceramic capacitor chip is conductively fixedly connected, and the connection part is the high-voltage input end; the other end electrode is conductively fixedly connected to an external metal connector, and the external metal connector is the low-voltage output end; the ceramic capacitor chips are connected in parallel and evenly distributed inside the external metal connector, and the external metal connector shields the ceramic capacitor chips.

[0005] The external metal connector is a hollow tubular structure or a hollow ring-shaped structure.

[0006] The ring-shaped capacitive voltage sensor structure can also be provided with a central metal connector. The high-voltage input end is the central metal connector, and the ceramic capacitor chips are conductively fixedly connected to the central metal connector. The ceramic capacitor chips are evenly distributed between the central metal connector and the external metal connector.

[0007] Preferably, the height of the external metal connector is 4 mm to 20 mm greater than the diameter of the ceramic capacitor chip.

[0008] The central metal connector is a hollow tubular or hollow ring-shaped structure with a height greater than the diameter of the ceramic capacitor chip. The hollow tubular or hollow ring-shaped structure and the external metal connector make the electric field of the ceramic capacitor chips evenly distributed. Preferably, the height of the hollow tubular or hollow ring-shaped structure is 4 mm to 20 mm greater than the diameter of the ceramic capacitor chip.

[0009] The central metal connector can also be a rod-shaped structure, and at least one end of the rod-shaped structure is provided with a threaded inner hole along its length direction. Preferably, the height of the rod-shaped structure is 4 mm to 20 mm greater than the diameter of the ceramic capacitor chip.

[0010] The central metal connector can also be a ring-shaped structure, and the ring-shaped structure is fixedly connected to a metal nut through a metal connecting wire.

[0011] An extraction component is fixedly connected to the outer wall of the external metal connector, and the extraction component can be a metal connecting wire, a metal connecting piece or a combination of the two.

[0012] Preferably, the external metal connector and the central metal connector are circular.

[0013] The beneficial effects of the present invention are as follows:

[0014] This structure uses an external metal connector to shield the stray capacitance generated by the cables of the power distribution switch monitoring terminal connected to the ceramic capacitor chip and other measuring devices, making up for the deficiency that the ceramic capacitor chip is vulnerable to clutter interference due to its small capacitance value and weak voltage signal.

[0015] When the central metal connector of this structure is a hollow tubular or hollow ring-shaped structure, the inner hole of the hollow tubular or hollow ring-shaped structure serves as the mounting bracket for the entire sensor structure. The high-voltage bus passes through the inner hole and makes contact conduction with the central metal connector, and the central connector becomes the high-voltage input end of this structure. The inner hole of the hollow tubular or hollow ring-shaped structure effectively shields the electromagnetic interference generated by the high-voltage bus on the ceramic capacitor chip.

[0016] At the same time, the central metal connector and the external metal connector of the hollow tubular or hollow ring-shaped structure wrap the ceramic capacitor chip, which not only shields the ceramic capacitor chip and reduces the partial discharge value, but also plays a voltage equalization role, making the electrode facing area at both ends of the ceramic capacitor chip the complete conductive layer area, avoiding the electric field interference caused by the uneven electric field due to the possible misalignment of the electrodes at both ends when only using the ceramic capacitor chip, ensuring the stability of the voltage signal, and improving the overall safety performance.

[0017] When this structure is in use, it does not need to change the original installation design of the smart grid and can be directly installed in the existing smart grid. Brief Description of the Drawings

[0018] Figure 1 is a three-dimensional schematic diagram of the present invention;

[0019] Figure 2 is an assembled structure schematic diagram of the present invention;

[0020] Figure 3 is a schematic diagram of the hollow tubular structure;

[0021] Figure 4 is a schematic diagram of the hollow ring-shaped structure;

[0022] Figure 5 is a schematic diagram of the rod-shaped structure;

[0023] Figure 6 is a schematic diagram of the ring-shaped structure;

[0024] Figure 7 is a schematic diagram of the structure without a central metal connector in the fourth embodiment. Detailed Description of the Invention

[0025] For the above technical solutions, preferred embodiments are now given and specifically described in conjunction with the drawings.

[0026] Example 1:

[0027] Refer to Figures 1 to 4 。

[0028] In this embodiment, the structure of the ring-shaped capacitive voltage sensor includes three ceramic capacitive chips 2, which are evenly distributed and connected to the outer periphery of the hollow tubular central metal connector 1. The first electrode 21 of the ceramic capacitive chip 2 is electrically and fixedly connected to the central metal connector 1, and the second electrode 22 is electrically and fixedly connected to the hollow ring-shaped external metal connector 3. The ceramic capacitive chips 2 are connected in parallel through the central metal connector 1 and the external metal connector 3. The ceramic capacitive chips 2 are evenly distributed between the central metal connector 1 and the external metal connector 3. The external metal connector 3 shields the ceramic capacitive chips 2. The central metal connector 1 is the high-voltage input end of this structure, and the external metal connector 3 is the low-voltage output end of this structure.

[0029] In this embodiment, the number of ceramic capacitive chips 2 is three, which are circular sheet structures and are formed and sintered by using electronic ceramic materials. On both circular end faces of the ceramic capacitive chip 2, a conductive layer 20 with a certain thickness is evenly coated. The material of the conductive layer 20 is generally silver. Electrodes are respectively soldered at the central parts of the conductive layer 20, including a first electrode 21 and a second electrode 22. The first electrode 21 is a metal insert; the second electrode 22 is a combination of the same metal insert 221 as the first electrode 21 and a metal connecting wire 222 connected by welding. The first electrode 21 can also be a single metal connecting wire 222 or a combination of a metal insert 221 and a metal connecting wire 222 connected by welding. The second electrode 22 can also be a single metal insert 221 or a metal connecting wire 222 alone. In this embodiment, the metal insert is preferably an insert with a trapezoidal cross-section. The end with a larger outer diameter of the trapezoidal structure insert is welded to the central part of the conductive layer 20, so as to increase the welding contact area between the electrode and the conductive layer 20 and make it firmly fixed.

[0030] The central metal connector 1 can also be a hollow ring-shaped structure. The central metal connectors 1 with a hollow tubular structure and a hollow ring-shaped structure are preferably circular structures, and the circular structure can play a better role in electric field shielding and uniform electric field. The height of the central metal connector 1 is 6 mm higher than the diameter of the ceramic capacitive chip 2.

[0031] One end of the metal insert of the ceramic capacitor chip 2 with a smaller outer diameter is conductively and fixedly connected to the central part of the outer wall height of the central metal connector 1; if the electrode is a metal connecting wire or a combination of a metal connecting wire and a metal insert, one end of the metal connecting wire is welded to the central part of the outer wall height of the central metal connector 1. The three ceramic capacitor chips 2 are evenly distributed around the outer periphery of the central metal connector 1, forming an axisymmetric structure with the central metal connector 1; the number of ceramic capacitor chips 2 can also be two or more than three, and all the ceramic capacitor chips are evenly distributed around the outer periphery of the central metal connector 1 and form an axisymmetric structure with the central metal connector 1.

[0032] The external metal connector 3 can also be a hollow tubular structure; the external metal connectors 3 with a hollow tubular structure and a hollow ring mesh structure are preferably circular structures, and the circular structure can play a better electric field shielding role. The height of the external metal connector 3 is higher than the diameter of the ceramic capacitor chip 2 by 6 mm. The other end of the metal connecting wire 222 in the second electrode 22 is conductively and fixedly connected to the central part of the inner wall height of the external metal connector 3; if the second electrode 22 is a metal insert, one end of the metal insert with a smaller outer diameter is welded to the central part of the inner wall height of the external metal connector 3. Thus, the three ceramic capacitor chips 2 are evenly distributed between the central metal connector 1 and the external metal connector 3, and form a concentric ring and an axisymmetric structure with the central metal connector 1 and the external metal connector 3, and all the ceramic capacitor chips 2 are in a parallel structure with each other.

[0033] A lead-out component 4 is conductively and fixedly connected to the outer wall of the external metal connector 3, and the lead-out component 4 is formed by welding and combining a metal connecting wire 41 and a metal connecting piece 42. The metal connecting piece 42 is a copper-tin-plated sheet structure and is provided with an installation through hole. During use, a low-voltage wire is conductively and fixedly connected to the installation through hole on the metal connecting piece 42. According to the installation requirements during use, the lead-out component 4 can also be only the metal connecting wire 41, and during use, the low-voltage wire is directly conductively and fixedly connected to the metal connecting wire 41.

[0034] In use, the inner hole of the hollow tubular or hollow ring-shaped central metal connector 1 serves as the mounting bracket for the entire sensor structure. The high-voltage busbar passes through the inner hole and makes contact with the central metal connector 1 to achieve conduction, thereby connecting this structure to the external power grid. The hollow tubular or hollow ring-shaped central metal connector 1 serves as the high-voltage electrode, and the external metal connector 3 serves as the low-voltage electrode. When the lead-out component 4 is connected and conducted to the zero-sequence measurement terminal of the supporting measurement port of the FTU, zero-sequence measurement is achieved; when the lead-out component 4 is connected and conducted to the phase-sequence measurement terminal of the supporting measurement port of the FTU, phase-sequence measurement is achieved; when the lead-out component 4 is connected to the high-voltage side electronic device to provide power extraction for it. The inner hole of the hollow tubular or hollow ring-shaped central metal connector 1 effectively shields the electromagnetic interference generated by the high-voltage busbar on the ceramic capacitor chip 2; the external metal connector 3 shields the stray capacitance generated by the cables of the distribution switch monitoring terminal connected to this structure and other measuring devices, compensating for the deficiency that the ceramic capacitor chip 2 is vulnerable to clutter interference due to its small capacitance value and weak voltage signal. Moreover, the central metal connector 1 and the external metal connector 3 wrap the ceramic capacitor chip 2, which not only shields the ceramic capacitor chip 2 and reduces the partial discharge value, but also plays a voltage equalization role, making the electrode facing area at both ends of the ceramic capacitor chip 2 the complete conductive layer area, avoiding the electric field interference caused by the uneven electric field due to the possible misalignment of the electrodes at both ends when using only the ceramic capacitor chip 2, ensuring the stability of the voltage signal and improving the overall safety performance.

[0035] In use, the number of ceramic capacitor chips 2 is determined according to the requirements for capacitance and withstand voltage during the use in the high-voltage smart grid, and can be two or more than three.

[0036] Embodiment 2:

[0037] See Figure 5 。

[0038] In this embodiment, on the basis of Embodiment 1, the hollow tubular or hollow ring-shaped central metal connector is replaced with a rod-shaped structure.

[0039] In this embodiment, the ring-shaped capacitive voltage sensor structure includes three ceramic capacitor chips 2. Threaded inner holes 11 are provided at the central parts of both ends of the rod-shaped central metal connector 1 along its length direction. According to the user's usage requirements, threaded inner holes 11 can also be provided only at the central part of one end of the rod-shaped central metal connector 1 along its length direction. The height of the rod-shaped central metal connector 1 is 10 mm higher than the diameter of the ceramic capacitor chip 2. The first electrode 21 of the ceramic capacitor chip 2 is welded and fixed at the central part of the height of the rod-shaped central metal connector 1, and the three ceramic capacitor chips 2 are evenly distributed and connected to the outer periphery of the rod-shaped central metal connector 1.

[0040] In use, the middle part of the high-voltage bus of the external smart grid is cut off, and a screw is connected to each of the two broken ends. These two screws are respectively connected in cooperation with the two threaded inner holes 11 at both ends of the rod-shaped central metal connector 1; or a screw is connected to the outermost end of the high-voltage bus of the smart grid, and this screw is connected in cooperation with the threaded inner hole 11 at one end of the rod-shaped central metal connector 1. Thus, high-voltage electricity is input into this structure through the rod-shaped central metal connector 1 to realize the connection between this structure and the external power grid. The external metal connector 3 shields the stray capacitance generated by the cables of the distribution switch monitoring terminal connected to this structure and other measuring devices, making up for the deficiency that the ceramic capacitor chip 2 is vulnerable to clutter interference due to its small capacitance value and weak voltage signal; and the central metal connector 1 and the external metal connector 3 wrap the ceramic capacitor chip 2, which not only shields the ceramic capacitor chip 2 and reduces the partial discharge value, but also plays a voltage equalization role, making the area of the electrodes facing each other at both ends of the ceramic capacitor chip 2 the complete conductive layer area, avoiding the electric field interference caused by the uneven electric field that may occur due to the misalignment of the electrodes at both ends when using only the ceramic capacitor chip 2, ensuring the stability of the voltage signal and improving the overall safety performance.

[0041] Embodiment Three:

[0042] See Figure 6 。

[0043] In this embodiment, on the basis of Embodiment One, the hollow tubular or hollow ring-shaped central metal connector is replaced with a ring-shaped structure.

[0044] In this embodiment, it includes two ceramic capacitor chips 2. The central metal connector 1 is a metal ring 12 formed by winding metal connecting wires. A metal connecting wire 13 is welded to the outside of the metal ring 12, and the other end of the metal connecting wire 13 is welded with a metal nut 14. The first electrode 21 of the ceramic capacitor chip 2 is welded and fixed to the metal ring 12, so that the two ceramic capacitor chips 2 are symmetrically distributed and connected to the outer periphery of the metal ring 12. This structure is cast with an insulating material, and this insulating material is epoxy resin. Only the threaded opening of the metal nut 14 and the mounting through hole of the metal connecting piece 42 are exposed to facilitate the installation connection with the external power grid.

[0045] In use, a screw is connected to the outermost end of the high-voltage bus of the external smart grid, and this screw is connected in cooperation with the metal nut 14. Thus, high-voltage electricity is input into this structure through the ring-shaped central metal connector 1 to realize the connection between this structure and the external power grid. The external metal connector 3 shields the stray capacitance generated by the cables of the distribution switch monitoring terminal connected to this structure and other measuring devices, making up for the deficiency that the ceramic capacitor chip 2 is vulnerable to clutter interference due to its small capacitance value and weak voltage signal.

[0046] Embodiment Four:

[0047] See Figure 7

[0048] Based on the first embodiment, this embodiment does not provide a central metal connector 1. The first electrode 21 of the ceramic capacitor chip 2 is directly conductively fixed and connected, and the connection point 15 is the high-voltage input terminal; the second electrode 22 is welded and fixed to the external metal connector 3, and the external metal connector 3 is the low-voltage output terminal; the ceramic capacitor chips 2 are connected in parallel and evenly distributed inside the external metal connector 3, and the external metal connector 3 shields the ceramic capacitor chips 2; an extraction component 4 is conductively fixed and connected to the outside of the external metal connector 3, and the extraction component 4 is a metal connecting wire 41.

[0049] During use, the high-voltage busbar of the external smart grid is directly conductively fixed and connected to the connection point 15, so that high-voltage electricity is input into this structure through the connection point 15, realizing the connection between this structure and the external power grid.

[0050] In this embodiment, the external metal connector 3 shields the stray capacitance generated by the cables of the power distribution switch monitoring terminal connected to this structure and other measuring devices, making up for the deficiency that the ceramic capacitor chip 2 is vulnerable to clutter interference due to its small capacitance value and weak voltage signal, ensuring the stability of the voltage signal and improving the overall safety performance.

[0051] In all the above embodiments, the conductively fixed connection mentioned is preferably a welded fixed method, and can also be a connection and fixing method such as hinged or riveted.

[0052] This structure is used as an integrated sensor structure as a zero-sequence capacitor, a phase-sequence capacitor, or a power-taking capacitor according to user needs. During use, the number of ceramic capacitor chips 2 is determined according to the requirements for the capacitance and withstand voltage during the use of the high-voltage smart grid, and can also be more than three.

Claims

1. A ring-shaped capacitive voltage sensor structure, characterized in that , including at least two ceramic capacitor chips. One end electrode of the ceramic capacitor chip is conductively and fixedly connected to the central metal connector, and the central metal connector is the high-voltage input end. The central metal connector is a hollow tubular or hollow ring-shaped structure with a height greater than the diameter of the ceramic capacitor chip. The other end electrode of the ceramic capacitor chip is conductively and fixedly connected to the external metal connector, and the external metal connector is the low-voltage output end. The ceramic capacitor chips are connected in parallel and evenly distributed between the central metal connector and the external metal connector. The height of the external metal connector is greater than the diameter of the ceramic capacitor chip, and the external metal connector shields the ceramic capacitor chips. The hollow tubular or hollow ring-shaped structure and the external metal connector make the electric field of the ceramic capacitor chips evenly distributed.

2. The annular capacitive voltage sensor structure according to claim 1, characterized in that The external metal connector is a hollow tubular structure or a hollow ring-shaped structure.

3. The annular capacitance voltage sensor structure according to claim 2, wherein The height of the external metal connector is 4 mm to 20 mm greater than the diameter of the ceramic capacitor chip.

4. The annular capacitive voltage sensor structure according to any one of claims 1 to 3, characterized in that, The height of the central metal connector of the hollow tubular or hollow ring-shaped structure is 4 mm to 20 mm greater than the diameter of the ceramic capacitor chip.

5. The ring-shaped capacitive voltage sensor structure according to claim 4, wherein, A lead-out component is conductively and fixedly connected to the outer wall of the external metal connector.

6. The annular capacitance voltage sensor structure according to claim 5, characterized in that, The external metal connector is circular.

7. The annular capacitive voltage sensor structure according to claim 6, wherein, The central metal connector is circular.

8. The ring-shaped capacitive voltage sensor structure according to any one of claims 5 to 7, characterized in that, The lead-out component is a metal connecting wire, a metal connecting piece, or a combination of the two.

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