Grounding backflow on-line monitoring device

Abstract

The utility model relates to a grounding backflow on-line monitoring device, which belongs to the field of grounding backflow monitoring and comprises a grounding monitoring box, a wire outlet hole is arranged at the bottom of the grounding monitoring box, and a sealing assembly is arranged on the wire outlet hole. According to the grounding backflow on-line monitoring device, the sealing assembly is arranged, an upper first sealing plate and a lower first sealing plate are fixed to the inner bottom wall and the outer bottom wall of the grounding monitoring box through bolts respectively, a cable penetrates through a cable outlet hole to extend into the grounding monitoring box, and the cable is clamped in an arc-shaped groove; a positioning hole in a first sealing plate is aligned with a threaded rod, a positioning hole in a second sealing plate is aligned with the threaded rod, the first sealing plate and the second sealing plate are in butt joint and closed, then a fastening nut is screwed, the rubber sealing block can abut against the outer wall of a cable, the sealing effect is achieved, and a sealing gasket pressed by the first sealing plate and the second sealing plate has the sealing effect on a cable outlet hole. And through a double-layer sealing structure, the sealing effect is further improved.

Description

Technical Field

[0001] The utility model relates to the technical field of grounding monitoring, in particular to an on-line monitoring device for grounding return current. Background Technique

[0002] On-line monitoring of grounding return current is a new type of power monitoring product, which is installed in the substation centralized control room. Its current electrode and voltage electrode are arranged around the substation or in a relatively open area inside the substation to realize the monitoring of the grounding impedance, ground potential distribution, integrity of the grounding grid inside the station; step voltage, touch voltage (around important equipment), grounding conduction resistance of equipment, rail-to-ground return current and other grounding grid performance indicators. The grounding grid is one of the widely used safety technologies today. The reliable and effective connection between the grounding lead of traction power equipment and the grounding grid is the fundamental guarantee for the safe operation of power equipment and the personal safety of operators.

[0003] At present, an outlet hole is usually arranged on the grounding monitoring box for the introduction and export of cables. As the channel for the entry and exit of cables, the sealing performance of the outlet hole directly affects the use effect and safety of the grounding monitoring box. In order to ensure the sealed isolation between the box body and the external environment, a sealing member is usually arranged at the outlet hole. However, the sealing member is easily affected by environmental factors during long-term exposure to the environment, damaging the sealing ability of the sealing member, resulting in poor sealing effect. Therefore, an on-line monitoring device for grounding return current is proposed. Summary of the Utility Model

[0004] Aiming at the deficiencies of the prior art, the utility model provides an on-line monitoring device for grounding return current, which has the advantage of good sealing effect, and solves the problem that the sealing ability of the sealing member is easily damaged by environmental factors during long-term exposure to the environment, resulting in poor sealing effect.

[0005] To achieve the above object, the utility model provides the following technical scheme: an on-line monitoring device for grounding return current, including a grounding monitoring box, an outlet hole is opened at the bottom of the grounding monitoring box, and a sealing component is arranged on the outlet hole.

[0006] The sealing component includes two first sealing plates and second sealing plates. Fixed pieces are fixed on the left and right sides of the first sealing plate and the second sealing plate. Bolts are threadedly connected inside the fixed pieces. Card slots are opened on the opposite sides of the first sealing plate and the second sealing plate. Rubber sealing blocks are clamped inside the card slots. Two threaded rods are fixed on the side of the first sealing plate close to the second sealing plate. Positioning holes are opened inside the second sealing plate, and one end of the threaded rod penetrates through the positioning hole and extends to the outside.

[0007] Further, a fastening nut is threadedly connected to the outside of the threaded rod, and the fastening nut abuts against the side wall of the second sealing plate.

[0008] Furthermore, threaded grooves are provided on both the outer wall and the inner wall of the grounding monitoring box, and the bolts are threadedly connected inside the threaded grooves.

[0009] Furthermore, an arc-shaped groove is provided on one side of the rubber sealing block, and a limiting rib is fixed on the outer wall of the rubber sealing block.

[0010] Furthermore, limiting grooves located on the inner wall of the clamping groove are provided inside both the first sealing plate and the second sealing plate, and the limiting ribs are clamped inside the limiting grooves.

[0011] Furthermore, the wire outlet hole is of a rectangular hole structure, and the size of the closed first sealing plate and second sealing plate is larger than the size of the wire outlet hole.

[0012] Furthermore, embedding grooves located on the inner wall of the wire outlet hole are provided on both the inner wall and the outer wall of the grounding monitoring box, and a sealing gasket is pasted inside the embedding grooves.

[0013] Compared with the prior art, the technical solution of the present application has the following beneficial effects:

[0014] For this on-line monitoring device for grounding return, by setting up the sealing assembly, first fix the upper and lower first sealing plates on the inner bottom wall and the outer bottom wall of the grounding monitoring box respectively through bolts, pass the cable through the wire outlet hole and extend it into the grounding monitoring box, and make the cable be stuck inside the arc-shaped groove. Then align the positioning hole on the second sealing plate with the threaded rod, make the first sealing plate and the second sealing plate be butted and closed, and then tighten the fastening nut. The rubber sealing block can be pressed tightly against the outer wall of the cable to achieve the sealing effect, and the sealing gasket pressed by the first sealing plate and the second sealing plate seals the wire outlet hole. Through the double-layer sealing structure, the sealing effect is further improved. Description of the Drawings

[0015] Figure 1 is a schematic structural diagram of the present utility model;

[0016] Figure 2 is a top cross-sectional view of the sealing assembly of the structure of the present utility model;

[0017] Figure 3 is the structure of the present utility model Figure 1 is an enlarged view of the structure at A in the figure;

[0018] Figure 4 is a three-dimensional view of the rubber sealing block of the structure of the present utility model;

[0019] Figure 5 is a system diagram of the grounding monitoring box of the structure of the present utility model.

[0020] In the figure: 1. Grounding monitoring box; 2. Mounting plate; 3. Assembly hole; 4. First sealing plate; 5. Second sealing plate; 6. Threaded rod; 7. Positioning hole; 8. Tightening nut; 9. Rubber sealing block; 10. Card slot; 11. Arc-shaped groove; 12. Limit convex strip; 13. Limit groove; 14. Fixed piece; 15. Bolt; 16. Embedded groove; 17. Sealing gasket; 18. Wire outlet hole. Detailed implementation mode

[0021] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0022] Please refer to Figures 1 to 5 , a grounding return online monitoring device in this embodiment includes a grounding monitoring box 1. A wire outlet hole 18 is opened at the bottom of the grounding monitoring box 1, and a sealing component is arranged on the wire outlet hole 18.

[0023] The sealing component includes two first sealing plates 4 and second sealing plates 5. Fixed pieces 14 are fixed on the left and right sides of the first sealing plates 4 and the second sealing plates 5. Bolts 15 are threadedly connected inside the fixed pieces 14. Card slots 10 are opened on the opposite sides of the first sealing plates 4 and the second sealing plates 5. Rubber sealing blocks 9 are clamped inside the card slots 10. Two threaded rods 6 are fixed on the side of the first sealing plate 4 close to the second sealing plate 5. A positioning hole 7 is opened inside the second sealing plate 5, and one end of the threaded rod 6 penetrates through the positioning hole 7 and extends to the outside.

[0024] Among them, two mounting plates 2 are fixed on the left and right sides of the grounding monitoring box 1. Assembly holes 3 are opened inside the mounting plates 2. This structure is used to fix the grounding monitoring box 1 at the position where it needs to be installed.

[0025] Please refer to Figure 2 , in this embodiment, a tightening nut 8 is threadedly connected to the outside of the threaded rod 6. The tightening nut 8 abuts against the side wall of the second sealing plate 5. Threaded grooves are opened on both the outer wall and the inner wall of the grounding monitoring box 1, and the bolts 15 are threadedly connected inside the threaded grooves.

[0026] The grounding monitoring box 1 continuously collects real-time monitoring data of the grounding grid through a grounding module, conducts intelligent judgment after background processing, realizes real-time control of the safety performance of the grounding grid, and adopts a digital mode in the whole process of data collection, transmission, processing and output. Each sub-system is constructed based on the IEC61850 communication specification, which conforms to the hierarchical structure of networked secondary equipment in a digital substation and facilitates the later expansion work of implanting into a digital substation. The voltage stabilizing module set in the grounding monitoring box 1 will not affect the normal operation of the test equipment when the power grid fluctuates greatly.

[0027] When the grounding return online monitoring device works, it uses a high-power heterodyne device to excite a loop current between the measured grounding grid and the current electrode, uses a multi-channel voltage collector to synchronously collect the voltage waveforms between each measured device and the voltage electrode, and calculates the heterodyne voltage difference between each device and the zero potential through filtering analysis, so as to calculate the grounding resistance of each device.

[0028] The output frequency of this device is 40Hz and 60Hz. It adopts military electronic countermeasure digital analysis filtering technology, has extremely strong anti-interference ability and sharp frequency selection characteristics. Through high-precision frequency selection and automatic range switching technology, it automatically switches the range according to the change of the grounding resistance, ensuring the measurement accuracy in the high and low range.

[0029] As Figure 5 shown: The variable-frequency signal source outputs a stable power signal with a frequency of f. The offset between f and the power grid power frequency f0 is △f. The high-power signal enters the transformer, and the coupling isolates the device from the device, matches the loop impedance, and outputs a larger signal. In principle, by measuring the current I flowing through the grounding grid and the voltage drop U generated on the grounding grid, the grounding impedance is Z = U / I. That is, by measuring the variable-frequency voltage signal and current signal, the corresponding parameters are obtained. The device described in the present invention adopts short-distance measurement technology. The distance between the current electrode and the measured grounding grid is relatively short, and the position of the voltage electrode needs to be determined by a calibration method, that is, after the actual resistance value of the grounding grid is measured by a conventional method, the zero potential point between the current electrode and the measured grounding grid is found by a probing method and the voltage electrode is laid at that place. For the linear circuit composed of the measured grounding grid, current electrode and the earth, when the position of the current electrode is fixed, the zero potential position will not change with the change of the test current. Therefore, it can ensure that the measured resistance value is the grounding impedance value of the measured grounding grid, thus realizing the online monitoring function.

[0030] It is worth mentioning that the grounding return online monitoring device described in the present invention is a test device that can timely monitor the characteristic parameters of the grounding grid system. By real-time monitoring the change trend of the grounding impedance index of the grounding grid and the conduction condition of the device grounding, relevant departments can timely master the safety performance of the grounding grid and formulate corresponding countermeasures, effectively preventing the occurrence of personal and equipment safety accidents.

[0031] The utility model sets a sealing component. First, the upper and lower first sealing plates 4 are respectively fixed on the inner bottom wall and the outer bottom wall of the grounding monitoring box 1 through bolts 15. The cable is passed through the wire outlet hole 18 and extends to the inside of the grounding monitoring box 1, and the cable is clamped inside the arc-shaped groove 11. Then, the positioning hole 7 on the second sealing plate 5 is aligned with the threaded rod 6, and the first sealing plate 4 and the second sealing plate 5 are butted and closed. After tightening the fastening nut 8, the rubber sealing block 9 can be tightly pressed against the outer wall of the cable to achieve the sealing effect. Through the double-layer sealing structure, the sealing effect is further improved.

[0032] It should be noted that a voltage stabilizing module, an inverter, a filtering component and a controller are arranged inside the grounding monitoring box 1. All components are integrated inside the grounding monitoring box 1, and the grounding monitoring box 1 is installed in the substation centralized control room. Its current electrode and voltage electrode are arranged in the relatively open areas around or inside the substation. The device adopts the current most advanced digital frequency selection measurement (electronic countermeasure) technology, has super strong anti-interference ability, and completely eliminates the errors brought to the measurement by the interference of power frequency induction, zero-sequence current, harmonics and stray signals; the device uses a pure sine wave high-power signal source as the test power supply and collects data at multiple frequency points, overcoming the limitations of the double-point different-frequency interpolation method; the device has powerful functions, excellent performance and is convenient to use.

[0033] Please refer to Figure 3 , Figure 4 On one side of the rubber sealing block 9, an arc-shaped groove 11 is opened. A limiting convex strip 12 is fixed on the outer wall of the rubber sealing block 9. Limiting grooves 13 are opened inside the first sealing plate 4 and the second sealing plate 5 and located on the inner wall of the clamping groove 10. The limiting convex strip 12 is clamped inside the limiting groove 13.

[0034] By clamping the limiting convex strip 12 inside the limiting groove 13, the rubber sealing block 9 can be positioned, so that the rubber sealing block 9 is clamped inside the clamping groove 10, thus facilitating the subsequent replacement of the rubber sealing block 9.

[0035] It should be noted that the wire outlet hole 18 is a rectangular hole structure. The closing size of the first sealing plate 4 and the second sealing plate 5 is larger than the size of the wire outlet hole 18. The two groups of closed first sealing plates 4 and second sealing plates 5 are respectively attached to the outer wall and the inner wall of the grounding monitoring box 1. By pressing the first sealing plate 4 and the second sealing plate 5 at the wire outlet hole 18, the wire outlet hole 18 can be sealed and blocked.

[0036] Among them, embedding grooves 16 are opened on both the inner wall and the outer wall of the grounding monitoring box 1 and located on the inner wall of the wire outlet hole 18. A sealing gasket 17 is pasted inside the embedding groove 16.

[0037] It should be noted that by pressing the sealing gasket 17 on the upper wire outlet hole 18 of the ground connection monitoring box 1 through the first sealing plate 4 and the second sealing plate 5, the wire outlet hole 18 can be sealed.

[0038] The working principle of the above embodiment is as follows: When wiring, first paste the sealing gasket 17 inside the embedding groove 16, then fix the upper and lower first sealing plates 4 on the inner bottom wall and the outer bottom wall of the grounding monitoring box 1 respectively through bolts 15, pass the cable through the wire outlet hole 18 and extend it into the grounding monitoring box 1, and make the cable stuck inside the arc-shaped groove 11. Then align the positioning hole 7 on the second sealing plate 5 with the threaded rod 6, make the first sealing plate 4 and the second sealing plate 5 butt and close, and then tighten the fastening nut 8. The rubber sealing block 9 can be pressed tightly against the outer wall of the cable to achieve the sealing effect. The sealing gasket 17 pressed by the first sealing plate 4 and the second sealing plate 5 achieves the sealing effect on the wire outlet hole 18. And the sealing gasket 17 is pressed on the side wall of the monitoring box 1 by the first sealing plate 4 and the second sealing plate 5, which plays a certain protective role for the sealing gasket 17 and reduces the influence of environmental factors. This sealing assembly further improves the sealing effect through a double-layer sealing structure.

[0039] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or sequence between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without more limitations, an element defined by the statement "comprising a..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the element.

[0040] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A ground return online monitoring device, comprising a ground monitoring box (1), characterized in that: The bottom of the grounding monitoring box (1) is provided with a wire outlet hole (18), and a sealing component is provided on the wire outlet hole (18); The sealing assembly comprises two first sealing plates (4) and two second sealing plates (5), the left and right sides of the first sealing plate (4) and the second sealing plate (5) are both fixed with fixing plates (14), the internal threads of the fixing plates (14) are connected with bolts (15), the first sealing plate (4) and the second sealing plate (5) are both provided with a card slot (10) on the opposite side, the inside of the card slot (10) is clamped with a rubber sealing block (9), the first sealing plate (4) is fixed with two threaded rods (6) on the side close to the second sealing plate (5), the inside of the second sealing plate (5) is provided with a positioning hole (7), and one end of the threaded rod (6) passes through the positioning hole (7) and extends to the outside.

2. The ground return current online monitoring device according to claim 1, characterized in that: The external thread of the threaded rod (6) is connected with a fastening nut (8).

3. A ground return current online monitoring device according to claim 2, characterized in that: The fastening nut (8) is tightly pressed against the side wall of the second sealing plate (5).

4. The ground return current online monitoring device according to claim 1, characterized in that: The outer wall and the inner wall of the grounding monitoring box (1) are both provided with thread grooves, and the bolts (15) are threadedly connected inside the thread grooves.

5. The ground return current online monitoring device according to claim 1, characterized in that: An arc-shaped groove (11) is formed on one side of the rubber sealing block (9).

6. The ground return current online monitoring device according to claim 1, characterized in that: The outer wall of the rubber sealing block (9) is fixed with a limiting convex strip (12).

7. The ground return current online monitoring device according to claim 6, characterized in that: The first sealing plate (4) and the second sealing plate (5) are both provided with limiting grooves (13) located on the inner wall of the clamping groove (10).

8. The ground return current online monitoring device according to claim 7, characterized in that: The limiting convex strip (12) is clamped inside the limiting groove (13).

9. The ground return current online monitoring device according to claim 1, characterized in that: The wire outlet hole (18) is a rectangular hole structure, and the closed size of the first sealing plate (4) and the second sealing plate (5) is larger than the size of the wire outlet hole (18).

10. The ground return current online monitoring device according to claim 1, characterized in that: The inner wall and the outer wall of the grounding monitoring box (1) are both provided with an embedding groove (16) located on the inner wall of the outlet hole (18), and a sealing gasket (17) is pasted inside the embedding groove (16).

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