Urban rail transit stray current monitoring system and method

Abstract

The embodiment of the application provides a kind of urban rail transit stray current monitoring system and method.The system is designed by three modules of measurement system, error control and anti-interference, with the advantages of high precision, high adaptability and high stability.The system is constructed based on voltammetry and Kirchhoff's current law, with high-precision voltmeter of 1 resolution, to accurately capture the weak voltage drop of steel rail, without interfering with the original loop, and then compared with the total current of traction substation for cross-validation, to ensure the accuracy and reliability of the results.For the fluctuation of rail resistance affected by temperature and humidity and other factors, resistance-temperature and humidity model is established in laboratory, and resistance value is corrected by real-time parameter collection on site, to effectively offset the error and adapt to complex conditions.In the face of strong electromagnetic interference in tunnel, software and hardware are used to resist interference, hardware uses shielded cable and filter circuit to suppress interference, and software uses sliding average filtering algorithm to smooth noise, to form closed-loop protection and ensure signal stability.

Description

Technical Field

[0001] This application relates to the field of safety monitoring technology, and in particular to a stray current monitoring system and method for urban rail transit. Background Technology

[0002] With the acceleration of urbanization, urban rail transit, with its advantages of high efficiency, convenience, and large capacity, has become a core backbone transportation mode for alleviating urban traffic congestion. Urban rail transit traction systems mostly adopt DC traction power supply mode. After the current is supplied to the railcar via the contact network, it needs to return to the negative terminal of the traction substation through the rails. During this process, some current deviates from the preset normal conduction circuit and flows unexpectedly in the surrounding environment, forming stray currents (also known as "stray currents"). These stray currents can cause electrochemical corrosion to subway rails, insulating fasteners, and buried metal pipelines (such as gas pipelines and water supply pipelines) near the line. Over time, this can lead to rail wear, pipeline damage, and even serious safety accidents such as gas leaks and pipeline ruptures, endangering the operational safety of rail transit and the safety of surrounding public areas. Therefore, accurate monitoring of stray currents in urban rail transit and the location of leak points have become a key requirement for ensuring the safe and stable operation of rail transit.

[0003] Existing stray current measurements mostly rely on the reference electrode method, which involves embedding an electrode in concrete as a reference point for potential measurement, using a voltmeter to measure the polarization potential between the rail and the reference electrode, thereby obtaining the stray current value.

[0004] However, the above methods have limitations such as being susceptible to environmental interference, only being able to detect local data, and having excessively high equipment costs. Summary of the Invention

[0005] This application provides a stray current monitoring system and method for urban rail transit, which can achieve high-precision real-time monitoring of stray current and accurate location of leakage points in urban rail transit.

[0006] In a first aspect, embodiments of this application provide a stray current monitoring system for urban rail transit, comprising:

[0007] Voltage measurement module, current calculation module, data acquisition and processing module, and resistance dynamic calibration and error compensation module;

[0008] The voltage measurement module is connected in parallel to both ends of the rail section to measure the voltage drop of the rail section.

[0009] The dynamic resistance calibration and error compensation module is used to dynamically correct the longitudinal resistance of the rail in combination with environmental parameters.

[0010] The current calculation module is used to calculate the return current flowing through the rail segment based on the voltage drop, in conjunction with the corrected longitudinal resistance of the rail.

[0011] The data acquisition and processing module is used to collect the voltage drop in real time to verify the received return current, and compare the verified return current with the total feed current of the traction substation to calculate the stray current.

[0012] In one possible implementation, the system further includes an anti-interference module;

[0013] The anti-interference module uses a combination of hardware and software to perform anti-interference processing on the voltage drop, environmental parameters, longitudinal resistance of the rail, and return current, thereby suppressing electromagnetic interference.

[0014] In one possible implementation, the dynamic resistance calibration and error compensation module is equipped with a temperature sensor and a humidity sensor. The module then dynamically corrects the longitudinal resistance of the rail in conjunction with environmental parameters, including:

[0015] The dynamic resistance calibration and error compensation module collects environmental parameters in real time based on the temperature sensor and humidity sensor;

[0016] Based on the environmental parameters, a pre-configured resistance-temperature-humidity correlation model is invoked to correct the longitudinal resistance of the rail. The resistance-temperature-humidity correlation model is established by applying a known current to rails of different lengths and measuring the voltage drop in a laboratory environment with adjustable temperature and humidity.

[0017] In one possible implementation, the anti-interference module includes a hardware anti-interference unit and a software anti-interference unit;

[0018] The hardware anti-interference unit is configured with independent transmission channels for different types of signals. It uses shielded cables, independent filter circuits and partitioned opto-isolation to physically isolate the voltage drop, the environmental parameters, the longitudinal resistance of the rail and the return current to prevent crosstalk between different signals.

[0019] The software anti-interference unit uses partitioned storage and independent algorithm processing for different types of data, and employs moving average filtering algorithm or wavelet transform algorithm to smooth and reduce noise in the corresponding data.

[0020] In one possible implementation, the system further includes a locomotive positioning module;

[0021] The signal output terminal of the locomotive positioning module is electrically connected to the signal input terminal of the data acquisition and processing module, and is used to transmit the real-time position information of the rail locomotive to the data acquisition and processing module.

[0022] When the difference between the verified return current of the current rail segment and the total feed current of the traction substation exceeds a preset threshold, the current rail segment is identified as a stray current leakage point by combining the real-time location information transmitted by the locomotive positioning module.

[0023] In one possible implementation, the system can also be connected to the current acquisition terminal of the rail transit drainage collection network to verify the stray current leakage point by acquiring the current change data of the drainage collection network of the current rail section.

[0024] Secondly, embodiments of this application provide a method for monitoring stray currents in urban rail transit, applied to the urban rail transit stray current monitoring system described in any one of the first aspects, the method comprising:

[0025] The voltage drop at both ends of the rail section is collected by the voltage measurement module and transmitted to the data acquisition and processing module.

[0026] The environmental parameters of the rail transit site are collected in real time by the resistance dynamic calibration and error compensation module, and the longitudinal resistance of the rail is dynamically corrected in combination with the environmental parameters. The corrected longitudinal resistance of the rail is then sent to the current calculation module.

[0027] The current calculation module calculates the return current flowing through the rail section by combining the corrected longitudinal resistance of the rail with the voltage drop, and then transmits the return current to the data acquisition and processing module.

[0028] The data acquisition and processing module verifies the return current based on the real-time voltage drop, and compares the verified return current with the total feed current of the traction substation to calculate the stray current.

[0029] In one possible implementation, the method further includes:

[0030] The voltage drop, environmental parameters, longitudinal resistance of the rail, and return current are subjected to zoned isolation anti-interference processing through an anti-interference module.

[0031] In one possible implementation, the method further includes:

[0032] The real-time location information of the rail locomotive is obtained through the locomotive positioning module.

[0033] When the difference between the verified return current of the current rail segment and the total feed current of the traction substation exceeds a preset threshold, the current rail segment is identified as a stray current leakage point based on the real-time location information.

[0034] In one possible implementation, the step of acquiring environmental parameters of the rail transit site in real time through the dynamic resistance calibration and error compensation module, and dynamically correcting the longitudinal resistance of the rail in combination with the environmental parameters, includes:

[0035] The dynamic resistance calibration and error compensation module collects the environmental parameters in real time.

[0036] Based on the environmental parameters, a pre-configured resistance-temperature-humidity correlation model is invoked to correct the longitudinal resistance of the rail. The resistance-temperature-humidity correlation model is established by applying a known current to rails of different lengths and measuring the voltage drop in a laboratory environment with adjustable temperature and humidity.

[0037] Thirdly, embodiments of this application provide a rail vehicle including the stray current monitoring system for urban rail transit as described in any of the first aspects, the system being used to perform the second aspect and / or various possible implementations of the second aspect.

[0038] Fourthly, embodiments of this application provide a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the second aspect and / or various possible implementations of the second aspect as described above.

[0039] Fifthly, embodiments of this application provide a computer program product, including a computer program that, when executed by a processor, implements the second aspect and / or various possible implementations of the second aspect as described above.

[0040] The stray current monitoring system and method for urban rail transit provided in this application acquires the voltage drop across the two ends of a rail section through a voltage measurement module and transmits the voltage drop to a data acquisition and processing module. A dynamic resistance calibration and error compensation module acquires real-time environmental parameters of the rail transit site and dynamically corrects the longitudinal resistance of the rail based on these environmental parameters. The corrected longitudinal resistance is then sent to a current calculation module. This module, combining the corrected longitudinal resistance and voltage drop, calculates the return current flowing through the rail section and transmits the return current to the data acquisition and processing module. The data acquisition and processing module verifies the return current based on real-time voltage drop data and compares the verified return current with the total feed current of the traction substation to calculate the stray current. An anti-interference module performs zoned isolation anti-interference processing on voltage drop, environmental parameters, rail longitudinal resistance, and return current. The locomotive positioning module acquires the real-time position information of the track locomotive. When the difference between the verified return current and the total feed current of the traction substation for the current rail segment exceeds a preset threshold, the current rail segment is identified as a stray current leakage point based on the real-time position information. This method improves measurement accuracy and anti-interference capabilities, overcomes the shortcomings of existing technologies in local monitoring and positioning, effectively prevents the electrochemical corrosion risk of stray current to the track and surrounding buried pipelines, and ensures the safe and stable operation of urban rail transit. Attached Figure Description

[0041] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0042] Figure 1 This application provides a schematic diagram of the stray current monitoring system for urban rail transit.

[0043] Figure 2 A flowchart illustrating the stray current monitoring method for urban rail transit provided in this application;

[0044] Figure 3 This is a schematic diagram of an example structure.

[0045] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0046] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0047] First, let me explain the terms used in this application:

[0048] Stray current, also known as "stray current", leakage current, series current, or diffuse current, refers to current that flows outside the designed or specified circuit, that is, current that deviates from the originally set normal conduction path and flows unexpectedly in the surrounding environment.

[0049] With the acceleration of urbanization, urban rail transit, with its advantages of high efficiency, convenience, and large capacity, has become a core backbone transportation mode for alleviating urban traffic congestion. Urban rail transit traction systems mostly adopt DC traction power supply mode. After the current is supplied to the railcar via the contact network, it needs to return to the negative terminal of the traction substation through the rails. During this process, some current deviates from the preset normal conduction circuit and flows unexpectedly in the surrounding environment, forming stray currents (also known as "stray currents"). These stray currents can cause electrochemical corrosion to subway rails, insulating fasteners, and buried metal pipelines (such as gas pipelines and water supply pipelines) near the line. Over time, this can lead to rail wear, pipeline damage, and even serious safety accidents such as gas leaks and pipeline ruptures, endangering the operational safety of rail transit and the safety of surrounding public areas. Therefore, accurate monitoring of stray currents in urban rail transit and the location of leak points have become a key requirement for ensuring the safe and stable operation of rail transit.

[0050] Existing stray current measurements mostly rely on the reference electrode method, which involves embedding electrodes in concrete as a reference point for potential measurement. A voltmeter is used to measure the polarization potential between the rail and the reference electrode to obtain the stray current value. However, this method has limitations such as being susceptible to environmental interference, only being able to detect local data, and having excessively high equipment costs.

[0051] The core logic of stray current measurement using the reference electrode method is "polarization potential measurement → stray current conversion." The accuracy of the potential measurement is a crucial prerequisite for ensuring the reliability of the current calculation results. Maintaining this accuracy requires simultaneously satisfying two key conditions: the electrochemical equilibrium between the reference electrode and the concrete medium, and the signal stability of the measurement circuit. The humidity, pH value, and ion concentration of the concrete dynamically change with external environmental factors such as rainfall infiltration, temperature fluctuations, concrete carbonation, and chemical erosion. These changes directly disrupt the electrochemical equilibrium at the interface between the reference electrode and the concrete, causing a drift in the reference electrode's reference potential. The measured rail polarization potential value deviates from the true value, which in turn causes the calculated stray current data to be distorted. At the same time, during the measurement process, the rail and the reference electrode need to be connected by wires to form a long-distance signal transmission loop. Harmonic currents of the rail transit traction system and electromagnetic fields of surrounding power equipment will cause electromagnetic interference to the weak millivolt-level potential signal. The continuous vibration generated by the train operation may also cause the reference electrode to loosen its contact with the concrete and the wire joint to have poor contact, which will further cause the potential signal to be superimposed, causing interference noise or even interruption. Ultimately, this will lead to inaccurate polarization potential measurement values ​​and affect the reliability of stray current calculation results.

[0052] To address the aforementioned technical problems, this application provides a stray current monitoring system and method for urban rail transit, achieving high-precision real-time monitoring of stray currents and accurate location of leakage points in urban rail transit. Specifically, existing stray current measurements largely rely on the reference electrode method, which involves embedding electrodes in concrete as a reference point for potential measurement. A voltmeter is used to measure the polarization potential between the rail and the reference electrode to obtain the stray current value. However, this method has limitations, including susceptibility to environmental interference, the ability to detect only localized data, and high equipment costs. Considering these issues, the inventors investigated whether a measurement system could be constructed based on the voltmeter-ammeter method and Kirchhoff's current law, achieving high-precision real-time monitoring of stray currents and accurate location of leakage points in urban rail transit. A high-resolution voltmeter captures the slight voltage drop across the rails, dynamically corrects errors using a laboratory-calibrated resistance-temperature-humidity model, and employs shielding, filtering, and algorithmic noise reduction to combat strong electromagnetic interference. This approach ensures both measurement accuracy and stability, and enables the location of stray current leakage points across the entire track area via locomotive movement, effectively preventing the risk of electrochemical corrosion of the track and surrounding buried pipelines by stray currents. Based on this, the technical solution proposed in this application is presented.

[0053] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0054] Figure 1 The schematic diagram of the stray current monitoring system for urban rail transit provided in this application is as follows: Figure 1 As shown, all modules of the system are integrated and deployed on a track inspection locomotive, which moves along the subway mainline to achieve continuous monitoring of the entire line. The overall system is based on the volt-ampere method and Kirchhoff's current law to construct a measurement system, which includes: a voltage measurement module, a current calculation module, a data acquisition and processing module, a resistance dynamic calibration and error compensation module, an anti-interference module, and a locomotive positioning module. Each module works collaboratively through electrical connections and dedicated signal transmission lines. The specific deployment location is adapted to the installation space inside the locomotive and does not affect the normal operation of the locomotive.

[0055] The voltage measurement module is connected in parallel to both ends of the rail section to measure the voltage drop of the rail section.

[0056] The voltage measurement module uses a high-precision digital voltmeter, which is connected in parallel to both ends of the rail section under the locomotive via a dedicated fixed bracket. The two measuring probes of the voltmeter are connected to the conductive contacts on both sides of the rail. The contacts are treated with an anti-oxidation coating to ensure good contact and avoid contact resistance from affecting the measurement accuracy.

[0057] The core function of the voltage measurement module is to collect the voltage drop of the rail section in real time. For example, the acquisition frequency can be set to 10Hz, that is, 10 sets of voltage data are collected per second. After preliminary filtering, the collected data is transmitted to the data acquisition and processing module through the signal transmission line to provide basic data for subsequent return current calculation.

[0058] The dynamic resistance calibration and error compensation module is used to dynamically correct the longitudinal resistance of the rail in combination with environmental parameters;

[0059] The current calculation module is used to calculate the return current flowing through the rail section based on the voltage drop, in conjunction with the corrected longitudinal resistance of the rail.

[0060] For example, the current calculation module uses a dedicated signal processing chip to achieve bidirectional signal connection with the data acquisition and processing module. On the one hand, it receives the corrected longitudinal resistance value of the rail transmitted by the resistance dynamic calibration and error compensation module, and on the other hand, it receives the voltage drop data transmitted by the voltage measurement module (forwarded by the data acquisition and processing module). Based on Ohm's law (I=U / R), it calculates the return current flowing through the rail section.

[0061] Specifically, the current calculation module has a built-in arithmetic unit that substitutes the received voltage drop data (U) and the corrected longitudinal rail resistance value (R) into the formula to calculate the return current in real time. The calculation results are synchronously transmitted to the data acquisition and processing module for subsequent verification and stray current estimation.

[0062] The data acquisition and processing module is used to collect the voltage drop in real time to verify the received return current, and compare the verified return current with the total feed current of the traction substation to calculate the stray current.

[0063] The voltage measurement module uses a high-precision digital voltmeter (resolution up to 1). The device is connected in parallel to both ends of the rail section to measure the voltage drop of that section of rail, and the measurement data is transmitted in real time for data processing through the data acquisition module.

[0064] The data acquisition and processing module records voltage data in real time using a microcontroller or data acquisition card, calculates current values, and compares them with the total current supplied by the traction substation to estimate stray current.

[0065] Optionally, the system also includes an anti-interference module, which uses a combination of hardware and software to process voltage drop, environmental parameters, longitudinal rail resistance and return current to suppress electromagnetic interference.

[0066] The dynamic resistance calibration and error compensation module is equipped with temperature and humidity sensors. This module dynamically corrects the longitudinal resistance of the rail based on environmental parameters, including:

[0067] The dynamic resistance calibration and error compensation module collects environmental parameters in real time based on temperature and humidity sensors.

[0068] The longitudinal resistance of the rail is corrected by calling a pre-configured resistance-temperature-humidity correlation model based on environmental parameters. The resistance-temperature-humidity correlation model is established by applying a known current to rails of different lengths and measuring the voltage drop in a laboratory environment with adjustable temperature and humidity.

[0069] The anti-interference module includes a hardware anti-interference unit and a software anti-interference unit.

[0070] The hardware anti-interference unit is configured with independent transmission channels for different types of signals. It uses shielded cables, independent filter circuits and partitioned opto-isolation to physically isolate voltage drop, environmental parameters, longitudinal resistance of rails and return current to prevent crosstalk between different signals.

[0071] The software anti-interference unit uses partitioned storage and independent algorithm processing for different types of data, and employs moving average filtering algorithm or wavelet transform algorithm to smooth and reduce noise in the corresponding data.

[0072] The hardware anti-interference unit is configured with independent transmission channels for different types of signals. Voltage drop signals, environmental parameters (temperature and humidity), resistance correction data, and return current are transmitted using independent shielded cables. Each signal channel is equipped with an independent RC filter circuit to filter out high-frequency electromagnetic interference. At the same time, opto-isolators are set at the signal input terminals of each module to achieve opto-isolation of signals, suppress common-mode interference and differential-mode interference, and avoid crosstalk between different signals.

[0073] The software anti-interference submodule is integrated into the data acquisition and processing module. It adopts a partitioned storage (different data are stored in different cache areas) and independent algorithm processing for different types of data: for voltage drop signals and return current, a moving average filtering algorithm is used to smooth data noise; for temperature and humidity data and resistance correction data, a wavelet transform algorithm is used to eliminate random interference, ensuring that the software anti-interference operation of different data does not affect each other, and further improving data accuracy.

[0074] The system also includes a locomotive positioning module;

[0075] The signal output terminal of the locomotive positioning module is electrically connected to the signal input terminal of the data acquisition and processing module, which is used to transmit the real-time position information of the rail locomotive to the data acquisition and processing module;

[0076] When the difference between the verified return current of the current rail section and the total feed current of the traction substation exceeds a preset threshold, the current rail section is identified as a stray current leakage point by combining the real-time location information transmitted by the locomotive positioning module.

[0077] Optionally, the system can also connect to the current acquisition terminal of the rail transit drainage collection network to verify stray current leakage points by collecting current change data of the drainage collection network of the current rail section.

[0078] Optionally, in actual situations, the longitudinal resistance of the rail is affected by factors such as temperature, humidity, and oxidation of the contact surface, which will cause the resistance value to change, resulting in the superposition of current calculation errors. Therefore, the longitudinal resistance of the rail needs to be dynamically calibrated and calculated for compensation during measurement and calculation.

[0079] (1) Laboratory calibration: In a laboratory environment with adjustable temperature and humidity, a known current is applied to rails of different lengths, the voltage drop is measured, and the measurement is repeated after adjusting the temperature and humidity to establish a resistance-temperature-humidity model.

[0080] (2) On-site calculation compensation: Real-time environmental data is collected by temperature and humidity sensors, and the rail resistance value is corrected by combining the calibration model to reduce measurement and calculation errors.

[0081] Figure 2 This is a flowchart illustrating the stray current monitoring method for urban rail transit provided in this application, as shown below. Figure 2 As shown, this method is applied to the stray current monitoring system for urban rail transit in the aforementioned embodiments. The method includes:

[0082] S201: The voltage drop at both ends of the rail section is collected by the voltage measurement module and transmitted to the data acquisition and processing module.

[0083] In this step, in order to calculate the return current, the voltage drop at both ends of the rail section can be collected by the voltage measurement module to obtain the raw basic data for calculating the return current.

[0084] Specifically, a voltage measurement module (high-precision digital voltmeter) deployed under the locomotive is reliably connected to both ends of the rail section being measured via an anti-oxidation conductive probe. It collects the voltage drop signal at both ends of the rail section in real time at a preset frequency (e.g., 10Hz). The collected raw signal undergoes preliminary filtering to remove obvious spike interference. The voltage drop data is then transmitted to the data acquisition and processing module via a dedicated signal line and stored in a buffer.

[0085] S202: The dynamic resistance calibration and error compensation module collects environmental parameters of the rail transit site in real time, and dynamically corrects the longitudinal resistance of the rail in combination with the environmental parameters, and sends the corrected longitudinal resistance of the rail to the current calculation module.

[0086] To mitigate the impact of environmental factors such as temperature and humidity on rail resistance and improve calculation accuracy, an environmental parameter acquisition and correction method is used based on a dynamic resistance calibration and error compensation module.

[0087] Specifically, the dynamic resistance calibration and error compensation module collects on-site environmental parameters in real time through temperature and humidity sensors.

[0088] The module's internal computing unit calls the pre-stored "resistance-temperature-humidity" correlation model.

[0089] Substitute real-time temperature and humidity parameters into the model to calculate and output the corrected longitudinal resistance of the rail.

[0090] The corrected resistance value is sent to the current calculation module to provide accurate parameters for subsequent calculations.

[0091] S203: The current calculation module, combined with the corrected longitudinal resistance and voltage drop of the rail, calculates the return current flowing through the rail section and transmits the return current to the data acquisition and processing module.

[0092] In order to calculate the return current flowing through the rail based on the corrected resistance and voltage drop, the current calculation module simultaneously receives two key inputs: the corrected resistance value transmitted from S202, and the voltage drop data collected and forwarded by S201.

[0093] Based on Ohm's law I=U / R, the return current flowing through this section of rail is calculated in real time. The calculation results are initially verified for reasonableness, and obvious outliers are eliminated. The calculated return current is then transmitted to the data acquisition and processing module.

[0094] S204: The return current is verified based on the real-time voltage drop through the data acquisition and processing module, and the verified return current is compared with the total feed current of the traction substation to calculate the stray current.

[0095] In this step, to ensure the reliability of the return current data and to calculate the stray current based on Kirchhoff's laws, the data acquisition and processing module calls the voltage drop acquired by S201 and, in conjunction with the correction resistor of S202, recalculates the return current.

[0096] The recalculated result is compared with the return current transmitted from S203. If the error is within a preset threshold, the data is considered valid. The total feed current of the traction substation is received in real time via wireless communication. According to Kirchhoff's current law The magnitude of the stray current is calculated.

[0097] Stray current, return current, and other data are stored and synchronized to the locomotive display terminal.

[0098] Optionally, the method further includes:

[0099] S205: The anti-interference module performs zoned isolation anti-interference processing on voltage drop, environmental parameters, longitudinal resistance of rails, and return current.

[0100] To suppress electromagnetic interference on-site and ensure the stability and accuracy of all data, the hardware aspect involves configuring independent shielded cable transmission channels for four types of data: voltage drop, environmental parameters, correction resistor, and return current. Each channel is equipped with an independent filter circuit and opto-isolator to achieve physical isolation.

[0101] At the software level: In the data acquisition and processing module, different types of data are stored in partitions and denoised using independent filtering algorithms (such as moving average filtering for current signals and wavelet transform for environmental parameters).

[0102] Ensure that the anti-interference operations for different data are physically and logically independent and do not affect each other.

[0103] In one possible implementation, the method further includes:

[0104] S206: The real-time location information of the rail locomotive is obtained through the locomotive positioning module.

[0105] To provide accurate location data for locating stray current leakage points, the locomotive positioning module can be used to collect the locomotive's real-time location information.

[0106] Specifically, the locomotive positioning module (such as GPS + transponder dual-mode positioning) is activated to collect the locomotive's real-time location information at a preset frequency. The positioning data is filtered and calibrated to improve positioning accuracy (up to ±1m). The location information is transmitted to the data acquisition and processing module and timestamped with the currently monitored current data.

[0107] S207: When the difference between the verified return current of the current rail section and the total feed current of the traction substation exceeds the preset threshold, the current rail section is identified as the stray current leakage point by combining real-time location information.

[0108] In this step, the stray current leakage range can be accurately located by combining the current difference and location information.

[0109] Specifically, the data acquisition and processing module monitors the difference between the verified return current and the total feed current in real time. When the difference exceeds a preset threshold, it is determined that there is stray current leakage in that section of rail. The real-time locomotive location information obtained from S206 is used, combined with the currently measured rail section, to pinpoint the location of the leak. Current changes in the corresponding section's drainage collection network are collected; if the current increases synchronously, the accuracy of the location result is further verified. Information such as the leak location and the magnitude of the leakage current is output and stored.

[0110] The stray current monitoring method for urban rail transit provided in this application involves: acquiring the voltage drop across the two ends of a rail section using a voltage measurement module and transmitting the voltage drop to a data acquisition and processing module; acquiring real-time environmental parameters of the rail transit site using a dynamic resistance calibration and error compensation module; dynamically correcting the longitudinal resistance of the rail based on these environmental parameters; and sending the corrected longitudinal resistance to a current calculation module. The current calculation module then calculates the return current flowing through the rail section using the corrected longitudinal resistance and voltage drop, and transmits the return current to the data acquisition and processing module. The processing module verifies the return current based on real-time voltage drop data and compares the verified return current with the total feed current of the traction substation to calculate the stray current. An anti-interference module performs zoned isolation anti-interference processing on voltage drop, environmental parameters, rail longitudinal resistance, and return current. The locomotive positioning module acquires the real-time position information of the track locomotive. When the difference between the verified return current and the total feed current of the traction substation for the current rail segment exceeds a preset threshold, the current rail segment is identified as the stray current leakage point based on the real-time position information. This method improves measurement accuracy and anti-interference capabilities, overcomes the shortcomings of existing technologies in local monitoring and positioning, effectively prevents the electrochemical corrosion risk of stray current to the track and surrounding buried pipelines, and ensures the safe and stable operation of urban rail transit.

[0111] Figure 3 Here is a schematic diagram of an example structure, such as Figure 3 As shown in the diagram, the figure includes traction substations A and B, overhead contact line, rails, and locomotives. Traction substations A and B are the core facilities that provide power to the overhead contact line. The overhead contact line is a power supply line suspended above the rails, providing power to the electric locomotives. The rails are both the tracks on which the locomotives travel and the main conductors for the return of traction current. The locomotives obtain power from the overhead contact line to drive the train's load.

[0112] The current It is a positive feed current, flowing from the positive terminal of traction substation A through the contact wire to the locomotive.

[0113] It is a negative feed current, flowing from the locomotive through the rails back to the negative terminal of traction substation A.

[0114] This refers to the rail current, which is the portion of the locomotive return current in the rail.

[0115] Stray current refers to the current that leaks from the rails into the ground, drainage network, integrated grounding network, or metal pipes.

[0116] Current flows out from the positive terminal of traction substation A, through the contact wire ( Upon reaching the locomotive, the drive motor performs its work, and the current returns from the wheelset below the locomotive's pantograph to the rail, forming a return current. The current eventually flows back to the negative terminal of traction substation A, completing a closed loop. Ideally, all return currents ( All should be along the rails ( The current flows back to the substation. However, in practice, because the rails are not completely insulated from the ground, some current leaks from the rails into the surrounding soil and metal structures; this leaked current is called stray current. ).

[0117] from Figure 3 As can be seen, the stray current mainly flows in the following directions:

[0118] Drainage net: A metal mesh specifically designed to collect stray currents and guide them back to the traction substation, reducing corrosion to other structures.

[0119] Integrated grounding grid: The grounding system for substations and facilities along the line.

[0120] Structural steel reinforcement / metal pipes: such as steel reinforcement in tunnel linings, underground gas, water supply and drainage, communication and other metal pipelines.

[0121] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0122] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the above-described method.

[0123] The aforementioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0124] An exemplary readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can reside in an Application Specific Integrated Circuit (ASIC). Alternatively, the processor and the readable storage medium can exist as discrete components in the device.

[0125] The division of units is merely a logical functional division; in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0126] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0127] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0128] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0129] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0130] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A stray current monitoring system for urban rail transit, characterized in that, include: Voltage measurement module, current calculation module, data acquisition and processing module, and resistance dynamic calibration and error compensation module; The voltage measurement module is connected in parallel to both ends of the rail section to measure the voltage drop of the rail section. The dynamic resistance calibration and error compensation module is used to dynamically correct the longitudinal resistance of the rail in combination with environmental parameters. The current calculation module is used to calculate the return current flowing through the rail segment based on the voltage drop, in conjunction with the corrected longitudinal resistance of the rail. The data acquisition and processing module is used to collect the voltage drop in real time to verify the received return current, and compare the verified return current with the total feed current of the traction substation to calculate the stray current.

2. The system according to claim 1, characterized in that, The system also includes an anti-interference module; The anti-interference module uses a combination of hardware and software to perform anti-interference processing on the voltage drop, environmental parameters, longitudinal resistance of the rail, and return current, thereby suppressing electromagnetic interference.

3. The system according to claim 1, characterized in that, The dynamic resistance calibration and error compensation module is equipped with a temperature sensor and a humidity sensor. The module dynamically corrects the longitudinal resistance of the rail based on environmental parameters, including: The dynamic resistance calibration and error compensation module collects environmental parameters in real time based on the temperature sensor and humidity sensor; Based on the environmental parameters, a pre-configured resistance-temperature-humidity correlation model is invoked to correct the longitudinal resistance of the rail. The resistance-temperature-humidity correlation model is established by applying a known current to rails of different lengths and measuring the voltage drop in a laboratory environment with adjustable temperature and humidity.

4. The system according to claim 2, characterized in that, The anti-interference module includes a hardware anti-interference unit and a software anti-interference unit; The hardware anti-interference unit is configured with independent transmission channels for different types of signals. It uses shielded cables, independent filter circuits and partitioned opto-isolation to physically isolate the voltage drop, the environmental parameters, the longitudinal resistance of the rail and the return current to prevent crosstalk between different signals. The software anti-interference unit uses partitioned storage and independent algorithm processing for different types of data, and employs moving average filtering algorithm or wavelet transform algorithm to smooth and reduce noise in the corresponding data.

5. The system according to claim 1, characterized in that, The system also includes a locomotive positioning module; The signal output terminal of the locomotive positioning module is electrically connected to the signal input terminal of the data acquisition and processing module, and is used to transmit the real-time position information of the rail locomotive to the data acquisition and processing module. When the difference between the verified return current of the current rail segment and the total feed current of the traction substation exceeds a preset threshold, the current rail segment is identified as a stray current leakage point by combining the real-time location information transmitted by the locomotive positioning module.

6. The system according to claim 5, characterized in that, The system can also be connected to the current acquisition terminal of the rail transit drainage collection network. By collecting the current change data of the drainage collection network of the current rail section, the stray current leakage point can be verified.

7. A method for monitoring stray currents in urban rail transit, characterized in that, The method, applied to the stray current monitoring system for urban rail transit according to any one of claims 1 to 6, comprises: The voltage drop at both ends of the rail section is collected by the voltage measurement module and transmitted to the data acquisition and processing module. The environmental parameters of the rail transit site are collected in real time by the resistance dynamic calibration and error compensation module, and the longitudinal resistance of the rail is dynamically corrected in combination with the environmental parameters. The corrected longitudinal resistance of the rail is then sent to the current calculation module. The current calculation module calculates the return current flowing through the rail section by combining the corrected longitudinal resistance of the rail with the voltage drop, and then transmits the return current to the data acquisition and processing module. The data acquisition and processing module verifies the return current based on the real-time voltage drop, and compares the verified return current with the total feed current of the traction substation to calculate the stray current.

8. The method according to claim 7, characterized in that, The method further includes: The voltage drop, environmental parameters, longitudinal resistance of the rail, and return current are subjected to zoned isolation anti-interference processing through an anti-interference module.

9. The method according to claim 7, characterized in that, The method further includes: The real-time location information of the rail locomotive is obtained through the locomotive positioning module. When the difference between the verified return current of the current rail segment and the total feed current of the traction substation exceeds a preset threshold, the current rail segment is identified as a stray current leakage point based on the real-time location information.

10. The method according to claim 7, characterized in that, The method of acquiring environmental parameters of the rail transit site in real time through a dynamic resistance calibration and error compensation module, and dynamically correcting the longitudinal resistance of the rail based on these environmental parameters, includes: The dynamic resistance calibration and error compensation module collects the environmental parameters in real time. Based on the environmental parameters, a pre-configured resistance-temperature-humidity correlation model is invoked to correct the longitudinal resistance of the rail. The resistance-temperature-humidity correlation model is established by applying a known current to rails of different lengths and measuring the voltage drop in a laboratory environment with adjustable temperature and humidity.

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