A coal mine / underground dynamic stray current signal feature identification method

Abstract

The application provides a coal mine / underground dynamic stray current signal feature identification method, including the following steps: 1, calculating the overpotential signal according to the dynamic stray current planned potential signal; 2, calculating the adjacent potential difference signal based on the overpotential signal; 3, traversing the adjacent potential difference signal to judge the dynamic stray current interference period; 4, counting the total interference time in the dynamic stray current signal; 5, calculating the proportion of the total interference time in the total time of the dynamic stray current signal. The application can realize accurate identification of the coal mine / underground dynamic stray current signal feature, is helpful to judging the stray current source according to the polarization potential signal, and is favorable for accurate implementation of the stray current protection measures.

Description

Technical Field

[0001] This invention relates to a method for identifying complex signal features, and more particularly to a method for identifying dynamic stray current signal features in coal mines / subways. Background Technology

[0002] Stray current leakage exists in coal mine locomotive transportation systems and subway DC traction systems. Dynamic stray current signals are high-frequency fluctuating signals with certain periodic characteristics, including interference periods and non-interference periods. During dynamic stray current interference periods, the polarization potential signal exhibits high-frequency fluctuations and randomness, with a relatively large amplitude; during non-dynamic stray current interference periods, the polarization potential signal amplitude is lower, and the overpotential signal fluctuates around zero. Because non-interference periods exist within the dynamic stray current signal, accurately determining the total interference time over a given operating period is crucial for assessing the overall risk of stray current corrosion in coal mine / subway transportation systems.

[0003] Currently, the interference time in dynamic stray current signals is primarily determined by the operating time of locomotives in coal mine / metro transportation systems. However, this method struggles to accurately determine the actual interference time when multiple transportation systems experience simultaneous interference. Therefore, it is necessary to determine the actual duration of dynamic stray current interference by examining the signal's own time-frequency characteristics. Summary of the Invention

[0004] To achieve the above objectives, this invention provides a method for identifying the characteristics of dynamic stray current signals in coal mines / subways to determine the actual time of dynamic stray current interference.

[0005] The technical solution implemented by this invention is as follows:

[0006] A method for identifying dynamic stray current signals in coal mines / subways includes the following steps:

[0007] Step 1: Obtain the dynamic stray current polarization potential signal P = [P(t1), P(t2), P(t3), ..., P(t...] of the coal mine / subway transportation system. i ),...,P(t N [], Natural potential P of the main structure of coal mine / subway traction system n =[P n (t1),P n (t2),P n (t3),...,P n (t i ),...,P(t N ], where t1, t2, t3, ..., t i ,...,t NFor different polarization potential test times, t1 is the start time of the coal mine / metro locomotive operation. Calculate the overpotential signal ΔP=[ΔP(t1),ΔP(t2),ΔP(t3),...,ΔP(t...]. i ),...,ΔP(t N )],ΔP(t i The calculation method for ) is as follows:

[0008] ΔP(t i )=P(t i )-P n (t i )

[0009] Step 2: For each overpotential value in the overpotential signal ΔP, calculate the adjacent potential difference signal ΔP. a =[ΔP a (1),ΔP a (2),ΔP a (3),…,ΔP a (i),…,ΔP a [(N-1)],ΔP a The calculation method for (i) is as follows:

[0010] ΔP a (i)=|ΔP(t i+1 )-ΔP(t i )|

[0011] Step 3: From ΔP a (1) Start by iterating through adjacent potential difference signals ΔP a Set a threshold ε for ΔP a Each value ΔP a For (i), the following judgment is made:

[0012] If ΔP a (i)>ε and ΔP a (i+1)>ε and ΔP a If (i-1)>ε, then t i-1 To t i+1 All are within the dynamic stray current interference time;

[0013] If ΔP a (i)>ε and ΔP a (i+1)>ε and ΔP a (i-1)<ε, then t i To t i+1 During the time of dynamic stray current interference, t i-2 To t i Not during periods of dynamic stray current interference;

[0014] If ΔPa (i)>ε and ΔP a (i+1)<ε and ΔP a (i-1)<ε, then t i-1 To t i t i+1 To t i+2 All are within the dynamic stray current interference time, t i-1 To t i+1 During stray current interference time;

[0015] If ΔP a (i) < ε and ΔP a (i+1)<ε and ΔP a (i-1)<ε, then t i-1 To t i+1 None of them are within the dynamic stray current interference time;

[0016] If ΔP a (i) < ε and ΔP a (i+1)<ε and ΔP a If (i-1)>ε, then t i-2 To t i During the time of dynamic stray current interference, t i To t i+2 Not during periods of dynamic stray current interference;

[0017] If ΔP a (i) < ε and ΔP a (i+1)>ε and ΔP a If (i-1)>ε, then t i-2 To t i-1 t i+1 To t i+2 All are within the dynamic stray current interference time, t i-1 To t i+1 Not during periods of dynamic stray current interference;

[0018] If ΔP a (i)>ε and ΔP a (i+1)<ε and ΔP a If (i-1)>ε, then t i-1 To t i During the time of dynamic stray current interference, t i To t i+2 Not during periods of dynamic stray current interference;

[0019] If ΔP a (i) < ε and ΔP a (i+1)>ε and ΔP a (i-1)<ε, then t i-1 To ti+1 Not during the time of dynamic stray current interference, t i+1 To t i+2 During the period of dynamic stray current interference.

[0020] Step 4: Based on the judgment result in Step 3, calculate the total interference time T in the dynamic stray current signal P. c .

[0021] Step 5: Calculate the interference time T c The proportion R of the total time of the dynamic stray current signal is calculated as follows:

[0022]

[0023] In step 5, the threshold ε is determined as follows for the overpotential signal ΔP:

[0024]

[0025] Where N is the number of overpotential values ​​in the overpotential signal ΔP.

[0026] Beneficial effects:

[0027] This invention provides a method for identifying the characteristics of dynamic stray current signals in coal mines / subways, which can determine the actual time of dynamic stray current interference based on the time-frequency characteristics of the signal itself.

[0028] This invention enables accurate identification of dynamic stray current signal characteristics in coal mines / subways, helps determine the source of stray current based on polarization potential signals, and facilitates the accurate implementation of stray current protection measures. Attached Figure Description

[0029] Figure 1 This is a flowchart of the method for identifying the frequency characteristics of dynamic stray current signals in coal mines / subways proposed in this invention.

[0030] Figure 2 This is a schematic diagram illustrating the dynamic stray current interference judgment in this invention;

[0031] Figure 3 This is a schematic diagram of the steel-concrete structure electrochemical corrosion test bench used to determine the threshold ε in this invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention.

[0033] Please see Figure 1-3A method for identifying dynamic stray current signals in coal mines / subways is implemented through the following steps:

[0034] Step 1: Measure the dynamic stray current polarization potential signal P = [P(t1), P(t2), P(t3), ..., P(t...] using a copper / copper sulfate reference electrode monitoring system pre-installed in the coal mine / subway transportation system. i ),...,P(t N [], Natural potential P of the main structure of coal mine / subway traction system n =[P n (t1),P n (t2),P n (t3),...,P n (t i ),...,P(t N ], where t1, t2, t3, ..., t i ,...,t N For different polarization potential test times, t1 is the start time of the coal mine / metro locomotive operation. Calculate the overpotential signal ΔP=[ΔP(t1),ΔP(t2),ΔP(t3),...,ΔP(t...]. i ),...,ΔP(t N )],ΔP(t i The calculation method for ) is as follows:

[0035] ΔP(t i )=P(t i )-P n (t i )

[0036] Step 2: For each overpotential value in the overpotential signal ΔP, calculate the adjacent potential difference signal ΔP. a =[ΔP a (1),ΔP a (2),ΔP a (3),…,ΔP a (i),…,ΔP a [(N-1)],ΔP a The calculation method for (i) is as follows:

[0037] ΔP a (i)=|ΔP(t i+1 )-ΔP(t i )|

[0038] Step 3: Set the threshold ε, which is determined as follows:

[0039] An electrochemical corrosion test bench with a steel-concrete structure was constructed to simulate the stray current leakage environment of a coal mine / subway, such as... Figure 3 As shown, the working electrode is a steel bar, the reference electrode is placed in a sponge completely immersed in chloride ion solution, and the sponge is placed on top of the steel-concrete structure sample. The auxiliary electrode is a graphite electrode rod, which is placed 3 cm parallel to the steel bar during sample casting. Two titanium alloy meshes are connected to the positive and negative terminals of the power supply to provide a stray current path for flowing into the steel-concrete structure. The stray current leakage amplitude I at the location within the coal mine / subway transportation system section is calculated using a resistive network model. s and I s This serves as the output current value of the power supply in the corrosion test bench. Before conducting the corrosion half-potential test, the steel-mixed sample must be pre-immersed in a chloride ion solution with Ig. s The current amplitude was applied for 24 hours. The average corrosion half-potential P of the reinforcing steel in the steel-concrete structure was measured over 1 hour using a three-electrode system. h and P h As a threshold ε.

[0040] Based on the determined threshold ε, from ΔP a (1) Start by iterating through adjacent potential difference signals ΔP a For ΔP a Each value ΔP a For (i), the following judgment is made:

[0041] If ΔP a (i)>ε and ΔP a (i+1)>ε and ΔP a If (i-1)>ε, then t i-1 To t i+1 All are within the dynamic stray current interference time;

[0042] If ΔP a (i)>ε and ΔP a (i+1)>ε and ΔP a (i-1)<ε, then t i To t i+1 During the time of dynamic stray current interference, t i-2 To t i Not during periods of dynamic stray current interference;

[0043] If ΔP a (i)>ε and ΔP a (i+1)<ε and ΔP a (i-1)<ε, then t i-1 To t i t i+1 To t i+2 All are within the dynamic stray current interference time, t i-1 To t i+1 During stray current interference time;

[0044] If ΔP a (i) < ε and ΔP a (i+1)<ε and ΔP a (i-1)<ε, then t i-1 To t i+1 None of them are within the dynamic stray current interference time;

[0045] If ΔP a (i) < ε and ΔP a (i+1)<ε and ΔP a If (i-1)>ε, then t i-2 To t i During the time of dynamic stray current interference, t i To t i+2 Not during periods of dynamic stray current interference;

[0046] If ΔP a (i) < ε and ΔP a (i+1)>ε and ΔP a If (i-1)>ε, then t i-2 To t i-1 t i+1 To t i+2 All are within the dynamic stray current interference time, t i-1 To t i+1 Not during periods of dynamic stray current interference;

[0047] If ΔP a (i)>ε and ΔP a (i+1)<ε and ΔP a If (i-1)>ε, then t i-1 To t i During the time of dynamic stray current interference, t i To t i+2 Not during periods of dynamic stray current interference;

[0048] If ΔP a (i) < ε and ΔP a (i+1)>ε and ΔP a (i-1)<ε, then t i-1 To t i+1 Not during the time of dynamic stray current interference, t i+1 To t i+2 During the period of dynamic stray current interference.

[0049] Step 4: Based on the judgment result in Step 3, calculate the total interference time T in the dynamic stray current signal P. c .

[0050] Step 5: Calculate the interference time T cThe proportion R of the total time of the dynamic stray current signal is calculated as follows:

[0051]

[0052] For the overpotential signal ΔP, the threshold ε is determined as follows:

[0053]

[0054] Where N is the number of overpotential values ​​in the overpotential signal ΔP.

[0055] The examples described herein are merely preferred embodiments of the invention and are not intended to limit the concept and scope of the invention. Any modifications and improvements made by those skilled in the art to the technical solutions of the invention without departing from the design concept of the invention should fall within the protection scope of the invention.

Claims

1. A method for identifying dynamic stray current signal characteristics in coal mines / subways, characterized in that, Includes the following steps: Step 1: Obtain the dynamic stray current polarization potential signal P = [P(t1), P(t2), P(t3), ..., P(t...] of the coal mine / subway transportation system. i ),...,P(t N [], Natural potential P of the main structure of coal mine / subway traction system n =[P n (t1),P n (t2),P n (t3),...,P n (t i ),...,P(t N ], where t1, t2, t3, ..., t i ,...,t N For different polarization potential test times, t1 is the start time of the coal mine / subway locomotive operation. Calculate the overpotential signal ΔP = [ΔP(t1), ΔP(t2), ΔP(t3), ..., ΔP(t...]. i ),...,ΔP(t N )],ΔP(t i The calculation method for ) is as follows: ΔP(t i )=P(t i )-P n (t i ); Step 2: For each overpotential value in the overpotential signal ΔP, calculate the adjacent potential difference signal ΔP. a =[ΔP a (1),ΔP a (2),ΔP a (3),…,ΔP a (i),…,ΔP a [(N-1)],ΔP a The calculation method for (i) is as follows: ΔP a (i)=ΔP(t i+1 )-ΔP(t i ); Step 3: From ΔP a (1) Start by iterating through adjacent potential difference signals ΔP a Set a threshold ε for ΔP a Each value ΔP a (i), perform the following judgment: If ΔP a (i)>ε and ΔP a (i+1)>ε and ΔP a If (i-1)>ε, then t i-1 To t i+1 All are within the dynamic stray current interference time; If ΔP a (i)>ε and ΔP a (i+1)>ε and ΔP a (i-1)<ε, then t i To t i+1 During the time of dynamic stray current interference, t i-2 To t i Not during periods of dynamic stray current interference; If ΔP a (i)>ε and ΔP a (i+1)<ε and ΔP a (i-1)<ε, then t i-1 To t i t i+1 To t i+2 All are within the dynamic stray current interference time, t i-1 To t i+1 During stray current interference time; If ΔP a (i) < ε and ΔP a (i+1)<ε and ΔP a (i-1)<ε, then t i-1 To t i+1 None of them are within the dynamic stray current interference time; If ΔP a (i) < ε and ΔP a (i+1)<ε and ΔP a If (i-1)>ε, then t i-2 To t i During the time of dynamic stray current interference, t i To t i+2 Not during periods of dynamic stray current interference; If ΔP a (i) < ε and ΔP a (i+1)>ε and ΔP a If (i-1)>ε, then t i-2 To t i-1 t i+1 To t i+2 All are within the dynamic stray current interference time, t i-1 To t i+1 Not during periods of dynamic stray current interference; If ΔP a (i)>ε and ΔP a (i+1)<ε and ΔP a If (i-1)>ε, then t i-1 To t i During the time of dynamic stray current interference, t i To t i+2 Not during periods of dynamic stray current interference; If ΔP a (i) < ε and ΔP a (i+1)>ε and ΔP a (i-1)<ε, then t i-1 To t i+1 Not during the time of dynamic stray current interference, t i+1 To t i+2 During the period of dynamic stray current interference; Step 4: Based on the judgment result in Step 3, calculate the total interference time T in the dynamic stray current signal P. c ; Step 5: Calculate the interference time T c The total time T of the dynamic stray current signal N The percentage R within is calculated as follows:

2. The method for identifying dynamic stray current signal characteristics in coal mines / subways according to claim 1, characterized in that, For the overpotential signal ΔP, the threshold ε is determined as follows: Where N is the number of overpotential values ​​in the overpotential signal ΔP.

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