Grounding grid corrosion detection method, system and sensor

Abstract

The present invention relates to the field of grounding grid detection technology, and proposes a grounding grid corrosion detection method, system, and sensor, which include the following steps: setting an excitation magnetic field on the ground above the grounding grid flat steel, magnetizing the flat steel under the action of the excitation magnetic field to generate an induced magnetic field; driving a vibrating coil to vibrate back and forth linearly at a constant frequency and amplitude within a spatial magnetic field formed by the superposition of the excitation magnetic field and the induced magnetic field; collecting and analyzing the AC induced voltage generated at both ends of the vibrating coil, and judging the grounding grid corrosion state based on the change in the amplitude of the AC induced voltage. The present invention is a completely contactless detection method, which drives the vibrating coil to vibrate back and forth linearly at a constant frequency and amplitude within a spatial magnetic field formed by the superposition of the excitation magnetic field and the induced magnetic field, generating an AC induced voltage at both ends of the vibrating coil, and judging the presence of corrosion on the current grounding grid flat steel based on the change in the amplitude of the AC induced voltage.

Description

Technical Field

[0001] The present invention relates to the technical field of grounding grid detection, and more specifically, to a grounding grid corrosion detection method, system and sensor based on vibration coil modulation. Background Art

[0002] Grounding grids are essential for the safe operation of substations and for the safety of operators. Grounding grid conductors are buried underground, and due to factors such as poor welding or soil corrosion, the flat steel of the grounding grid may corrode, thereby reducing the original design performance of the grounding grid. Assessing the corrosion status of the grounding grid is a key task for operations and maintenance departments.

[0003] Among the research on grounding grid detection methods, the main representative methods include the surface potential distribution detection method. This method detects the surface potential distribution of the substation grounding grid by injecting a current of a certain frequency and amplitude into the grounding grid and the soil. Corrosion and breakpoints in the grounding grid conductor are then detected based on the surface potential distribution characteristics. However, this method has the disadvantage that injecting the excitation current into the grounding grid requires driving an excitation electrode into the ground. In practice, this is difficult to do if there is a hardened layer above the grounding grid. The electrochemical detection method inserts a corrosion detection sensor into the soil to measure the electrochemical properties of the metal conductor in the surrounding soil during the corrosion process, thereby diagnosing the corrosion situation. However, this method can only reflect the corrosion situation at the probe location, and the sensor is difficult to insert into the hardened layer in actual engineering scenarios, which has certain limitations. The electromagnetic detection method injects a sinusoidal current of a certain frequency into the grounding grid through a down conductor, measures the distribution of the ground surface magnetic induction intensity, and determines the corrosion status and location of the grounding grid by comparing the magnetic field distribution characteristics and patterns between the corroded and uncorroded parts of the grounding grid and combining it with transient electromagnetic apparent resistivity imaging technology. However, since the grounding lead of the grounding grid needs to be released and the grounding end needs to be connected to the current, that is, the excitation electrode also needs to be driven into the ground, there is a problem of low detection efficiency during the operation. Summary of the Invention

[0004] In order to overcome the defects of the prior art described above, such as the need to drive excitation electrodes into the ground and the low detection efficiency, the present invention provides a grounding grid corrosion detection method, system and sensor.

[0005] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0006] A method for detecting grounding grid corrosion comprises the following steps:

[0007] S1. An excitation magnetic field is set on the ground above the flat steel of the grounding grid. The flat steel is magnetized under the action of the excitation magnetic field, generating an induced magnetic field.

[0008] S2. driving the vibration coil to vibrate reciprocatingly at a constant frequency and amplitude within a spatial magnetic field formed by the superposition of the excitation magnetic field and the induced magnetic field;

[0009] S3. Collect and analyze the AC induced voltage generated at both ends of the vibration coil, and determine the corrosion state of the grounding grid based on the change in the amplitude of the AC induced voltage.

[0010] This technical solution is a completely contactless detection method. It drives a vibrating coil to vibrate linearly at a constant frequency and amplitude within a spatial magnetic field formed by the superposition of an excitation magnetic field and an induced magnetic field. The vibrating coil cuts through the magnetic field within the spatial magnetic field, vibrating at a constant frequency and amplitude. An AC induced voltage is generated across the coil, the amplitude of which is determined by the magnetic permeability of the grounding grid steel. When the grounding grid steel is corroded, its magnetic permeability varies significantly. Specifically, the magnetic permeability of iron is significantly greater than that of rust. Therefore, a significant decrease in the amplitude of the AC induced voltage indicates corrosion on the grounding grid steel.

[0011] As a preferred solution, in the step S1, the step of setting an excitation magnetic field on the ground above the flat steel of the grounding grid includes: passing a direct current signal into an excitation coil winding with a magnetic core, and the excitation coil winding generates an excitation magnetic field.

[0012] As a preferred solution, in step S2, a motor and a crank slider mechanism are used to drive the vibration coil to perform reciprocating linear vibration at a constant frequency and amplitude in a spatial magnetic field formed by the superposition of the excitation magnetic field and the induced magnetic field.

[0013] As a preferred solution, in the step S3, when the amplitude of the AC induced voltage decreases, it is determined that there is ground grid corrosion at the corresponding position; wherein, in one movement cycle, the AC induced voltage generated at both ends of the vibrating coil Expressed as:

[0014]

[0015] Where B is the magnetic field strength, L is the length of the two ends of the vibration coil, represents the speed of the vibrating coil when it makes a periodic motion parallel to the x-direction; N is the number of turns of the coil winding, I is the input DC signal, Le is the effective magnetic circuit of the magnetic core, r is the length of the crank, l is the length of the connecting rod between the crank and the slider, and t is time.

[0016] Furthermore, the present invention also proposes a grounding grid corrosion detection system, which applies the grounding grid corrosion detection method proposed in any of the above technical solutions, and includes a DC power supply module, an excitation coil winding with a magnetic core, a vibration coil, a drive mechanism, and a detection module.

[0017] Among them, the DC power supply module is used to modulate the size and polarity of the DC signal and output it; the excitation coil winding is connected to the DC power supply module to form a loop; the driving mechanism is used to drive the vibration coil to perform reciprocating linear vibration at a constant frequency and amplitude in the spatial magnetic field formed by the superposition of the excitation magnetic field and the induced magnetic field; the detection module is used to collect the AC induced voltage generated at both ends of the vibration coil and analyze it. When the amplitude of the AC induced voltage is lower than the preset threshold, a corrosion detection signal is output.

[0018] As a preferred solution, the driving mechanism includes a motor and a slider-crank mechanism, the output shaft of the motor is connected to the crank driving end of the slider-crank mechanism through a coupling, and the slider end of the slider-crank mechanism is connected to the vibration coil.

[0019] As a preferred solution, the system also includes an alarm module, the input end of which is connected to the output end of the detection module; when the detection module outputs a corrosion detection signal, the detection module simultaneously outputs a working signal to the alarm module, and the alarm module works and issues an alarm.

[0020] As a preferred embodiment, the system also includes a magnetic shielding shell, the bottom of which is open, and the DC power supply module, excitation coil winding, vibration coil and drive mechanism are arranged in the magnetic shielding shell to ensure that the DC signal input to the excitation coil winding is only affected by the DC power supply module.

[0021] Furthermore, the present invention also proposes a sensor, including the grounding grid corrosion detection system proposed by any of the above technical solutions, for detecting the corrosion state of the grounding grid.

[0022] As a preferred solution, universal wheels are provided at the bottom of the sensor to facilitate the movement of the grounding grid corrosion detection system and to facilitate the grounding grid corrosion detection system to detect the entire grounding grid.

[0023] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

[0024] The present invention proposes a detection method without contact with the grounding grid. By driving a vibrating coil to vibrate back and forth linearly at a constant frequency and amplitude in a spatial magnetic field formed by the superposition of an excitation magnetic field and an induced magnetic field, an AC induced voltage is generated at both ends of the vibrating coil. The presence of corrosion on the flat steel of the current grounding grid is judged based on the change in the amplitude of the AC induced voltage. This can avoid the operation of driving excitation electrodes into the ground, effectively improve detection efficiency, and reduce work difficulty. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a flow chart of the grounding grid corrosion detection method in Example 1.

[0026] Figure 2Schematic diagram of the vibration state of the vibration coil in Example 1.

[0027] Figure 3 This is an architectural diagram of the grounding grid corrosion detection system of Example 2.

[0028] Figure 4 This is an architectural diagram of the grounding grid corrosion detection system of Example 3.

[0029] Figure 5 This is a diagram of the architecture of the sensor of Example 4. DETAILED DESCRIPTION

[0030] The accompanying drawings are for illustrative purposes only and are not to be construed as limiting this patent;

[0031] In order to better illustrate this embodiment, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product size;

[0032] It is understandable to those skilled in the art that some well-known structures and descriptions thereof may be omitted in the drawings.

[0033] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0034] Example 1

[0035] This embodiment proposes a grounding grid corrosion detection method, such as Figure 1 FIG. 1 is a flow chart of the grounding grid corrosion detection method according to the present embodiment.

[0036] The grounding grid corrosion detection method proposed in this embodiment includes the following steps:

[0037] S1. An excitation magnetic field is set on the ground above the flat steel of the grounding grid. The flat steel is magnetized under the action of the excitation magnetic field to generate an induced magnetic field.

[0038] In this embodiment, a direct current signal is passed into the excitation coil winding 2 with a magnetic core, and the excitation coil winding 2 generates an excitation magnetic field.

[0039] The flat steel is magnetized under the action of the excitation magnetic field to generate an induced magnetic field. At this time, the excitation magnetic field generated by the excitation coil winding 2 and the induced magnetic field generated by the flat steel are superimposed to form a spatial magnetic field.

[0040] S2. Drive the vibration coil 3 to perform reciprocating linear vibration at a constant frequency and amplitude in the spatial magnetic field formed by the superposition of the excitation magnetic field and the induced magnetic field.

[0041] In one embodiment, a motor 41 and a crank slider mechanism 42 are used to drive the vibration coil 3 to perform reciprocating linear vibration at a constant frequency and amplitude in a spatial magnetic field formed by the superposition of an excitation magnetic field and an induced magnetic field.

[0042] The crank slider mechanism 42 includes a crank and a slider, the motor 41 is connected to one end of the crank via a connector, the other end of the crank is connected to the slider, and the vibration coil 3 is provided on the slider.

[0043] S3. Collect and analyze the AC induced voltage generated at both ends of the vibration coil 3, and determine the corrosion state of the grounding grid based on the amplitude change of the AC induced voltage.

[0044] In this embodiment, when the amplitude of the AC induced voltage decreases, it is determined that ground grid corrosion exists at the corresponding position.

[0045] In the specific implementation process, a constant current I is passed through the coil winding outside the excitation coil, and the excitation coil generates an excitation magnetic field with a magnetic field strength of:

[0046]

[0047] Where N is the number of turns of the coil winding, I is the input DC signal, and Le is the effective magnetic circuit of the core.

[0048] The grounding grid flat steel is magnetized in the excitation magnetic field H and exhibits a certain degree of magnetism. At this time, the flat steel has a certain magnetic induction intensity B1:

[0049]

[0050] Where μ is the magnetic permeability of flat steel, and its value is μ=μ r μ0,μ r is the relative magnetic permeability, μ0 is the vacuum magnetic permeability.

[0051] The spatial magnetic field strength is the superposition of the magnetic field generated by the excitation and the magnetic field generated by the magnetization of the flat steel:

[0052]

[0053] Wherein, μ0H represents the magnetic induction intensity of the vibration coil 3.

[0054] Among the grounding grid flat steel materials, there is a huge difference in the magnetic permeability of iron and rust, as shown in Table 1 below.

[0055] Table 1 Magnetic permeability of common media in flat steel structures of grounding grids

[0056]

[0057] As can be seen from the table above, when the grounding grid flat steel is corroded, the relative magnetic permeability of the flat steel μ is much smaller than that of iron, because the relative magnetic permeability of rust is much smaller than that of iron. r will decrease. According to the above formula, we can know that μ r The decrease in will reduce the spatial magnetic field strength B.

[0058] In this embodiment, the vibration coil 3 is driven to perform reciprocating linear vibration at a constant frequency and amplitude in the spatial magnetic field formed by the superposition of the excitation magnetic field and the induced magnetic field, and the vibration coil 3 cuts the magnetic flux lines at a constant frequency and amplitude in the spatial magnetic field.

[0059] The vibration coil 3 is analyzed in a back and forth motion, such as Figure 2 The figure shows the vibration state of the vibration coil 3 in this embodiment. Based on the known grounding grid topology, assuming that the direction parallel to the grounding grid flat steel is the x direction and the direction perpendicular to the grounding grid is the y direction, the vibration coil 3 cuts through the magnetic field to generate an induced voltage at the two ends of the coils a and b. When the vibration coil 3 performs a periodic motion parallel to the x direction, its speed is for:

[0060]

[0061] Wherein, T is the period of the motor 41 movement, r is the crank length, l is the length of the connecting rod connecting the crank and the slider, and t is time.

[0062] In one motion cycle, the AC induced voltage generated at both ends of the vibration coils 3a and b is Expressed as:

[0063]

[0064] Where L is the length of the two ends of the vibration coil 3c, d.

[0065] When the grounding grid flat steel is corroded, the relative magnetic permeability μ r will decrease, μ r The decrease of will reduce the spatial magnetic field strength B. According to the above formula, the whole vibration coil 3 moves back and forth to generate an AC induced voltage, μ r The decrease in the amplitude of the AC induced voltage will reduce the amplitude of the AC induced voltage. Therefore, the corrosion of the flat steel can be detected by the change in the amplitude of the AC induced voltage.

[0066] Furthermore, the reciprocating frequency of the motor 41 is set to f M =1 / T, then the frequency of the reciprocating motion of the vibration coil 3 is f M , so the output AC induced voltage frequency is f E =f M , that is, the final AC induced voltage frequency is the same as the reciprocating frequency of the motor 41.

[0067] In this embodiment, the input current signal is a direct current, and the output is an alternating current induced voltage with the same frequency as the reciprocating motion of the motor 41. In this embodiment, the input direct current signal is modulated into an alternating current quantity through a spatial magnetic field, which can reduce the influence of the direct current interference field caused by other metals in the measurement environment.

[0068] This embodiment is a corrosion detection method that does not contact the grounding grid. It uses a vibration coil 3 to modulate the DC signal into an AC signal, reducing the influence of the DC interference field caused by other metals in the measurement environment. During use, corrosion detection can be completed directly by detecting the amplitude change of the output AC induced voltage, which can avoid the operation of driving excitation electrodes into the ground, effectively improving detection efficiency and reducing work difficulty.

[0069] Example 2

[0070] This embodiment proposes a grounding grid corrosion detection system based on vibration coil 3 modulation, and applies the grounding grid corrosion detection method based on vibration coil 3 modulation proposed in Example 1. Figure 3 , which is an architecture diagram of the grounding grid corrosion detection system based on the modulation of the vibration coil 3 in this embodiment.

[0071] The grounding grid corrosion detection system based on vibration coil 3 modulation proposed in this embodiment includes a DC power supply module 1, an excitation coil winding 2 with a magnetic core, a vibration coil 3, a driving mechanism 4 and a detection module 5.

[0072] The DC power supply module 1 in this embodiment is used to modulate the magnitude and polarity of a DC signal and output it. By modulating the magnitude and polarity of the DC signal, the amplitude and direction of the excitation magnetic field can be adjusted.

[0073] The excitation coil winding 2 with a magnetic core in this embodiment is connected to the DC power supply module 1 to form a loop.

[0074] The vibration coil 3 in this embodiment is connected to the driving end of the driving mechanism 4, and the driving mechanism 4 drives the vibration coil 3 to perform reciprocating linear vibration at a constant frequency and amplitude in the spatial magnetic field formed by the superposition of the excitation magnetic field and the induced magnetic field.

[0075] In one embodiment, the driving mechanism 4 includes a motor 41 and a slider-crank mechanism 42 . The output shaft of the motor 41 is connected to the crank driving end of the slider-crank mechanism 42 via a coupling. The slider end of the slider-crank mechanism 42 is connected to the vibration coil 3 .

[0076] The detection module 5 in this embodiment is used to collect and analyze the AC induced voltage generated at both ends of the vibration coil 3, and output a corrosion detection signal when the amplitude of the AC induced voltage is lower than a preset threshold.

[0077] During the specific implementation process, a grounding grid corrosion detection system is placed on the ground above the grounding grid flat steel to be detected. The DC power supply module 1 in the grounding grid corrosion detection system outputs a DC signal to the excitation coil winding 2 with a magnetic core. The excitation coil winding 2 forms an excitation magnetic field on the ground above the grounding grid flat steel. At this time, the steel is magnetized under the action of the excitation magnetic field to generate an induced magnetic field.

[0078] The control driving mechanism 4 works and drives the vibration coil 3 to vibrate back and forth linearly at a constant frequency and amplitude in the spatial magnetic field formed by the superposition of the excitation magnetic field and the induced magnetic field. At this time, the vibration coil 3 cuts the magnetic lines of force in the spatial magnetic field, and the AC induced voltage generated at both ends of the vibration coil 3 is transmitted to the detection module 5 for collection and analysis. The detection module 5 judges the corrosion state of the grounding grid according to the amplitude change of the AC induced voltage. When the amplitude of the AC induced voltage is lower than the preset threshold, that is, when the amplitude of the AC induced voltage drops significantly, it indicates that there is grounding grid corrosion at the current position, and the detection outputs a corrosion detection signal.

[0079] In this embodiment, grounding grid corrosion detection is achieved without contact with the grounding grid, which can effectively improve the efficiency of grounding grid corrosion detection.

[0080] Example 3

[0081] This embodiment makes improvements based on the grounding grid corrosion detection system proposed in Example 2. Figure 4 FIG. 1 is a diagram showing the architecture of the grounding grid corrosion detection system of this embodiment.

[0082] The grounding grid corrosion detection system proposed in this embodiment includes:

[0083] DC power supply module 1, used to modulate the magnitude and polarity of the DC signal and output it;

[0084] An excitation coil winding 2 with a magnetic core, the excitation coil winding 2 is connected to the DC power supply module 1 to form a loop;

[0085] A vibration coil 3, and a driving mechanism 4 for driving the vibration coil 3 to perform reciprocating linear vibration at a constant frequency and amplitude within a spatial magnetic field formed by the superposition of an excitation magnetic field and an induced magnetic field;

[0086] The detection module 5 is used to collect and analyze the AC induced voltage generated at both ends of the vibration coil 3, and output a corrosion detection signal when the amplitude of the AC induced voltage is lower than a preset threshold.

[0087] Furthermore, the system of this embodiment also includes an alarm module 6, the input end of the alarm module 6 is connected to the output end of the detection module 5; when the detection module 5 outputs a corrosion detection signal, the detection module 5 simultaneously outputs a working module to the alarm module 6, and the alarm module 6 works and issues an alarm.

[0088] Furthermore, the system of this embodiment is integrated into a magnetic shielding housing 7 , and the bottom of the magnetic shielding housing 7 is opened to ensure that the DC component is only affected by the input electrical signal.

[0089] Furthermore, a universal wheel 8 is provided at the bottom of the system of this embodiment, which facilitates the stable movement of the grounding grid corrosion detection system integrated with a DC power supply module 1, an excitation coil winding 2, a vibration coil 3 and a driving mechanism 4 on the ground above the grounding grid, thereby avoiding the shaking of the equipment and affecting the detection accuracy of the induced AC voltage.

[0090] During the specific implementation process, a grounding grid corrosion detection system is placed on the ground above the grounding grid flat steel to be detected. The DC power supply module 1 in the grounding grid corrosion detection system outputs a DC signal to the excitation coil winding 2 with a magnetic core. The excitation coil winding 2 forms an excitation magnetic field on the ground above the grounding grid flat steel. At this time, the steel is magnetized under the action of the excitation magnetic field to generate an induced magnetic field.

[0091] The control driving mechanism 4 works and drives the vibration coil 3 to vibrate back and forth linearly at a constant frequency and amplitude in the spatial magnetic field formed by the superposition of the excitation magnetic field and the induced magnetic field. At this time, the vibration coil 3 cuts the magnetic lines of force in the spatial magnetic field, and the AC induced voltage generated at both ends of the vibration coil 3 is transmitted to the detection module 5 for collection and analysis. The detection module 5 judges the corrosion state of the grounding grid according to the amplitude change of the AC induced voltage. When the amplitude of the AC induced voltage is lower than the preset threshold, that is, when the amplitude of the AC induced voltage drops significantly, it indicates that there is grounding grid corrosion at the current position. The detection module 5 outputs a corrosion detection signal and sends a working signal to the alarm module 6 at the same time. The alarm module 6 works and issues an alarm.

[0092] After completing the detection of the current position, the system is moved along the grounding grid installation position by pushing the magnetic shielding shell 7, and the next position is detected until the corrosion detection of the entire grounding grid is completed.

[0093] Example 4

[0094] This embodiment proposes a sensor such as Figure 5 FIG. 1 is a schematic diagram of the structure of the sensor of this embodiment.

[0095] The sensor proposed in this embodiment includes the grounding grid corrosion detection system proposed in Example 2 or Example 3, specifically, including a DC power supply module 1, an excitation coil winding 2 with a magnetic core, a vibration coil 3, a driving mechanism 4 and a detection module 5.

[0096] Among them, the DC power supply module 1 is used to modulate the size and polarity of the DC signal and output it; the excitation coil winding 2 is connected to the DC power supply module 1 to form a loop; the driving mechanism 4 is used to drive the vibration coil 3 to perform reciprocating linear vibration at a constant frequency and amplitude in the spatial magnetic field formed by the superposition of the excitation magnetic field and the induced magnetic field; the detection module 5 is used to collect the AC induced voltage generated at both ends of the vibration coil 3 and analyze it. When the amplitude of the AC induced voltage is lower than the preset threshold, a corrosion detection signal is output.

[0097] Furthermore, the driving mechanism 4 in this embodiment includes a motor 41 and a crank slider mechanism 42 , the output shaft of the motor 41 is connected to the crank driving end of the crank slider mechanism 42 through a coupling, and the slider end of the crank slider mechanism 42 is connected to the vibration coil 3 .

[0098] Furthermore, the sensor in this embodiment also includes a magnetic shielding shell 7, the bottom of which is open, and the DC power supply module 1, excitation coil winding 2, vibration coil 3 and drive mechanism 4 are arranged in the magnetic shielding shell 7, so as to ensure that the DC signal input to the excitation coil winding 2 is only affected by the DC power supply module 1.

[0099] During the specific implementation process, the staff only needs to hold the sensor or add a universal wheel 8 to the bottom of the sensor, and place the sensor on the ground above the flat steel of the grounding grid and move it at a constant speed to complete the grounding grid corrosion detection work without contact with the grounding grid.

[0100] The DC power supply module 1 in the sensor outputs a DC signal to the excitation coil winding 2 with a magnetic core. The excitation coil winding 2 forms an excitation magnetic field on the ground above the flat steel of the grounding grid. The steel is magnetized under the action of the excitation magnetic field, generating an induced magnetic field. The control drive mechanism 4 operates and drives the vibration coil 3 to perform reciprocating linear vibrations at a constant frequency and amplitude within the spatial magnetic field formed by the superposition of the excitation magnetic field and the induced magnetic field. At this time, the vibration coil 3 cuts the magnetic flux lines within the spatial magnetic field, generating an AC induced voltage at both ends of the vibration coil 3 and transmitting it to the detection module 5 for collection and analysis. The detection module 5 determines the corrosion status of the grounding grid based on the amplitude change of the AC induced voltage. When the amplitude of the AC induced voltage is lower than the preset threshold, that is, when the amplitude of the AC induced voltage drops significantly, it indicates that the grounding grid is corroded at the current location, and the detection module 5 outputs a corrosion detection signal.

[0101] The same or similar reference numerals correspond to the same or similar components;

[0102] The terms used in the drawings to describe positional relationships are for illustrative purposes only and should not be construed as limiting this patent;

[0103] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A grounding grid corrosion detection method, characterized in that: The following steps are involved: S1. An excitation magnetic field is set on the ground above the flat steel of the grounding grid. The excitation magnetic field is generated by passing a direct current signal into an excitation coil winding with a magnetic core. The flat steel is magnetized under the action of the excitation magnetic field, generating an induced magnetic field. S2, using a motor and a crank slider mechanism to drive the vibration coil to perform reciprocating linear vibration at a constant frequency and amplitude in a spatial magnetic field formed by the superposition of the excitation magnetic field and the induced magnetic field; S3, collecting and analyzing the AC induced voltage generated at both ends of the vibration coil, and judging the ground grid corrosion state according to the amplitude change of the AC induced voltage, wherein, when the amplitude of the AC induced voltage is lower than the preset threshold, it is judged that the ground grid corrosion exists at the corresponding position; wherein, in one movement cycle, the AC induced voltage generated at both ends of the vibration coil is Expressed as: Where, B is the spatial magnetic field strength, L is the length of both ends of the vibration coil, Indicates that the vibrating coil is parallel to x The speed of a direction during a period of motion; is the vacuum permeability of the flat steel, is the relative magnetic permeability of the flat steel, N is the number of turns of the coil winding, I is the input DC signal, Le is the effective magnetic circuit of the core, r is the crank length, l is the length of the connecting rod between the crank and the slider, t For time.

2. A grounding grid corrosion detection system, applied to the grounding grid corrosion detection method according to claim 1, characterized in that: include: A DC power supply module is used to modulate the magnitude and polarity of a DC signal and output it; an excitation coil winding with a magnetic core, the excitation coil winding being connected to the DC power supply module to form a loop; A vibration coil and a driving mechanism for driving the vibration coil to perform reciprocating linear vibration at a constant frequency and amplitude within a spatial magnetic field formed by the superposition of an excitation magnetic field and an induced magnetic field; The detection module is used to collect and analyze the AC induced voltage generated at both ends of the vibration coil, and output a corrosion detection signal when the amplitude of the AC induced voltage is lower than a preset threshold.

3. The grounding grid corrosion detection system according to claim 2, characterized in that: The driving mechanism includes a motor and a crank slider mechanism. The output shaft of the motor is connected to the crank driving end of the crank slider mechanism through a coupling, and the slider end of the crank slider mechanism is connected to the vibration coil.

4. The grounding grid corrosion detection system according to claim 3, characterized in that: The system further comprises an alarm module, the input end of which is connected to the output end of the detection module; when the detection module outputs a corrosion detection signal, the detection module simultaneously outputs a working signal to the alarm module, and the alarm module operates and issues an alarm.

5. The grounding grid corrosion detection system according to claim 4, characterized in that: The system further comprises a magnetic shielding shell, the bottom of which is open, and the DC power supply module, the excitation coil winding, the vibration coil and the driving mechanism are arranged in the magnetic shielding shell.

6. A sensor, characterized in that: The invention comprises a grounding grid corrosion detection system according to any one of claims 2 to 5.

7. The grounding grid corrosion detection system according to claim 6, characterized in that: The bottom of the sensor is provided with a universal wheel.

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