On-line monitoring circuit, method and system for longitudinal resistance of track

Abstract

The invention provides a track longitudinal resistance on-line monitoring circuit, method and system, and the circuit comprises a position detector which is independently powered and is disposed at the front end of a to-be-detected track; the voltage measuring module and the track are arranged in parallel; the detection circuit is connected with the track in series and comprises a first branch circuit, a second branch circuit and a third branch circuit which are arranged in parallel, the first branch circuit comprises a control branch circuit, the second branch circuit comprises a current measurement module and a diode which are arranged in series, and the third branch circuit comprises an insulation joint. Real-time monitoring of the rail longitudinal resistance can be carried out even when an urban rail power supply system runs online, the control branch can freely adjust starting and stopping of the detection process, the control branch can be matched with the position detector to avoid the influence of traction current generated when a train runs on a measurement result, the accuracy degree of the monitoring result is greatly improved, and the reliability of the monitoring result is improved. The method has the remarkable advantages of high detection precision, flexibility in use, high efficiency, wide application range and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of track detection, and in particular to an online monitoring circuit, method and system for track longitudinal resistance. Background Art

[0002] In urban rail transit systems, it is crucial to ensure the safety, stability and efficiency of the power supply system. At present, most urban rail transit systems in my country use 1500V or 750V DC power supply systems. The traction current of the system is emitted from the positive pole of the traction substation, and the traction current is provided to the train through the contact network, and then the current is returned to the negative pole of the traction substation through the running rail. However, in this return process, due to the incomplete insulation between the track and the ground, and the longitudinal resistance of the track itself, the return current generates rail potential when passing through the track.

[0003] The generation of rail potential poses a threat to the safety of passengers, especially when passengers get on and off the train, they may encounter step voltage. Excessive rail potential will increase the step voltage, thereby increasing the risk of electric shock. In addition, excessive rail potential will also cause protective devices (such as rail potential limiting devices) to operate frequently, affecting the normal operation of the train and may even cause safety problems such as fire in the shield door.

[0004] In order to reduce the potential of the rails, protect the safety of passengers, and ensure the normal operation of the rail transit system, CJJ / T 49-2020 "Technical Standard for Corrosion Protection of Stray Current in Subways" puts forward specific requirements for the longitudinal resistance of the rails. The standard stipulates that the return rails should maintain continuity and smooth return flow, including the use of welding or low-resistance electrical rail gap connection devices. At the same time, the longitudinal resistance of the running rails after parallel connection of the up and down lines should not be less than 0.01Ω / km. This means that during the construction and operation of the subway, the longitudinal resistance of the track needs to be measured regularly to ensure that it meets the specified standards.

[0005] However, the existing track longitudinal resistance measurement technology faces many challenges. In practical applications, traditional micro-resistance measuring instruments are affected by factors such as the measurement point location, temperature, time, and measurement length, which limits the accuracy of the measurement results. In addition, the measurement process often needs to be carried out after the train stops running, which limits the real-time and convenience of the measurement. At the same time, the existing technical solutions are difficult to avoid the influence of the traction current generated by the train running on the measurement results. Summary of the invention

[0006] To this end, the technical problem to be solved by the present invention is to overcome the problem in the prior art that the track longitudinal resistance is difficult to monitor in real time and the accuracy of the detection results is limited, and to provide a track longitudinal resistance online monitoring circuit, method and system.

[0007] To solve the above technical problems, the present invention provides an online monitoring circuit for the longitudinal resistance of a track, comprising a position detector, a voltage measurement module and a detection circuit; the position detector is powered separately, is not directly connected to the track, and is arranged at the front end of the track; a voltage measurement module, the voltage measurement module is arranged in parallel with the track; the detection circuit, the detection circuit is arranged in series with the track, and includes a first branch, a second branch and a third branch, the first branch, the second branch and the third branch are arranged in parallel with each other, wherein the first branch includes at least one control branch, the second branch includes a current measurement module and a diode arranged in series, and the third branch includes at least one insulating node, the insulating node is arranged on the track to connect the first branch or the second branch to the track.

[0008] In one embodiment of the present invention, the control branch is a thyristor, the current direction in the control branch is opposite to that of the diode, and when the detection circuit is in a non-measurement state, the first branch is turned on; when the detection circuit is in a measurement state, the second branch is turned on.

[0009] In one embodiment of the present invention, a control system is further included, and the position detector, the voltage measurement module and the detection circuit are respectively connected to the control system.

[0010] In one embodiment of the present invention, the position detector is powered separately, is not directly connected to the track, and is arranged at the front end of the track. The input end of the voltage measurement module is connected to the track detection starting point, and the output end of the voltage measurement module is connected to the track detection end point.

[0011] In one embodiment of the present invention, the input end of the current measurement module is connected to the track, the output end of the current measurement module is connected to the anode of the diode, and the cathode of the diode is connected to the track.

[0012] The present invention also provides a method for monitoring track longitudinal resistance, which detects the longitudinal resistance of the track through the above-mentioned track longitudinal resistance online monitoring circuit, and includes the following steps: S1, monitoring the position of the train through a position detector, when the train is not close to the track section to be detected, the voltage measurement module is in an operating state, and the voltage of the track section to be detected is measured by the voltage measurement module as U; when the train is close to the track section to be detected, the voltage measurement module stops working; S2, when the voltage measurement module is in an operating state, the first branch and the third branch are disconnected, and the second branch is connected at the same time, and the current of the track section to be detected is measured by the current measurement module as I; S3, calculating the longitudinal resistance of the track section to be detected at this time as R, where R=U / I.

[0013] In one embodiment of the present invention, when longitudinal resistance detection is not required, the first branch is turned on.

[0014] The present invention also provides a track longitudinal resistance monitoring system, which comprises the above-mentioned track longitudinal resistance online monitoring circuit.

[0015] The above technical solution of the present invention has the following advantages compared with the prior art: The track longitudinal resistance online monitoring circuit, method and system described in the present invention can perform real-time monitoring of the track longitudinal resistance even when the urban rail power supply system is online, through the settings of the position detector, the voltage measurement module and the detection circuit. The control system can freely adjust the start and stop of the detection process, and it can also cooperate with the position detector to avoid the influence of the traction current generated by the train operation on the measurement result, thereby greatly improving the accuracy of the monitoring result. Compared with conventional detection technology, the present application can ensure that the train is always in normal operation, and the detection process is not affected by changes in the external environment. It has significant advantages such as high detection accuracy, flexible use, high efficiency and wide application range, and has broad application prospects in this industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0017] Figure 1 It is a schematic diagram of the link structure of the online monitoring circuit of the track longitudinal resistance in the preferred embodiment of the present invention.

[0018] Explanation of the reference numerals in the specification: 100, position detector; 200, detection circuit; VT1, control branch; SI1, current measurement module; D1, diode; F1, insulation joint; 300, voltage measurement module; 400, drainage network; 500, train; 600, track; 700, traction substation; 800, control system. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention. Embodiment 1

[0020] See also Figure 1As shown, this embodiment provides an online monitoring circuit for the longitudinal resistance of a track, which includes a position detector 100, which is powered separately, is not directly connected to the track 600, and is arranged at the front end of the track; a voltage measuring module 300, which is arranged in parallel with the track 600; a detection circuit 200, which is connected to the track 600 of the section to be tested and is arranged in series with the track 600, and includes a first branch, a second branch and a third branch, and the first branch, the second branch and the third branch are arranged in parallel with each other, wherein the first branch includes at least one control branch VT1, the second branch includes a current measurement module SI1 and a diode D1 arranged in series, and the third branch includes at least one insulating node F1, and the insulating node F1 is arranged on the track 600 to connect the first branch or the second branch to the track 600.

[0021] The track longitudinal resistance online monitoring circuit described in this embodiment can perform real-time monitoring of the track 600 longitudinal resistance even when the urban rail power supply system is online through the setting of a position detector, a voltage measurement module and a detection circuit. The control branch VT1 can freely adjust the opening and closing of the detection process, and it can also cooperate with the position detector 100 to avoid the influence of the traction current generated by the operation of the train 500 on the measurement result, thereby greatly improving the accuracy of the monitoring result. Compared with conventional detection technology, the present application can ensure that the train 500 is always in normal operation, and the detection process is not affected by changes in the external environment. It has significant advantages such as high detection accuracy, flexible use, high efficiency, and a wide range of applications, and has broad application prospects in this industry.

[0022] by Figure 1 The track longitudinal resistance online monitoring circuit shown is a reference. The current in this embodiment is transmitted from left to right. The position detector 100 is powered separately, is not directly connected to the track 600, and is arranged at the front end of the track. This embodiment also includes a control system 800, and the position detector 100 is connected to the control system. When the train 500 runs on the detection track section, a traction current will be generated, and the traction current will cause a change in the resistance value, and this change is not a real change in the resistance itself, which will cause measurement errors. In this application, when the position detector 100 detects that the train 500 is close to the track section to be detected, it can cut off the voltage measurement module 300 through the control system, so that the voltage value fed back by the voltage measurement module 300 in this application is always stable and accurate.

[0023] See also Figure 1As shown, in this example, the input end of the voltage measurement module 300 is connected to the detection starting point of the track 600, and the output end of the voltage measurement module 300 is connected to the detection end point of the track 600 to detect the voltage of the track section to be detected. The voltage measurement module 300 is a voltmeter, which is used to feed back the voltage value of the track section to be detected in real time. This embodiment also includes a control system 800, and the voltage measurement module 300 is connected to the control system.

[0024] See also Figure 1 As shown, the detection circuit 200 is arranged in series with the track section to be detected to realize real-time measurement of the current in the track section to be detected. In this embodiment, the control branch VT1 is a thyristor, and the current direction in the control branch VT1 is opposite to that of the diode D1. When the detection branch is in a non-measurement state, the first branch is turned on; when the detection branch is in a measurement state, the second branch is turned on. Specifically, the input end of the current measurement module SI1 is connected to the track, the output end of the current measurement module SI1 is connected to the positive electrode of the diode D1, and the negative electrode of the diode D1 is connected to the track. The current in this embodiment is conducted from left to right, so the positive electrode of the diode D1 is set at Figure 1 The left side of the circuit shown has the negative pole on the right side. Correspondingly, in the detection state, the cathode of the thyristor faces Figure 1 On the left side of the circuit shown, the anode faces the right side, so that the current can flow smoothly through the second branch. When there is no need to detect, the first branch can be turned on to form a short circuit in the second branch, thereby ensuring that the train 500 can always be in a stable operating state, and it is not necessary to put it in a stopped state to detect the longitudinal resistance of the track. In other embodiments, the control branch can also be set to other switches and other structures with the same control function, and the present invention does not impose specific restrictions on this. Furthermore, the detection circuit is also connected to the control system 800. In actual use, the operator can preset parameters for the detection process through the control system, thereby maximizing the degree of automation of the present application, and can also adjust the detection process in real time through the control branch VT1, thereby improving the flexibility of use of the present application. Embodiment 2

[0025] This embodiment provides a method for monitoring longitudinal resistance of a track, which detects the longitudinal resistance of a track 600 by using the online monitoring circuit for longitudinal resistance of the track described in the first embodiment, and includes the following steps: S1. Monitor the position of the train 500 through the position detector 100. When the train 500 is not close to the track section to be detected, the voltage measurement module is in operation, and the voltage of the track section to be detected measured by the voltage measurement module 300 is U; When the train 500 approaches the track section to be detected, the voltage measurement module stops working; S2. When the voltage measurement module is in operation, the first branch and the third branch are disconnected, and the second branch is connected at the same time. The current of the track section to be detected is measured as I through the current measurement module SI1. In this embodiment, when longitudinal resistance detection is not required, the first branch can be turned on. At this time, the second branch is short-circuited, and the current can form a path through the first branch, thereby ensuring that the train 500 can always be in normal operation.

[0026] S3. Calculate the longitudinal resistance of the track 600 in the section to be detected as R, where R=U / I. Thus, the present application can calculate the current and voltage in the section to be detected to obtain accurate longitudinal resistance of the track. Embodiment 3

[0027] This embodiment provides a track longitudinal resistance detection system, which includes the track longitudinal resistance online monitoring circuit described in the first embodiment.

[0028] In summary, the online monitoring circuit, method and system of the track longitudinal resistance described in the present invention, through the setting of the position detector, the voltage measurement module and the detection circuit, can perform real-time monitoring of the track longitudinal resistance even when the urban rail power supply system is online. The control branch VT1 can freely adjust the opening and closing of the detection process, and it can also cooperate with the position detector 100 to avoid the influence of the traction current generated by the operation of the train 500 on the measurement results, thereby greatly improving the accuracy of the monitoring results. Compared with conventional detection technology, the present application can ensure that the train 500 is always in normal operation, and the detection process is not affected by changes in the external environment. It has the significant advantages of high detection accuracy, flexible use, high efficiency, and a wide range of applications, and has broad application prospects in this industry.

[0029] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A track longitudinal resistance online monitoring circuit, characterized in that: include: A position detector, which is powered independently, is not directly connected to the track, and is disposed at the front end of the track; A voltage measuring module, wherein the voltage measuring module is arranged in parallel with the track; A detection circuit, the detection circuit is arranged in series with the track, and includes a first branch, a second branch and a third branch, the first branch, the second branch and the third branch are arranged in parallel with each other, wherein the first branch includes at least one control branch, the second branch includes a current measurement module and a diode arranged in series, and the third branch includes at least one insulating node, and the insulating node is arranged on the track to connect the first branch or the second branch to the track.

2. The track longitudinal resistance online monitoring circuit according to claim 1 is characterized in that: The control branch is a thyristor, and the direction of the current in the control branch is opposite to that of the diode. When the detection circuit is in a non-measurement state, the first branch is turned on; when the detection circuit is in a measurement state, the second branch is turned on.

3. The track longitudinal resistance online monitoring circuit according to claim 1 is characterized in that: It also includes a control system, and the position detector, the voltage measurement module and the detection circuit are respectively connected to the control system.

4. The track longitudinal resistance online monitoring circuit according to claim 1 is characterized in that: The position detector is powered separately, is not directly connected to the track, and is arranged at the front end of the track. The input end of the voltage measurement module is connected to the track detection starting point, and the output end of the voltage measurement module is connected to the track detection end point.

5. The track longitudinal resistance online monitoring circuit according to claim 1 is characterized in that: The input end of the current measurement module is connected to the track, the output end of the current measurement module is connected to the anode of the diode, and the cathode of the diode is connected to the track.

6. A method for monitoring track longitudinal resistance, characterized in that: The longitudinal resistance detection of the track is performed by the track longitudinal resistance online monitoring circuit according to any one of claims 1 to 5, comprising the following steps: S1. Monitor the train position through the position detector. When the train is not close to the track section to be detected, the voltage measurement module is in operation, and the voltage of the track section to be detected measured by the voltage measurement module is U; When the train approaches the track section to be detected, the voltage measurement module stops working; S2, when the voltage measurement module is in operation, the first branch and the third branch are disconnected, and the second branch is connected, and the current of the track section to be detected is measured by the current measurement module as I; S3. Calculate the longitudinal resistance of the track section to be tested as R, where R=U / I.

7. The method for monitoring track longitudinal resistance according to claim 6, characterized in that: When the longitudinal resistance detection is not required, the first branch is turned on.

8. A track longitudinal resistance detection system, characterized in that: The invention comprises an online monitoring circuit for track longitudinal resistance as described in any one of claims 1 to 5.

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