Metering voltage transformer with multi-layer shielding insulation structure

Abstract

The utility model discloses a metering voltage transformer with a multi-layer shielding insulation structure, which comprises a voltage transformer body, an external shielding insulation assembly is covered outside the voltage transformer body, and the external shielding insulation assembly comprises three concentrically embedded shielding covers. The corresponding outer walls and inner walls of every two adjacent shielding cases are fixedly connected through a plurality of insulating connecting pieces, an insulating cavity is formed between every two adjacent shielding cases, through holes are coaxially formed in the corresponding positions of the inner wall of one side of each shielding case, grounding guide rods are arranged in the three through holes, and the grounding guide rods are connected with the insulating cavities through the insulating connecting pieces. The grounding guide rod penetrates through all the shielding cases, through the external shielding insulation assembly, under the conditions that multiple layers of shielding cases cooperate in a division mode and shielding electromagnetic interference and shielding effectiveness are not reduced, structural transformation of the interior of the mutual inductor can be avoided, installation is easy and convenient, and design and manufacturing difficulty is reduced; parts are convenient to check and replace during later maintenance, and cost and time are reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of electric power equipment, and particularly to a metering voltage transformer of multilayer shielding insulation structure. BACKGROUND

[0002] In the power system, the accurate measurement of the metering voltage transformer is crucial for the energy metering and the stable operation of the power system. In order to reduce the influence of external electromagnetic interference on the measurement accuracy of the metering voltage transformer and ensure its electrical insulation performance, the existing technical means usually add conductive shielding layers and insulation layers inside the metering voltage transformer. However, this method has many drawbacks. On the one hand, the limited space layout inside the voltage transformer needs to be fully considered, and even the internal structure of the voltage transformer may need to be modified, which not only increases the design and manufacturing difficulty, but also may affect the original performance and structural stability of the voltage transformer. On the other hand, the material performance of these conductive shielding layers and insulation layers is easily affected by environmental factors such as temperature and humidity. Under different environmental conditions, the conductivity, insulation and other properties of the material may change, resulting in a decrease in shielding and insulation effect, and reducing the reliability of the entire system. In addition, during the later maintenance and repair process, due to the limited operation space inside the transformer, the maintenance work is difficult, and the maintenance cost and time cost are increased.

[0003] How to invent a metering voltage transformer of multilayer shielding insulation structure to improve these problems has become a problem that needs to be solved by technicians in the field. CONTENT OF THE UTILITY MODEL

[0004] In order to make up for the above shortcomings, the utility model provides a metering voltage transformer of multilayer shielding insulation structure, aiming at improving the problem that the shielding and insulation protection structure of the existing metering voltage transformer is mostly set inside, which increases the design and manufacturing difficulty, may affect the original performance and structural stability of the voltage transformer, and is not convenient for later maintenance and repair.

[0005] The utility model is realized as follows: a metering voltage transformer of multilayer shielding insulation structure, comprising a voltage transformer body, an external shielding insulation assembly is covered outside the voltage transformer body, the external shielding insulation assembly comprises three concentric embedded shielding covers, and the outer wall and the inner wall corresponding to the adjacent two shielding covers are fixedly connected through a plurality of insulation connecting pieces, and then an insulation cavity is formed between the adjacent two shielding covers, a through hole is coaxially arranged at the corresponding position of one side inner wall of each shielding cover, a grounding guide rod is arranged in the three through holes, and the grounding guide rod penetrates all the shielding covers.

[0006] In the preferred technical scheme of the utility model, three shielding covers are respectively inner shielding cover, middle shielding cover and outer shielding cover from inside to outside, and a plurality of irregular electromagnetic shielding teeth are integrally arranged on each side outer wall of the inner shielding cover, the middle shielding cover and the outer shielding cover.

[0007] In the preferred technical scheme of the utility model, each electromagnetic shielding tooth is trapezoidal cross section structure.

[0008] In the preferred technical scheme of the utility model, the outer shielding cover opening is integrally formed with the connecting frame for installing the voltage transformer body.

[0009] In the preferred technical scheme of the utility model, the insulation cavity spacing between the middle shielding cover and the outer shielding cover is greater than the insulation cavity spacing between the middle shielding cover and the inner shielding cover.

[0010] In the preferred technical scheme of the utility model, the ground lead outer wall is provided with three groups of elastic contact pieces corresponding to three through holes, and is fixedly connected with the inner wall of each through hole through the elastic contact pieces.

[0011] In the preferred technical scheme of the utility model, the number of each group of elastic contact pieces is at least three and is fixedly connected in annular uniform distribution on the outer wall of the ground lead, and each elastic contact piece is arc V-shaped structure.

[0012] The utility model discloses a kind of multi-layer shielding insulation structure's measurement voltage transformer, and the beneficial effects are as follows: when using, through the shielding insulation component of external, it can be in multi-layer shielding cover cooperation, without reducing shielding electromagnetic interference and shielding effectiveness, it can also avoid structural modification to the inside of mutual inductor, installation is simple, reduce design manufacturing difficulty;When maintaining later, it is convenient to check and replace component, reduce cost and time. BRIEF DESCRIPTION OF DRAWINGS

[0013] In order to more clearly illustrate the technical scheme of the embodiments of the utility model, the following will be briefly introduced to the drawings needed to be used in the embodiments, and should be understood that the following drawings only show some embodiments of the utility model, and should not be regarded as the limitation to the scope, for ordinary skilled person in the art, other related drawings can also be obtained according to these drawings without creative labor.

[0014] Figure 1 It is the overall structure schematic perspective drawing provided by the embodiment of the utility model;

[0015] Figure 2 It is the overall sectional structure schematic perspective drawing provided by the embodiment of the utility model.

[0016] Figure 3 The overall cross-section structure schematic perspective view of the external shielding insulation assembly provided by the utility model embodiment is shown in the figure.

[0017] Figure 4 The external shielding insulation assembly provided by the utility model embodiment is shown in the figure. Figure 3 The overall structure schematic perspective view of the enlarged A part is shown in the figure.

[0018] In the figure, 1 is a voltage transformer body; 2 is an inner shielding cover; 3 is a middle shielding cover; 4 is an outer shielding cover; 401 is a connecting frame; 5 is an insulation connecting piece; 6 is an insulation cavity; 7 is an electromagnetic shielding tooth; 8 is a grounding rod; 801 is an elastic contact piece. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical scheme and advantages of the utility model embodiments clearer, the technical scheme in the utility model embodiments will be described clearly and completely below in combination with the drawings in the utility model embodiments. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the utility model.

[0020] Referring to Figures 1 to 4 The utility model provides a kind of technical scheme: a multilayer shielding insulation structure's measurement voltage transformer, including voltage transformer body 1, voltage transformer body 1 is covered with external shielding insulation assembly, external shielding insulation assembly includes three concentric embedded shielding cover, and the outer wall between corresponding adjacent two shielding covers and inner wall is fixedly connected by several insulation connecting pieces 5, and then the insulation cavity 6 is formed between adjacent two shielding covers, the through hole is coaxially set in each shielding cover side inner wall corresponding position, three through holes are provided with grounding rod 8, and grounding rod 8 penetrates all shielding covers.

[0021] Referring to Figures 2 to 4 Three shielding covers are inner shielding cover 2, middle shielding cover 3 and outer shielding cover 4 from inside to outside, and inner shielding cover 2, middle shielding cover 3 and outer shielding cover 4 are integrally provided with several irregularly distributed electromagnetic shielding teeth 7 on each side outer wall.

[0022] The inner shielding cover 2, the middle shielding cover 3 and the outer shielding cover 4 can be made of metal materials with good electrical conductivity and magnetic conductivity, such as aluminum alloy, copper alloy, ferromagnetic alloy, etc. The inner shielding cover 2 is closest to the voltage transformer body 1 and is mainly responsible for shielding high-frequency electromagnetic radiation from the internal circuit of the voltage transformer body 1. During the operation of the voltage transformer body 1, the internal windings, iron core and other components will generate high-frequency electromagnetic signals. If these signals are not shielded, they may interfere with the surrounding electronic components and affect the measurement accuracy. The inner shielding cover 2 uses its good electrical conductivity to guide the induced current generated by the high-frequency electromagnetic signals to the grounding rod 8, thereby achieving shielding of high-frequency electromagnetic interference. The middle shielding cover 3 is between the inner shielding cover 2 and the outer shielding cover 4. It can further shield the high-frequency electromagnetic interference that the inner shielding cover 2 fails to completely shield, and also plays a certain shielding role against low-frequency magnetic field interference from the outside. For some high-frequency electromagnetic signals that leak out through the inner shielding cover 2, the middle shielding cover 3 can absorb and conduct them again; at the same time, for the external low-frequency magnetic field, the material and structure of the middle shielding cover 3 can also block and attenuate it to a certain extent. The outer shielding cover 4 is the outermost layer of the shielding structure and is mainly responsible for shielding various electromagnetic interferences from the external environment, including electromagnetic radiation from other electrical equipment, radio waves, etc. External electromagnetic interference can have a great impact on the measurement results of the voltage transformer. The outer shielding cover 4 blocks the external electromagnetic signals by its good electrical conductivity and magnetic conductivity, protecting the internal circuit of the voltage transformer from interference. The irregularly distributed electromagnetic shielding teeth 7 make the propagation of electromagnetic signals on the surface of the shielding cover more complex, increasing the number of reflection and refraction of electromagnetic signals, thereby more effectively consuming electromagnetic energy and improving shielding effectiveness.

[0023] Further, each electromagnetic shielding tooth 7 is in a trapezoidal cross-sectional structure.

[0024] The trapezoidal cross-sectional electromagnetic shielding tooth 7 can guide electromagnetic signals to reflect and refract in different directions, making electromagnetic energy more dispersed, thereby more effectively reducing the strength of electromagnetic signals and improving shielding effect. Compared with other shapes of cross-section, the trapezoidal cross-section has better mechanical properties, which can increase the structural stability of the electromagnetic shielding tooth and reduce the possibility of damage due to external force during use.

[0025] Further, the outer shielding cover 4 is integrally formed with a connecting frame 401 at the edge of the opening for mounting with the voltage transformer body 1.

[0026] In the processing of the outer shielding cover 4, the connecting frame 401 is integrally formed at the opening edge. The mounting hole is formed on the connecting frame 401, and the outer shielding cover 4 is fixedly connected with the voltage transformer body 1 by using the connecting member such as bolt. During the installation process, the sealing gasket can be added at the connecting position to improve the sealing performance of the connection. The setting of the connecting frame 401 provides convenience for the installation of the outer shielding cover 4 and the voltage transformer body 1, simplifies the installation process, and improves the installation efficiency.

[0027] Further, the interval of the insulation cavity 6 between the middle shielding cover 3 and the outer shielding cover 4 is greater than the interval of the insulation cavity 6 between the middle shielding cover 3 and the inner shielding cover 2.

[0028] According to the distribution rule of the electric field between the shielding covers, the outer electric field strength is relatively large. Appropriately increasing the interval of the insulation cavity 6 between the middle shielding cover 3 and the outer shielding cover 4 can better withstand the electric field pressure, reduce the risk of breakdown, and optimize the electric field distribution of the entire shielding insulation structure. The insulation cavities 6 with different intervals can form a gradient insulation effect, enhance the insulation performance of the entire shielding insulation structure, and improve the reliability and safety of the measuring voltage transformer.

[0029] Further, the outer wall of the grounding rod 8 is provided with three groups of elastic contact pieces 801 corresponding to the positions of the three through holes, and is fixedly connected with the inner walls of the three through holes through the elastic contact pieces 801, respectively.

[0030] The elastic contact pieces 801 are made of phosphor bronze sheets with good elasticity and conductivity, and the outer wall thereof is silver-plated to reduce the contact resistance and improve the conductivity and corrosion resistance. The elastic contact pieces 801 are processed into the required shape and size by stamping or mechanical processing. The three groups of elastic contact pieces 801 are installed and fixed at the positions corresponding to the three through holes on the outer wall of the grounding rod 8. During the installation, the elastic contact pieces 801 and the grounding rod 8 and the elastic contact pieces 801 and the inner walls of the through holes are ensured to have good contact, and appropriate contact pressure is applied. During the operation of the voltage transformer body 1, the voltage transformer body 1 may be affected by external factors such as vibration. The elasticity of the elastic contact pieces 801 can provide buffering during vibration to prevent the contact position from loosening due to vibration and to ensure that the equipotential connection between the shielding covers can still be reliably achieved in a vibrating environment. The silver-plated outer wall and the appropriate contact pressure can effectively reduce the contact resistance between the elastic contact pieces 801 and the grounding rod 8 and the inner walls of the shielding cover through holes, ensure smooth conduction of electric charges, and improve the stability and reliability of the equipotential connection.

[0031] Further, the number of each group of elastic contact pieces 801 is at least three, and the elastic contact pieces 801 are uniformly distributed and fixedly connected in a ring shape on the outer wall of the grounding rod 8. Each elastic contact piece 801 is in an arc V-shaped structure.

[0032] The elastic contact piece 801 is processed into an arc V-shaped structure. The curvature of the arc surface and the angle of the V-shaped structure are ensured to ensure that the elastic contact piece 801 can provide appropriate elasticity and contact pressure. At least three elastic contact pieces 801 in each group and annular uniform distribution increase the contact points of the grounding guide rod 8 and the inner wall of the shielding cover hole, making the current conduction more uniform, reducing the risk of local overheating and poor contact, and improving the reliability of equipotential connection. The arc V-shaped structure of the elastic contact piece 801 can better adapt to different assembly conditions and vibration environments. During assembly, the arc surface structure can better fit the inner wall of the hole, and the V-shaped structure provides good elastic deformation capability and can automatically adjust the contact state during vibration to ensure the stability of the contact.

[0033] Working principle: When the voltage transformer body 1 works to generate high-frequency electromagnetic radiation, or external electromagnetic interference exists, the outer shielding cover 4 first blocks the external electromagnetic signal, and the surface electromagnetic shielding tooth 7 increases signal reflection and refraction energy consumption. Part of the signal that breaks through is shielded again by the middle shielding cover 3 to block the low-frequency magnetic field, and the electromagnetic shielding tooth 7 assists to improve the effect. The inner shielding cover 2 aims at the high-frequency radiation inside the transformer body 1, and the induced current is led out through the grounding guide rod 8. In terms of insulation, the insulating connecting piece 5 between adjacent shielding covers and the insulating cavity 6 realize electrical isolation, and the large spacing insulating cavity 6 between the middle layer and the outer layer optimizes the electric field distribution. The grounding guide rod 8 ensures the equipotential connection of each shielding cover through the elastic contact piece 801, and guarantees the overall electromagnetic shielding and insulation performance.

[0034] It should be noted that the specific model and specifications of the voltage transformer body 1 need to be selected and determined according to the actual specifications of the device, and the specific selection calculation method uses the existing technology in the art, so it will not be described in detail.

[0035] The power supply of the voltage transformer body 1 and its principle are clear to those skilled in the art, and will not be described in detail here.

[0036] The above only describes preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can be changed and varied. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A multi-layer shielded insulation structure for metering voltage transformers, comprising a voltage transformer body, wherein the voltage transformer body is externally covered with an external shielding insulation assembly, characterized in that, The external shielding insulation assembly includes three concentrically embedded shielding covers, and the outer and inner walls of two adjacent shielding covers are fixedly connected by several insulating connectors, thereby forming an insulating cavity between two adjacent shielding covers. Each shielding cover has a through hole coaxially opened on one side of its inner wall at a corresponding position, and a grounding rod is installed in the three through holes. The grounding rod passes through all the shielding covers.

2. The metering voltage transformer with a multi-layer shielded insulation structure as described in claim 1, characterized in that: The three shielding covers, from the inside out, are an inner shielding cover, a middle shielding cover, and an outer shielding cover. Each of the inner shielding cover, the middle shielding cover, and the outer shielding cover has a number of irregularly distributed electromagnetic shielding teeth integrally provided on the outer wall of each side.

3. The metering voltage transformer with a multi-layer shielded insulation structure as described in claim 2, characterized in that: Each of the electromagnetic shielding teeth has a trapezoidal cross-section structure.

4. The metering voltage transformer with a multi-layer shielded insulation structure as described in claim 2, characterized in that: The outer shield has an integrally formed connecting frame around its opening for mounting to the voltage transformer body.

5. The metering voltage transformer with a multi-layer shielded insulation structure as described in claim 2, characterized in that: The spacing between the insulating cavities of the middle shield and the outer shield is greater than the spacing between the insulating cavities of the middle shield and the inner shield.

6. The metering voltage transformer with a multi-layer shielded insulation structure as described in claim 1, characterized in that: The outer wall of the grounding rod is provided with three sets of elastic contact pieces corresponding to the three through holes, and each set is fixedly connected to the inner wall of each through hole through the elastic contact pieces.

7. The metering voltage transformer with a multi-layer shielded insulation structure as described in claim 6, characterized in that: Each group of elastic contact pieces consists of at least three pieces, which are evenly distributed in a ring and fixedly connected to the outer wall of the grounding conductor. Each elastic contact piece has an arc-shaped V-shaped structure.

Images