WO2019025452A1

WO2019025452A1 - Device and method for monitoring a return line for railway electrification current

Info

Publication number: WO2019025452A1
Application number: PCT/EP2018/070760
Authority: WO
Inventors: Andriy Zynovchenko
Original assignee: Rail Power Systems Gmbh
Priority date: 2017-08-03
Filing date: 2018-07-31
Publication date: 2019-02-07
Also published as: DE102017007252B3

Abstract

The invention relates to a monitoring device and a method for monitoring the integrity of at least two return line connection conductors 6, connected in parallel, of a return line for the electrification current of a railway power supply installation. The invention additionally relates to a return line system comprising a return line and a monitoring device for monitoring the integrity of at least two return line connection conductors 6, connected in parallel, of the return line. The monitoring device according to the invention comprises a current feed means 7 for feeding a monitoring current at a predefined frequency into at least one of the at least two return line connection conductors 6 connected in parallel, and sensors 11 associated with the return line connection conductors 6 in order to detect the current flowing in the return line connection conductors. In addition, the monitoring device comprises an evaluation unit 10, which receives the signals of the sensors 11 and is designed in such a way that it is checked whether the monitoring current at the predefined frequency is detected by the sensors associated with the return line connection conductors. If a sensor 11 associated with a return line connection conductor 6 does not detect the monitoring current at the predefined frequency, then it is concluded that a return line connection conductor 6 has been lost or that a return line connection conductor is faulty, for example on account of cable theft or cable breakage.

Description

DEVICE AND METHOD FOR MONITORING A REVERSE FOR

THE BAHNSTROM

The invention relates to a monitoring device and a method for

continuous monitoring of the integrity of at least two return conductor connecting conductors of a return line for the traction current of a railway energy supply system that is independent of the train backflow current. In addition, the concerns

Invention, a return system with a return line and a

Monitoring device for monitoring the integrity of the at least two parallel return path connection return conductors.

In railway systems with electrically operated rail vehicles, the train return current via the return line back to the rail energy supply system, such as a substation as a traction energy source, out. The return line comprises, according to the standard EN 50122-1: 2011 + AI: 2011 + A2: 2016, all the conductors that form the intended path for the train return current. These ladders can be next to the rails

(Rail return) and the parallel to the rail guide laid return conductors, which are connected at intervals to the rails, including the

Include return line conductors to which the rails or other parts of the return line are connected to the substation (EN 50122-1: 2011 + AI: 2011 + A2: 2016).

For safe and reliable rail operation, the integrity of the return line must be ensured. On the line side, the connection of the return line conductors is usually carried out via a return busbar, at which the

Return line conductors are connected together with the rail return. In general, a plurality of return line leads are present. In a so-called fourth-rail energy supply concept, the

Return conductor together with the current return rail to the Return conductor busbar connected. From the track side

Return conductor busbar, the return line conductors are routed to the substation and connected in the substation to a lower side return conductor busbar. The return line conductors are connected in parallel between the track-side return busbar and the lower-side return busbar. When

Return line terminators are commonly used cables. These are laid between the railway line and the substation. Because of big ones

Cross-sections of, for example, 500 mm ² and a high content of high-quality non-ferrous metal, copper or aluminum, these cables are at risk of theft, especially if no continuous burial of the cable is possible or if the access to the above-ground running track return busbar can be obtained with cable connections by unauthorized persons. Besides the loss of high quality

Non-ferrous metal and complex repairs may have a cable theft nor the consequences described below.

Although the separation of only one of a plurality of parallel return line conductors has no consequences in practice, it leads to the fact that the redundancy of N + 1 required according to the prior art is no longer present. N is the number of return line conductors, which is dimensioned for a current load of 100%.

Failure of multiple return line leads will increase the

Resistance of the return line. Possible consequences of this are:

- Increasing the rail potential and possibly creating dangerous

Contact voltages,

- frequent response of voltage limiting devices, known as VLDs, when installed, with their overload and failure as a possible consequence, increased stray current risk in DC railways.

By separating several return line conductors takes the

Current load of the remaining conductors proportional to. If the error state goes unnoticed, an overload of the remaining return line conductors with subsequent failure depending on their current carrying capacity and line utilization is likely. Such a further development of the error with subsequent failure All return line conductors can lead to unscheduled restrictions in train operation up to their complete operational setting. It is therefore important to monitor the condition of individual return line conductors. In order to be able to react as quickly as possible to the damage, for example as a result of a cable theft, with regard to both operational countermeasures and prosecution, continuous monitoring is advantageous both during railway operation and during rest periods.

From EP 2 862 744 A2 a method is known for monitoring a return line of a railway track laid parallel to the rails, in which the return lines in the

Traces and in the return cable flowing currents are detected and the sum of the currents in the rails is compared with the return current in the return conductor. When the difference in operating currents exceeds a predetermined value, a signal is generated to indicate an interruption of the return cable. The disadvantage of the method is that the cable monitoring is possible only in the operating times under trajectory return flow. A cable theft or cable break can not be recognized in the idle rest periods with the above method.

DE 10 2014 111 734 AI and DE 10 2013 005 901 AI describe

Surveillance approaches for a power cable. The working principles require the use of special power cables. The disadvantage here is that the use of special cables comes only in the construction of a new facility in question. However, a new laying of the special cables as return conductor connecting conductors in substations that have already been built and in operation proves to be generally unreasonable from an economic point of view.

From US 9 417 268 B2 a test pliers is known, with which one can measure the grounding resistance of an electrical system. In practice, the known test probes are used to verify the integrity of the earthing system in substations. The test probes are suitable and intended for periodic testing of individual conductors. A continuous monitoring of a conductor is not possible in practice with a Prüfzange. Another disadvantage is that with a Prüfzange not several conductors at the same time can be monitored. In addition, a measurement with a test pliers is not possible if the conductors to be tested lead the operating current. This is due to the design of the magnetic circuits of the test probes, which are generally at high conductor currents, for example, at conductor currents greater than 40 A, in saturation and therefore do not allow a test measurement at operating current. Therefore, a monitoring of a conductor with the Prüfzange during the train operating times, ie the flowing web return flow, not possible.

The present invention has for its object to provide a monitoring device that allows simultaneous monitoring of multiple parallel connected return line conductors of a return path for the train return current in both the train operating times and the idle rest periods to a

Identify and report cable theft or cable break of a return line conductor. The monitoring should be possible permanently or in relatively short time intervals. In addition, the invention has the object, a

Return system with a return and such

To provide a monitoring device, wherein the return line comprises a plurality of

Return conductor leads has. Another object of the invention is to provide a method which allows simultaneous monitoring of multiple return conductors connected in parallel both in the train operating times and the rest periods without interruption or in relatively short time intervals.

The solution of these objects is achieved according to the invention with the features of

independent claims. The dependent claims relate to advantageous

Embodiments of the invention.

With the monitoring device according to the invention, at least two return conductor connection conductors connected in parallel can be monitored simultaneously both in the train operating times and in the rest periods. The monitoring of a plurality of

Return leads can be made without interruption or automatically at fixed, relatively short intervals. The monitoring device allows the

Monitoring the integrity of return cable conductors designed as cables, with which the rails or other parts of the return line with the

Track energy supply system, such as the substation, are connected.

The monitoring device according to the invention comprises a current feed device for feeding a monitoring current having a predetermined frequency into at least one of the at least two return conductor connecting conductors connected in parallel and sensors associated with the return line connecting conductors for detecting the monitoring current flowing in the return line conductors. In addition, the monitoring device has a signal receiving the signals of the sensors

Evaluation device, which is designed such that it is checked whether the monitoring current is detected at the predetermined frequency with the sensors, which are assigned to the return line conductors. At a loss of one

Return lead terminal or faulty return lead, for example due to cable theft or cable break, is then closed when the monitor current at the predetermined frequency is not detected with a sensor associated with a return lead terminal.

The current injection means for feeding a monitoring current may comprise an AC power source having a periodic, for example a

sinusoidal or rectangular alternating current generated. The alternating current may also have any other periodic waveform. To reduce the

Interferences, the AC should have a fundamental frequency that is not the

Frequencies of other signals or a multiple of these frequencies, which are expected in the vicinity of the return line conductors, i. E. the frequency should differ from the frequencies commonly used in energy and railway technology, or a multiple thereof. For example, the frequency of the monitoring current should not be a multiple of a 16.7 Hz frequency. In practice, for example, a frequency of 125 Hz can be used for the monitoring current.

In one embodiment, the evaluation device has a device for generating a control or message signal, which is designed such that a control or Message signal is generated when with a sensor that is assigned to a return line conductor, the monitoring current is not detected at the predetermined frequency. But it is also possible to generate a control or message signal for the opposite case, that the monitoring current is detected at the predetermined frequency. The control or message signal may also be a signal that contains information indicating the status.

A further embodiment provides that the evaluation device has an optical and / or acoustic signal device which receives the control or signaling signals and which is designed such that it is signaled with an optical and / or acoustic signal when a control or signaling signal is generated or a control - or alarm signal is not generated. The optical and / or acoustic signal device can be designed differently. For example, the signaling device can be a screen or have one or more signal lamps or one or more alarm devices (siren or loudspeaker) in order to be able to output warning messages. The control or message signal or the control or message signals can also be transmitted to an existing control or monitoring center.

In practice, there is a risk of false detection of a condition due to possible network transients or glitches. Another embodiment therefore provides a

Evaluation device, which has a timer with a predetermined delay time, wherein the evaluation device is designed such that the generation of the control or message signal takes place only after the expiration of the delay time, i. not at the moment when the monitoring current is no longer detected. Within the specified time interval can thus be checked whether an accident is actually present. For example, it can be checked whether the monitoring current does not flow over the entire time interval, so that a short-term interruption due to network transients or glitches can not lead to a false report.

In a preferred embodiment, the power feed device has at least one inductive current transformer associated with a return line conductor. The magnetic core of a current transformer is preferably designed so that this At the highest operating current of this return line conductor is still in the linear range of its magnetization curve and thus the transmission of the

Monitoring current from the secondary winding in the primary winding allows. The sensors for detecting the monitoring current are preferably inductive sensors. Rogowski coils have proved to be particularly advantageous.

The return line system according to the invention comprises a return line and the

The monitoring device according to the invention, wherein the return line comprises a plurality of return line conductors. The return line conductors are connected in parallel in the return line system according to the invention between a return conductor busbar on the railway line and a return conductor busbar in the railway energy supply system.

The monitoring current need only be fed into one of the two return line conductors in the case of two return line conductors, so that the current flows via the one return line conductor, the return busbar at the railway line, the other return line conductor, and the return busbar in the

Rail energy system can flow back into the one return line connection conductor.

In the case of a plurality of return conductor connecting conductors connected in parallel, for reasons of redundancy or improvement of the quality of the measuring signals, a monitoring current can also be fed into a plurality of return line conductors. For this purpose, the current supply device can have a plurality of preferably inductive current transformers. One embodiment provides a current injection device for feeding a monitoring current at a predetermined frequency into at least two of the return path return conductors present.

The inventive method for monitoring the integrity of at least two parallel connected return line conductors of a return line for the

Bahnrückstrom a railway energy supply system is characterized in that a monitoring current with a predetermined frequency in at least one of at least two return line conductors are fed, the return line conductors are assigned sensors for detecting a current flowing in the return line conductors, and the signals of the sensors are evaluated with an evaluation device such that a loss of a return connection conductor or a faulty return line conductor is concluded, if with a sensor associated with a return line conductor, the monitoring current is not detected at the predetermined frequency.

In the following an embodiment of the invention is explained in more detail with reference to the single figure, which shows a simplified representation of a portion of the return path for the web return current of a railway energy supply system together with the monitoring device according to the invention.

Hereinafter, a return system is understood to mean the arrangement comprising at least a portion of the conductors forming the intended path for the web return current and the monitoring device according to the invention. In the figure, a part of the return line is shown. This part of the return line has a trackside

Return conductor busbar 1, at which in the figure in dashed lines

indicated conductors 2 are connected to those not shown in the figure

Run rails (rail return) or the power return rail. In addition, this part of the return line has a lower-side return busbar 3, to which a traction energy source 4, such as a traction rectifier or traction transformer, leading conductors 5 are connected. Between the track-side return busbar 1 and the lower side

Return conductor busbar 3 is a plurality of return line conductors 6 connected in parallel. In the present embodiment, the return line has four

Return line conductor 6, of which in the figure two

Return line conductors are shown in dashed lines to indicate that at least two return line conductors are provided. But it can also be provided more than four return line conductors. When a rail vehicle receives the operating current via its current collector, the return current flows via the rail return line or current return rail to the track-side return busbar 1, from the trackside

Return conductor busbar 1 via the parallel connected return line conductor 6 to the lower side return conductor busbar 3 and the lower side

Return conductor busbar 3 via the conductor 5 back to the traction energy source. 4

The monitoring device has a power supply device 7, which has an AC power source 8, for example a frequency converter or frequency generator with or without amplifiers, and inductive current transformers 9 associated with the return line conductors 6, with which the alternating current is fed to the return line conductors 6. The return conductor connecting conductor 6 surrounding the current transformer 9 represents the primary winding of the current transformer, while its secondary winding is connected to the AC power source. The magnetic circuit of the current transformer 9 is designed such that it is still in the linear range of its magnetization curve at the highest expected operating current and thus enables the transmission of the monitoring current from the secondary winding in the primary winding. The alternating current has a given frequency, which in the present

Embodiment 125 Hz. This frequency differs from the frequencies that AC currents around the return line conductors usually have.

In the present embodiment, two return line connecting conductors 6 are each assigned an inductive current transformer 9, so that a monitoring current with a predetermined frequency is fed into the two return line conductors 6. This alternating current can flow in a circuit that of the over the

Return conductor busbars 1, 3 connected return line conductors 6 is formed. The feeding of the monitoring current into two return line conductors 6 improves the redundancy and improves the quality of the measuring signals. The feeding of the monitoring current can also be done only in one of the return line conductor 6. In addition, the monitoring device has an evaluation device 10, which has inductive sensors 11 assigned to the individual return connection conductors 6. Instead of just a single evaluation device having a plurality of inductive sensors, it is also possible to provide a plurality of evaluation units with only one sensor or a plurality of sensors. The inductive sensors 11 are preferably air coils which have no ferromagnetic core, in particular Rogowski coils.

The evaluation device 10 is designed such that it is checked whether the monitoring current is detected at the predetermined frequency with the inductive sensors 11, which are assigned to the return line connecting conductors 6. At a loss or a faulty return line conductor 6, the evaluation device 10 closes when with a sensor 11, which is assigned to a return line conductor, the monitoring current is not detected at the predetermined frequency. The

Evaluation device 10 may have one or more filters in order to be able to filter out the alternating current with the predetermined frequency. In addition, the

Evaluation device 10 have the individual sensors 11 associated comparators, which compare the measured with the sensors 11 currents with reference values. If the AC measured in the respective return lead 6 is smaller than the reference value, it is concluded that the return lead is no longer present or defective. The evaluation device 10 has a device 10A, which is designed such that in this case a control or message signal is generated. The evaluation device 10 has a timer 10B, which specifies a specific delay time. The control or signaling signal is generated only when the current measured in the respective return line conductor 6 is below the reference value over the entire time duration which the timer 10B specifies. This rules out that short-term disturbances lead to false alarms.

In addition, the evaluation device 10 has an optical and / or acoustic signal device 10C. The signaling device 10C receives the control or

Signaling signals and signals when a fault has occurred. The loss or defect of the relevant return conductor 6 or the relevant

Return conductor 6 may be displayed on a screen, for example become. The signal device IOC can, for example, an acoustic

Signalers have to give an alarm. The control or message signal or the control or message signals can also be forwarded via a signal line or transmission link 12 to a control or monitoring center, not shown in the figure.

Claims

claims

1. Monitoring device for continuous and from the web backflow

independent monitoring of the integrity of at least two parallel return conductors (6) of a return for the

Railway return current of a railway energy supply system, characterized in that the monitoring system comprises: a current feed device (7) for feeding a monitoring current with a predetermined frequency in at least one of the at least two parallel return conductor conductor (6), the return line conductors (6) associated sensors (11) for detecting the current flowing in the return line conductors, and an evaluation device (10) receiving the signals from the sensors (11), which is designed to check whether the sensors (11) associated with the return line conductors (6) the monitoring current is detected at the predetermined frequency, with a loss of a

Return lead terminal or a faulty return line conductor is closed, if with a sensor (11), the one

Return conductor (6) is assigned, the monitoring current is not detected at the predetermined frequency.

2. Monitoring device according to claim 1, characterized in that the evaluation device (10) has a device (10A) for generating a control or message signal, which is designed such that a control or message signal is generated when with a sensor (11), which is associated with a return line conductor (6), the monitoring current at the predetermined frequency not is recorded or recorded.

3. Monitoring device according to claim 2, characterized in that the monitoring device has a control or signaling signals receiving optical and / or acoustic signaling device (IOC), which is designed such that is displayed with an optical and / or acoustic signal when a control or alarm signal is generated or a control or message signal is not generated.

4. Monitoring device according to claim 2 or 3, characterized in that the evaluation device (10) a timer (10 B) with a predetermined

Delay time, wherein the evaluation device (10) is designed such that the generation of a control or message signal takes place only after the expiration of the delay time.

5. Monitoring device according to one of claims 1 to 4, characterized

in that the current feed device (7) has at least one inductive current transformer (9) which is assigned to a return line conductor (6).

6. Monitoring device according to one of claims 1 to 5, characterized

in that the sensors (11) for detecting the monitoring current are inductive sensors.

7. return system with a return line and a monitoring device according to one of claims 1 to 6, wherein the return line comprises a plurality of return line conductors (6).

8. Monitoring device according to one of claims 1 to 7, characterized

characterized in that the return line conductors (6) are connected between a

Return conductor busbar (1) on the railway line and a

Return conductor busbar (3) parallel in the rail energy supply system are switched.

9. Monitoring device according to one of claims 1 to 8, characterized

in that a current supply device (7) for supplying a monitoring current having a predetermined frequency is provided in at least two return path connecting conductors (6) of the return line connected in parallel.

10. Process for continuous and independent from the train backflow

Monitoring the integrity of at least two parallel connected

Rückleitungsanschlussleitem (6) a return line for the web return current of a rail energy supply system, characterized in that a monitoring current with a predetermined frequency in at least one of the at least two return line conductor (6) is fed to the Rückleitungsanschlussleitem (6) sensors (11) for detecting a in the Rückleitungsanschlussleitem be associated with flowing current, and the signals of the sensors (11) are evaluated with an evaluation device (10) such that a loss of a return line conductor or a faulty return line conductor is concluded when associated with a sensor which is associated with a return line conductor (6), the

Monitoring current is not detected at the predetermined frequency.

11. The method according to claim 10, characterized in that a tax or

Message signal is generated when with a sensor (11), the one

Return line connection conductor (6) is assigned, the monitoring current at the predetermined frequency is not detected or detected.

12. The method according to claim 11, characterized in that with an optical and / or acoustic signal device (10C), an optical and / or acoustic signal is generated when a control or message signal is generated or a control or message signal is not generated.

13. The method according to claim 11 or 12, characterized in that the generation of the control or message signal takes place only after a delay time.

14. The method according to any one of claims 10 to 14, characterized in that the return line conductor (6) between a return conductor busbar (1) on the railway line and a return conductor busbar (3) in the

Track energy supply system are connected in parallel.

15. The method according to any one of claims 10 to 14, characterized in that the monitoring current is fed at a predetermined frequency in at least one of the at least two parallel-connected return line conductor of the return line and connected in at least two parallel

Return line connection conductors is monitored.