A mutual inductor grounding protection device

Abstract

The utility model belongs to grounding guarantee technical field discloses a mutual -inductor grounding guarantee device, including connecting device for connecting ground terminal, and connecting device is connected with guide rod device for making ground terminal and mutual -inductor cover plate form interlock, and guide rod device includes thimble, and the thimble is provided with sliding connection device, and the outside of thimble is provided with stroke groove, and sliding connection device is located inside stroke groove, the utility model discloses can pass through the physical interlock mechanism of ground state and mutual -inductor cover plate state, ensures that mutual -inductor must reliable grounding before opening mutual -inductor cover plate to provide guarantee for the operation safety of mutual -inductor product.

Description

Technical Field

[0001] This utility model relates to the field of grounding protection technology, specifically to a transformer grounding protection device. Background Technology

[0002] Instrument transformers are key equipment in power systems for realizing power metering, voltage measurement, relay protection and automatic control. Their core technology is to use the principle of electromagnetic induction to proportionally convert high voltage and large current on the primary side into standard secondary signals.

[0003] However, a significant and dangerous blind spot exists in the current instrument transformer maintenance process: when measuring parameters such as capacitance and dielectric loss, the grounding connection of the final screen (grounding terminal) of the primary winding must be temporarily disconnected as required. However, after maintenance work is completed, maintenance personnel are highly susceptible to negligence, forgetfulness, or unclear on-site markings, failing to reliably restore this grounding connection. This means that the existing grounding connection method can only guarantee reliable connection after the instrument transformer product has passed factory inspection; it cannot prevent grounding restoration issues after pre-commissioning acceptance testing or maintenance testing. This seemingly minor oversight actually creates a serious safety hazard. When the instrument transformer is reconnected to the grid, an equipotential capacitive voltage divider will form between its primary winding high voltage and the disconnected final screen. This will cause a floating overvoltage of hundreds or even thousands of volts to the ground on the final screen (low-voltage terminal), which should be reliably grounded. This high voltage can cause partial discharge and accelerate the aging of the insulation medium, or even directly and instantly break down the insulation of the final screen leads or secondary terminal box, causing permanent damage to the instrument transformer, or even triggering equipment explosions, single-phase grounding of the power grid, and other serious accidents, severely threatening the safe and stable operation of the power grid.

[0004] It is evident that the existing current transformer structure lacks anti-misoperation protection and relies solely on the most unreliable link of "personnel remembering to restore," which is a technical shortcoming that urgently needs to be addressed in operation and maintenance. Utility Model Content

[0005] The purpose of this utility model is to provide a grounding protection device for current transformers to overcome the problems existing in the prior art. This utility model can ensure that the current transformer must be reliably grounded before the current transformer cover is opened through a physical interlocking mechanism between the grounding state and the current transformer cover state, thereby providing a guarantee for the safe operation of the current transformer product.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A current transformer grounding protection device includes a connecting device for connecting a grounding terminal, and the connecting device is connected to a guide rod device for interlocking the grounding terminal with the current transformer cover plate. Furthermore, the connecting device includes a first connecting piece for connecting the grounding terminal of the coupling capacitor and the grounding terminal of the electromagnetic unit, and the first connecting piece is connected to a second connecting piece for connecting the grounding terminal of the electromagnetic unit, the grounding terminal of the housing, and the guide rod device; Furthermore, the guide rod device includes a ejector pin, on which a sliding connecting device is provided. A stroke groove is provided on the outside of the ejector pin, and the sliding connecting device is located inside the stroke groove. The second connecting piece is connected to the ejector pin. Furthermore, the sliding connection device includes a spring, a buckle, and a pin, wherein the spring is coiled on the outer surface of the ejector pin, and the buckle and pin are disposed on the outside of the ejector pin; Furthermore, the second connecting piece is connected to the end of the ejector pin away from the latch; Furthermore, the buckle is located on the side of the ejector pin, and the pin is located at the rear of the ejector pin; Furthermore, the pin is located at the end of the spring away from the latch; Furthermore, a movable groove is provided on the travel groove, with the pin located at one end of the movable groove and the buckle located at the other end of the movable groove, for the movement of the pin to realize a detachable connection between the pin and the buckle; Furthermore, the width of the movable slot is adapted to the length of the pin and the buckle; Furthermore, the movable groove is L-shaped.

[0007] The above technical solution has the following advantages or beneficial effects: This utility model provides a grounding protection device for a current transformer. Firstly, its core advantage lies in constructing a rigid constraint mechanism of "no grounding, no cover." Through the ingenious cooperation of components such as the pin, travel groove, spring, buckle, and pin in the guide rod device, physical interlocking between the grounding state and the current transformer cover state is achieved. Specifically, when the connecting nut of the grounding terminal (including the coupling capacitor grounding terminal N, the electromagnetic unit grounding terminal X, and the housing grounding terminal) is removed (i.e., in the ungrounded state), the operator must pull the pin outwards, causing the pin to move along the travel groove and eventually embed into the buckle for fixation. During this process, the pin extends vertically, and its excess portion forms a physical obstruction, preventing the current transformer cover of the secondary terminal box from being closed and locked. The aforementioned setup physically mandates that operators must, after completing the test, reliably restore the connection of all grounding terminals, ensuring the pins separate from the latches and the ejector pins return to their spring positions before smoothly closing the transformer cover. This fundamentally eliminates the possibility of the equipment operating in an ungrounded state due to personnel forgetfulness, negligence, or simplified operating procedures. It upgrades the traditional safety management model, which relies on personnel responsibility, to a reliable anti-misoperation model guaranteed by hardware structure, significantly improving the inherent safety level of the equipment. Secondly, the shaped moving slot design provides a clear movement trajectory for the pins, ensuring the reliability and repeatability of the action; the spring provides a stable restoring force, ensuring smooth and accurate switching of interlock states. Finally, through the connecting piece design, this device can simultaneously accommodate and connect the grounding terminals of the coupling capacitor, electromagnetic unit, and housing, covering the key grounding parts of the transformer, significantly improving its applicability. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the structure of a transformer grounding protection device shown in some embodiments of the present invention; Figure 2 This is a front view of the guide rod device shown in some embodiments of the present invention; Figure 3 This is a right view of the guide rod device shown in some embodiments of the present invention; Figure 4 This is a top view of the guide rod device shown in some embodiments of the present invention; In the diagram, 1 is the travel groove; 2 is the spring; 3 is the ejector pin; 4 is the connecting device; 5 is the current transformer cover plate; 6 is the guide rod device; 7 is the buckle; 8 is the pin; and 9 is the moving groove. Detailed Implementation

[0009] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this invention. Therefore, the drawings and description are considered exemplary in nature and not restrictive.

[0010] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0011] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0012] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0013] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0014] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0015] Example: Figure 1 This is a schematic diagram of the structure of a transformer grounding protection device according to some embodiments of the present utility model. The transformer grounding protection device includes a connecting device 4 and a guide rod device 6. The connecting device 4 is used to connect the grounding terminal. The connecting device 4 is connected to the guide rod device 6 to interlock the grounding terminal with the transformer cover plate 5. In some embodiments of this utility model, the connecting device 4 is an integral connecting piece, including a first connecting piece for connecting the grounding terminal N of the coupling capacitor and the grounding terminal X of the electromagnetic unit. The first connecting piece is connected to a second connecting piece for connecting the grounding terminal X of the electromagnetic unit, the grounding terminal of the housing, and the guide rod device 6. During use, the grounding terminal N of the coupling capacitor and the grounding terminal X of the electromagnetic unit need to be connected through the first connecting piece to fix the N and X terminals at zero potential. The grounding terminal X of the electromagnetic unit, the grounding terminal of the housing, and the guide rod device 6 are connected through the second connecting piece.

[0016] Figure 2 This is a front view of the guide rod device shown in some embodiments of this utility model. Figure 3 This is a right view of the guide rod device shown in some embodiments of the present invention. Figure 4 This is a top view of the guide rod device shown in some embodiments of the present utility model. The guide rod device 6 includes a ejector pin 3, a sliding connecting device and a stroke groove 1. The sliding connecting device is disposed on the ejector pin 3, the stroke groove 1 is disposed on the outside of the ejector pin 3, the sliding connecting device is located inside the stroke groove 1, and the second connecting piece is connected to the ejector pin 3. In some embodiments of this utility model, the sliding connection device includes a spring 2, a buckle 7 and a pin 8. The spring 2 is arranged around the outer surface of the ejector pin 3, and the buckle 7 and the pin 8 are arranged on the outside of the ejector pin 3. In some embodiments of this utility model, the second connecting piece is connected to the end of the ejector pin 3 away from the buckle 7; In some embodiments of this utility model, the buckle 7 is disposed on the side of the ejector pin 3, and the pin 8 is disposed on the rear of the ejector pin 3; In some embodiments of this utility model, the pin 8 is located at the end of the spring 2 away from the buckle 7; In some embodiments of this utility model, a movable groove 9 is provided on the travel groove 1, a pin 8 is located at one end of the movable groove 9, and a buckle 7 is located at the other end of the movable groove 9, for the movement of the pin 8 so as to realize the detachable connection between the pin 8 and the buckle 7. In some embodiments of this utility model, the width of the movable groove 9 is adapted to the length of the pin 8 and the buckle 7; In some embodiments of this utility model, the movable groove 9 is L-shaped; This utility model device uses a mechanical structure consisting of spring 2, buckle 7, and pin 3 to ensure that the grounding terminal of the product is in a grounded state before commissioning. This device is mainly used to improve the existing grounding method of the grounding terminal of the current transformer and to improve the shortcomings of the current transformer after maintenance where the grounding terminal of the product is not grounded, thereby providing a guarantee for the reliable grounding of the current transformer product before operation.

[0017] The structure and working principle of this utility model will be further explained below: The purpose of this utility model is to provide a transformer grounding protection device. The grounding protection device is fixed in the secondary output box. The working state of the control selection device pin 3 is used to ensure the grounding of the grounding terminal. When the grounding protection device is in the grounding buckle 7 position, the grounding terminal of the product is in the grounding state, and the transformer cover 5 of the secondary output box can be closed. When the grounding protection device is in the maintenance state, the grounding of the grounding terminal is disconnected, the grounding protection device pin 3 is in the working state, and the transformer cover 5 of the secondary output box cannot be closed.

[0018] Specifically, when using this device, during on-site acceptance and maintenance tests, the connecting nuts at the grounding terminal N of the coupling capacitor, the grounding terminal X of the electromagnetic unit, and the grounding terminal of the housing need to be removed. Then, pull the pin 3 in the guide rod device 6 outwards in the direction perpendicular to the wiring plate (e.g., Figure 2 and Figure 3 As shown, pulling towards the bottom separates the grounding terminal N of the coupling capacitor, the grounding terminal X of the electromagnetic unit, and the grounding terminal of the housing from the connecting device 4 to meet the requirements of the field test. The pulling force drives the pin 3 in the guide rod device 6 to move towards the bottom, that is, the pin 8 moves towards the bottom along the moving groove 9, so that the pin 8 is fixed in the buckle 7 of the stroke groove 1. At this time, the pin 3 extends beyond the outer edge of the secondary terminal box in the vertical direction. At this time, the transformer cover 5 of the secondary terminal box cannot be sealed due to the obstruction of the extended part of the pin 3, so that the grounding terminal and the transformer cover 5 are interlocked.

[0019] When the pin 8 and the buckle 7 are disassembled, the pin 8 returns to its original position under the elastic force of the spring 2, and the transformer cover 5 can be sealed at this time.

[0020] This utility model uses mechanical structures such as spring 2, buckle 7, pin 3, and stroke groove 1 to interlock the grounding terminal of the current transformer with the current transformer cover plate 5 of the secondary terminal box. This ensures that the grounding terminal of the current transformer is in a grounded state when the current transformer cover plate 5 is closed, preventing overvoltage from damaging the current transformer product due to overvoltage at the grounding terminal N of the coupling capacitor, the grounding terminal X of the electromagnetic unit, and the grounding terminal of the housing.

[0021] The following explains the relevant terms that appear in the content of this utility model: Low-voltage terminals: The current transformer product needs to be connected to the carrier accessory or the directly grounded terminal; Secondary junction box: The secondary junction box is a protective device for connecting the secondary terminals of the current transformer product to the field wiring.

[0022] The instrument transformer grounding protection device provided by this utility model aims to fundamentally eliminate serious accidents caused by failure to restore grounding after maintenance. It establishes a mechanical interlock mechanism between the cover of the instrument transformer's secondary output box and the grounded state of the low-voltage terminal, achieving mandatory protection against misoperation. Specifically, the device ensures that the cover of the secondary output box can only be successfully closed and locked when the low-voltage terminal is reliably grounded; conversely, once the cover is closed, the low-voltage terminal is guaranteed to be grounded. The interlock structure effectively eliminates the risk of terminals becoming energized due to human forgetfulness, negligence, or misoperation, thereby avoiding accidents caused by overvoltage damaging the instrument transformer during commissioning and providing crucial and reliable technical protection for the safe operation of the power grid.

[0023] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. It will be apparent to those skilled in the art that this utility model is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of this utility model is defined by the appended claims rather than the foregoing description, and thus all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this utility model. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0024] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of this utility model and should not be used to limit the scope of protection of this utility model. Any modifications made to the technical solutions based on the technical concept proposed by this utility model shall fall within the scope of protection of the claims of this utility model.

Claims

1. A transformer grounding protection device, characterized in that, Includes a connecting device (4) for connecting the grounding terminal, and the connecting device (4) is connected to a guide rod device (6) for interlocking the grounding terminal with the transformer cover plate (5); The connecting device (4) includes a first connecting piece for connecting the grounding terminal of the coupling capacitor and the grounding terminal of the electromagnetic unit. The first connecting piece is connected to a second connecting piece for connecting the grounding terminal of the electromagnetic unit, the grounding terminal of the housing, and the guide rod device (6). The guide rod device (6) includes a push pin (3), a sliding connection device is provided on the push pin (3), a stroke groove (1) is provided on the outside of the push pin (3), the sliding connection device is located inside the stroke groove (1), and the second connecting piece is connected to the push pin (3).

2. The transformer grounding protection device according to claim 1, characterized in that, The sliding connection device includes a spring (2), a buckle (7) and a pin (8). The spring (2) is arranged around the outer surface of the ejector pin (3), and the buckle (7) and the pin (8) are arranged outside the ejector pin (3).

3. The transformer grounding protection device according to claim 2, characterized in that, The second connecting piece is connected to the end of the ejector pin (3) away from the buckle (7).

4. A transformer grounding protection device according to claim 2, characterized in that, The buckle (7) is located on the side of the ejector pin (3), and the pin (8) is located at the rear of the ejector pin (3).

5. A transformer grounding protection device according to claim 4, characterized in that, The pin (8) is located at the end of the spring (2) away from the buckle (7).

6. A transformer grounding protection device according to claim 2, characterized in that, The travel groove (1) is provided with a moving groove (9), the pin (8) is located at one end of the moving groove (9), and the buckle (7) is located at the other end of the moving groove (9) for the movement of the pin (8) to realize the pin (8) and the buckle (7) to form a detachable connection.

7. A transformer grounding protection device according to claim 6, characterized in that, The width of the movable groove (9) is adapted to the length of the pin (8) and the buckle (7).

8. A transformer grounding protection device according to claim 6, characterized in that, The moving slot (9) is L-shaped.

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