A resistance testing device for tap windings of a dry-type transformer

Abstract

This utility model belongs to the field of electrical measurement technology, specifically a resistance testing device for tap windings of a dry-type transformer. It includes a transformer, with each resistance column of the transformer externally connected to a tap. A docking mechanism is connected to each tap, and the docking mechanism includes a fixing ring with a energizing rod at its center. This testing device, utilizing clamps, push rods, springs, and other components, can quickly clamp and fix the tap, ensuring stable docking of the energizing rod with the tap and guaranteeing reliable energization during resistance testing. Insulating components such as limit rods and clamps prevent leakage and interference during testing, improving accuracy. Structures such as the collar assembly, rotating frame, and sliding rod can adapt to different tap specifications, enhancing the device's versatility. Furthermore, its simple operation reduces the difficulty for testing personnel, making resistance testing of dry-type transformer tap windings more efficient and stable.

Description

Technical Field

[0001] This utility model relates to the field of electrical measurement technology, and in particular to a resistance testing device for the tap winding of a dry-type transformer. Background Technology

[0002] In dry-type transformer tap winding resistance testing, the connection between the tap and the testing device is a crucial step. Currently, bolted tap connections are commonly used for testing; however, this method presents several problems in practice. Firstly, tightening the bolts is cumbersome, requiring manual tightening of each bolt individually. For testing scenarios with multiple taps, this is time-consuming and labor-intensive, significantly slowing down the testing process. Secondly, long-term use of bolts can lead to stripping and corrosion, resulting in loose connections, unstable contact resistance, and severely affecting the accuracy of the resistance test data, failing to accurately reflect the winding performance. Furthermore, frequent bolt disassembly and reassembly cause significant wear and tear on the physical structure of the tap and testing terminals, shortening equipment lifespan and increasing maintenance costs.

[0003] To address the above problems, this utility model proposes a resistance testing device for the tap winding of a dry-type transformer. Utility Model Content

[0004] Based on the existing problems with rapid clamping technology, this utility model proposes a resistance testing device for the tap winding of a dry transformer.

[0005] This utility model proposes a resistance testing device for the tap winding of a dry-type transformer, including a transformer. Each resistance column of the transformer is externally connected to a tap, and a docking mechanism is connected at each tap. The docking mechanism includes a fixing ring, a energizing rod at the center of the fixing ring, a limiting rod fixedly connected to the outer surface of the energizing rod, a circular protrusion at the center of the fixing ring, the upper surface of the circular protrusion being fixedly connected to the lower surface of the limiting rod, one end of the energizing rod penetrating the circular protrusion, a clamping plate on one side of the upper surface of the fixing ring, the clamping plate being divided into two, a push rod being slidably connected at the separation point of the clamping plate, and slots adapted to the lower end of the push rod being arrayed at the separation point of the two clamping plates.

[0006] Preferably, slots are provided along both sides of the clamping plate, and a limit fork is slidably inserted into the inner wall of the slot. Springs are embedded in both ends of the clamping plate, and the ends of the two clamping plates are elastically connected through the ends of the springs. An arc-shaped groove is provided on the surface of the fixing ring, and the arc-shaped groove is located directly below the clamping plate.

[0007] Preferably, a collar assembly is attached to the lower surface of the fixed ring. The collar assembly includes an annular plate and a connecting post. Two annular plates are fixedly connected by the connecting post. One end of the annular plate is protruding, and the upper surface of the protrusion is fixedly connected to the lower end of the push rod. A rotating frame is rotatably connected between the two annular plates via bearings. A sliding rod is slidably connected to the inner wall of the rotating frame. One end of the sliding rod is fixedly connected to a fixed post. The upper end of the fixed post is rotatably connected to the lower surface of the fixed ring via bearings. A clamping block is rotatably connected to one end of the sliding rod via a pin.

[0008] Preferably, the clamping block, the limiting rod, the limiting fork, and the push rod are all made of insulating material, and the surface of the clamping block is adapted to the outer surface of the tap.

[0009] Preferably, a resistance tester is connected to the end of the energized rod away from the fixed ring, and the resistance tester is connected to the energized rod through a shielded wire, the outer surface of which is wrapped with an insulating protective sleeve.

[0010] Preferably, a grounding wire is provided at one end of the annular plate of the collar assembly.

[0011] The beneficial effects of this utility model are as follows: By setting up a docking mechanism, using components such as clamps, push rods, and springs, the tap changer can be quickly clamped and fixed, ensuring a stable connection between the energizing rod and the tap changer, and guaranteeing the reliability of the energized connection during resistance testing. Insulating components such as limit rods and clamps prevent leakage and interference during testing, improving test accuracy. Structures such as collar assemblies, rotating frames, and sliding rods can adapt to tap changers of different specifications, enhancing the device's versatility. Furthermore, the device is easy to operate, reducing the difficulty for testers and making the resistance testing of dry-type transformer tap windings more efficient and stable. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of a resistance testing device for the tap winding of a dry-type transformer proposed in this utility model; Figure 2 This is a sectional view of the fixed ring of a resistance testing device for tap windings of a dry-type transformer proposed in this utility model. Figure 3 This is a cross-sectional view of the collar assembly of a resistance testing device for tap windings of a dry-type transformer proposed in this utility model. Figure 4 This is a diagram showing the connection between the rotating frame and the sliding rod of a resistance testing device for tap windings of a dry-type transformer proposed in this utility model. Figure 5 This utility model provides a spring position diagram for a resistance testing device for tap windings of a dry-type transformer. Figure 6 This utility model proposes a resistance testing device for the tap winding of a dry-type transformer. Figure 5 Enlarged view of point A in the middle.

[0013] In the diagram: 1. Transformer; 2. Tap changer; 3. Connecting mechanism; 31. Fixing ring; 32. Energizing rod; 33. Limiting rod; 34. Clamping plate; 35. Push rod; 36. Limiting fork; 37. Spring; 38. Arc groove; 39. Collar assembly; 310. Rotating frame; 311. Slide rod; 312. Clamping block; 313. Fixing column. Detailed Implementation

[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 of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0015] Reference Figures 1-6 A resistance testing device for tap windings of a dry-type transformer includes a transformer 1. Each resistance column of the transformer 1 is externally connected to a tap 2. A docking mechanism 3 is connected to the tap 2. The docking mechanism 3 includes a fixing ring 31. A current-carrying rod 32 is provided at the center of the fixing ring 31. A limit rod 33 is fixedly connected to the outer surface of the current-carrying rod 32. A circular protrusion is provided at the center of the fixing ring 31. The upper surface of the circular protrusion is fixedly connected to the lower surface of the limit rod 33. One end of the current-carrying rod 32 passes through the circular protrusion. A clamping plate 34 is provided on one side of the upper surface of the fixing ring 31. The clamping plate 34 is divided into two parts. A push rod 35 is slidably connected at the separation point of the clamping plate 34. The separation point of the two clamping plates 34 is provided with slots that are adapted to the lower end of the push rod 35.

[0016] In this embodiment, slots are provided along both sides of the clamping plate 34, and a limit fork 36 is slidably inserted into the inner wall of the slot. Springs 37 are embedded in both ends of the clamping plate 34, and the ends of the two clamping plates 34 are elastically connected through the ends of the springs 37. An arc-shaped groove 38 is provided on the surface of the fixing ring 31, and the arc-shaped groove 38 is located directly below the clamping plate 34.

[0017] In this embodiment, a collar assembly 39 is attached to the lower surface of the fixing ring 31. The collar assembly 39 includes annular plates and connecting posts. The two annular plates are fixedly connected by the connecting posts. One end of the annular plate is set to protrude. The upper surface of the protrusion is fixedly connected to the lower end of the push rod 35. A rotating frame 310 is rotatably connected between the two annular plates by bearings. A slide rod 311 is slidably connected to the inner wall of the rotating frame 310. A fixing post 313 is fixedly connected to one end of the slide rod 311. The upper end of the fixing post 313 is rotatably connected to the lower surface of the fixing ring 31 by bearings. A clamping block 312 is rotatably connected to one end of the slide rod 311 by a pin.

[0018] Specifically, the design of the clamping plate 34 being divided into two forms a clamping arm. The slots at the separation point are distributed in a linear array. Before the push rod 35 slides along the sliding channel of the clamping plate 34, the two clamping plates 34 are pulled first. The lower ends of the two clamping plates 34 are slidably connected to the T-shaped slots opened on the surface of the fixing ring 31. The lower ends of the two clamping plates 34 are provided with limiting rods that are adapted to the T-shaped slots to separate them. Then, the push rod 35 is pushed to slide in the arc-shaped groove 38. The radius of curvature of the arc-shaped groove 38 is perfectly matched with the rotation trajectory of the clamping plate 34 to ensure that there is no jamming during the movement.

[0019] The limiting fork 36 adopts a U-shaped structure, and the insertion parts at both ends are adapted to the slot gap. After the clamping plate 34 is adjusted to a suitable opening angle, the two ends of the limiting fork 36 are placed between the two clamping plates 34. The operation does not need to consider that the two clamping plates 34 contract under the action of the spring 37, causing the push rod 35 to be pushed unsmoothly. After the push rod 35 is pushed, the limiting fork 36 is removed from between the two clamping plates 34. After the two clamping plates 34 clamp and limit the lower end of the push rod 35, the lower end of the clamping plate 34 can be inserted into the slot to lock the position of the clamping plate 34.

[0020] The two annular plates of the collar assembly 39 are arranged in parallel, and the connecting columns are evenly distributed along the circumference of the annular plates to ensure structural stability. The protruding part at one end of the annular plate is rigidly connected to the lower end of the push rod 35 by bolts. When the push rod 35 is pushed to make a circular motion, it will drive the collar assembly 39 to rotate around the center of the fixed ring 31. The rotating frame 310 has a rectangular frame structure and is connected to the annular plate through a deep groove ball bearing. The slider at the end of the slide rod 311 slides with the slide rail. When the collar assembly 39 rotates, the fixed column 313 drives the slide rod 311 to slide along the rotating frame 310. At the same time, under the rotation of the rotating frame 310, the slide rod 311 makes the clamping block 312 fit tightly against the outer surface of the tap joint 2.

[0021] In this embodiment, the clamping block 312, the limiting rod 33, the limiting fork 36, and the push rod 35 are all made of insulating material, and the surface of the clamping block 312 is adapted to the outer surface of the tap 2.

[0022] Specifically, the insulation material is made of high-strength glass fiber reinforced epoxy resin, which can effectively block current conduction and avoid the risk of electric shock to test personnel during operation; the U-shaped fork head of the limit fork 36 is rounded at the end to avoid scratching the insulating surface of the clamp plate 34 when inserted into the slot; the outer surface of the push rod 35 is provided with anti-slip texture, which enhances the friction when gripping without affecting its insulation properties.

[0023] In this embodiment, a resistance tester is connected to the end of the energized rod 32 away from the fixing ring 31. The resistance tester and the energized rod 32 are connected by a shielded wire, and the outer surface of the shielded wire is wrapped with an insulating protective sleeve.

[0024] Specifically, the current-carrying rod 32 is made of copper with a nickel-plated surface, which ensures excellent conductivity and improves oxidation resistance. The connection between the resistance tester and the current-carrying rod 32 is existing technology and will not be described in detail.

[0025] In this embodiment, a grounding wire is provided at one end of the annular plate of the collar assembly 39.

[0026] Specifically, the grounding wire uses multi-strand soft copper stranded wire. One end is connected to the protruding part of the 39-ring plate of the collar assembly through a copper lug, and conductive paste is applied to reduce contact resistance. The other end is equipped with a grounding clamp with a maximum opening width of 30mm, which can be adapted to grounding stakes of different specifications. The insulating sheath of the grounding wire is made of polyvinyl chloride. Before testing, the grounding wire should be connected to the grounding stake first to prevent electric shock after the test is completed.

[0027] Operating principle: Before testing, insert the energizing rod 32 into the tap 2. The operator pulls the clamping plate 34, then places the insertion end of the limiting fork 36 into the clamping plate 34. With the limiting fork 36 at one end of the clamping plate 34, push the push rod 35 to slide along the arc groove 38. The collar assembly 39 rotates under the action of the push rod 35. Under the action of the rotating frame 310, the sliding rod 311 slides along the rotating frame 310. The rotating frame 310 simultaneously changes the sliding direction of the sliding rod 311, guiding one end of the sliding rod 311 to the tap. The clamping block 312, which is rotatably connected to the sliding rod 311 through a pin, fits tightly against the outer surface of the tap 2. Then, the limiting fork 36 placed between the two clamping plates 34 is removed. Under the action of the spring 37, the two clamping plates 34 move closer to each other, clamping the lower end of the push rod 35. Finally, the limiting fork 36 is inserted into the slot. After the connection is completed, the grounding wire is connected to the grounding stake, and the test begins.

[0028] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A resistance testing device for dry-type transformer tap windings, comprising a transformer (1), characterized in that: Each resistor column of the transformer (1) is externally connected to a tap (2), and a docking mechanism (3) is connected to the tap (2). The docking mechanism (3) includes a fixing ring (31), and a power-carrying rod (32) is provided at the center of the fixing ring (31). A limit rod (33) is fixedly connected to the outer surface of the power-carrying rod (32). A circular protrusion is provided at the center of the fixing ring (31). The upper surface of the circular protrusion is fixedly connected to the lower surface of the limit rod (33). One end of the power-carrying rod (32) passes through the circular protrusion. A clamping plate (34) is provided on one side of the upper surface of the fixing ring (31). The clamping plate (34) is divided into two. A push rod (35) is slidably connected at the separation point of the clamping plate (34). The two clamping plates (34) are arrayed with slots that are adapted to the lower end of the push rod (35).

2. A resistance testing device for dry-type transformer tap windings as claimed in claim 1, characterized in that: Slots are provided along both sides of the clamp (34), and a limit fork (36) is slidably inserted into the inner wall of the slot. Springs (37) are embedded in both ends of the clamp (34), and the two ends of the clamp (34) are elastically connected through the two ends of the springs (37). An arc groove (38) is provided on the surface of the fixing ring (31), and the arc groove (38) is located directly below the clamp (34).

3. A resistance testing device for dry-type transformer tap windings as claimed in claim 2, characterized in that: The lower surface of the fixed ring (31) is fitted with a collar assembly (39), which includes an annular plate and a connecting post. The two annular plates are fixedly connected by the connecting post. One end of the annular plate is set to protrude. The upper surface of the protrusion is fixedly connected to the lower end of the push rod (35). The two annular plates are rotatably connected by a rotating frame (310) through a bearing. The inner wall of the rotating frame (310) is slidably connected to a slide rod (311). One end of the slide rod (311) is fixedly connected to a fixed post (313). The upper end of the fixed post (313) is rotatably connected to the lower surface of the fixed ring (31) through a bearing. One end of the slide rod (311) is rotatably connected to a clamping block (312) by a pin.

4. A resistance testing device for a tapped winding of a dry-type transformer as defined in claim 3, characterized in that: The clamp (312), the limiting rod (33), the limiting fork (36), and the push rod (35) are all made of insulating material, and the surface of the clamp (312) is adapted to the outer surface of the tap (2).

5. A resistance testing device for a tapped winding of a dry-type transformer as defined in claim 4, characterized in that: A resistance tester is connected to one end of the energizing rod (32) away from the fixing ring (31). The resistance tester and the energizing rod (32) are connected by a shielded wire, and the outer surface of the shielded wire is wrapped with an insulating protective sleeve.

6. A resistance testing device for a tapped winding of a dry-type transformer as defined in claim 5, characterized in that: A grounding wire is provided at one end of the annular plate of the collar assembly (39).

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