Guided wave detection technology for grounding damage status of power transmission and transformation equipment

Abstract

The invention relates to the technical field of grounding body detection of power transmission and transformation equipment, and in particular to a waveguide detection process for the damage state of grounding body of power transmission and transformation equipment. An elastic wave vibration source is installed on one end of a grounding grid down conductor extending out of soil, and a plurality of acceleration sensors are installed on the part of the grounding grid down conductor extending out of soil. The elastic wave vibration source and the plurality of acceleration sensors are electrically connected to a corrosion detection system. The elastic wave vibration source continuously strikes the grounding grid down conductor to generate elastic waves. The plurality of acceleration sensors collect elastic wave information and transmit it to the corrosion detection system to detect corrosion information of the grounding grid down conductor. The technical solution of the invention can detect echo signals of the grounding grid down conductor by using a plurality of acceleration sensors, and can effectively extract corrosion information of the grounding grid down conductor.

Description

Technical Field

[0001] The invention relates to the technical field of grounding body detection for power transmission and transformation equipment, and in particular to a waveguide detection process for damage status of grounding body for power transmission and transformation equipment. Background Art

[0002] The power system will be subjected to huge fault current when it is struck by lightning or a short circuit occurs. The grounding grid, as a common reference potential point, can quickly conduct the fault current into the earth and reduce the ground potential rise, thereby ensuring the safety of power workers and power equipment.

[0003] The grounding grid is composed of a grounding grid and a down conductor, which is generally made of flat steel with a cross-section of 60mm*6mm or round steel with a diameter of 20mm. The grounding grid is generally laid horizontally in a long hole or square hole shape and buried 0.5m-1.5m below the surface. The main function of the down conductor is to connect the power equipment to the grounding grid. One part of it is buried in the soil and connected to the grounding grid, and the other part is exposed to the air and connected to the power equipment that needs to be grounded.

[0004] Most grounding grids are made of galvanized round steel or flat steel. Grounding grids buried in the soil for many years are prone to corrosion. As a necessary facility for the safe and reliable operation of the power system, the traditional inspection method is to dig out the grounding grid for inspection and judge the corrosion status of the grounding grid by naked eye observation or knocking. However, this method requires the substation to be shut down and the excavation takes a long time and labor. The grounding electrode may also be partially wrapped, which also brings certain difficulties to naked eye identification.

[0005] At present, the existing methods for diagnosing grounding grid corrosion have certain limitations. In addition, most studies are aimed at corrosion detection of grounding grids, and there are few studies on grounding grid down conductors. In grounding accidents, most accidents are caused by the detachment of the welding point between the down conductor and the grounding grid or defects in the down conductor itself.

[0006] Therefore, how to perform efficient and non-destructive detection of the corrosion status of the grounding grid down conductor has become a technical problem that needs to be solved urgently by technical personnel in this field. Summary of the invention

[0007] The present invention provides a waveguide detection process for the damage state of the grounding body of power transmission and transformation equipment, which is used to solve the problem of how to shorten the disinfection and sterilization time and improve the disinfection and sterilization efficiency.

[0008] The present invention provides a waveguide detection process for the damage state of the grounding body of power transmission and transformation equipment, comprising the following steps:

[0009] S1, clamping one end of the grounding grid down conductor extending out of the ground between the upper fixing plate and the lower fixing plate, and installing a plurality of acceleration sensors on the end of the grounding grid down conductor extending out of the ground;

[0010] S2, electrically connecting the plurality of acceleration sensors to the corrosion detection system respectively;

[0011] S3. The electromagnetic spring inside the housing is energized by the transmitter, so that the electromagnetic spring shortens and pulls the piston plate downward, and the piston plate drives the upper bias magnet, the magnetostrictive rod and the lower bias magnet to move downward, and the lower bias magnet abuts against the push rod, so that the push rod is subjected to downward pressure, and the pressure is applied to the grounding grid down conductor, thereby causing the magnetostrictive rod to be subjected to prestress;

[0012] S4, inputting an excitation current into the coil through the transmitter, the coil intermittently generates a magnetic field, causing the magnetostrictive rod in the magnetic field to produce intermittent deformation and drive the top rod to intermittently hit the grounding grid down conductor through the lower bias magnet, thereby generating elastic waves in the grounding grid down conductor;

[0013] S5. While performing step S4, the transmitter applies an excitation current of the same frequency to the electromagnetic spring, so that the electromagnetic spring is intermittently deformed, and the deformation frequency of the electromagnetic spring and the magnetostrictive rod is the same. The magnetostrictive rod drives the top rod to hit the grounding grid down conductor through the lower bias magnet to generate elastic waves;

[0014] S6. Multiple acceleration sensors record reflected echo signals. The reflected echo signals are collected by an AD signal collector after passing through a signal amplifier and then transmitted to a computer through a data transmission module. After the computer processes the reflected echo signals, the corrosion information of the grounding grid down conductor can be obtained.

[0015] In some embodiments, the liquid pump is started while performing step S4 and step S5 to circulate the cooling oil in the upper cavity and the cooling oil in the middle cavity to absorb the heat generated by the coil and the electromagnetic spring.

[0016] In some embodiments, a plurality of acceleration sensors are arranged linearly on the ground grid down conductor.

[0017] In some embodiments, the interior of the shell is provided with an upper cavity, a middle cavity and a lower cavity.

[0018] In some embodiments, a piston plate is slidably connected in the upper cavity, the top of the piston plate is connected to the upper bias magnet, a winding frame is fixedly connected below the piston plate, a coil is wound on the winding frame, a magnetostrictive rod is installed in the winding frame, the upper end of the magnetostrictive rod is connected to the upper bias magnet, and the lower end is connected to the lower bias magnet, an electromagnetic spring is sleeved on the outer side of the winding frame, the upper end of the electromagnetic spring is fixedly connected to the piston plate, and the lower end of the electromagnetic spring is fixedly connected to the bottom of the upper cavity.

[0019] In some embodiments, a floating ring is slidably connected within the middle cavity.

[0020] In some embodiments, a push rod is slidably connected in the lower cavity, and a ring plate is sleeved on the push rod.

[0021] In some embodiments, the middle cavity below the floating ring is connected to the upper cavity through an oil transfer assembly, the upper cavity and the middle cavity below the floating ring are filled with cooling oil, the lower cavity is filled with cooling oil, and the ring plate is immersed in the cooling oil in the lower cavity.

[0022] In some embodiments, the oil delivery assembly includes two channels, the upper end of the channel is connected to the upper cavity, and the lower end of the channel is connected to the middle cavity below the floating ring, and a liquid pump is installed in one of the channels.

[0023] In some embodiments, the upper fixing plate and the lower fixing plate are connected by bolts.

[0024] The beneficial effects of the present invention are as follows:

[0025] 1. The electromagnetic spring is powered by the transmitter to shorten the electromagnetic spring. The electromagnetic spring pulls the piston plate downward to apply force. The piston plate drives the upper bias magnet, magnetostrictive rod, and lower bias magnet to apply force downward. The lower bias magnet presses against the top rod to apply force to the grounding grid down conductor. Providing an elastic wave front to the grounding grid down conductor can ensure that the top rod is tightly against the grounding grid down conductor, and that the grounding grid down conductor can provide a stable and continuous elastic wave, thereby reducing detection errors.

[0026] 2. Start the liquid pump while testing to circulate the cooling oil in the upper cavity and the cooling oil in the middle cavity, which can absorb the heat generated by the coil and the electromagnetic spring, thereby achieving a cooling effect and avoiding overheating. The temperature at the collision point between the lower bias magnet and the ejector rod will also rise, and the heat generated at the collision point will be absorbed by the cooling oil under the floating ring.

[0027] 3. Part of the noise generated by the lower bias magnet constantly hitting the ejector pin will be absorbed as it passes through the cooling oil under the floating ring.

[0028] 4. The temperature between the top rod and the grounding grid lead wire will rise due to impact, and the cooling oil in the lower cavity can absorb the heat at the impact point.

[0029] 5. Part of the noise generated by the ejector rod continuously striking the grounding grid lead wire will be absorbed when passing through the cooling oil in the lower cavity.

[0030] 6. The cooling oil level in the lower cavity is higher than the top surface of the ring plate, and the cooling oil can provide greater resistance. Therefore, after completing a single impact process, the ejector rod can quickly decelerate and stop under the action of the cooling oil, reducing the stroke of the ejector rod in a single impact, so that the ejector rod in the technical solution of the present invention can perform higher-frequency impacts, and the time of a single detection is greatly shortened. During the continuous impact process, the shell itself will also vibrate up and down. Under the action of the cooling oil inside the floating ring and the middle cavity, when the shell vibrates up and down, the cooling oil inside the floating ring and the middle cavity will also vibrate up and down, but the lower surface of the floating ring is in contact with the cooling oil in the middle cavity, and the floating ring will have a certain buffering effect on the vibration of the shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of the elastic wave vibration source of the present invention from one perspective;

[0032] Figure 2 yes Figure 1 Schematic diagram of the structure inside the elastic wave source shown;

[0033] Figure 3 It is a flow chart of the guided wave detection process for the damage status of the grounding body of power transmission and transformation equipment;

[0034] In the accompanying drawings, 1 is a shell; 2 is an upper cavity; 3 is a piston plate; 4 is an upper bias magnet; 5 is a magnetostrictive rod; 6 is a lower bias magnet; 7 is a winding frame; 8 is a coil; 9 is an electromagnetic spring; 10 is a middle cavity; 11 is a channel; 12 is a liquid pump; 13 is a floating ring; 14 is a lower cavity; 15 is a push rod; 16 is a ring plate; 17 is an upper fixing plate; 18 is a lower fixing plate; 19 is a bolt; 20 is a grounding grid lead-in wire. DETAILED DESCRIPTION

[0035] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] As described in the background technology, most traditional studies are aimed at corrosion detection of grounding grids, and there are fewer studies on grounding grid down conductors. In grounding accidents, most accidents are caused by the detachment of the down conductor and the grounding grid welding point or the defects of the down conductor itself. Therefore, how to perform efficient and non-destructive detection of the corrosion state of the grounding grid down conductor has become a technical problem that needs to be solved urgently by technical personnel in this field.

[0037] To solve the above problems, refer to Figure 1 , Figure 2 and Figure 3The present invention provides a waveguide detection process for the damage state of the grounding body of power transmission and transformation equipment, comprising the following steps:

[0038] S1, clamp one end of the grounding grid down conductor 20 extending out of the ground between the upper fixing plate 17 and the lower fixing plate 18, and install a plurality of acceleration sensors at the end of the grounding grid down conductor 20 extending out of the ground;

[0039] S2, electrically connecting the plurality of acceleration sensors to the corrosion detection system respectively;

[0040] S3, the electromagnetic spring 9 inside the housing 1 is energized through the transmitter, so that the electromagnetic spring 9 is shortened and pulls the piston plate 3 to move downward, and the piston plate 3 drives the upper bias magnet 4, the magnetostrictive rod 5 and the lower bias magnet 6 to move downward, and the lower bias magnet 6 abuts against the push rod 15, so that the push rod 15 is subjected to downward pressure, and the pressure is applied to the grounding grid down conductor 20, thereby causing the magnetostrictive rod 5 to be subjected to prestress;

[0041] S4, inputting an excitation current to the coil 8 through the transmitter, the coil 8 intermittently generates a magnetic field, causing the magnetostrictive rod 5 in the magnetic field to intermittently deform and drive the top rod 15 to intermittently hit the grounding grid down conductor 20 through the lower bias magnet 6, thereby generating elastic waves in the grounding grid down conductor 20;

[0042] S5, while performing step S4, the transmitter applies an excitation current of the same frequency to the electromagnetic spring 9, so that the electromagnetic spring 9 is intermittently deformed, and the deformation frequency of the electromagnetic spring 9 and the magnetostrictive rod 5 is the same, and the magnetostrictive rod 5 drives the top rod 15 to hit the grounding grid down conductor 20 through the lower bias magnet 6 to generate elastic waves;

[0043] S6. Multiple acceleration sensors record reflected echo signals. The reflected echo signals are collected by an AD signal collector after passing through a signal amplifier and then transmitted to a computer through a data transmission module. After the computer processes the reflected echo signals, corrosion information of the grounding grid down conductor 20 can be obtained.

[0044] Specifically, the computer can be electrically connected to the embedded control system, and the embedded control system is electrically connected to the transmitter, so that the technical solution of the present invention can realize automatic control, continuous detection, real-time response, and rapid processing of the echo signal generated by the impact. The current size of the electromagnetic spring 9 is controlled by the transmitter so that the prestress of the magnetostrictive rod 5 reaches the required value. Before providing elastic waves to the grounding grid down conductor 20, it is necessary to first complete step S2 to ensure that the top rod 15 is tightly against the grounding grid down conductor 20, to ensure the consistency of the elastic waves provided by the grounding grid down conductor 20, and the transmitter is powered by an adjustable DC power supply; the coil 8 and the electromagnetic spring 9 will synchronously act on the magnetostrictive rod 5, so that the magnetostrictive rod 5 drives the top rod 15 to impact the grounding grid down conductor 20 through the lower bias magnet 6 to generate elastic waves, and can provide stronger elastic waves to the grounding grid down conductor 20.

[0045] Preferably, the liquid pump 12 is started while performing step S4 and step S5 to circulate the cooling oil in the upper cavity 2 and the cooling oil in the middle cavity 10 to absorb the heat generated by the coil 8 and the electromagnetic spring 9 .

[0046] Preferably, a plurality of acceleration sensors are arranged linearly on the grounding grid down conductor 20 .

[0047] Specifically, linearly arranged acceleration sensors can receive echoes evenly and promptly, thereby reducing detection errors.

[0048] Preferably, an upper cavity 2 , a middle cavity 10 and a lower cavity 14 are provided inside the shell 1 .

[0049] Preferably, a piston plate 3 is slidably connected in the upper cavity 2, the top of the piston plate 3 is connected to the upper bias magnet 4, a winding frame 7 is fixedly connected below the piston plate 3, a coil 8 is wound on the winding frame 7, a magnetostrictive rod 5 is installed in the winding frame 7, the upper end of the magnetostrictive rod 5 is connected to the upper bias magnet 4, and the lower end is connected to the lower bias magnet 6, an electromagnetic spring 9 is sleeved on the outer side of the winding frame 7, the upper end of the electromagnetic spring 9 is fixedly connected to the piston plate 3, and the lower end of the electromagnetic spring 9 is fixedly connected to the bottom of the upper cavity 2.

[0050] Preferably, a floating ring 13 is slidably connected in the middle cavity 10 .

[0051] Specifically, when the housing 1 vibrates, the floating ring 13 will form a reverse force relative to the housing 1, which plays a buffering role on the housing 1 and maintains the stability of the entire detection process.

[0052] Preferably, a push rod 15 is slidably connected in the lower cavity 14 , and a ring plate 16 is sleeved on the push rod 15 .

[0053] Preferably, the middle cavity 10 below the floating ring 13 is connected to the upper cavity 2 through an oil transfer assembly, the upper cavity 2 and the middle cavity 10 below the floating ring 13 are filled with cooling oil, the lower cavity 14 is filled with cooling oil, and the ring plate 16 is immersed in the cooling oil in the lower cavity 14.

[0054] Specifically, the cooling oil can cool the impact and friction points on the one hand, and can also serve as a medium for buffering and vibration reduction on the other hand.

[0055] Preferably, the oil delivery assembly includes two channels 11 , the upper ends of the channels 11 are connected to the upper chamber 2 , and the lower ends are connected to the middle chamber 10 below the floating ring 13 , and a liquid pump 12 is installed in one of the channels 11 .

[0056] Specifically, the liquid pump 12 can circulate the cooling oil in the upper cavity 2 and the cooling oil in the middle cavity 10, thereby quickly absorbing the heat generated by the coil 8 and the electromagnetic spring 9, thereby achieving a cooling effect and improving the accuracy of detection.

[0057] Preferably, the upper fixing plate 17 and the lower fixing plate 18 are connected by bolts 19 .

[0058] Specifically, the grounding grid down conductor 20 is clamped between the upper fixing plate 17 and the lower fixing plate 18 , and is fastened by bolts 19 .

[0059] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0060] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0061] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0062] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples" or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0063] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A waveguide detection process for the damage status of the grounding body of power transmission and transformation equipment, characterized in that: The following steps are involved: S1, clamping one end of the grounding grid down conductor (20) extending out of the ground between an upper fixing plate (17) and a lower fixing plate (18), and installing a plurality of acceleration sensors on the end of the grounding grid down conductor (20) extending out of the ground; S2, electrically connecting the plurality of acceleration sensors to the corrosion detection system respectively; S3, energizing the electromagnetic spring (9) inside the housing (1) through the transmitter, so that the electromagnetic spring (9) shortens and pulls the piston plate (3) downward, the piston plate (3) drives the upper bias magnet (4), the magnetostrictive rod (5) and the lower bias magnet (6) to move downward, the lower bias magnet (6) abuts against the push rod (15), so that the push rod (15) is subjected to downward pressure, and the pressure is applied to the grounding grid down conductor (20), thereby causing the magnetostrictive rod (5) to be subjected to prestress; S4, inputting an excitation current into the coil (8) through the transmitter, the coil (8) intermittently generates a magnetic field, causing the magnetostrictive rod (5) in the magnetic field to generate intermittent deformation and drive the top rod (15) to intermittently impact the grounding grid down conductor (20) through the lower bias magnet (6), thereby generating elastic waves in the grounding grid down conductor (20); S5. While performing step S4, the transmitter applies an excitation current of the same frequency to the electromagnetic spring (9), so that the electromagnetic spring (9) is intermittently deformed, and the deformation frequency of the electromagnetic spring (9) and the magnetostrictive rod (5) is the same. The magnetostrictive rod (5) drives the top rod (15) to hit the grounding grid down conductor (20) through the lower bias magnet (6) to generate elastic waves; S6. A plurality of acceleration sensors record reflected echo signals. The reflected echo signals are collected by an AD signal collector after passing through a signal amplifier and then transmitted to a computer through a data transmission module. After the computer processes the reflected echo signals, corrosion information of the grounding grid down conductor (20) can be obtained.

2. The waveguide detection process for the damage status of the grounding body of the power transmission and transformation equipment according to claim 1 is characterized in that: While performing steps S4 and S5, the liquid pump (12) is started to circulate the cooling oil in the upper chamber (2) and the cooling oil in the middle chamber (10) to absorb the heat generated by the coil (8) and the electromagnetic spring (9).

3. The waveguide detection process for the damage status of the grounding body of the power transmission and transformation equipment according to claim 1 is characterized in that: The plurality of acceleration sensors are arranged linearly on the grounding grid down conductor (20).

4. The waveguide detection process for the damage status of the grounding body of the power transmission and transformation equipment according to claim 1 is characterized in that: An upper chamber (2), a middle chamber (10) and a lower chamber (14) are arranged inside the housing (1).

5. The waveguide detection process for the damage state of the grounding body of the power transmission and transformation equipment according to claim 4 is characterized in that: The piston plate (3) is slidably connected in the upper chamber (2), the top of the piston plate (3) is connected to the upper bias magnet (4), the bottom of the piston plate (3) is fixedly connected to a winding frame (7), a coil (8) is wound on the winding frame (7), the magnetostrictive rod (5) is installed in the winding frame (7), the upper end of the magnetostrictive rod (5) is connected to the upper bias magnet (4), and the lower end is connected to the lower bias magnet (6), an electromagnetic spring (9) is sleeved on the outer side of the winding frame (7), the upper end of the electromagnetic spring (9) is fixedly connected to the piston plate (3), and the lower end of the electromagnetic spring (9) is fixedly connected to the bottom of the upper chamber (2).

6. The waveguide detection process for the damage state of the grounding body of the power transmission and transformation equipment according to claim 4 is characterized in that: A floating ring (13) is slidably connected in the middle cavity (10).

7. The waveguide detection process for the damage state of the grounding body of the power transmission and transformation equipment according to claim 6 is characterized in that: A push rod (15) is slidably connected in the lower chamber (14), and a ring plate (16) is sleeved on the push rod (15).

8. The waveguide detection process for the damage state of the grounding body of the power transmission and transformation equipment according to claim 7 is characterized in that: The middle cavity (10) below the floating ring (13) is connected to the upper cavity (2) via an oil transfer assembly; the upper cavity (2) and the middle cavity (10) below the floating ring (13) are both filled with cooling oil; the lower cavity (14) is filled with cooling oil; and the ring plate (16) is immersed in the cooling oil in the lower cavity (14).

9. The waveguide detection process for the damage state of the grounding body of the power transmission and transformation equipment according to claim 8 is characterized in that: The oil delivery assembly comprises two channels (11), the upper ends of the channels (11) being in communication with the upper chamber (2), and the lower ends being in communication with the middle chamber (10) below the floating ring (13), wherein a liquid pump (12) is installed in one of the channels (11).

10. The waveguide detection process for the damage status of the grounding body of power transmission and transformation equipment according to claim 1 is characterized in that: The upper fixing plate (17) and the lower fixing plate (18) are connected via bolts (19).

Images