A measurement system and method for measuring and defining the current diffusion range in a coal mine / subway transportation system.

Abstract

This invention discloses a current diffusion range measurement system and definition method for a coal mine / subway transportation system. It comprises a simulated track bed, a sliding guide rail, a stepper motor, a slider, a ball screw, an electrode array, a transition resistor, a track potential controller, a diode, fine sand, a steel frame, a programmable DC power supply, a multi-channel signal acquisition system, a host computer, and a corrosion chamber shell. The electrode array is evenly distributed on the measurement plane, and each electrode array consists of four mutually perpendicular and intersecting reference electrodes. The slider is connected to the sliding guide rail by bolts. One end of the track potential controller is connected to the sliding guide rail, and the other end is connected to the simulated track bed. One end of the diode is connected to the sliding guide rail, and the other end is connected to the simulated track bed.

Description

Technical Field

[0001] This invention belongs to the field of coal mine / subway transportation, and in particular, it is a measurement system and method for measuring and defining the current diffusion range of a coal mine / subway transportation system. Background Technology

[0002] In coal mines and subways, DC electric locomotives are used as transportation devices. When these locomotives are running in the traction section, if insulation fails at the return rail, some of the returning traction current will flow into the ground through the point of insulation failure, resulting in stray currents in the coal mine / subway. Stray currents in coal mines / subways are one of the major negative impacts that must be considered when using DC electric locomotives for rail transportation. They seriously threaten the safe operation of the reinforced concrete structures in coal mine roadways / subway tunnels and are a crucial issue that must be considered in the construction, operation, and maintenance of underground spaces in coal mines / subways. Stray currents in coal mines can induce premature explosions of detonators, leading to gas and dust explosions in the mine, affecting the normal operation of underground electrical equipment, and causing electrochemical corrosion of underground metal structures. Stray currents in subways can cause abnormal increases in track potential, corroding the reinforced concrete structures within the subway system and surrounding third-party metal pipelines.

[0003] Determining the propagation range of stray currents in coal mines / subways is crucial for effectively assessing their impact on surrounding metal structures. Currently, the propagation range of stray currents is difficult to define accurately experimentally, hindering the implementation of relevant theoretical models and practical operating condition analyses. Therefore, this invention provides a measurement system and method for defining the current propagation range in coal mine / subway transportation systems, which is of great significance for evaluating the degree of current leakage in these systems. Summary of the Invention

[0004] Purpose of the invention: The purpose of this invention is to provide a current diffusion range measurement system based on coal mine / subway transportation systems, which automatically detects the stray current diffusion level by measuring the spatiotemporal distribution data of the ground potential gradient through a reference electrode array.

[0005] Technical solution: In order to achieve the above objectives, the technical solution adopted by the present invention is as follows: a current diffusion range measurement system for a coal mine / subway transportation system, the system comprising a steel frame (1), a track potential controller (2), a diode (3), a sliding table guide rail (4), a programmable DC power supply (5), a slider (7), a stepper motor (8), a transition resistor (9), a simulated track bed (10), a corrosion chamber shell (11), a multi-channel signal acquisition system (12), a host computer (13), fine sand (14), and an electrode array (15);

[0006] A certain concentration of chloride ion solution was injected into the fine sand (14) to simulate the underground soil environment and filled into the corrosion chamber, and the surface was leveled as a measurement plane.

[0007] The electrode array (15) is located on the measuring plane and inserted into the fine sand (14). Moreover, the electrode array (15) is connected to the multi-channel signal acquisition system (12). The polarization potential signal acquired by the electrode array (15) is transmitted to the host computer (13) for signal monitoring through the multi-channel signal acquisition system (12).

[0008] The simulated track bed (10) is made of reinforced concrete and contains transverse and longitudinal steel bars to simulate the drainage network. It is located on the measurement plane.

[0009] The steel frame (1) is located on the measuring plane, and the slide rail (4) is fixed on the steel frame (1) to simulate the rail. It is parallel to the measuring plane, and the simulated track bed (10) is located directly below the slide rail (4).

[0010] Multiple transition resistors (9) are provided between the slide rail (4) and the simulated track bed (10). Each transition resistor (9) is connected to the slide rail (4) at one end and to the simulated track bed (10) at the other end, and is used to simulate the insulating fastener between the rail and the track bed.

[0011] The slider (7) is located on the slide rail (4) and is used to simulate a DC electric locomotive running in the traction section. The slider (7) is driven by a stepper motor (8) to drive the slider (7) on the slide rail (4) to simulate the movement of a coal mine locomotive or a subway locomotive in the traction section.

[0012] The track potential controller (2) is connected to the slide rail (4) at one end and to the measuring plane at the other end. It is used to control the track potential within a safe range and prevent the track potential from being too high. The diode (3) is connected to the slide rail (4) at one end and to the simulated track bed (10) at the other end. It is used to simulate the diode grounding method of the rail.

[0013] The programmable DC power supply (5) has two sets of positive and negative terminals. One set of positive and negative terminals is connected to the stepper motor (8) respectively. In the other set of positive and negative terminals, the positive terminal is connected to the slider (7) and the negative terminal is connected to both ends of the slide rail (4), forming a power supply circuit.

[0014] Furthermore, the system also includes a ball screw (6), and the slider (7) is connected to the ball screw (6). The ball screw (6) is driven by a stepper motor (8) to drive the slider (7) to move on the slide rail (6) to simulate the movement of a coal mine locomotive or a subway locomotive in the traction section.

[0015] Furthermore, each electrode array (15) is composed of four reference electrodes that are perpendicularly and intersecting each other. Each electrode array (15) constitutes an array point on the measurement plane. The four reference electrodes in each electrode array (15) are used to measure the polarization potential of the four points to determine the potential gradient of the point in the x and y directions. The distance S1 between the two pairs of reference electrodes in the x and y directions is 8 to 12 cm. The spacing S2 between each electrode array on the measurement plane is 18 to 22 cm.

[0016] Furthermore, the electrode array (15) uses copper / copper sulfate long-lasting reference electrodes, with four reference electrodes inserted vertically into fine sand (14) as a group, and the reference electrodes are buried at a depth of 5 to 10 cm.

[0017] Furthermore, the slider (7) is used to simulate a coal mine locomotive / subway locomotive, and the running speed is controlled by a stepper motor (8) with a current amplitude of I, and it reciprocates on the slide rail at time intervals Δt.

[0018] The present invention also proposes a measurement method based on any one of the measurement systems described herein, the method comprising the following steps:

[0019] Step 1: By changing the stepper motor current amplitude I = [I1, I2, ..., I d ,…,I h Each time, a current amplitude I is taken from I. d And ensuring that the slider running interval Δt1 and the resistivity of fine sand ρ1 remain constant, the test is performed at any time t=[t1,t2,…,t d ,…,t h The polarization potential of each electrode on the plane; the resistivity of fine sand ρ=[ρ1,ρ2,…,ρ] is changed by changing the concentration of chloride ion solution. d ,…,ρ h Each time, a resistivity value ρ is taken from ρ. d And ensuring that the current amplitude I1 and the operating interval Δt1 remain constant, the test time t = [t1, t2, ..., t] is any time. d ,…,t h The polarization potential of each electrode on the plane; the running interval Δt = [Δt1, Δt2, ..., Δt] is changed by controlling the stepper motor. d ,…,Δt h Each time, a running interval value Δt is taken from Δt. d And ensuring that the current amplitude is I1 and the resistivity of the fine sand ρ1 remains constant, the test is performed at any time t = [t1, t2, ..., t d ,…,t h The polarization potential of each electrode on the plane. Where t d Let I represent any time t. dρ represents any current amplitude in I. d Let Δt represent any resistivity value in ρ. d Let Δt represent any operating interval value, and h represent the current amplitude I, test time t, fine sand resistivity ρ, and the total number of test parameters in the operating interval Δt. Based on the above three sets of tests, an electrode array polarization potential data set V is formed. p =[V p,1 (t1,I1,Δt1,ρ1),…,V p,1 (t h ,I h ,Δt1,ρ1),V p,2 (t1,I1,Δt1,ρ1),…,V p,2 (t h ,I1,Δt1,ρ h ),…,V p,q (t d ,I d ,Δt d ,ρ d ),…,V p,k (t1,I1,Δt1,ρ1),…,V p,k (t h ,I1,Δt h ,ρ1)];

[0020] Among them, V p,q (t d ,I d ,Δt d ,ρ d )={V p 1,1 (t d ,I d ,Δt d ,ρ d ),V p 1,2 (t d ,I d ,Δt d ,ρ d ),…,V p 1,m (t d ,I d ,Δt d ,ρ d ),…,V p i,1 (t d ,I d ,Δt d ,ρ d ),V p i,2 (t d ,Id , Δt d , ρ d ), …, V p i,j (t d , I d , Δt d , ρ d ), …, V p i,m (t d , I d , Δt d , ρ d ), …, V p n,1 (t d , I d , Δt d , ρ d ), V p n,2 (t d , I d , Δt d , ρ d ), …, V p n,m (t d , I d , Δt d , ρ d )},其中,V p i,j (t d , I d , Δt d , ρ d ) = [V p,1 i,j (t d , I d , Δt d , ρ d )V p,2 i,j (t d , I d , Δt d , ρ d )V p,3 i,j (t d , I d , Δt d , ρ d )V p,4 i,j (t d , I d , Δt d , ρ d )],并且,V p,1 i,j (t d,I d ,Δt d ,ρ d ) and V p,3 i,j (t d ,I d ,Δt d ,ρ d The current amplitudes are I, respectively. d The slider running interval is Δt d The resistivity is ρ d At t d The polarization potential V of the reference electrode arranged in the x-direction of the electrode array in the i-th row and j-th column at time i. p,2 i,j (t d ,I d ,Δt d ,ρ d ) and V p,4 i,j (t d ,I d ,Δt d ,ρ d The current amplitudes are I, respectively. d The slider running interval is Δt d The resistivity is ρ d At t d The polarization potential of the reference electrode arranged in the y direction of the electrode array in the i-th row and j-th column at time t; n and m represent that the electrode array has a total of n rows and m columns.

[0021] Step 2: Calculate the potential gradient V of each electrode array on the measurement plane. g =[V g,1 (t1,I1,Δt1,ρ1),…,V g,1 (t h ,I h ,Δt1,ρ1),V g,2 (t1,I1,Δt1,ρ1),…,V g,2 (t h ,I1,Δt1,ρ h ),…,V g,q (t d ,I d ,Δt d ,ρ d ),…,V g,k (t1,I1,Δt1,ρ1),…,V g,k (t h ,I1,Δt h [,ρ1)], the current amplitude is I d The slider running interval is Δt dThe resistivity is ρ d At t d At a given moment, the potential gradient V of an electrode array on a plane in the x and y directions is measured. g,q (t d ,I d ,Δt d ,ρ d )={V g 1,1 (t d ,I d ,Δt d ,ρ d ),V g 1,2 (t d ,I d ,Δt d ,ρ d ),…,V g 1,m (t d ,I d ,Δt d ,ρ d ),…,V g i,1 (t d ,I d ,Δt d ,ρ d ),V g i,2 (t d ,I d ,Δt d ,ρ d ),…,V g i,j (t d ,I d ,Δt d ,ρ d ),…,V g i,m (t d ,I d ,Δt d ,ρ d ),…,V g n,1 (t d ,I d ,Δt d ,ρ d ),V g n,2 (t d ,I d ,Δt d ,ρ d ),…,V g n,m (t d,I d ,Δt d ,ρ d )}, where V g i,j (t d ,I d ,Δt d ,ρ d )=[V g,1 i,j (t d ,I d ,Δt d ,ρ d V g,2 i,j (t d ,I d ,Δt d ,ρ d )], where V g,1 i,j (t d ,I d ,Δt d ,ρ d ) and V g,2 i,j (t d ,I d ,Δt d ,ρ d The measured current amplitudes of the electrode arrays in the i-th row and j-th column are I, respectively. d The slider running interval is Δt d The resistivity is ρ d At t d The potential gradient in the x and y directions of the plane is measured at a given time, and the calculation method is as follows:

[0022]

[0023]

[0024] Step 3: Calculate the absolute potential gradient |V| of all electrode arrays on the measurement plane under different current amplitudes, operating intervals, sand resistivity, and time intervals. g |=[|V g,1 (t1,I1,Δt1,ρ1)|,…,|V g,1 (t h ,I h ,Δt1,ρ1)|,|V g,2 (t1,I1,Δt1,ρ1)|,…,|V g,2 (t h ,I1,Δt1,ρ h )|,…,|V g,q (td ,I d ,Δt d ,ρ d )|,…,|V g,k (t1,I1,Δt1,ρ1)|,…,|V g,k (t h ,I1,Δt h ,ρ1)|],Current amplitude is I d The slider running interval is Δt d The resistivity is ρ d At t d The absolute potential gradient value of each electrode array on the measurement plane at time t is |V g,q (t d ,I d ,Δt d ,ρ d )|={|V g 1,1 (t d ,I d ,Δt d ,ρ d )|,|V g 1,2 (t d ,I d ,Δt d ,ρ d )|,…,|V g 1,m (t d ,I d ,Δt d ,ρ d )|,…,|V g i,1 (t d ,I d ,Δt d ,ρ d )|,|V g i,2 (t d ,I d ,Δt d ,ρ d )|,…,|V g i,j (t d ,I d ,Δt d ,ρ d )|,…,|V g i,m (t d ,I d ,Δt d ,ρ d )|,…,|V gn,1 (t d ,I,Δt d ,ρ d )|,|V g n,2 (t d ,I d ,Δt d ,ρ d )|,…,|V g n,m (t d ,I d ,Δt d ,ρ d The calculation method is as follows:

[0025]

[0026] Among them, |V g i,j (t d ,I d ,Δt d ,ρ d | is the current amplitude I d The slider running interval is Δt d The resistivity is ρ d At t d The absolute potential gradient value measured by the electrode array in the i-th row and j-th column at time i.

[0027] Step 4: Calculate the average value V of the absolute potential gradient of all electrode arrays on the measurement plane under different current amplitudes, operating intervals, sand resistivity, and time intervals. a =[V a,1 (t1,I1,Δt1,ρ1),…,V a,1 (t h ,I h ,Δt1,ρ1),V a,2 (t1,I1,Δt1,ρ1),…,V a,2 (t h ,I1,Δt1,ρ h ),…,V a,q (t d ,I d ,Δt d ,ρ d ),…,V a,k (t1,I1,Δt1,ρ1),…,V a,k (t h ,I1,Δt h [,ρ1)], the current amplitude is I d The slider running interval is Δt d The resistivity is ρd At t d The absolute potential gradient V of all electrode arrays on the plane at time t is measured. a,q (t d ,I d ,Δt d ,ρ d The method for calculating the average value is as follows:

[0028]

[0029] Step 5: Determine whether the location of each electrode array on the measurement plane is within the current diffusion range. For a current amplitude of I... d The slider running interval is Δt d The resistivity is ρ d At t d At any given time, the potential gradient value |V| at each point on the electrode array on the measurement plane is measured. g,q (t d ,I d ,Δt d ,ρ d The method is as follows:

[0030] Calculate the difference between the absolute potential gradient value and the average absolute potential gradient value of the electrode array at each point on the measurement plane. Then, use the absolute potential gradient value |V| of the electrode array in the i-th row and j-th column as an example. g i,j (t d ,I d ,Δt d ,ρ d Taking ΔV as an example, the following calculation is performed to obtain ΔV:

[0031]

[0032] Where max(·) and min(·) represent the maximum and minimum value functions, respectively;

[0033] Based on the obtained ΔV, determine whether the position of the electrode array in the i-th row and j-th column is within the current diffusion range. The specific method is as follows:

[0034] If ΔV>0, then the current amplitude is I. d The slider running interval is Δt d The resistivity is ρ d At t d At time i, the position of the electrode array in row i and column j is within the current diffusion range; if ΔV < 0, then the current amplitude is I. d The slider running interval is Δt d The resistivity is ρ d At t dAt any given moment, the positions of the electrode array in the i-th row and j-th column are outside the current diffusion range.

[0035] Beneficial effects: Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects:

[0036] The technical solution proposed in this invention can intelligently define the stray current diffusion range by using location information, current traction and locomotive operation data and resistivity. The implementation scheme is simple, highly reliable and economical. Attached Figure Description

[0037] Figure 1 This is a front view of the measurement system provided by the present invention;

[0038] Figure 2 This is a top view of the measurement system provided by the present invention;

[0039] Figure 3 A three-dimensional diagram of the measurement system provided by this invention;

[0040] Figure 4 This is a schematic diagram of the reference electrode array composition in this invention;

[0041] Figure 5 This is a schematic diagram illustrating the sliding block's simulation of subway train speed in this invention;

[0042] Figure 6 This is a flowchart of the current diffusion range definition method proposed in this invention;

[0043] In the figure: 1-Electrode array; 2-Measuring plane; 3-Stepper motor; 4-Slide rail; 5-Ball screw; 6-Programmable DC power supply; 7-Steel frame; 8-Rail potential controller; 9-Diode; 10-Transition resistor; 11-Simulated track bed; 12-Slider. Detailed Implementation

[0044] like Figure 1 As shown, this invention proposes a current diffusion range measurement system for a coal mine / subway transportation system. The system includes a steel frame (1), a track potential controller (2), a diode (3), a sliding table guide rail (4), a programmable DC power supply (5), a slider (7), a stepper motor (8), a transition resistor (9), a simulated track bed (10), a corrosion chamber shell (11), a multi-channel signal acquisition system (12), a host computer (13), fine sand (14), and an electrode array (15).

[0045] A certain concentration of chloride ion solution was injected into the fine sand (14) to simulate the underground soil environment and filled into the corrosion chamber, and the surface was leveled as a measurement plane.

[0046] The electrode array (15) is located on the measuring plane and inserted into the fine sand (14). Moreover, the electrode array (15) is connected to the multi-channel signal acquisition system (12). The polarization potential signal acquired by the electrode array (15) is transmitted to the host computer (13) for signal monitoring through the multi-channel signal acquisition system (12).

[0047] The simulated track bed (10) is made of reinforced concrete and contains transverse and longitudinal steel bars to simulate the drainage network. It is located on the measurement plane.

[0048] The steel frame (1) is located on the measuring plane, and the slide rail (4) is fixed on the steel frame (1) to simulate the rail. It is parallel to the measuring plane, and the simulated track bed (10) is located directly below the slide rail (4).

[0049] Multiple transition resistors (9) are provided between the slide rail (4) and the simulated track bed (10). Each transition resistor (9) is connected to the slide rail (4) at one end and to the simulated track bed (10) at the other end, and is used to simulate the insulating fastener between the rail and the track bed.

[0050] The slider (7) is located on the slide rail (4) and is used to simulate a DC electric locomotive running in the traction section. The slider (7) is driven by a stepper motor (8) to drive the slider (7) on the slide rail (4) to simulate the movement of a coal mine locomotive or a subway locomotive in the traction section.

[0051] The track potential controller (2) is connected to the slide rail (4) at one end and to the measuring plane at the other end. It is used to control the track potential within a safe range and prevent the track potential from being too high. The diode (3) is connected to the slide rail (4) at one end and to the simulated track bed (10) at the other end. It is used to simulate the diode grounding method of the rail.

[0052] The programmable DC power supply (5) has two sets of positive and negative terminals. One set of positive and negative terminals is connected to the stepper motor (8) respectively. In the other set of positive and negative terminals, the positive terminal is connected to the slider (7) and the negative terminal is connected to both ends of the slide rail (4), forming a power supply circuit.

[0053] Furthermore, the system also includes a ball screw (6), and the slider (7) is connected to the ball screw (6). The ball screw (6) is driven by a stepper motor (8) to move the slider (7) on the slide rail (6) to simulate the movement of a coal mine locomotive or subway locomotive within the traction zone. The slider (7) is controlled by the stepper motor (8) with a current amplitude of I, and reciprocates on the slide rail at time intervals Δt.

[0054] In this embodiment of the invention, each electrode array (15) is composed of four reference electrodes that are perpendicularly and intersecting each other. Each electrode array (15) constitutes an array point on the measurement plane. The four reference electrodes of each electrode array (15) are used to measure the polarization potential of the four points to determine the potential gradient of the point in the x and y directions. The distance S1 between the two pairs of reference electrodes in the x and y directions is 8 to 12 cm. The spacing S2 between each electrode array on the measurement plane is 18 to 22 cm.

[0055] As an optional solution, the electrode array (15) uses copper / copper sulfate long-lasting reference electrodes, with four reference electrodes inserted vertically into fine sand (14) as a group, and the reference electrodes are buried at a depth of 5 to 10 cm.

[0056] During the measurement process, a plastic film needs to be laid on the measurement surface to reduce the evaporation of moisture from the fine sand and ensure that the water content of the simulated soil environment is relatively stable.

[0057] like Figure 6 As shown, the present invention also proposes a measurement method based on any of the measurement systems described above, the method comprising the following steps:

[0058] Step 1: By changing the stepper motor current amplitude I = [I1, I2, ..., I d ,…,I h Each time, a current amplitude I is taken from I. d And ensuring that the slider running interval Δt1 and the resistivity of fine sand ρ1 remain constant, the test is performed at any time t=[t1,t2,…,t d ,…,t h The polarization potential of each electrode on the plane; the resistivity of fine sand ρ=[ρ1,ρ2,…,ρ] is changed by changing the concentration of chloride ion solution. d ,…,ρ h Each time, a resistivity value ρ is taken from ρ. d And ensuring that the current amplitude I1 and the operating interval Δt1 remain constant, the test time t = [t1, t2, ..., t] is any time. d ,…,t h The polarization potential of each electrode on the plane; the running interval Δt = [Δt1, Δt2, ..., Δt] is changed by controlling the stepper motor. d ,…,Δt h Each time, a running interval value Δt is taken from Δt. d And ensuring that the current amplitude is I1 and the resistivity of the fine sand ρ1 remains constant, the test is performed at any time t = [t1, t2, ..., t d ,…,t h The polarization potential of each electrode on the plane. Where t d Let I represent any time t. dρ represents any current amplitude in I. d Let Δt represent any resistivity value in ρ. d Let Δt represent any operating interval value, and h represent the current amplitude I, test time t, fine sand resistivity ρ, and the total number of test parameters in the operating interval Δt. Based on the above three sets of tests, an electrode array polarization potential data set V is formed. p =[V p,1 (t1,I1,Δt1,ρ1),…,V p,1 (t h ,I h ,Δt1,ρ1),V p,2 (t1,I1,Δt1,ρ1),…,V p,2 (t h ,I1,Δt1,ρ h ),…,V p,q (t d ,I d ,Δt d ,ρ d ),…,V p,k (t1,I1,Δt1,ρ1),…,V p,k (t h ,I1,Δt h ,ρ1)];

[0059] Among them, V p,q (t d ,I d ,Δt d ,ρ d )={V p 1,1 (t d ,I d ,Δt d ,ρ d ),V p 1,2 (t d ,I d ,Δt d ,ρ d ),…,V p 1,m (t d ,I d ,Δt d ,ρ d ),…,V p i,1 (t d ,I d ,Δt d ,ρ d ),V p i,2 (t d ,Id , Δt d , ρ d ), …, V p i,j (t d , I d , Δt d , ρ d ), …, V p i,m (t d , I d , Δt d , ρ d ), …, V p n,1 (t d , I d , Δt d , ρ<00,00521>, V p n,2 (t d , I d , Δt d , ρ d ), …, V<00,00528> n,m (t d , I d , Δt<o000532>[[ID=5x]], ρ d )}, where V p i,j (t d , I d , Δt d , ρ d ) = [V p,1 i,j (t d , I d , Δt d , ρ d )V p,2 i,j (t d , I d , Δt d , ρ d )V p,3 i,j (t d , I d , Δt d , ρ d )V p,4 i,j (t d , I d , Δt d , ρ d )], and V p,1 i,j (t d It should be noted that there may be some incorrect tags in the original text (such as "o000532" which might be a misprint). If possible, it is recommended to double-check and correct the original text for more accurate translation.,I d ,Δt d ,ρ d ) and V p,3 i,j (t d ,I d ,Δt d ,ρ d The current amplitudes are I, respectively. d The slider running interval is Δt d The resistivity is ρ d At t d The polarization potential V of the reference electrode arranged in the x-direction of the electrode array in the i-th row and j-th column at time i. p,2 i,j (t d ,I d ,Δt d ,ρ d ) and V p,4 i,j (t d ,I d ,Δt d ,ρ d The current amplitudes are I, respectively. d The slider running interval is Δt d The resistivity is ρ d At t d The polarization potential of the reference electrode arranged in the y direction of the electrode array in the i-th row and j-th column at time t; n and m represent that the electrode array has a total of n rows and m columns.

[0060] Step 2: Calculate the potential gradient V of each electrode array on the measurement plane. g =[V g,1 (t1,I1,Δt1,ρ1),…,V g,1 (t h ,I h ,Δt1,ρ1),V g,2 (t1,I1,Δt1,ρ1),…,V g,2 (t h ,I1,Δt1,ρ h ),…,V g,q (t d ,I d ,Δt d ,ρ d ),…,V g,k (t1,I1,Δt1,ρ1),…,V g,k (t h ,I1,Δt h [,ρ1)], the current amplitude is I d The slider running interval is Δt dThe resistivity is ρ d At t d At a given moment, the potential gradient V of an electrode array on a plane in the x and y directions is measured. g,q (t d ,I d ,Δt d ,ρ d )={V g 1,1 (t d ,I d ,Δt d ,ρ d ),V g 1,2 (t d ,I d ,Δt d ,ρ d ),…,V g 1,m (t d ,I d ,Δt d ,ρ d ),…,V g i,1 (t d ,I d ,Δt d ,ρ d ),V g i,2 (t d ,I d ,Δt d ,ρ d ),…,V g i,j (t d ,I d ,Δt d ,ρ d ),…,V g i,m (t d ,I d ,Δt d ,ρ d ),…,V g n,1 (t d ,I d ,Δt d ,ρ d ),V g n,2 (t d ,I d ,Δt d ,ρ d ),…,V g n,m (t d,I d ,Δt d ,ρ d )}, where V g i,j (t d ,I d ,Δt d ,ρ d )=[V g,1 i,j (t d ,I d ,Δt d ,ρ d V g,2 i,j (t d ,I d ,Δt d ,ρ d )], where V g,1 i,j (t d ,I d ,Δt d ,ρ d ) and V g,2 i,j (t d ,I d ,Δt d ,ρ d The measured current amplitudes of the electrode arrays in the i-th row and j-th column are I, respectively. d The slider running interval is Δt d The resistivity is ρ d At t d The potential gradient in the x and y directions of the plane is measured at a given time, and the calculation method is as follows:

[0061]

[0062]

[0063] Step 3: Calculate the absolute potential gradient |V| of all electrode arrays on the measurement plane under different current amplitudes, operating intervals, sand resistivity, and time intervals. g |=[|V g,1 (t1,I1,Δt1,ρ1)|,…,|V g,1 (t h ,I h ,Δt1,ρ1)|,|V g,2 (t1,I1,Δt1,ρ1)|,…,|V g,2 (t h ,I1,Δt1,ρ h )|,…,|V g,q (td ,I d ,Δt d ,ρ d )|,…,|V g,k (t1,I1,Δt1,ρ1)|,…,|V g,k (t h ,I1,Δt h ,ρ1)|],Current amplitude is I d The slider running interval is Δt d The resistivity is ρ d At t d The absolute potential gradient value of each electrode array on the measurement plane at time t is |V g,q (t d ,I d ,Δt d ,ρ d )|={|V g 1,1 (t d ,I d ,Δt d ,ρ d )|,|V g 1,2 (t d ,I d ,Δt d ,ρ d )|,…,|V g 1,m (t d ,I d ,Δt d ,ρ d )|,…,|V g i,1 (t d ,I d ,Δt d ,ρ d )|,|V g i,2 (t d ,I d ,Δt d ,ρ d )|,…,|V g i,j (t d ,I d ,Δt d ,ρ d )|,…,|V g i,m (t d ,I d ,Δt d ,ρ d )|,…,|V gn,1 (t d ,I,Δt d ,ρ d )|,|V g n,2 (t d ,I d ,Δt d ,ρ d )|,…,|V g n,m (t d ,I d ,Δt d ,ρ d The calculation method is as follows:

[0064]

[0065] Among them, |V g i,j (t d ,I d ,Δt d ,ρ d | is the current amplitude I d The slider running interval is Δt d The resistivity is ρ d At t d The absolute potential gradient value measured by the electrode array in the i-th row and j-th column at time i.

[0066] Step 4: Calculate the average value V of the absolute potential gradient of all electrode arrays on the measurement plane under different current amplitudes, operating intervals, sand resistivity, and time intervals. a =[V a,1 (t1,I1,Δt1,ρ1),…,V a,1 (t h ,I h ,Δt1,ρ1),V a,2 (t1,I1,Δt1,ρ1),…,V a,2 (t h ,I1,Δt1,ρ h ),…,V a,q (t d ,I d ,Δt d ,ρ d ),…,V a,k (t1,I1,Δt1,ρ1),…,V a,k (t h ,I1,Δt h [,ρ1)], the current amplitude is I d The slider running interval is Δt d The resistivity is ρd At t d The absolute potential gradient V of all electrode arrays on the plane at time t is measured. a,q (t d ,I d ,Δt d ,ρ d The method for calculating the average value is as follows:

[0067]

[0068] Step 5: Determine whether the location of each electrode array on the measurement plane is within the current diffusion range. For a current amplitude of I... d The slider running interval is Δt d The resistivity is ρ d At t d At any given time, the potential gradient value |V| at each point on the electrode array on the measurement plane is measured. g,q (t d ,I d ,Δt d ,ρ d The method is as follows:

[0069] Calculate the difference between the absolute potential gradient value and the average absolute potential gradient value of the electrode array at each point on the measurement plane. Then, use the absolute potential gradient value |V| of the electrode array in the i-th row and j-th column as an example. g i,j (t d ,I d ,Δt d ,ρ d Taking ΔV as an example, the following calculation is performed to obtain ΔV:

[0070]

[0071] Where max(·) and min(·) represent the maximum and minimum value functions, respectively;

[0072] Based on the obtained ΔV, determine whether the position of the electrode array in the i-th row and j-th column is within the current diffusion range. The specific method is as follows:

[0073] If ΔV>0, then the current amplitude is I. d The slider running interval is Δt d The resistivity is ρ d At t d At time i, the position of the electrode array in row i and column j is within the current diffusion range; if ΔV < 0, then the current amplitude is I. d The slider running interval is Δt d The resistivity is ρ d At t dAt any given moment, the positions of the electrode array in the i-th row and j-th column are outside the current diffusion range.

Claims

1. A measurement method realized based on a coal mine / underground transportation system current diffusion range measurement system, characterized in that, The system comprises a track potential controller (2), a diode (3), a sliding table guide rail (4), a programmable direct current power supply (5), a sliding block (7), a stepping motor (8), a transition resistor (9), an analog track bed (10), a corrosion box shell (11), a multi-channel signal acquisition system (12), an upper computer (13), fine sand (14), an electrode array (15); The fine sand (14) is injected with a preset concentration of chloride ion solution to simulate the underground soil environment and is filled in the corrosion box and leveled as a measurement plane; The electrode array (15) is located on the measurement plane and inserted into the fine sand (14), and the electrode array (15) is connected with the multi-channel signal acquisition system (12), and the polarization potential signals collected by the electrode array (15) are transmitted to the upper computer (13) through the multi-channel signal acquisition system (12); The analog track bed (10) is cast with reinforced concrete and contains transverse and longitudinal steel bars to simulate the drainage network, and the analog track bed (10) is located on the measurement plane; The sliding table guide rail (4) is located above the measurement plane, the analog track bed (10) is located directly below the sliding table guide rail (4), and the sliding table guide rail (4) is parallel to the measurement plane; a plurality of transition resistors (9) are arranged between the sliding table guide rail (4) and the analog track bed (10), one end of each transition resistor (9) is connected to the sliding table guide rail (4), and the other end is connected to the analog track bed (10), which is used to simulate the insulating fastener between the rail and the track bed; The sliding block (7) is located on the sliding table guide rail (4) and is used to simulate a direct current electric locomotive running in the traction section, and the sliding block (7) is driven by the stepping motor (8) to simulate the movement of a coal mine electric locomotive or a subway locomotive in the traction section on the sliding table guide rail (4); One end of the track potential controller (2) is connected to the sliding table guide rail (4), and the other end is connected to the measurement plane; one end of the diode (3) is connected to the sliding table guide rail (4), and the other end is connected to the analog track bed (10); The programmable direct current power supply (5) has two groups of positive and negative electrodes, one of which is connected to the current input and output port of the stepping motor (8), and the other group of positive and negative electrodes is connected to the sliding block (7) and the sliding table guide rail (4) at both ends, respectively, to form a power supply loop; The method comprises the following steps: Step 1: By changing the stepper motor current amplitude I = [I1, I2, ..., I d ,…,I h Each time, a current amplitude I is taken from I. d And ensuring that the slider running interval Δt1 and the resistivity of fine sand ρ1 remain constant, the test is performed at any time t=[t1,t2,…,t d ,…,t h The polarization potential of each electrode on the plane; the resistivity of fine sand ρ=[ρ1,ρ2,…,ρ] is changed by changing the concentration of chloride ion solution. d ,…,ρ h Each time, a resistivity value ρ is taken from ρ. d And ensuring that the current amplitude I1 and the operating interval Δt1 remain constant, the test time t = [t1, t2, ..., t] is any time. d ,…,t h The polarization potential of each electrode on the plane; the running interval Δt = [Δt1, Δt2, ..., Δt] is changed by controlling the stepper motor. d ,…,Δt h Each time, a running interval value Δt is taken from Δt. d And ensuring that the current amplitude is I1 and the resistivity of the fine sand ρ1 remains constant, the test is performed at any time t = [t1, t2, ..., t d ,…,t h The polarization potentials of each electrode on the plane; where t d Let I represent any time t. d ρ represents any current amplitude in I. d Let Δt represent any resistivity value in ρ. d Let h represent any operating interval value in Δt, and let I represent the current amplitude, test time t, sand resistivity ρ, and the total number of test parameters in the operating interval Δt. Based on the above three sets of tests, an electrode array polarization potential data set V is formed. p =[V p,1 (t1,I1,Δt1,ρ1),…,V p,1 (t h ,I h ,Δt1,ρ1),V p,2 (t1,I1,Δt1,ρ1),…,V p,2 (t h ,I1,Δt1,ρ h ),…,V p,q (t d ,I d ,Δt d ,ρ d ),…,V p,k (t1,I1,Δt1,ρ1),…,V p,k (t h ,I1,Δt h ,ρ1)] wherein V p,q (t d ,I d ,Δt d ,ρ d )={V p 1,1 (t d ,I d ,Δt d ,ρ d ),V p 1,2 (t d ,I d ,Δt d ,ρ d ),…,V p 1,m (t d ,I d ,Δt d ,ρ d ),…,V p i,1 (t d ,I d ,Δt d ,ρ d ),V p i,2 (t d ,I d ,Δt d ,ρ d ),…,V p i,j (t d ,I d ,Δt d ,ρ d ),…,V p i,m (t d ,I d ,Δt d ,ρ d ),…,V p n,1 (t d ,I d ,Δt d ,ρ d ),V p n,2 (t d ,I d ,Δt d ,ρ d ),…,V p n,m (t d ,I d ,Δt d ,ρ d )}, wherein V p i,j (t d ,I d ,Δt d ,ρ d )=[V p,1 i,j (t d ,I d ,Δt d ,ρ d V p,2 i,j (t d ,I d ,Δt d ,ρ d V p,3 i,j (t d ,I d ,Δt d ,ρ d V p,4 i,j (t d ,I d ,Δt d ,ρ d )], and V p,1 i,j (t d ,I d ,Δt d ,ρ d ) and V p,3 i,j (t d ,I d ,Δt d ,ρ d The current amplitudes are I, respectively. d The slider running interval is Δt d The resistivity is ρ d At t d The polarization potential V of the reference electrode arranged in the x-direction of the electrode array in the i-th row and j-th column at time i. p,2 i,j (t d ,I d ,Δt d ,ρ d ) and V p,4 i,j (t d ,I d ,Δt d ,ρ d The current amplitudes are I, respectively. d The slider running interval is Δt d The resistivity is ρ d At t d the polarization potential of the reference electrode arranged in the y direction of the electrode array at the i-th row and j-th column at the moment; n and m represent the total number of rows and columns of the electrode array, respectively; Step 2: Calculate the potential gradient V of each electrode array on the measurement plane. g =[V g,1 (t1,I1,Δt1,ρ1),…,V g,1 (t h ,I h ,Δt1,ρ1),V g,2 (t1,I1,Δt1,ρ1),…,V g,2 (t h ,I1,Δt1,ρ h ),…,V g,q (t d ,I d ,Δt d ,ρ d ),…,V g,k (t1,I1,Δt1,ρ1),…,V g,k (t h ,I1,Δt h [,ρ1)], the current amplitude is I d The slider running interval is Δt d The resistivity is ρ d At t d At a given moment, the potential gradient V of an electrode array on a plane in the x and y directions is measured. g,q (t d ,I d ,Δt d ,ρ d )={V g 1,1 (t d ,I d ,Δt d ,ρ d ),V g 1,2 (t d ,I d ,Δt d ,ρ d ),…,V g 1,m (t d ,I d ,Δt d ,ρ d ),…,V g i,1 (t d ,I d ,Δt d ,ρ d ),V g i,2 (t d ,I d ,Δt d ,ρ d ),…,V g i,j (t d ,I d ,Δt d ,ρ d ),…,V g i,m (t d ,I d ,Δt d ,ρ d ),…,V g n,1 (t d ,I d ,Δt d ,ρ d ),V g n,2 (t d ,I d ,Δt d ,ρ d ),…,V g n,m (t d ,I d ,Δt d ,ρ d )}, where V g i,j (t d ,I d ,Δt d ,ρ d )=[V g,1 i,j (t d ,I d ,Δt d ,ρ d V g,2 i,j (t d ,I d ,Δt d ,ρ d )], where V g,1 i,j (t d ,I d ,Δt d ,ρ d ) and V g,2 i,j (t d ,I d ,Δt d ,ρ d The measured current amplitudes of the electrode arrays in the i-th row and j-th column are I, respectively. d The slider running interval is Δt d The resistivity is ρ d The potential gradients in the x and y directions on the measurement plane at time t d The potential gradients in the x and y directions on the measurement plane at time t are measured, and the calculation method is shown as follows: Wherein, S1 is the distance between the two pairs of reference electrodes in x and y directions; Step 3: Calculate the absolute potential gradient value |V g | of each electrode array on the measurement plane at different current amplitudes, running intervals, sand resistivities and time points. g,1 | = [ |V g,1 (t1, I1, Δt1, ρ1) |, |V h (t2, I1, Δt1, ρ1) |, …, |V h (tn, I1, Δt1, ρ1) | ] g,2 | = [ |V g,2 (t1, I1, Δt1, ρ1) |, |V h (t2, I1, Δt1, ρ1) |, …, |V h (tn, I1, Δt1, ρ1) | ] g,q | = [ |V d (t1, I1, Δt1, ρ1) |, |V d (t2, I1, Δt1, ρ1) |, …, |V d (tn, I1, Δt1, ρ1) | ] d | = [ |V g,k (t1, I1, Δt1, ρ1) |, |V g,k (t2, I1, Δt1, ρ1) |, …, |V h (tn, I1, Δt1, ρ1) | ] h | = [ |V d (t1, I1, Δt1, ρ1) |, |V d (t2, I1, Δt1, ρ1) |, …, |V d (tn, I1, Δt1, ρ1) | ] d | = [ |V g,q (t1, I1, Δt1, ρ1) |, |V d (t2, I1, Δt1, ρ1) |, …, |V d (tn, I1, Δt1, ρ1) | ] d | = [ |V d (t1, I1, Δt1, ρ1) |, |V g (t2, I1, Δt1, ρ1) |, …, |V 1,1 (tn, I1, Δt1, ρ1) | ] d | = [ |V d (t1, I1, Δt1, ρ1) |, |V d (t2, I1, Δt1, ρ1) |, …, |V d (tn, I1, Δt1, ρ1) | ] g | = [ |V 1,2 (t1, I1, Δt1, ρ1) |, |V d (t2, I1, Δt1, ρ1) |, …, |V d (tn, I1, Δt1, ρ1) | ] d | = [ |V d (t1, I1, Δt1, ρ1) |, |V g (t2, I1, Δt1, ρ1) |, …, |V 1,m (tn, I1, Δt1, ρ1) | ] d | = [ |V d (t1, I1, Δt1, ρ1) |, |V d (t2, I1, Δt1, ρ1) |, …, |V d (tn, I1, Δt1, ρ1) | ] g | = [ |V i,1 (t1, I1, Δt1, ρ1) |, |V d (t2, I1, Δt1, ρ1) |, …, |V d (tn, I1, Δt1, ρ1) | ] d | = [ |V d (t1, I1, Δt1, ρ1) |, |V g (t2, I1, Δt1, ρ1) |, …, |V i,2 (tn, I1, Δt1, ρ1) | ] d ,I d ,Δt d ,r d )|,…,|V g i,j (t d ,I d ,Δt d ,r d )|,…,|V g i,m (t d ,I d ,Δt d ,r d )|,…,|V g n,1 (t d ,I,Δt d ,r d )|,|V g n,2 (t d ,I d ,Δt d ,r d )|,…,|V g n,m (t d ,I d ,Δt d ,r d )|},calculation method as follows: wherein |V g i,j (t d ,I d ,Δt d ,ρ d )| is the absolute potential gradient value measured by the electrode array at the i-th row and j-th column at time t d , with the current amplitude I d , the slider running interval Δt d , and the resistivity ρ d . Step 4: Calculate the average value V of the absolute potential gradient of all electrode arrays on the measurement plane under different current amplitudes, operating intervals, sand resistivity, and time intervals. a =[V a,1 (t1,I1,Δt1,ρ1),…,V a,1 (t h ,I h ,Δt1,ρ1),V a,2 (t1,I1,Δt1,ρ1),…,V a,2 (t h ,I1,Δt1,ρ h ),…,V a,q (t d ,I d ,Δt d ,ρ d ),…,V a,k (t1,I1,Δt1,ρ1),…,V a,k (t h ,I1,Δt h [,ρ1)], the current amplitude is I d The slider running interval is Δt d The resistivity is ρ d At t d The absolute potential gradient V of all electrode arrays on the plane at time t is measured. a,q (t d ,I d ,Δt d ,ρ d The method for calculating the average value is as follows: Step 5: judging whether the position of each electrode array on the measuring plane is within the current diffusion range, and the current amplitude is I d , the slider running interval is Δt d , the resistivity is ρ d , the potential gradient value of each electrode array point on the measuring plane at time t d is |V g,q (t d , I d , Δt d , ρ d )| , the method is: The difference between the absolute potential gradient value of the electrode array at each point on the measurement plane and the average value of the absolute potential gradient is calculated respectively, and the absolute potential gradient value of the electrode array at the i-th row and the j-th column is represented as |V g i,j (t d ,I d ,Δt d ,ρ d )|, and ΔV is obtained by the following calculation: Wherein, max(·) and min(·) represent the maximum and minimum functions, respectively; According to the obtained ΔV, it is judged whether the position of the i-th row and j-th column electrode array is within the diffusion range of the current.

2. The measurement method according to claim 1, characterized in that, In step (5), the specific method for judging whether the position of the i-th row and j-th column electrode array is within the diffusion range of the current according to the obtained ΔV is as follows: If ΔV > 0, the current amplitude is I d , the slider running interval is Δt d , the resistivity is p d , the i-th row and the j-th column electrode array are within the current diffusion range at the time t d ; if ΔV < 0, the current amplitude is I d , the slider running interval is Δt d , the resistivity is p d , the i-th row and the j-th column electrode array are outside the current diffusion range at the time t d .

3. The measurement method according to claim 1, characterized in that, The system further comprises a steel frame (1), which is located on the measurement plane, and the sliding table guide rail (4) is fixed at both ends of the steel frame (1) to simulate the rail.

4. The measurement method according to claim 1, characterized by, The system further comprises a ball screw (6) connected with the sliding block (7), and the ball screw (6) is driven by a stepping motor (8) to drive the sliding block (7) to simulate the movement of a coal mine electric locomotive or a subway locomotive in a traction section on the sliding rail (4).

5. The method of claim 1, wherein, Each electrode array (15) is composed of four reference electrodes which are perpendicular to each other, and each electrode array (15) constitutes an array point on the measurement plane, and the four reference electrodes of each electrode array (15) are used to measure the polarization potential of four points to determine the potential gradient of the points in the x and y directions, the distance between the two pairs of reference electrodes in the x and y directions is S1, and the distance between each electrode array on the measurement plane is S2.

6. The measurement method according to claim 1, characterized by, The electrode array (15) adopts a copper / copper sulfate long-term reference electrode, and the four reference electrodes are vertically inserted into fine sand (14) as a group, and the buried depth of the reference electrode is 5-10 cm.

7. The measurement method according to claim 1, characterized by, The sliding block (7) is used to simulate a coal mine electric locomotive / subway locomotive, and the running speed is controlled by the current amplitude I through the stepping motor (8), and the sliding block (7) reciprocates on the sliding rail with a time interval Δt.

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