Rogowski coil fixing tool

Abstract

The utility model relates to the technical field of electrical performance testing devices, in particular to a Rogowski coil fixing tool. The Rogowski coil fixing tool comprises a positioning plate, the positioning plate is formed by splicing more than two sub-plates, each sub-plate defines a positioning hole used for being in positioning fit with a busbar, and an inner ring limiting structure and an outer ring limiting structure are arranged on the positioning plate by taking the circle center of the positioning hole as the center. A coil arrangement position for positioning the Rogowski coil is defined between the inner ring limiting structure and the outer ring limiting structure, a coil fixing plate is arranged at the coil arrangement position on the positioning plate, and the coil fixing plate is used for fixing the Rogowski coil on the positioning plate. The tool can ensure that the measured busbar is located at the center of the Rogowski coil, so that the measurement precision of the Rogowski coil is improved, in addition, physical isolation exists between the busbar penetrating through the positioning hole and the Rogowski coil, and the situation that the measurement precision is reduced along with the temperature rise of the busbar due to the fact that the Rogowski coil is in contact with the busbar can be avoided.

Description

Technical Field

[0001] This utility model relates to the technical field of electrical performance testing devices, specifically to a Rogowski coil fixing fixture. Background Technology

[0002] High-capacity testing refers to the testing of the breaking and closing capabilities of high-voltage switchgear using high-power power supplies, as well as the ability of certain high-voltage electrical equipment to withstand high voltage and high current. High-capacity testing has a wide range of applications, especially for high-voltage circuit breakers, where it is a crucial test for performance evaluation. Because the rated voltage and rated current values ​​of high-voltage circuit breakers have a wide range, the voltage and current measurements required in the test must also be increased accordingly. To ensure the accuracy and reliability of the test, high-precision Rogowski coils with good linearity are typically selected to measure current changes during the test.

[0003] A Rogowski coil is a hollow toroidal coil that can be directly wound around the conductor being measured to measure its current. It offers advantages such as real-time current measurement, fast response, no saturation, high bandwidth, and wide applicability. During testing, the Rogowski coil is typically wound directly around the busbar. However, the conductor being measured may not be centered within the coil, leading to an uneven magnetic field distribution. Since the Rogowski coil operates based on the law of electromagnetic induction, this uneven magnetic field disrupts the linear relationship between the output voltage and the measured current, affecting the measurement accuracy. According to the Rogowski coil's instruction manual, the accuracy is 0.2% when the conductor is centered, and typically 1% when it deviates from the center. Clearly, the measurement accuracy decreases due to the conductor's deviation. Furthermore, when current flows through the busbar, it generates… The Rogowski coil, wound around the busbar, generates a large amount of heat, causing it to heat up. As shown in the article "Analysis and Simulation Calculation of Mutual Inductance of Rogowski Coils" published by Hefei University of Technology, the mutual inductance coefficient of the Rogowski coil changes linearly with temperature, especially in the range of -20℃ to 60℃, where the change is the largest, approximately 1%. Therefore, when the Rogowski coil is in a high-temperature environment, its permeability may decrease, affecting its sensitivity and measurement accuracy. Furthermore, due to the low insulation level of the Rogowski coil, when measuring circuit breaker current under high voltage conditions, insulation breakdown may occur, leading to measurement errors or even damage and failure of the Rogowski coil.

[0004] Therefore, a fixture is needed to install the Rogowski coil, so that the busbar can pass through the center of the Rogowski coil and the Rogowski coil can be isolated from the busbar to avoid the measurement accuracy being reduced due to the Rogowski coil heating up with the busbar. Utility Model Content

[0005] The purpose of this invention is to provide a Rogowski coil fixing fixture to ensure that the busbar can pass through the center of the Rogowski coil and to isolate the Rogowski coil from the busbar, thereby preventing the measurement accuracy from decreasing as the Rogowski coil heats up with the busbar.

[0006] To achieve the above objectives, the Rogowski coil fixing fixture of this utility model adopts the following technical solution:

[0007] A Rogowski coil fixing fixture includes a positioning plate, which is composed of two or more sub-plates spliced ​​together. Each sub-plate forms a positioning hole for positioning and mating with a busbar. An inner ring limiting structure and an outer ring limiting structure are provided on the positioning plate with the center of the positioning hole as the center. The inner and outer ring limiting structures form a coil arrangement position for positioning the Rogowski coil. A coil fixing plate is provided on the positioning plate at the coil arrangement position, and the coil fixing plate is used to fix the Rogowski coil on the positioning plate.

[0008] Furthermore, there are two sub-boards, which are detachably connected by a connecting plate.

[0009] Furthermore, connecting plates are respectively provided on both sides of the positioning plate.

[0010] Furthermore, the connecting plates are arranged around the positioning holes, and the connecting plates on the same side of the positioning plates are arranged opposite each other in pairs. A tie rod is connected between the oppositely arranged connecting plates to clamp the busbar through the connecting plates.

[0011] Furthermore, the connecting plate has a flange on the side near the positioning hole, and the flange constitutes a clamping plate for clamping the busbar.

[0012] Furthermore, the pull rod is disposed on the clamping plate, and the pull rod is disposed at both ends of the clamping plate.

[0013] Furthermore, the outer ring limiting structure is an outer ring limiting hole, and the inner ring limiting structure is an inner ring limiting hole.

[0014] Furthermore, both the inner ring limiting hole and the outer ring limiting hole are threaded holes, and the coil fixing plate is engaged with the positioning plate by bolts provided in the inner ring limiting hole and the outer ring limiting hole.

[0015] Furthermore, the positioning plate is an insulating plate.

[0016] Furthermore, the connecting plate is an insulating plate, and the pull rod is an insulating pull rod.

[0017] Beneficial Effects: The Rogowski coil fixing fixture of this utility model is a pioneering invention. This fixture includes a positioning plate, which is spliced ​​from two or more sub-plates. Each sub-plate forms a positioning hole for positioning and mating with the busbar. The design of the sub-plate splicing form can quickly complete the docking and separation of the positioning plate, thereby enabling the positioning plate to be quickly placed on the busbar and facilitating disassembly. The coil fixing plate can restrict the Rogowski coil at the inner and outer ring limiting structures set on the positioning plate. Since the inner and outer ring limiting structures and the positioning hole are arranged concentrically, it can be ensured that the busbar passing through the positioning hole is at the center of the Rogowski coil, thereby improving the measurement accuracy of the Rogowski coil. In addition, there is a certain distance between the inner ring limiting structure of the Rogowski coil and the positioning hole, so that the Rogowski coil and the busbar can form a physical isolation, thereby avoiding the situation where the Rogowski coil comes into contact with the busbar and the temperature rises with the busbar, resulting in a decrease in measurement accuracy. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the Rogowski coil fixing fixture of this utility model;

[0019] Figure 2 This is a schematic diagram of a Rogowski coil structure;

[0020] Figure 3 This is a schematic diagram of the sub-plate structure;

[0021] Figure 4 for Figure 1 A schematic diagram of the upper middle connecting plate;

[0022] Figure 5 for Figure 1 A schematic diagram of the lower middle connecting plate;

[0023] Figure 6 This is a schematic diagram of the cross-section of the connecting plate;

[0024] Figure 7 This is a schematic diagram of the tie rod structure;

[0025] Figure 8 This is a schematic diagram of the coil fixing plate structure;

[0026] Figure 9 This is a schematic diagram illustrating the use of one embodiment of the Rogowski coil fixing fixture of this utility model.

[0027] In the diagram: 1. Positioning plate; 2. Sub-plate; 3. Positioning hole; 4. Rogowski coil; 5. Coil arrangement position; 6. Coil fixing plate; 7. Connecting plate; 8. Bolt; 9. Tie rod; 10. Clamping plate; 11. Outer ring limiting hole; 12. Inner ring limiting hole. Detailed Implementation

[0028] The features and performance of this utility model will be further described in detail below with reference to the embodiments.

[0029] The Rogowski coil fixing fixture of this utility model isolates the Rogowski coil and the busbar in the simplest physical isolation method to avoid contact between the two. Furthermore, by restricting the Rogowski coil to the positioning plate, the busbar passes through the center of the Rogowski coil to improve the measurement accuracy of the Rogowski coil.

[0030] Based on the above inventive concept, as a basic solution, such as Figure 1-9 As shown, the Rogowski coil fixing fixture of this utility model includes a positioning plate 1, which is used to place and support the Rogowski coil 4. The positioning plate 1 is composed of two or more sub-plates 2 spliced ​​together, ensuring that the splice of each sub-plate 2 has an arc consistent with the shape of the busbar being measured, so that each sub-plate 2 can form a positioning hole 3 for positioning and cooperating with the busbar. With the center of the positioning hole 3 as the center, an inner ring limiting structure and an outer ring limiting structure are set on the positioning plate 1. The inner and outer ring limiting structures form a coil arrangement position 5 for positioning the Rogowski coil 4. When installing the Rogowski coil 4, the Rogowski coil 4 is restricted between the inner and outer ring limiting structures. The inner ring limiting structure and the positioning hole 3 form a positioning hole 3 for positioning the busbar. The circular isolation distance formed between the positioning holes 3 ensures that the Rogowski coil 4 installed on the positioning plate 1 is separated from the busbar passing through the positioning hole 3 by a certain distance, preventing the Rogowski coil 4 from contacting the busbar and heating up. Furthermore, since the inner and outer ring limiting structures are arranged concentrically with the positioning hole 3, the positioning hole 3 is ensured to be located at the center of the Rogowski coil 4, reducing uneven electromagnetic distribution and thus improving the measurement accuracy of the Rogowski coil 4. A coil fixing plate 6 is provided on the positioning plate 1 at the coil arrangement position 5. The coil fixing plate 6 is used to fix the Rogowski coil 4 on the positioning plate 1, which can prevent the Rogowski coil 4 from slipping during use.

[0031] As a preferred implementation method, such as Figure 1As shown, there are two sub-plates 2, which are detachably connected by a connecting plate 7. The two sub-plates 2 are sufficient to form the positioning plate 1. Furthermore, splicing the two sub-plates 2 reduces the processing difficulty of the sub-plates 2 and simplifies the assembly process of the positioning plate 1, thereby improving the production efficiency of this fixing fixture. After splicing, the two sub-plates 2 form a positioning hole 3 for the busbar to pass through. Specifically, the size and shape of the splicing point of the sub-plates 2 can be adjusted according to the shape of the busbar. The connecting plate 7 connects and fixes the two sub-plates 2. The contact area between the connecting plate 7 and the two sub-plates 2 is large, which can improve... High structural strength and reliable connection ensure the stability of the tooling during use. The detachable connection between the connecting plate 7 and the two sub-plates 2 facilitates disassembly after use. The connecting plate 7 and the two sub-plates 2 can be connected by detachable bolts 8. The bolts 8 are simple and convenient to connect, easy to process and low in cost. In other embodiments, the connecting plate 7 is not provided. A mating plug can be provided on one of the splicing surfaces of the two sub-plates 2 and a mating groove can be provided on the other. The mating of the two sub-plates 2 is completed by the cooperation of the mating plug and the mating groove, which can also realize the detachable connection between the two sub-plates 2.

[0032] In a preferred embodiment, connecting plates 7 are respectively provided on both sides of the positioning plate 1. The presence of connecting plates 7 on both the front and rear sides of the positioning plate 1 provides stable support, enhances the overall structural stability, and helps resist external impacts or vibrations. This prevents relative slippage between the two sub-plates 2 of the positioning plate 1. The connecting plates 7 on both sides are connected to the positioning plate 1 by the same bolt 8, clamping the two connecting plates 7 onto the positioning plate 1. This ensures the stability and firmness of the two connecting plates 7 on the sub-plates 2, preventing loosening or detachment due to vibration or external forces. The combined action of the two connecting plates 7 forms a more robust structure, enabling the two sub-plates 2 to withstand greater loads and vibrations, thus extending the service life of the two connecting plates 7 and improving the strength and durability of the entire fixture. In other embodiments, only one connecting plate 7 connects the two sub-plates 2. Although the connection strength and reliability are relatively weaker compared to this preferred embodiment, it still serves the purpose of connection.

[0033] In a preferred embodiment, the connecting plates 7 are arranged around the positioning holes 3, and the connecting plates 7 on the same side of the positioning plate 1 are arranged opposite each other in pairs. A tie rod 9 is connected between the oppositely arranged connecting plates 7 to clamp the busbar through the connecting plates 7. Since the busbar under test passes through the positioning holes 3 in the positioning plate 1, and the connecting plates 7 are arranged opposite each other around the positioning holes 3 in pairs, the two oppositely arranged connecting plates 7 can contact and clamp the busbar. The connecting plates 7 connected to both ends of the tie rod 9 are further tightened by the tie rod 9. This not only allows the two oppositely arranged connecting plates 7 to clamp the busbar under test, but also improves the connection stability between the two connecting plates 7, further improving the stability of the fixing fixture. In addition, the clamping force of the tie rod 9 and the two connecting plates 7 on the busbar can be adjusted to adapt to different busbar sizes.

[0034] As a preferred implementation method, such as Figure 4-6 As shown, the connecting plate 7 has a flange on the side near the positioning hole 3. The flange forms a clamping plate 10 for clamping the busbar. The clamping plate 10 is vertically mounted on the corresponding connecting plate 7 and clamps the busbar. The contact area between the clamping plate 10 and the busbar is relatively large, which facilitates better clamping of the busbar and ensures that there is no relative movement between the busbar and the clamping plate 10. The pull rod 9 is mounted on the clamping plate 10, and the pull rod 9 is respectively provided at both ends of the clamping plate 10. The clamping plate 10 can provide a reliable connection position for the pull rod 9 to ensure the stability of the connection of the pull rod 9. The presence of pull rods 9 at both ends makes the clamping plate 10 more stable. Uniform tension reduces damage caused by uneven stress. Furthermore, the tie rods 9 at both ends of the clamping plate 10 and the two connecting plates 7 form a stable rectangular frame surrounding the measured busbar, making the fixture more stable and ensuring the two sub-plates 2 are firmly clamped onto the busbar, thus improving measurement accuracy. In other embodiments, the tie rod 9 is only provided at one end of the clamping plate 10. Compared to this preferred embodiment, the forces at both ends of the clamping plate 10 are relatively unbalanced, affecting its service life and the stability of the fixture. However, a single tie rod 9 can still achieve the purpose of tightening both clamping plates 10. It should be noted that, to ensure the connecting plate can be pulled by the tie rod while clamping the sub-plate, the hole for the bolt should be appropriately larger than the bolt diameter.

[0035] As a preferred implementation method, such as Figure 1As shown, the outer ring limiting structure is an outer ring limiting hole 11, and the inner ring limiting structure is an inner ring limiting hole 12. Setting both the inner and outer ring limiting structures as limiting holes facilitates the installation of the coil fixing plate 6. Both the inner ring limiting hole 12 and the outer ring limiting hole 11 are threaded holes. The coil fixing plate 6 is connected to the positioning plate 1 by bolts 8 located in the inner ring limiting hole 12 and the outer ring limiting hole 11. The bolt connection method is simple and easy to operate, and the cost of bolts 8 is low, thereby reducing the cost of the tooling. In other embodiments, a positioning pin can be used to connect the coil fixing plate 6 and the positioning plate 1 by engaging with the inner and outer ring limiting holes 11. Although compared to this preferred embodiment, the positioning pin is more troublesome to disassemble, and repeated installation and disassembly over a long period may cause loosening between the two, requiring periodic inspection or replacement, it still achieves the purpose of connecting the coil fixing plate 6 and the positioning plate 1.

[0036] In a preferred embodiment, the positioning plate 1 is an insulating positioning plate 1, the connecting plate 7 is an insulating plate, and the pull rod 9 is an insulating pull rod 9. Typically, the insulation level of the Rogowski coil 4 is low. When the Rogowski coil 4 measures current, it may break down due to its inability to withstand high voltage, causing damage to the Rogowski coil 4. In severe cases, it may even cause the test circuit to short-circuit to ground directly, resulting in irreparable losses. By setting all components of this fixture to have insulating properties, the insulation level of the Rogowski coil 4 can be improved, which helps to effectively protect the Rogowski coil 4.

[0037] The specific usage process of the Rogowski coil 4 fixing fixture of this utility model is as follows: Figure 9 As shown, the Rogowski coil fixing fixture of this utility model clamps the busbar into the positioning hole 3 by connecting two sub-plates 2. The Rogowski coil 4 and the busbar are physically isolated by a certain distance. The positioning plate 1 is then pressed and fixed by the connecting plates 7 on both sides of the positioning plate 1, which can prevent the two sub-plates 2 in the positioning plate 1 from moving relative to each other. Then, the two connecting plates 7 are connected and fixed by the pull rod 9 on the clamping plate 10, and the busbar is clamped in the rectangular frame formed by the pull rod 9 and the clamping plate 10, which further improves the stability of the fixture and ensures that there will be no relative displacement between the busbar and the positioning hole 3, which would cause the busbar to deviate from the center position of the Rogowski coil 4. In addition, the positioning plate 1, connecting plate 7 and pull rod 9 in this fixture are all insulating, which can improve the insulation of the Rogowski coil 4 and effectively prevent the Rogowski coil 4 from being broken down due to high voltage.

[0038] Taking the Rogowski coil 4, which is commonly used in large-capacity testing laboratories and has a diameter of approximately 254 mm, as an example, this Rogowski coil 4 is generally wrapped with an insulating sheath with an overall thickness of approximately 15 mm, i.e., a single-sided thickness of 7.5 mm. Therefore, the inner radius of the Rogowski coil 4 is r1≈119 mm, and the outer radius is r2≈135 mm. To ensure that the busbar can pass through the center of the coil, the circle for the inner ring limiting hole 12 is set to r3≈110 mm, and the circle for the outer ring limiting hole 11 is set to r4≈110 mm. The inner and outer ring limiting holes are both set to r5≈13 mm. The two ends of the coil fixing plate 6 are fixedly connected to the inner and outer ring limiting holes by bolts 8, so that the coil can be limited to a radius of 116mm to 143mm. The positioning hole 3 for the Φ100mm busbar to be tested to pass through is set to d≈100mm to ensure that the busbar fits against the hole wall. In addition, Φ13mm threaded holes and bolt holes are reserved at the corresponding positions of the two daughter plates 2 and each connecting plate 7 for the M12 bolts 8 to pass through, so that the connecting plate 7 can be pulled by the pull rod 9 while clamping the daughter plate 2, so that the clamping plate 10 can clamp the busbar to be tested passing through the positioning hole 3.

[0039] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. The patent protection scope of the present utility model shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present utility model shall also be included within the protection scope of the present utility model.

Claims

1. A Rogowski coil fixing fixture, characterized in that, The device includes a positioning plate, which is composed of two or more sub-plates spliced ​​together. Each sub-plate forms a positioning hole for positioning and cooperating with the busbar. An inner ring limiting structure and an outer ring limiting structure are provided on the positioning plate with the center of the positioning hole as the center. The inner and outer ring limiting structures form a coil arrangement position for positioning the Rogowski coil. A coil fixing plate is provided on the positioning plate at the coil arrangement position. The coil fixing plate is used to fix the Rogowski coil on the positioning plate.

2. The Rogowski coil fixing fixture according to claim 1, characterized in that, There are two sub-boards, which are detachably connected by a connecting plate.

3. The Rogowski coil fixing fixture according to claim 2, characterized in that, The connecting plates are respectively provided on both sides of the positioning plate.

4. The Rogowski coil fixing fixture according to claim 3, characterized in that, The connecting plates are arranged around the positioning holes, and the connecting plates on the same side of the positioning plates are arranged opposite each other. A tie rod is connected between the oppositely arranged connecting plates to clamp the busbar through the connecting plates.

5. The Rogowski coil fixing fixture according to claim 4, characterized in that, The connecting plate has a flange on the side near the positioning hole, and the flange forms a clamping plate for clamping the busbar.

6. The Rogowski coil fixing fixture according to claim 5, characterized in that, The pull rod is disposed on the clamping plate, and the pull rod is disposed at both ends of the clamping plate.

7. The Rogowski coil fixing fixture according to claim 1, characterized in that, The outer ring limiting structure is an outer ring limiting hole, and the inner ring limiting structure is an inner ring limiting hole.

8. The Rogowski coil fixing fixture according to claim 7, characterized in that, Both the inner and outer ring limiting holes are threaded holes, and the coil fixing plate is engaged with the positioning plate by bolts provided in the inner and outer ring limiting holes.

9. The Rogowski coil fixing fixture according to any one of claims 1-8, characterized in that, The positioning plate is an insulating plate.

10. The Rogowski coil fixing fixture according to claim 4, characterized in that, The connecting plate is an insulating plate, and the pull rod is an insulating pull rod.

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