A method and device for displaying grounding point from the ground below a high-voltage line

Abstract

The present invention relates to a method and device for displaying a grounding point from the ground below a high-voltage line, which is applicable to a pole tower without a grounding wire and belongs to the technical field of power system inspection. The technical scheme is: an electrode 1 (5) and an electrode 2 (6) are buried under the ground (2) close to the pole tower, a signal processor (4) is composed of a calculation module and a grounding fault indication module, the output ends of the electrode 1 (5) and the electrode 2 (6) are respectively connected to the two input ends of the isolation transformer T1; the grounding fault indication module is composed of a flip card indication circuit and a night-time start light lightning circuit connected in sequence. The present invention determines whether it is a grounding point by detecting the grounding lead current of the high-voltage transmission line and the ground potential difference, and then sends a corresponding signal. It can be used for all high-voltage transmission lines without a grounding wire to conveniently and quickly find the grounding point.

Description

Technical Field

[0001] The invention relates to a method and a device for displaying a grounding point from the ground below a high-voltage line, which is suitable for a pole tower without a grounding wire and belongs to the technical field of power system inspection. Background Art

[0002] At present, 35kV and 10kV high-voltage transmission lines are mostly grounding accidents, and the thunderstorm season is the peak of frequent grounding accidents. If a grounding fault occurs in a transmission line, if there is no auxiliary equipment such as lightning arrester switch, there are only insulators. Due to external mechanical damage, overvoltage, cracking, deglazing, natural aging and serious contamination (dust pollution and filth), the insulators of overhead lines will cause flashover discharge or breakdown, resulting in grounding and causing large-scale power outages. Such accidents often occur on 10kV 35kV lines. Insulators cause grounding accidents. If the insulator has an obvious breakdown point, it can be seen with a high-power telescope when looking for grounding, and it can also be found by searching with an unmanned helicopter. After confirming that it is the grounding point, a new insulator can be directly replaced. However, only about 40% of the insulators have obvious breakdown points, and 60% of the insulators are not very obvious in appearance after internal fragmentation, and cannot be directly observed from the appearance. High-power telescopes and unmanned helicopters cannot find it. It can only rely on manual climbing operations, careful observation or actual measurement of the quality of the insulators with instruments. The problems with the existing technology are: it is the most difficult job for front-line workers to find the grounding point of the transmission line. In actual work, the grounding point is mainly found by visual inspection; someone has designed a fault indicator, but its working principle is to detect the 5th harmonic after the line is grounded, which has many false operations and is unreliable, and the actual application effect is not good. The pole towers of high-voltage lines are divided into two types: those with grounding wires and those without grounding wires. For the pole towers with grounding wires, the applicant's invention patent 201510792698.X, "A lightning arrester grounding indicator and lightning arrester grounding indication method" has solved the above problems. However, for the pole towers without grounding wires, the existing technology has no effective solution. Summary of the invention

[0003] The purpose of the present invention is to provide a method and device for displaying a grounding point from the ground below a high-voltage line, which is suitable for a pole tower without a grounding wire. By detecting the grounding lead current of the high-voltage transmission line and the ground potential difference, it is determined whether it is a grounding point, and then a corresponding signal is sent. The method and device can be used for all high-voltage transmission lines without a grounding wire, and the grounding point can be found conveniently and quickly, thereby solving the above-mentioned problems existing in the background technology.

[0004] The technical solution of the present invention is:

[0005] A device for displaying a grounding point from the ground below a high-voltage line, wherein a solar cell panel is arranged on the upper part of a pole tower, a signal processor, an alarm display and a color flipping plate indicator are arranged on the lower part of the pole tower, an electrode 1 and an electrode 2 are buried under the ground near the pole tower, the pole tower, the electrode 1 and the electrode 2 are in a straight line, the electrode 1 is located between the pole tower and the electrode 2, the electrode 1 is close to the pole tower, the electrode 1 and the electrode 2 are 1 meter apart, the center line of the electrode 1, the center line of the electrode 2 and the center line of the pole tower are parallel to each other, and the three center lines are located in the same plane perpendicular to the ground; the signal processor is composed of an operation module and a grounding fault indication module, the operation module includes: an isolation transformer T1, an AC limiting circuit, a current limiting protection circuit and an amplifier circuit are connected in sequence, the output ends of the electrode 1 and the electrode 2 are respectively connected to the two input ends of the isolation transformer T1; The ground fault indication module is composed of a flip indication circuit and a night start light lightning circuit connected in sequence. The flip indication circuit is composed of a field effect tube Q4, a transistor Q3, a relay K1, a color flip plate motor M and a flip limit S1 connected in sequence. The output end of the amplifier circuit is connected to the field effect tube Q4. The color flip plate motor M drives the color flip plate indicator. The flip limit S1 is located on the color flip plate indicator. The night start light lightning circuit is composed of an on-off oscillation circuit, a transistor Q1, light emitting tubes LED1-6 and a voltage comparison circuit connected in sequence. The light emitting tubes LED1-6 are alarm displays. The color flip plate indicator is composed of a color flip plate motor M, a flip limit S1 and a color plate. A color plate is provided on the motor shaft of the color flip plate motor M. The color plate has two colors. The color flip plate motor M drives the color plate to rotate. The color plate matches the flip limit S1 to limit the rotation angle of the color plate.

[0006] The solar panel is composed of a solar panel, a lithium battery pack and a voltage stabilizing circuit connected in sequence. The solar panel is connected to the lithium battery pack for charging. The lithium battery pack outputs power after passing through the voltage stabilizing circuit to supply power to the signal processor, the alarm display and the color flipping plate indicator.

[0007] The AC amplitude limiting circuit is composed of a resistor R1 and a diode D1, the current limiting protection circuit is composed of a resistor R2 and a resistor R3, and the amplifier circuit is composed of a chip U2, which is a VG54-123-M chip produced by Shanghai Microcrystalline Technology Company.

[0008] Isolation transformer T1 isolates high potential to ensure the safety of instruments and personnel; resistor R1 and diode D1 form an AC limiting circuit to control the AC signal below 3V, and after passing through resistor R2 and resistor R3 to form a current limiting protection circuit, it enters the chip U2 of the amplifier circuit. This chip is the VG54-123-M chip produced by Shanghai Microcrystalline Technology Co., Ltd. This chip has high input sensitivity, and the typical value is VT=61mv. The core function is to amplify tiny currents and is used to determine whether the amplifier circuit outputs a high level. When the local line current is greater than 0.01A and there is a delay greater than 5 milliseconds, the output is a high level.

[0009] The comparison circuit is composed of a voltage comparison chip U4, a photodiode, a resistor R6, a resistor R7 and a resistor R8. During the day, when the sunlight is strong, the comparison circuit outputs a high level, the transistor Q2 is not turned on, and the alarm display does not work. At night, it outputs a low level, the transistor Q2 is turned on, and the on-off oscillation circuit is composed of a 555 chip U3, a capacitor C11, a resistor R4, a resistor R5, a diode D2 and a diode D3. The 555 chip U3 outputs a low level for 3 seconds and a high level for 2 seconds, controlling the on and off of the transistor Q1, causing the light-emitting tubes LED1-6 to flash, making it easy for inspection personnel to find it from a distance.

[0010] The voltage comparison chip U4 is LM393, and the photodiode is a GJI photodiode.

[0011] The color flip plate indicator, signal processor and alarm display are arranged in a barrel-shaped shell, the upper opening is provided with a protective cover, and the outer wall of the shell is provided with an alarm display; the inner bottom is provided with a circuit board of the signal processor and an isolation transformer T1, the upper part of the shell is provided with a color flip plate motor M, the motor shaft of the color flip plate motor M is arranged vertically upward, and a color plate is provided on the motor shaft. The color plate has two colors, red and white. The color plate is located in the protective cover, and a flip limit S1 is provided on the protective cover to limit the rotation angle of the color plate, and a window is opened on the protective cover.

[0012] A method for displaying a grounding point from the ground below a high-voltage line, using the above device to detect and display whether an insulator on a tower of a high-voltage line without a grounding wire is struck by lightning, wherein there is no lightning arrester on the tower of the high-voltage line without a grounding wire, and only the insulator supports the high-voltage conductor to pass through; the specific steps are as follows:

[0013] When an insulator is broken down and a ground fault occurs, the ground current is directed to the earth along the tower; a step voltage appears on the ground below the tower, spreading outward from the tower as the center; the electrode 1 and the electrode 2 buried under the ground generate a voltage difference signal, which enters the isolation transformer T1, and the isolation transformer T1 isolates the high potential to ensure safety; the output signal passes through the AC limiting circuit to control the AC signal below 3V; after passing through the current limiting protection circuit, it enters the amplifier circuit, and when the current is greater than 0.01A and there is a delay greater than 5 milliseconds, the output is high level; the rest outputs are low level;

[0014] The output high level makes the field effect tube Q4 conduct, and connects to the negative pole of the solar cell panel power supply; the flip indicator circuit works, first the transistor Q3 conducts the relay K1 to act, the color flipping plate motor M rotates, and the color plate rotates from one color to another, which is convenient for daytime patrol personnel to find; after the color plate rotates into place, it touches the flip limit S1, and the color flipping plate motor M stops rotating; if it is daytime and the sunlight is strong, the voltage comparison circuit outputs a high level, and the alarm display does not work; if it is night, the voltage comparison circuit outputs a low level, and the alarm display works; it emits a flash of light, which is convenient for patrol personnel to find from a distance.

[0015] The beneficial effects of the present invention are as follows: the present invention is applicable to pole towers without grounding wires, determines whether it is a grounding point by detecting the grounding lead current of the high-voltage transmission line and the ground potential difference, and then sends out a corresponding signal. The present invention can be used for all high-voltage transmission lines without grounding wires to conveniently and quickly find grounding points. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of an embodiment of the present invention;

[0017] Figure 2 is a schematic diagram of a housing according to an embodiment of the present invention;

[0018] Figure 3 is a schematic diagram of the interior of a housing according to an embodiment of the present invention;

[0019] FIG4 is a system block diagram of the present invention;

[0020] Figure 5 It is a specific diagram of an embodiment of the present invention;

[0021] Figure 6 is a schematic diagram of a solar cell panel according to an embodiment of the present invention;

[0022] Figure 7 is a schematic diagram of a computing module according to an embodiment of the present invention;

[0023] Figure 8 Schematic diagram of the card flipping indication circuit and night-time start-up light lightning circuit of an embodiment of the present invention;

[0024] In the figure: tower 1, ground 2, solar panel 3, signal processor 4, electrode one 5, electrode two 6, alarm display 7, color flip plate indicator 8, housing 9, motor shaft 10, shield 11, color plate 12, window 13, solar panel 14. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0026] A device for displaying a grounding point from the ground below a high-voltage line, wherein a solar cell panel 3 is arranged on the upper part of a pole tower 1, a signal processor 4, an alarm display 7 and a color flip plate indicator 8 are arranged on the lower part of the pole tower 1, an electrode 1 5 and an electrode 2 6 are buried under the ground 2 close to the pole tower, the pole tower, the electrode 1 5 and the electrode 2 6 are in a straight line, the electrode 1 5 is located between the pole tower and the electrode 2 6, the electrode 1 5 is close to the pole tower, the electrode 1 5 and the electrode 2 6 are 1 meter apart, the center line of the electrode 1 5, the center line of the electrode 2 6 and the center line of the pole tower 1 are parallel to each other, and the three center lines are located in the same plane perpendicular to the ground; the signal processor 4 is composed of a calculation module and a ground fault indication module, the calculation module includes: an isolation transformer T1, an AC limiting circuit, a current limiting protection circuit and an amplifier circuit are connected in sequence, the output ends of the electrode 1 5 and the electrode 2 6 are respectively connected to the two ends of the isolation transformer T1 An input end; the ground fault indication module is composed of a flip indication circuit and a night start light lightning circuit connected in sequence, the flip indication circuit is composed of a field effect tube Q4, a triode Q3, a relay K1, a color flip plate motor M and a flip limit S1 connected in sequence, the output end of the amplifier circuit is connected to the field effect tube Q4, the color flip plate motor M drives the color flip plate indicator 8, and the flip limit S1 is located on the color flip plate indicator 8; the night start light lightning circuit is composed of an on-off oscillation circuit, a triode Q1, a light emitting tube LED1-6 and a voltage comparison circuit connected in sequence; the light emitting tube LED1-6 is an alarm display 7, the color flip plate indicator 8 is composed of a color flip plate motor M, a flip limit S1 and a color plate 12, a color plate 12 is provided on the motor shaft 10 of the color flip plate motor M, and the color plate has two colors, the color flip plate motor M drives the color plate to rotate, the color plate matches the flip limit S1, and the rotation angle of the color plate is limited.

[0027] The solar panel 3 is composed of a solar panel 14, a lithium battery pack BT1 and a voltage stabilizing circuit connected in sequence. The solar panel is connected to the lithium battery pack for charging. The lithium battery pack outputs power after the voltage stabilizing circuit to supply power to the signal processor 4, the alarm display 7 and the color flipping plate indicator 8.

[0028] The AC amplitude limiting circuit is composed of a resistor R1 and a diode D1, the current limiting protection circuit is composed of a resistor R2 and a resistor R3, and the amplifier circuit is composed of a chip U2, which is a VG54-123-M chip produced by Shanghai Microcrystalline Technology Company.

[0029] Isolation transformer T1 isolates high potential to ensure the safety of instruments and personnel; resistor R1 and diode D1 form an AC limiting circuit to control the AC signal below 3V, and after passing through resistor R2 and resistor R3 to form a current limiting protection circuit, it enters the chip U2 of the amplifier circuit. This chip is the VG54-123-M chip produced by Shanghai Microcrystalline Technology Co., Ltd. This chip has high input sensitivity, and the typical value is VT=61mv. The core function is to amplify tiny currents and is used to determine whether the amplifier circuit outputs a high level. When the local line current is greater than 0.01A and there is a delay greater than 5 milliseconds, the output is a high level.

[0030] The comparison circuit is composed of a voltage comparison chip U4, a photodiode, a resistor R6, a resistor R7 and a resistor R8. When the sunlight is strong during the day, the comparison circuit outputs a high level, the transistor Q2 is not turned on, and the alarm display 7 does not work; at night, the output is a low level, the transistor Q2 is turned on, and the on-off oscillation circuit is composed of a 555 chip U3, a capacitor C11, a resistor R4, a resistor R5, a diode D2 and a diode D3. The 555 chip U3 outputs a low level for 3 seconds and a high level for 2 seconds, controls the on and off of the transistor Q1, and makes the light-emitting tubes LED1-6 flash, which is convenient for inspection personnel to find from a distance.

[0031] The voltage comparison chip U4 is LM393, and the photodiode is a GJI photodiode.

[0032] The color flip plate indicator 8, signal processor 4 and alarm display 7 are arranged in a barrel-shaped shell 9, the upper end opening is provided with a protective cover 11, and the outer wall of the shell 9 is provided with an alarm display 7; the inner bottom is provided with a circuit board and an isolation transformer T1 of the signal processor 4, and the upper part of the shell is provided with a color flip plate motor M, the motor shaft 10 of the color flip plate motor M is arranged vertically upward, and a color plate 12 is provided on the motor shaft 10. The color plate 12 has two colors, red and white. The color plate 12 is located in the protective cover 11, and a flip limit S1 is provided on the protective cover to limit the rotation angle of the color plate, and a window 13 is opened on the protective cover.

[0033] A method for displaying a grounding point from the ground below a high-voltage line, using the above device to detect and display whether an insulator on a tower of a high-voltage line without a grounding wire is struck by lightning, wherein there is no lightning arrester on the tower of the high-voltage line without a grounding wire, and only the insulator supports the high-voltage conductor to pass through; the specific steps are as follows:

[0034] When an insulator is broken down and a ground fault occurs, the ground current is directed to the earth along the tower; a step voltage appears on the ground below the tower 1 and spreads to the surrounding area with the tower as the center; the electrode 1 5 and the electrode 2 6 buried under the ground 2 generate a voltage difference signal and enter the isolation transformer T1, which isolates the high potential to ensure safety; the output signal passes through the AC limiting circuit to control the AC signal below 3V; after passing through the current limiting protection circuit, it enters the amplifier circuit, and when the current is greater than 0.01A and there is a delay greater than 5 milliseconds, the output is high level; the rest outputs are low level;

[0035] The output high level makes the field effect tube Q4 conduct, and connects to the negative pole of the power supply of the solar cell panel 3; when the flip indicator circuit works, first the transistor Q3 conducts and the relay K1 is activated, the color flipping plate motor M rotates, and the color plate rotates from one color to another, which is convenient for daytime patrol personnel to find; after the color plate rotates into place, it touches the flip limit S1, and the color flipping plate motor M stops rotating; if it is daytime and the sunlight is strong, the voltage comparison circuit outputs a high level, and the alarm display 7 does not work; if it is night, the voltage comparison circuit outputs a low level, and the alarm display 7 works; it emits a flash of light, which is convenient for patrol personnel to find from a distance.

[0036] In the embodiment, when a ground fault occurs due to a defect in an insulator, the ground current will be directed to the earth along the straight pole. A potential (i.e., step voltage) appears on the ground below the pole, spreading outward from the pole as the center. If a person approaches at this time, it is very dangerous and may be electrocuted by the step voltage. This proves from the side that if two electrodes are installed, one close to the pole and the other one meter away from it, there will be a strong potential difference between the two electrodes, and a ground signal can be obtained. The overall block diagram of the present invention is attached. Figure 4 , see the attached block diagram of the embodiment Figure 5 .

[0037] Solar panel 3 is a long-term power source, see the schematic diagram attached Figure 6 The micro 12v20ma solar panel takes energy, charges the 15V iron-lithium battery pack BT1 through the diode D1 and capacitor C1, and then provides a long-term and reliable working power supply for the subsequent circuits through the 7812V voltage stabilizing circuit.

[0038] See the attached schematic diagram of the operation module Figure 7, Electrode 1 5 and electrode 2 6 are installed in the soil 2 below the tower 1, one meter apart, and the isolation transformer T1 isolates the high potential to ensure the safety of the instrument and personnel. Resistor R1 and diode D1 limit the AC amplitude to control the AC signal below 3V; after the current limiting protection of resistors R2 and R3, it enters the chip U2, which is the VG54-123-M chip produced by Shanghai Microcrystalline Technology Co., Ltd., with high input sensitivity, and the typical value is VT=61mv. The core function is to amplify small currents. When the local line current is greater than 0.01A and there is a delay greater than 5 milliseconds, the output is high level.

[0039] See the attached schematic diagram of the flip indicator circuit and the night start light lightning circuit Figure 8 ; When the ground signal is output, the 7th pin of the U2 chip outputs a high level. The field effect tube Q4 is turned on, which is equivalent to connecting the negative pole of the power supply. First, the transistor Q3 is turned on, the relay K1 is activated, the color flip motor M rotates, the color plate 12 rotates from white to red, and the flip limit S1 is touched to open, and the color flip motor M stops rotating. The voltage comparison chip U4 is an LM393 voltage comparison chip, which forms a voltage comparison circuit with the photosensitive diode GJI, resistors R6, R7, and R8.

[0040] If it is daytime and the sunlight is strong, the output is high level, the transistor Q2 is not turned on, the alarm display 7 does not work during the day, and the color-changing plate motor M works; if it is at night, the voltage comparison circuit outputs a low level, the transistor Q2 is turned on, the 555 chip U3 and the capacitor C11, the resistor R4, the resistor R5, the diode D2, and the diode D3 form an on-off oscillation circuit, and the 3rd pin of the 555 chip U3 outputs a low level for 3 seconds and a high level for 2 seconds, which controls the on and off of the transistor Q1, making the light-emitting tubes LED1-6 flash, that is, the alarm display 7 flashes, which is convenient for inspection personnel to find from a distance.

[0041] In the embodiment, the solar panel 14 is a 12v50mA photovoltaic panel, which is integrally cast with a strong magnet through epoxy resin, so as to be directly adhered to the structural hardware. Electrode 1 and motor 2 are made of carbon rods, which have high conductivity and are corrosion-resistant, so as to be buried underground for a long time.

[0042] The present invention has a clear working principle and is easy to install. It is also more convenient to detect the condition of the equipment at any time. After the transmission line is grounded, a display can be shown on the ground below the grounding point, without the need to climb up the pole tower to check, thus laying a foundation for accurately and quickly finding the accident point and restoring power supply.

Claims

1. A device for displaying the grounding point from the ground below a high-voltage line, characterized in that: A solar panel (3) is provided on the upper part of the pole tower (1), a signal processor (4), an alarm display (7) and a color-changing plate indicator (8) are provided on the lower part of the pole tower (1), and an electrode 1 (5) and an electrode 2 (6) are buried under the ground (2) near the pole tower. The pole tower, the electrode 1 (5) and the electrode 2 (6) are in a straight line, the electrode 1 (5) is located between the pole tower and the electrode 2 (6), the electrode 1 (5) is close to the pole tower, the electrode 1 (5) and the electrode 2 (6) are 1 meter apart, the center line of the electrode 1 (5), the center line of the electrode 2 (6) and the center line of the pole tower (1) are parallel to each other, and the three center lines are located in the same plane perpendicular to the ground; the signal processor (4) is composed of a calculation module and a ground fault indication module, the calculation module includes: an isolation transformer T1, an AC limiting circuit, a current limiting protection circuit and an amplifier circuit connected in sequence, the output ends of the electrode 1 (5) and the electrode 2 (6) are respectively connected to the isolation transformer The ground fault indication module is composed of a flip indication circuit and a night start light lightning circuit connected in sequence, the flip indication circuit is composed of a field effect tube Q4, a triode Q3, a relay K1, a color flip plate motor M and a flip limit S1 connected in sequence, the output end of the amplifier circuit is connected to the field effect tube Q4, the color flip plate motor M drives the color flip plate indicator (8), and the flip limit S1 is located on the color flip plate indicator (8); the night start light lightning circuit is composed of an on-off oscillation circuit, a triode Q1, a light emitting tube LED1-6 and a voltage comparison circuit connected in sequence; the light emitting tube LED1-6 is an alarm display (7), the color flip plate indicator (8) is composed of a color flip plate motor M, a flip limit S1 and a color plate (12), the motor shaft (10) of the color flip plate motor M is provided with a color plate (12), the color plate has two colors, the color flip plate motor M drives the color plate to rotate, the color plate matches the flip limit S1, and the rotation angle of the color plate is limited; The color flip plate indicator (8), the signal processor (4) and the alarm display (7) are arranged in a barrel-shaped housing (9), the upper opening of which is provided with a protective cover (11), and the outer wall of the housing (9) is provided with an alarm display (7); the inner bottom is provided with a circuit board of the signal processor (4) and an isolation transformer T1, the upper part of the housing is provided with a color flip plate motor M, the motor shaft (10) of the color flip plate motor M is arranged vertically upward, a color plate (12) is provided on the motor shaft (10), the color plate (12) has two colors, red and white, the color plate (12) is located in the protective cover (11), a flip limiter S1 is provided on the protective cover to limit the rotation angle of the color plate, and a window (13) is opened on the protective cover; The voltage comparison circuit is composed of a voltage comparison chip U4, a photodiode, a resistor R6, a resistor R7 and a resistor R8. During the day when the sunlight is strong, the voltage comparison circuit outputs a high level, the transistor Q2 is not turned on, and the alarm display (7) does not work; at night, the voltage comparison circuit outputs a low level, the transistor Q2 is turned on, and the on-off oscillation circuit is composed of a 555 chip U3, a capacitor C11, a resistor R4, a resistor R5, a diode D2 and a diode D3. The 555 chip U3 outputs a low level for 3 seconds and a high level for 2 seconds, controlling the on and off of the transistor Q1, causing the light-emitting diodes LED1-6 to flash, making it easier for inspection personnel to detect from a distance.

2. A device for displaying a grounding point from the ground below a high-voltage line according to claim 1, characterized in that: The solar panel (3) is composed of a solar panel (14), a lithium battery pack BT1 and a voltage stabilizing circuit connected in sequence. The solar panel is connected to the lithium battery pack for charging. The lithium battery pack outputs power after passing through the voltage stabilizing circuit to supply power to the signal processor (4), the alarm display (7) and the color flipping plate indicator (8).

3. A method for displaying a grounding point from the ground below a high-voltage line, using the device described in claim 1 or 2 to detect and display whether an insulator on a tower of a high-voltage line without a grounding wire is broken by lightning, wherein there is no lightning arrester on the tower of the high-voltage line without a grounding wire, and only the insulator supports the high-voltage wire to pass through; the specific steps are as follows: When an insulator is broken down and a ground fault occurs, the ground current is directed to the ground along the tower; a step voltage appears on the ground below the tower (1) and spreads outward from the tower as the center; the electrode 1 (5) and the electrode 2 (6) buried under the ground (2) generate a voltage difference signal, which enters the isolation transformer T1, and the isolation transformer T1 isolates the high potential to ensure safety; the output signal passes through the AC limiting circuit to control the AC signal below 3V; after passing through the current limiting protection circuit, it enters the amplification circuit, and when the current is greater than 0.01A and there is a delay greater than 5 milliseconds, the output is a high level; the rest outputs a low level; The output high level turns on the field effect transistor Q4, which is connected to the negative pole of the power supply of the solar cell panel (3); the flip indicator circuit works, first the transistor Q3 turns on the relay K1, the color flip motor M rotates, and the color plate rotates from one color to another, which is convenient for daytime patrol personnel to find; after the color plate rotates to the right position, it triggers the flip limit S1, and the color flip motor M stops rotating; if it is daytime and the sunlight is strong, the voltage comparison circuit outputs a high level, and the alarm display (7) does not work; if it is nighttime, the voltage comparison circuit outputs a low level, and the alarm display (7) works; it emits a flash of light, which is convenient for patrol personnel to find from a distance.

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