Railway signal cable insulation characteristic monitoring system and method

Abstract

The invention discloses a railway signal cable insulation characteristic monitoring system and method. The system comprises a signal generator, a signal distributor, a signal acquisition processor and a repeater, the signal generator is connected with the signal distributor; the signal distributor and the signal acquisition processor are connected with a plurality of signal cables; for a signal cable, the signal distributor and the signal acquisition processor are connected with the winding of the main cable; repeaters are arranged between the winding of the main cable and the winding of the branch cable adjacent to the main cable, between the windings of every two adjacent branch cables and at the far end of the winding of the branch cable farthest from the main cable, and the repeaters are connected with the signal distributor and are switched between a feedback path and a connecting path. According to the invention, on-line real-time monitoring of the insulation characteristics of the railway signal cable is realized.

Description

Technical Field

[0001] This invention relates to a system and method for monitoring the insulation characteristics of railway signal cables, belonging to the field of railway signal cable monitoring technology. Background Technology

[0002] Since the railway signaling system entered the era of automation (centralized electrical control), signal cables have been widely used as special cables. Because my country's railways implement a centralized power supply mode, that is, the power supply equipment in the machine room supplies power to the automated equipment in the throat area and the section, signal cables must be used to connect the machine room to the outdoor and section equipment. Therefore, various signal cables that meet the control needs of signaling equipment have emerged and have risen from industry standards to national standards.

[0003] The insulation characteristics of signal cables refer to the insulation insulation between core wires and between core wires and ground. These insulation characteristics are the basic conditions for ensuring the normal operation of outdoor electromechanical and electronic equipment, and directly affect train operation safety and the normal operation of railway transportation. Therefore, measuring the insulation characteristics of signal cables has become one of the key points of railway maintenance work.

[0004] Traditional methods for measuring the insulation characteristics of signal cables involve disconnecting the power supply and load during measurements in non-electrically centralized eras, and then periodically measuring each core of the signal cable using a megohmmeter. In electrically centralized eras, the currently popular method involves setting up a distribution panel (or cabinet) connected to the signal cable in the machine room. A measuring device consisting of an insulation index testing circuit, power supply, and PC is connected to the distribution panel (or cabinet). The power supply and load are periodically disconnected, and the measuring device automatically measures the insulation between and to ground of each signal cable core on the distribution panel (or cabinet) according to its number. This method is highly efficient and reduces missed measurements. However, in practice, due to the demands of railway transportation efficiency, the number of signal cables has increased proportionally with the development of automated signaling equipment. A large railway station can have tens of thousands of signal cable cores, making the measurement work extremely arduous. If the load is disconnected during measurement (i.e., the power supply and load are removed), it will directly affect transportation efficiency and easily lead to train accidents.

[0005] In summary, since the power supply and load need to be disconnected, the two methods mentioned above still only measure the insulation characteristics of signal cables and do not belong to the monitoring level. Therefore, designing a technical solution that can implement online real-time monitoring of the insulation characteristics of signal cables is an urgent problem to be solved. Summary of the Invention

[0006] The purpose of this invention is to provide a system and method for monitoring the insulation characteristics of railway signal cables, which enables online real-time monitoring of the insulation characteristics of railway signal cables.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] An insulation characteristic monitoring system for railway signal cables is disclosed. The signal cable includes a main cable and multiple branch cables connected in series with the main cable. Both the main cable and the branch cables consist of a winding and multiple twisted groups arranged around the winding. The railway signal cable insulation characteristic monitoring system includes a signal generator, a signal distributor, a signal acquisition processor, and a repeater. The signal generator is connected to the signal distributor. The signal distributor and the signal acquisition processor are connected to multiple signal cables. For a given signal cable, the signal distributor and the signal acquisition processor are connected to the winding of the main cable. The winding of the main cable and the winding of the adjacent branch cable are connected in phase... A repeater is provided between the windings of two adjacent branch cables and at the far end of the winding of the branch cable furthest from the main cable. The repeater is connected to the signal distributor. When monitoring the insulation characteristics of the signal cable, except for the repeater at the farthest end which forms a feedback path, the other repeaters form a connection path, so that the repeater forming the feedback path forms a monitoring loop with the signal distributor and the signal acquisition processor. When measuring the location of insulation defects in the signal cable, the repeaters from the near end to the far end form feedback paths in sequence, so that the repeater forming the feedback path forms a measurement loop with the signal distributor and the signal acquisition processor, while the other repeaters in the measurement loop form a connection path.

[0009] A method for monitoring the insulation characteristics of railway signal cables based on the aforementioned railway signal cable insulation characteristic monitoring system includes:

[0010] Step 1: The signal acquisition processor sends monitoring commands to the signal generator and the signal distributor;

[0011] Step 2: The signal generator sends a monitoring signal to the signal distributor;

[0012] Step 3: The signal distributor sends the monitoring signals one by one into each of the signal cables;

[0013] Step 4: The signal acquisition processor receives the monitoring feedback signals returned by each of the signal cables through the monitoring loop formed by the repeater, based on the monitoring and distribution instructions issued by the signal distributor.

[0014] Step 5: The signal acquisition processor compares the monitoring signal sent into the signal cable with the monitoring feedback signal returned by the signal cable to determine whether there is an insulation defect;

[0015] Step 6: Complete the monitoring of the insulation characteristics of the signal cable.

[0016] The advantages of this invention are:

[0017] On the one hand, this invention enables online real-time monitoring of the insulation characteristics of railway signal cables, and can promptly report which signal cable has an insulation defect without shutting down the load (without disconnecting the power supply and load), without affecting the use of existing loads (such as train operation equipment), with high working efficiency, no missed measurements, and meets the needs of railway transportation efficiency. It is fundamentally different from traditional methods for measuring the insulation characteristics of signal cables, and fills the gap in the existing online real-time monitoring of the insulation characteristics of railway signal cables.

[0018] On the other hand, the present invention can quickly determine the location of insulation defects in signal cables (whether it is in the main cable or a branch cable) and further locate the fault point (insulation index deterioration or breakage), which helps maintenance personnel to handle the problem quickly, prevent load operation interruption, shorten train failure time, and improve railway transportation efficiency. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the components of the railway signal cable insulation characteristic monitoring system of the present invention.

[0020] Figure 2 This is a block diagram of a signal generator.

[0021] Figure 3 This is a block diagram of a signal distributor.

[0022] Figure 4 This is a block diagram of the signal acquisition processor. Detailed Implementation

[0023] The railway signal cable insulation characteristic monitoring system of this invention is implemented by adding (or installing) it on the existing signal cable that connects the power supply and the load, without having to shut down the load (meaning disconnecting the power supply and the load), and without affecting the normal use of the load.

[0024] Specifically, existing signal cables in the prior art consist of a main cable 80 and multiple branch cables 90 connected in series with the main cable 80. The main cable 80 consists of a winding 81 and multiple twisted groups 82 evenly distributed around the winding 81. Similarly, the branch cables 90 consist of a winding 91 and multiple twisted groups 92 evenly distributed around the winding 91. Figure 1 The diagram only schematically shows two twisted groups 82 of the main cable 80 and two twisted groups 92 of the branch cable 90.

[0025] Furthermore, for the main cable 80 and branch cables 90, windings 81 and 91 include multiple spare core wires, and twisted groups 82 and 92 include multiple transmission core wires. Each twisted group 82 in the main cable 80 is connected in series with the corresponding twisted group 82 in each branch cable 90. The twisted group 82 of the main cable 80 is connected to the power supply, and the twisted group 82 of the branch cable 90 at the farthest end (i.e., the branch cable 90 furthest from the main cable 80) is connected to the load (such as a crane). The transmission core wires are used to transmit power signals to the load through the main cable 80 and branch cables 90, and to provide feedback on load status information. The spare core wires within the windings 81 of the main cable 80 and 91 of the branch cables 90 are not connected to each other. Figure 1 The two spare core wires 810 of the main cable 80 winding 81 and the two spare core wires 910 of the branch cable 90 winding 91 are shown only schematically.

[0026] In view of the existing signal cables in the prior art, the present invention utilizes two spare core wires from each of the main cable 80 winding 81 and the branch cable 90 winding 91 as monitoring core wires.

[0027] This invention defines the far end and the near end. For the branch cable 90, the end closer to the trunk cable 80 is the near end and the end farther away is the far end. Correspondingly, the end of the trunk cable 80 connected to the signal distributor 20 and the signal acquisition processor 30 is the near end and the end connected to the branch cable 90 is the far end. The far end and the near end of other devices are defined according to the above definition.

[0028] Specifically, this invention proposes a railway signal cable insulation characteristic monitoring system for signal cables. The signal cable includes a main cable 80 and multiple branch cables 90 connected in series with the main cable 80. Both the main cable 80 and the branch cables 90 consist of a winding and multiple twisted groups arranged around the winding. Figure 1The railway signal cable insulation characteristic monitoring system of the present invention includes a signal generator 10, a signal distributor 20, a signal acquisition processor 30, and a repeater 50; the signal generator 10 is connected to the signal distributor 20; the signal distributor 20 and the signal acquisition processor 30 are connected to multiple signal cables; for a signal cable, the signal distributor 20 and the signal acquisition processor 30 are connected to the winding 81 of the main cable 80; a repeater 50 is provided between the winding 81 of the main cable 80 and the winding 91 of the branch cable 90 adjacent to the main cable 80, between two adjacent windings 91 of the branch cable 90, and at the far end of the winding 91 of the branch cable 90 furthest from the main cable 80, and the repeater 50 is connected to the signal distributor 20. When monitoring the insulation characteristics of the signal cable, except for the repeater 50 at the farthest end (i.e., the repeater 50 at the far end of the branch cable 90 that is furthest from the main cable 80) which forms a feedback path, the other repeaters 50 form a connection path so that the repeater 50 forming the feedback path forms a monitoring loop with the signal distributor 20 and the signal acquisition processor 30. When measuring the location of insulation defects in the signal cable, the repeaters 50 from the near end to the far end form feedback paths in sequence so that the repeater 50 forming the feedback path forms a measurement loop with the signal distributor 20 and the signal acquisition processor 30, while the other repeaters 50 in the measurement loop (except for the repeater 50 forming the feedback path) form a connection path.

[0029] like Figure 1 In the actual design, the signal acquisition processor 30 is connected to the signal generator 10 and the signal distributor 20, and the signal distributor 20 is connected to the signal acquisition processor 30, wherein:

[0030] When monitoring the insulation characteristics of signal cables, the signal acquisition processor 30 sends a monitoring command to the signal generator 10, so that the signal generator 10 sends a monitoring signal to the signal distributor 20. At the same time, the signal acquisition processor 30 sends a monitoring command to the signal distributor 20, so that the signal distributor 20 sends a monitoring signal to each signal cable one by one. Based on the monitoring and distribution command issued by the signal distributor 20, the signal acquisition processor 30 receives the monitoring feedback signal returned by each signal cable one by one.

[0031] When measuring the location of insulation defects in signal cables, the signal acquisition processor 30 sends a measurement command to the signal generator 10, causing the signal generator 10 to send a measurement signal to the signal distributor 20. At the same time, the signal acquisition processor 30 sends a measurement command to the signal distributor 20, causing the signal distributor 20 to send measurement signals to each signal cable that is determined to have insulation defects. Based on the measurement distribution command issued by the signal distributor 20, the signal acquisition processor 30 receives the measurement feedback signals returned by each signal cable that is determined to have insulation defects.

[0032] In actual design, the windings of both the main cable 80 and the branch cable 90 include multiple spare core wires, with two of these spare core wires serving as monitoring core wires. For example... Figure 1 The two spare core wires 810 of the main cable 80 and the two spare core wires 910 of the branch cable 90 shown are used as monitoring core wires. The signal distributor 20 and the signal acquisition processor 30 are respectively connected to the two monitoring core wires of the winding 81 of the main cable 80. Under the control of the signal distributor 20, the repeater 50 switches between the feedback path and the connection path. The repeater 50 forming the feedback path connects the two monitoring core wires connected to its near end, and the repeater 50 forming the connection path connects the two monitoring core wires connected to its near end and far end respectively.

[0033] Specifically, when monitoring the insulation characteristics of the signal cable, the repeater 50 at the farthest end connects the two monitoring cores of the branch cable 90 at the farthest end to each other. The repeater 50 located between the main cable 80 and its adjacent branch cable 90 connects the two monitoring cores of the winding 81 of the main cable 80 to the two monitoring cores of the winding 91 of the branch cable 90 one by one. The repeater 50 located between two adjacent branch cables 90 connects the two monitoring cores of the winding 91 of the two adjacent branch cables 90 one by one, thus forming a monitoring loop. That is, the monitoring signal is sent from the signal distributor 20, sent into the signal cable and transmitted all the way to the repeater 50 at the farthest end, and then returned to the signal acquisition processor 30.

[0034] When measuring the location of insulation defects in signal cables: If a feedback path is formed between the main cable 80 and the repeater 50 between it and its adjacent branch cable 90, then the repeater 50 connects the two monitoring cores of the main cable 80 to form a measurement loop. That is, the measurement signal is sent from the signal distributor 20 into the signal cable, transmitted to the repeater 50, and then returned to the signal acquisition processor 30. If a feedback path is formed between the repeaters 50 between two adjacent branch cables 90, then the repeater 50 connects the two monitoring cores of the branch cable 90 connected to its near end. This repeater 50, the signal distributor 20, and the signal acquisition processor 30 form a measurement loop. For other repeaters in the measurement loop... If repeater 50 is located between the main cable 80 and its adjacent branch cable 90, then the two monitoring cores of the winding 81 of the main cable 80 and the two monitoring cores of the winding 91 of the branch cable 90 are connected one-to-one. If it is located between two adjacent branch cables 90, then the two monitoring cores of the winding 91 of the two adjacent branch cables 90 are connected one-to-one. If the repeater 50 at the farthest end forms a feedback path, then the measurement signal is sent from the signal distributor 20, sent into the signal cable and transmitted all the way to the farthest repeater 50, and then returned to the signal acquisition processor 30. That is, the entire signal cable forms a measurement loop through the repeater 50, the signal distributor 20 and the signal acquisition processor 30.

[0035] In this invention, whether monitoring the insulation characteristics of the signal cable or measuring the location of insulation defects in the signal cable, the repeater 50 at the farthest end is only used to form a feedback path.

[0036] In this invention, multiple signal cables are associated with one monitoring system. Within each monitoring system, all signal cables are connected to both a signal distributor 20 and a signal acquisition processor 30. In practical applications, the number of monitoring systems deployed is determined by the station size, i.e., by the number of signal cables being monitored. Figure 1 Only one signal cable is shown schematically.

[0037] like Figure 2 The signal generator 10 includes a voltage regulator isolation circuit 11, a shaping and frequency divider circuit 12, and a CPU 13. The input terminal of the voltage regulator isolation circuit 11 is connected to the power supply (AC 220V), and the output terminal is connected to the signal distributor 20 via the shaping and frequency divider circuit 12 and the CPU 13 in sequence. The shaping and frequency divider circuit 12 and the CPU 13 are connected to the signal acquisition processor 30 to receive monitoring commands or measurement commands.

[0038] Specifically, the voltage regulation and isolation circuit 11 is used to regulate the input power supply, and it also isolates the power supply from the shaping and frequency division circuit 12. The shaping and frequency division circuit 12 is used to shape (e.g., filter out waveform glitches) and divide the signal output from the voltage regulation and isolation circuit 11 to output a monitoring signal when a monitoring command is received, and a measurement signal when a measurement command is received. The CPU 13 is used to output the received monitoring / measurement signals. The voltage regulation and isolation circuit 11 and the shaping and frequency division circuit 12 are well-known circuits in the art.

[0039] Here, the monitoring signal and the measurement signal are waveforms with a set shape, amplitude and frequency. The frequency of this waveform is different from the frequency of the signal transmitted by the transmission core wire in the twisted assembly. The waveforms of the monitoring signal and the measurement signal may be the same or different.

[0040] like Figure 3 The signal distributor 20 includes a CPU 21 and an output circuit 22. The input terminal of the CPU 21 is connected to the CPU 13 of the signal generator 10, and the output terminal is connected to a corresponding monitoring core wire of the main cable 80 winding 81 of each signal cable via the output circuit 22. The CPU 21 is connected to the signal acquisition processor 30 to receive monitoring or measurement commands issued by the signal acquisition processor 30, and to issue monitoring distribution commands or measurement distribution commands to the signal acquisition processor 30. The CPU 21 is also connected to the repeater 50 to issue switching commands to the repeater 50 to realize the switching between the feedback path and the connection path.

[0041] Specifically, the output circuit 22 is used to output monitoring signals / measurement signals under the control of the CPU 21. When the CPU 21 receives a monitoring command, it controls the output circuit 22 to sequentially send monitoring signals to the corresponding monitoring core wire in the winding 81 of the main cable 80 of each signal cable. Simultaneously, the CPU 21 sends a monitoring allocation command to the signal acquisition processor 30, which includes the time interval for sending monitoring signals to each signal cable, i.e., informing the signal acquisition processor 30 of the time point for receiving monitoring feedback signals. When the CPU 21 receives a measurement command, it controls the output circuit 22 to sequentially send measurement signals to the corresponding monitoring core wire in the winding 81 of the main cable 80 of each signal cable determined to have insulation defects. Simultaneously, the CPU 21 sends a measurement allocation command to the signal acquisition processor 30, which includes the sequence of which signal cables to send measurement signals to and the time interval for sending each measurement signal, i.e., informing the signal acquisition processor 30 of the sequence of which signal cables to receive measurement feedback signals and the time point for receiving them. Here, the monitoring allocation command is formed based on the monitoring command issued by the signal acquisition processor 30; similarly, the measurement allocation command is formed based on the measurement command issued by the signal acquisition processor 30. The output circuit 22 is a circuit well known in the art.

[0042] like Figure 4 The signal acquisition processor 30 includes a CPU 32, which is connected to the power supply via a voltage regulation and isolation circuit 31. The CPU 32 is connected to a corresponding monitoring core wire of the main cable 80 winding 81 of each signal cable via an input circuit 33. The CPU 32 is connected to the signal generator 10 to issue monitoring commands or measurement commands, and the CPU 32 is connected to the signal distributor 20 to issue monitoring commands or measurement commands, and to receive monitoring distribution commands or measurement distribution commands.

[0043] Specifically, the voltage regulation and isolation circuit 31 is used to regulate the input power supply (AC 220V) to power the CPU 32, and the voltage regulation and isolation circuit 31 isolates the power supply from the CPU 32. The input circuit 33 is used to receive monitoring feedback signals / measurement feedback signals under the control of the monitoring allocation command / measurement allocation command received by the CPU 32. When the CPU 32 receives the monitoring allocation command, the CPU 32 controls the input circuit 33 to receive the monitoring feedback signal sequentially from the corresponding monitoring core wire in the winding 81 of the main cable 80 of each signal cable according to the monitoring allocation command. The monitoring feedback signal is fed back to the CPU 32, which compares the monitoring signal with the monitoring feedback signal to determine which signal cable has an insulation defect, and then further determines the location of the insulation defect in the signal cable. When the CPU 32 receives the measurement allocation command, the CPU 32 controls the input circuit 33 to receive the measurement feedback signal sequentially from the corresponding monitoring core wire in the main cable 80 of each signal cable that is determined to have an insulation defect according to the measurement allocation command. The measurement feedback signal is fed back to the CPU 32, which compares the measurement signal with the measurement feedback signal to determine the location of the insulation defect in the signal cable. For a single signal cable, measurement signals are issued to the sequentially formed measurement loops. Preferably, the signal strength of these measurement signals can be adjusted according to the length of the measurement loop. The input circuit 33 is a circuit well-known in the art.

[0044] In this invention, the power supply and the power supply for the load are independent power supplies.

[0045] In this invention, repeater 50 has a repeating function and a stable impedance value. Besides its function as a repeater for long-distance transmission, repeater 50 is also used to amplify signals and compensate for signal attenuation caused by long-distance transmission.

[0046] In this invention, the repeater 50 employs a device well-known in the art. The repeater 50 is used to form a feedback path or a connection path. When forming a feedback path, the repeater 50 connects the two monitoring core wires connected to its proximal end. When forming a connection path, the repeater 50 connects the two monitoring core wires connected to its proximal and distal ends respectively, one-to-one.

[0047] like Figure 1 The main cable 80 is connected to the branch cables 90 adjacent to the main cable 80, to two adjacent branch cables 90, and to the load via a cable box 70. A repeater 50 is located inside the cable box 70. Here, the repeater 50 connected to the farthest end of the farthest branch cable 90 is not connected to the load.

[0048] In practical applications, the monitoring system of this invention also includes a terminal 40, which typically includes a server. The terminal 40 is connected to the signal acquisition processor 30 and is used to receive, store, and display monitoring and measurement results. Users can view real-time data of the monitoring / measurement results as needed, and review monitoring / measurement data over a certain period of time. Additionally, the terminal 40 can also send instructions to the signal acquisition processor 30 to verify the monitoring / measurement results.

[0049] The working principle of this invention is as follows:

[0050] The insulation characteristics of a signal cable refer to the insulation characteristics of the twisted strands in operation. If the insulation index of the twisted strands decreases or breaks, the impedance of the transmission core will inevitably change. The electric field generated around the transmission core during signal transmission will also change accordingly, causing interference to the monitoring signal transmitted within the monitoring core. Therefore, this invention monitors changes in the insulation index and their trends by monitoring changes in the monitoring signal, providing early warning or alarm when the insulation index decreases or breaks. Here, the waveform shape and amplitude of the monitoring signal may be affected by interference.

[0051] When a decrease or breakage of the insulation index is detected, the present invention will automatically switch to the measurement program. That is, the present invention converts the monitoring signal into a measurement signal and forms measurement loops of different lengths by controlling the formation form of each repeater (feedback path or connection path). Based on the degree of change of the measurement signal in the measurement loop and the transmission time, the location where the decrease or breakage of the insulation index occurs is determined for each measurement loop, that is, the fault point where the insulation defect occurs.

[0052] Based on the above-described railway signal cable insulation characteristic monitoring system of the present invention, the present invention also proposes a method for monitoring the insulation characteristics of railway signal cables, which includes:

[0053] Step 1: The signal acquisition processor 30 sends monitoring commands to the signal generator 10 and the signal distributor 20;

[0054] Step 2: Signal generator 10 sends a monitoring signal to signal distributor 20;

[0055] Step 3: The signal distributor 20 sends the monitoring signals to each signal cable one by one;

[0056] Step 4: Based on the monitoring and distribution instructions issued by the signal distributor 20, the signal acquisition processor 30 receives the monitoring feedback signals returned by each signal cable through the monitoring loop formed by the repeater 50.

[0057] Step 5: The signal acquisition processor 30 compares the monitoring signal sent into the signal cable with the monitoring feedback signal returned by the signal cable to determine whether there is an insulation defect, so as to issue a warning / alarm when an insulation defect is found.

[0058] Step 6: Complete the monitoring of the insulation characteristics of the signal cable.

[0059] In practice, if at least one signal cable is determined to have an insulation defect, the following are also included:

[0060] Step 7: The signal acquisition processor 30 sends measurement commands to the signal generator 10 and the signal distributor 20;

[0061] Step 8: Signal generator 10 sends a measurement signal to signal distributor 20;

[0062] Step 9: The signal distributor 20 sends the measurement signal to each signal cable that is determined to have an insulation defect. For each signal cable, a measurement signal is sent to the measurement loop formed in sequence.

[0063] Step 10: Based on the measurement distribution command issued by the signal distributor 20, the signal acquisition processor 30 receives the measurement feedback signal returned by each signal cable that is determined to have insulation defects through the measurement loop formed by the repeater 50.

[0064] Step 11: The signal acquisition processor 30 compares the measurement signal sent into the signal cable with the measurement feedback signals returned by the signal cable to determine the location of insulation defects in each signal cable;

[0065] Step 12: Determine the location of the insulation defect in the signal cable. That is, for a signal cable that is determined to have an insulation defect, the above process can be used to determine whether the insulation defect is located in the main cable 80 or a branch cable 90.

[0066] In practice, the comparison between the monitoring signal and the monitoring feedback signal refers to whether the shape and amplitude of the waveform are the same: if the shape and amplitude are the same, the signal cable has no insulation defects; otherwise, if the shape or amplitude is different, the signal cable has insulation defects (abnormal insulation characteristics).

[0067] For a measurement loop of a signal cable, the comparison between the measurement signal and the measurement feedback signal refers to comparing whether the shape and amplitude of the waveforms are the same. If the shape and amplitude are the same, the portion of the signal cable within this measurement loop does not have an insulation defect; conversely, if the shape or amplitude is different, the portion of the signal cable within this measurement loop, near the repeater 50 forming the feedback path (main cable 80 or branch cable 90), has an insulation defect. Preferably, when an insulation defect is determined for a measurement loop, subsequent received measurement feedback signals are no longer compared with the measurement signal.

[0068] In this invention, the monitoring signal and the measurement signal are waveforms with a set shape (such as square wave, sawtooth wave, pulse wave or sine wave, etc.), amplitude and frequency. The frequency of the waveform is different from the frequency of the signal transmitted by the transmission core wire in the twisted group. The waveforms of the monitoring signal and the measurement signal may be the same or different.

[0069] In actual implementation, after determining whether the insulation defect occurs in the main cable 80 or a branch cable 90, the following steps may be included: for measurement feedback signals whose waveform shape or amplitude changes, the transmission time of the measurement signal in the measurement loop is obtained based on the emission time of the measurement signal and the feedback time of the measurement feedback signal, so as to calculate the fault point where the insulation defect occurs, that is, to calculate the distance between the fault point and the near end of the signal cable, so as to achieve accurate location of the fault point.

[0070] The advantages of this invention are:

[0071] On the one hand, this invention enables online real-time monitoring of the insulation characteristics of railway signal cables, and can promptly report which signal cable has an insulation defect without shutting down the load (without disconnecting the power supply and load), without affecting the use of existing loads (such as train operation equipment), with high working efficiency, no missed measurements, and meets the needs of railway transportation efficiency. It is fundamentally different from traditional methods for measuring the insulation characteristics of signal cables, and fills the gap in the existing online real-time monitoring of the insulation characteristics of railway signal cables.

[0072] On the other hand, the present invention can quickly determine the location of insulation defects in signal cables (whether it is in the main cable or a branch cable) and further locate the fault point (insulation index deterioration or breakage), which helps maintenance personnel to handle the problem quickly, prevent load operation interruption, shorten train failure time, and improve railway transportation efficiency.

[0073] The above description describes the preferred embodiments of the present invention and the technical principles applied thereto. For those skilled in the art, any obvious changes such as equivalent transformations or simple substitutions based on the technical solutions of the present invention, without departing from the spirit and scope of the present invention, shall fall within the protection scope of the present invention.

Claims

1. A railway signal cable insulation characteristic monitoring system for signal cables, the signal cable comprising a main cable and multiple branch cables connected in series with the main cable, wherein the main cable and each branch cable are composed of a winding and multiple twisted groups arranged around the winding, characterized in that, The railway signal cable insulation characteristic monitoring system includes a signal generator, a signal distributor, a signal acquisition processor, and a repeater; the signal generator is connected to the signal distributor; the signal distributor and the signal acquisition processor are connected to multiple signal cables; for a single signal cable, the signal distributor and the signal acquisition processor are connected to the winding of the main cable; the repeater is positioned between the winding of the main cable and the winding of an adjacent branch cable, between two adjacent windings of branch cables, and at the far end of the winding of the branch cable furthest from the main cable. The repeaters are connected to the signal distributor. When monitoring the insulation characteristics of the signal cable, except for the repeater at the farthest end which forms a feedback path, the other repeaters form a connection path, so that the repeater forming the feedback path forms a monitoring loop between the signal distributor and the signal acquisition processor. When measuring the location of insulation defects in the signal cable, the repeaters from the near end to the far end form feedback paths in sequence, so that the repeater forming the feedback path forms a measurement loop between the signal distributor and the signal acquisition processor, while the other repeaters in the measurement loop form a connection path.

2. The railway signal cable insulation characteristic monitoring system as described in claim 1, characterized in that, The signal acquisition processor is connected to the signal generator and the signal distributor, and the signal distributor is connected to the signal acquisition processor, wherein: When monitoring the insulation characteristics of signal cables, the signal acquisition processor sends a monitoring command to the signal generator, so that the signal generator sends a monitoring signal to the signal distributor. At the same time, the signal acquisition processor sends a monitoring command to the signal distributor, so that the signal distributor sends a monitoring signal to each of the signal cables one by one. Based on the monitoring and distribution command issued by the signal distributor, the signal acquisition processor receives the monitoring feedback signal returned by each of the signal cables one by one. When measuring the location of insulation defects in signal cables, the signal acquisition processor sends a measurement command to the signal generator, causing the signal generator to send a measurement signal to the signal distributor. Simultaneously, the signal acquisition processor sends a measurement command to the signal distributor, causing the signal distributor to send measurement signals to each of the signal cables determined to have insulation defects. Based on the measurement distribution command issued by the signal distributor, the signal acquisition processor receives measurement feedback signals returned by each of the signal cables determined to have insulation defects.

3. The railway signal cable insulation characteristic monitoring system as described in claim 1, characterized in that, The windings of the main cable and the branch cables each include multiple spare core wires, with two of the spare core wires serving as monitoring core wires. The signal distributor and the signal acquisition processor are respectively connected to the two monitoring core wires of the windings of the main cable. Under the control of the signal distributor, the repeater switches between a feedback path and a connection path. The repeater forming the feedback path connects the two monitoring core wires connected to its near end, and the repeater forming the connection path connects the two monitoring core wires connected to its near and far ends respectively.

4. The railway signal cable insulation characteristic monitoring system as described in claim 2, characterized in that, The signal generator includes a voltage stabilizing and isolation circuit, a shaping and frequency dividing circuit, and a CPU. The input terminal of the voltage stabilizing and isolation circuit is connected to the power supply, and the output terminal is connected to the signal distributor via the shaping and frequency dividing circuit and the CPU in sequence. The shaping and frequency dividing circuit and the CPU are connected to the signal acquisition processor to receive monitoring commands or measurement commands.

5. The railway signal cable insulation characteristic monitoring system as described in claim 2, characterized in that, The signal distributor includes a CPU and an output circuit. The input terminal of the CPU is connected to the signal generator, and the output terminal is connected via the output circuit to a corresponding monitoring core wire of the winding of the main cable of each of the signal cables. The CPU is connected to the signal acquisition processor to receive monitoring or measurement commands issued by the signal acquisition processor, and to issue monitoring distribution commands or measurement distribution commands to the signal acquisition processor. The CPU is also connected to the repeater to issue switching commands to the repeater.

6. The railway signal cable insulation characteristic monitoring system as described in claim 2, characterized in that, The signal acquisition processor includes a CPU, which is connected to a power supply via a voltage regulation and isolation circuit. The CPU is connected to a corresponding monitoring core wire of the winding of the main cable of each of the signal cables via an input circuit. The CPU is connected to the signal generator to issue monitoring or measurement commands; and the CPU is connected to the signal distributor to issue monitoring or measurement commands and to receive monitoring distribution commands or measurement distribution commands.

7. A method for monitoring the insulation characteristics of railway signal cables based on the railway signal cable insulation characteristic monitoring system according to any one of claims 1 to 6, characterized in that, include: Step 1: The signal acquisition processor sends monitoring commands to the signal generator and the signal distributor; Step 2: The signal generator sends a monitoring signal to the signal distributor; Step 3: The signal distributor sends the monitoring signals one by one into each of the signal cables; Step 4: The signal acquisition processor receives the monitoring feedback signals returned by each of the signal cables through the monitoring loop formed by the repeater, based on the monitoring and distribution instructions issued by the signal distributor. Step 5: The signal acquisition processor compares the monitoring signal sent into the signal cable with the monitoring feedback signal returned by the signal cable to determine whether there is an insulation defect; Step 6: Complete the monitoring of the insulation characteristics of the signal cable.

8. The method for monitoring the insulation characteristics of railway signal cables as described in claim 7, characterized in that, If it is determined that at least one of the signal cables has an insulation defect, then the following is also included: Step 7: The signal acquisition processor sends measurement commands to the signal generator and the signal distributor; Step 8: The signal generator sends a measurement signal to the signal distributor; Step 9: The signal distributor sends the measurement signal one by one to each of the signal cables that are determined to have insulation defects, wherein, for each signal cable, the measurement signal is sent to the measurement loop formed in sequence; Step 10: The signal acquisition processor receives, one by one, the measurement feedback signals returned by the measurement loop formed by the repeater for each of the signal cables that are determined to have insulation defects, based on the measurement distribution command issued by the signal distributor; Step 11: The signal acquisition processor compares the measurement signal sent into the signal cable with each measurement feedback signal returned by the signal cable to determine the location of insulation defects in each signal cable; Step 12: Determine the location of insulation defects in the signal cable.

9. The method for monitoring the insulation characteristics of railway signal cables as described in claim 8, characterized in that, The comparison between the monitoring signal and the monitoring feedback signal refers to whether the shape and amplitude of the waveforms are the same: if the shape and amplitude are the same, then the signal cable has no insulation defects; otherwise, the signal cable has insulation defects. For a measurement loop of a signal cable, the comparison between the measurement signal and the measurement feedback signal refers to comparing whether the shape and amplitude of the waveforms are the same: if the shape and amplitude are the same, then the portion of the signal cable in this measurement loop does not have an insulation defect; otherwise, the portion of the signal cable in this measurement loop adjacent to the repeater forming the feedback path has an insulation defect. When an insulation defect is determined for a measurement loop, subsequent received measurement feedback signals are no longer compared with the measurement signal. Wherein: the monitoring signal and the measurement signal are waveforms with a set shape, amplitude and frequency, the frequency of the waveform is different from the signal frequency transmitted by the transmission core wire in the twisted group, and the waveform of the monitoring signal and the measurement signal may be the same or different.

10. The method for monitoring the insulation characteristics of railway signal cables as described in claim 9, characterized in that, It also includes: for the measurement feedback signal whose waveform shape or amplitude changes, calculating the fault point where the insulation defect occurs based on the emission time of the measurement signal and the feedback time of the measurement feedback signal.

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