C interface load state monitoring equipment of LEU

Abstract

According to the equipment for monitoring the load state of the C interface of the LEU, a voltage signal of the C interface is monitored through high-resistance parallel connection, and a current signal of the C interface is monitored through current mutual inductance; the load is calculated through the signal voltage and the signal current; the monitoring equipment can adaptively monitor the combined load of cables and transponders with different lengths and calculate the load of the C interface in real time, not only reflects the load state, but also can obtain the state of an output source, gives a fault prompt when a fault occurs, and assists the positioning of a fault point; and when an open circuit or short circuit fault is monitored, the connection relation between the monitoring equipment and the C interface cable is disconnected, so that the influence of the equipment fault on C interface signal transmission is avoided. The method has the technical advantages that real-time monitoring of signals of the C interface of the LEU is achieved, fault reason analysis and fault maintenance suggestions are given when the C interface breaks down, and equipment connection is disconnected to recover the state of the C interface cable when an open circuit or short circuit fault occurs.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of railway communication signal, in particular to a kind of C interface load state monitoring equipment of LEU. BACKGROUND

[0002] LEU transmits effective train control information to active transponder through C interface, and transmission medium is two-core long cable, cable length is between several hundred meters to several thousand meters, and cable parameters of different road C interface signals are different, so current most about LEU C interface detection equipment only makes open circuit or short circuit judgment, and detection equipment needs to be electrically connected with C interface cable, and such detection equipment has the following disadvantages: 1, only when C interface appears dead failure, prompt can be made;2, lack of record of LEU historical operation information, it is difficult to make positioning analysis to fault point;3, cannot make early warning when performance of C interface running process appears to decline;4, because there is connection relationship with C interface cable, when detection equipment fails in connecting place, connection relationship cannot be disconnected in time, so as to affect the transmission of C interface signal.

[0003] In summary, a kind of C interface load state monitoring equipment is needed, which can avoid that equipment failure itself affects the transmission of C interface signal: can adapt to different cable length outdoor conditions, can record the running data of C interface whole process, can make early warning when output source or load performance appears to decline, can assist to make fault point positioning, and can disconnect the connection relationship between monitoring equipment and C interface cable when open circuit or short circuit fault is monitored to avoid that equipment failure itself affects the transmission of C interface signal. SUMMARY

[0004] In view of the problems in the prior art, the present application provides a design scheme for monitoring C interface load state which can prevent equipment failure.

[0005] The present application provides a kind of C interface load state monitoring equipment of LEU, the monitoring equipment includes high resistance parallel connection, current mutual inductance, filter circuit, demodulation circuit and processor;

[0006] C interface voltage signal is monitored by the high resistance parallel connection, and C interface current signal is monitored by the current mutual inductance simultaneously;

[0007] C1 voltage signal and C6 voltage signal are obtained by filter circuit from voltage signal, and C1 current signal and C6 current signal are also obtained by filter circuit from current signal;

[0008] C1 code is obtained by C1 voltage signal through demodulation circuit and is transmitted to processor, and C1 message result is obtained by C1 code through processor, C1 signal load is calculated by C1 signal voltage and C1 signal current, and C6 load is calculated by C6 signal voltage and C6 signal current simultaneously.

[0009] The monitoring device can adapt to monitor the combined load of cables and transponders of different lengths and can calculate the load of the C interface in real time, record all the data of the measured C interface load during the operation of the device;

[0010] The monitoring device simultaneously monitors voltage signals and current signals, not only reflecting the load state, but also obtaining the output source state, and giving a warning when the load decreases or the output source performance decreases, giving a fault prompt when a fault occurs, and assisting in fault point positioning;

[0011] The monitoring device disconnects the connection relationship between the monitoring device and the C interface cable when an open circuit or short circuit fault is monitored to avoid the influence of device itself failure on the transmission of C interface signals.

[0012] The technical effect of the present application: through the LEU C interface load monitoring device, the LEU C interface signal is monitored in real time and the monitoring data is recorded, through the analysis of the load monitoring data, the warning information can be sent, the fault cause analysis can be given when the C interface fails, and the fault maintenance suggestion can be given, and the device connection can be disconnected when an open circuit or short circuit fault occurs to restore the C interface cable state. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 The structure diagram of the LEU C interface load state monitoring device

[0014] Figure 2 The centralized parameter model diagram of the C interface cable

[0015] Figure 3 The implementation diagram of the LEU C interface load state monitoring device DETAILED DESCRIPTION

[0016] The technical solutions of the present application will be further specifically described below through examples. The following examples will help those skilled in the art to further understand the present application, but do not limit the present application in any form. It should be pointed out that, for those skilled in the art, without departing from the inventive concept, a number of modifications and improvements can be made, which all belong to the protection scope of the present application.

[0017] The present application provides a LEU C interface load state monitoring device which can prevent device failure, as shown in Figure 1 The device includes a parallel failure protection circuit, a high resistance parallel connection, a series failure protection circuit, a current transformer, a filter circuit, a demodulation circuit and a processor.

[0018] As shown in Figure 1As shown, the device monitors the C interface voltage signal through high resistance connection, and monitors the C interface current signal through current mutual inductance. The voltage signal is filtered to obtain C1 voltage signal and C6 voltage signal, and the current signal is also filtered to obtain C1 current signal and C6 current signal. One of the C1 voltage signals is demodulated to obtain C1 code and transmitted to the processor. The processor obtains C1 message result through the C1 code, and calculates C1 signal load through C1 signal voltage and C1 signal current, and calculates C6 load through C6 signal voltage and C6 signal current.

[0019] As shown in Figure 2 The C interface load cannot be simply regarded as a transponder. In actual conditions, the C interface load is the combination of the C interface long cable and the connected transponder, and the lumped parameters of cables of different lengths are different. That is, when the C interface is connected to cables of different lengths, even if the tail cable is connected to the same transponder, the C interface load at this time is not the same. The device calculates the C interface load in real time by monitoring the voltage and current at the same time, and can obtain the accurate value of the current C interface load under the condition of cables of different lengths, so as to realize the reference to the actual installation condition. Therefore, the device can adapt to monitor the combined load of cables and transponders of different lengths, and because the C interface load can be calculated in real time, the device can record all the data of the measured C interface load when the device is running.

[0020] The device monitors the voltage signal and the current signal at the same time, which can not only reflect the load state, but also obtain the output source state. The following gives the logical basis analysis: if the voltage signal and the current signal decrease at the same time and the decrease ratio is low, it can be warned that the output source performance decreases; if the voltage signal and the current signal decrease at the same time and the decrease ratio is high, it can be prompted that there is a fault and the positioning point is at the C interface output end; if the voltage signal decreases but the current signal increases and the fluctuation ratio compared with the normal value is small, it can be warned that the load decreases; if the voltage signal decreases but the current signal increases and the fluctuation ratio compared with the normal value is large, it can be prompted that there is a fault and the positioning point is at the load end.

[0021] Like common C interface detection devices, the device needs to have an electrical connection relationship with the C interface cable, as shown in Figure 3As shown, there are two access modes of parallel connection and series connection, considering that the two access modes of the device will affect the C interface signal transmission if failure occurs, so parallel failure protection circuit and series failure protection circuit are designed respectively. The working logic of the related failure protection circuit is as follows: the monitoring device monitors the C interface load in real time and reports the current working state, when a fault occurs, it is judged whether the fault is the same as the failure phenomenon of the device, and the same means starting the failure protection circuit. The device is installed at the C interface output end, so it can be determined that only when the C interface output end appears open circuit or short circuit fault, it is consistent with the failure phenomenon of the monitoring device, if the LEU end is open circuit during monitoring, it is not determined whether the fault is caused by the device failure, in order to prevent the device itself from affecting the transmission line, the processor starts the series failure protection circuit; if the LEU end is short circuit during monitoring, it is not determined whether the fault is caused by the device failure, in order to prevent the device itself from affecting the transmission line, the processor starts the parallel failure protection circuit; if it is other fault during monitoring, the failure protection circuit is not started.

[0022] The monitoring device has the following functions: 1. Collecting information of LEU C interface, including C1 signal voltage, C1 signal current, C1 signal code, C6 signal voltage, C6 signal current;

[0023] 2. Analyzing information of LEU C interface, including C1 load state, C1 message good code rate, C6 load state;

[0024] 3. Avoiding single point failure of monitoring device at C interface cable connection, including single point failure of parallel device and single point failure of series device. If the parallel device appears short circuit failure, it is equivalent to C interface cable short circuit, and the signal cannot be transmitted to the active transponder, and the active transponder will send default message; if the series device appears open circuit failure, it is equivalent to one cable of C interface open circuit, and the signal also cannot be transmitted to the active transponder, and the active transponder will send default message.

[0025] The parallel failure protection circuit has the following characteristics: when C interface load monitoring finds that C interface appears short circuit fault, the processor sends a signal to the parallel single point failure protection circuit to disconnect the connection of high resistance parallel connection on C interface cable, so as to avoid the failure caused by high resistance parallel connection module.

[0026] The high resistance parallel connection has the following characteristics: 1. The impedance of LEU C interface is much larger than the normal load impedance, including C1 signal impedance and C6 signal impedance, that is, signal impedance at frequency of 282.24 kHz to 564.48 kHz and signal impedance at frequency of 8.82 kHz; 2. Collecting C interface voltage signal, including C1 voltage signal and C6 voltage signal.

[0027] The series failure protection circuit has the following characteristics: when the C interface load monitoring finds that the C interface has an open circuit fault, the processor sends a signal to the series single-point failure protection circuit to disconnect the current transformer connection on the C interface cable, avoiding open circuit failure caused by the current transformer module.

[0028] The current transformer has the following characteristics: 1. The LEU C interface impedance is much smaller than the normal load impedance, including C1 signal impedance and C6 signal impedance, i.e. signal impedance at a frequency of 282.24 kHz to 564.48 kHz and signal impedance at a frequency of 8.82 kHz; 2. The C interface current signal is collected, including C1 current signal and C6 current signal; 3. The monitoring device converts the current signal into a voltage signal for analysis through a sampling resistor, and the current transformer sampling resistor is selected to be greater than or equal to two small resistance values, improving the reliability of the monitoring device.

[0029] The filter circuit has the following characteristics: 1. It includes a voltage filter circuit and a current filter circuit; 2. It includes a low-pass filter circuit and a high-pass filter circuit; 3. It can obtain C1 voltage signal, C6 voltage signal, C1 current signal and C6 current signal respectively.

[0030] The demodulation circuit has the following characteristics: 1. The DBPL code can be obtained from the C1 voltage signal; 2. The clock signal with a frequency of 564.48 kHz can be obtained from the DBPL code; 3. The C1 baseband code can be obtained through the DBPL code and the clock signal.

[0031] The processor has the following characteristics: 1. The C1 load state is obtained through the C1 voltage signal and the C1 current signal; 2. The C6 load state is obtained through the C6 voltage signal and the C6 current signal; 3. The C interface message is obtained through C1 signal decoding; 4. The original monitoring data and load state analysis results of the whole process are saved; 5. When a load change is monitored, a warning prompt is given and possible positioning analysis is given; 6. When an open circuit or short circuit fault is monitored, a signal can be sent to the single-point failure protection circuit module to disconnect the device connection on the C interface cable.

[0032] Preferably, the single-point failure protection circuit can be switched in the form of a relay, a controllable switch, etc.

[0033] Preferably, the high resistance parallel connection can be achieved by using a high resistance resistor, a matching transformer, etc.

[0034] Preferably, the current transformer can be achieved by using a current transformer, a current probe, etc.

[0035] Preferably, the filter circuit can be achieved by using a filter module, a passive filter, an active filter, etc.

[0036] Preferably, the demodulation circuit can employ gate circuits, phase-locked loops, FPGAs, or other similar methods.

[0037] Preferably, the processor can be a CPU, MCU, or other similar device.

[0038] Example 1: Load Change Alert

[0039] 1. The matching transformer and current transformer acquire information from the LEU C interface in real time, including the C interface voltage signal and the C interface current signal, and send the signals to the filter circuit.

[0040] 2. The passive filter receives the C-interface voltage signal from the matching transformer and separates the C1 and C6 voltage signals through a low-pass filter and a high-pass filter, respectively. At the same time, it receives the C-interface current signal from the current transformer and separates the C1 and C6 current signals through a low-pass filter and a high-pass filter, respectively, and sends the signals to the demodulation circuit and the processor.

[0041] 3. The gate circuit of the demodulation circuit receives the C1 voltage signal from the filter circuit, obtains the clock signal through the phase-locked loop, obtains the C1 baseband code through the shift register, and sends the C1 baseband code to the processor.

[0042] 4. The MCU receives C1 voltage signal, C6 voltage signal, C1 current signal, and C6 current signal from the filter circuit, and receives the C1 baseband code from the demodulation circuit. It then analyzes these signals to determine the C1 and C6 loads. The C1 and C6 signal loads are defined in the standard as 120Ω and 170Ω respectively. This definition specifies the amplitude of the LEU-C interface under standard load, which differs from the load in the application; therefore, the standard is not used to determine this. Figure 2 As shown, the C-interface load consists of a long cable and an active transponder. The cable parameters differ depending on the cable length. Figure 2 The values ​​of resistor R, inductor L, conductance G, and capacitor C in the active transponder are all different and difficult to determine. Therefore, the load state when the active transponder is working normally is used as the benchmark value. If a load change occurs during the monitoring process, it is considered abnormal. The range for judging abnormal load changes is configurable.

[0043] 5. The MCU retains monitoring data throughout the entire process, and can analyze abnormal data through data backtracking to provide maintenance suggestions.

[0044] The beneficial effects of this invention are that, by real-time monitoring, the status of the C interface during the operation of the LEU device is recorded, and its load status changes can be monitored in real time. When an abnormality is detected, an early warning can be issued immediately, and possible fault location points can be given based on historical data. Therefore, the timeliness of fault detection can be improved and the fault handling time can be reduced.

[0045] Example two: parallel device single point failure protection

[0046] High resistance parallel connection selection matching transformer is connected in parallel on the C interface cable, when the primary coil of the matching transformer appears short circuit failure, the C interface signal load is infinitesimal, and the active transponder is bypassed.

[0047] The MCU receives C1 voltage signals, C6 voltage signals, C1 current signals and C6 current signals from the filter circuit, receives C1 baseband codes from the demodulation circuit, and analyzes C1 load and C6 load, and takes the load state of the monitored active transponder when working normally as a reference value.

[0048] When C1 load and C6 load are far less than the load reference value, it is considered as short circuit.

[0049] After the MCU sends a short circuit fault prompt, a protection signal is sent to the parallel single point failure protection circuit module, and the parallel single point failure protection circuit selects a controllable switch S1, as shown in the figure, the switch S1 is closed when working normally, and the matching transformer is connected in parallel on the C interface cable, when the protection signal is received, the switch S1 is opened, and the connection of the matching transformer on the C interface cable is disconnected, so as to avoid the influence of the short circuit failure of the parallel matching transformer primary on the C interface signal transmission. Figure 3

[0050] The application has the advantages that the cable connection state of the C interface during the operation of the LEU device is restored by disconnecting the matching transformer, and the working state of the LEU C interface is protected and the abnormal reason is further analyzed through historical data when the short circuit abnormality is monitored.

[0051] Example three: series device single point failure protection

[0052] The current transformer is selected to be connected in series on one cable of the C interface, when the primary coil of the current transformer appears open circuit failure, the C interface signal load is infinite, and the signal cannot be transmitted to the active transponder; the secondary of the current transformer needs to be connected in parallel with a sampling resistor to convert the current signal into a voltage signal, and the sampling resistor is selected to be connected in parallel with multiple small resistances to avoid single resistance failure, as shown in the figure. Figure 3

[0053] The MCU receives C1 voltage signals, C6 voltage signals, C1 current signals and C6 current signals from the filter circuit, receives C1 baseband codes from the demodulation circuit, and analyzes C1 load and C6 load, and takes the load state of the monitored active transponder when working normally as a reference value.

[0054] When C1 load and C6 load are far greater than the load reference value, it is considered as open circuit.​​

[0055] After the MCU sends the open-circuit fault prompt, a protection signal is sent to the series single-point failure protection circuit module, and the series single-point failure protection circuit selects a controllable switch S2, as shown in the figure. Figure 3 When working normally, the switch S2 is open, and the current transformer is connected in series on the C interface cable, and after receiving the protection signal, the switch S2 is closed, and the connection of the bypass current transformer on the C interface cable is disconnected, thereby avoiding the influence of the open-circuit failure of the series current transformer primary on the C interface signal transmission.

[0056] The application has the beneficial effect that by disconnecting the current transformer, the cable connection state of the C interface during the operation of the LEU device is restored, and an immediate response is made when an open-circuit anomaly is monitored, so that the working state of the LEU C interface can be protected and the reason for the anomaly can be further analyzed through historical data.

[0057] The above only describes the preferred embodiments of the application and is not used to limit the protection scope of the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. A C interface load state monitoring device for LEU, comprising high resistance parallel connection, current mutual inductance, filter circuit, demodulation circuit and processor; The C interface voltage signal is monitored by the high resistance parallel connection, and the C interface current signal is monitored by the current mutual inductance; The voltage signal is filtered by the filter circuit to obtain C1 voltage signal and C6 voltage signal, and the current signal is also filtered by the filter circuit to obtain C1 current signal and C6 current signal; One of the C1 voltage signals is demodulated by the demodulation circuit to obtain C1 code element and transmitted to the processor, the processor obtains C1 message result by the C1 code element, calculates C1 signal load by C1 signal voltage and C1 signal current, and calculates C6 load by C6 signal voltage and C6 signal current; The monitoring device can adapt to monitor the combined load of different length cables and transponders, and can calculate the load of the C interface in real time, record all data of the measured C interface load when the device is running, and The monitoring device simultaneously monitors the voltage signal and the current signal, not only reflects the load state, but also obtains the output source state, and gives a warning when the load or the output source performance decreases, gives a fault prompt when a fault occurs, and assists in locating the fault point; When the monitoring device detects an open circuit or a short circuit fault, it disconnects the connection between the monitoring device and the C interface cable to avoid the influence of the device itself on the transmission of the C interface signal.

2. The apparatus of claim 1, wherein, If the voltage signal and the current signal decrease at the same time and the decrease ratio is low, a warning of the output source performance decrease can be given, if the voltage signal and the current signal decrease at the same time and the decrease ratio is high, a fault prompt can be given and the positioning point is at the C interface output end, if the voltage signal decreases but the current signal increases and the fluctuation ratio compared with the normal value is small, a warning of the load decrease can be given, if the voltage signal decreases but the current signal increases and the fluctuation ratio compared with the normal value is large, a fault prompt can be given and the positioning point is at the load end.

3. The apparatus of claim 1, wherein, The monitoring device further comprises parallel failure protection circuit and series failure protection circuit.

4. The apparatus of claim 3, wherein, If the LEU end is open during the monitoring process, the processor starts the series failure protection circuit to prevent the influence of the device itself on the transmission line; If the LEU end is short during the monitoring process, the processor starts the parallel failure protection circuit to prevent the influence of the device itself on the transmission line; If it is other fault during the monitoring process, the failure protection circuit is not started.

5. The apparatus of claim 4, wherein, When the C interface load monitoring device detects a short circuit fault in the C interface, the processor sends a signal to the parallel single-point failure protection circuit to disconnect the high resistance parallel connection on the C interface cable, avoiding the failure of the high resistance parallel connection module caused by the short circuit; When the C interface load monitoring device detects an open circuit fault in the C interface, the processor sends a signal to the series single-point failure protection circuit to disconnect the current mutual inductance on the C interface cable, avoiding the failure of the current mutual inductance module caused by the open circuit.

6. The apparatus of claim 5, wherein, High resistance parallel connection selection matching transformer is connected in parallel on C interface cable, when the primary coil of the matching transformer appears short circuit failure, the C interface signal load is infinitesimal, the active transponder is bypassed; when C1 load and C6 load are far less than the load reference value, it is considered as short circuit, when the protection signal is received, the connection of the matching transformer on the C interface cable is disconnected.

7. The apparatus of claim 5, wherein, Current transformer selection current transformer is connected in series on one cable of C interface, when the primary coil of the current transformer appears open circuit failure, the C interface signal load is infinite, the signal cannot be transmitted to the active transponder, the secondary of the current transformer needs to be connected in parallel with a sampling resistor to convert the current signal into a voltage signal, the sampling resistor is selected to be connected in parallel with multiple small resistance values to avoid single resistance failure; when C1 load and C6 load are far greater than the load reference value, it is considered as open circuit; when the protection signal is received, the connection of the bypass current transformer on the C interface cable is disconnected to avoid the influence of the open circuit failure of the primary of the series connected current transformer on the transmission of the C interface signal.

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