SK37496A3 - Process and arrangement for detecting and reporting the electrical condition of voltage flashover fuses - Google Patents

Abstract

The tracks of d.c. railways (rail earth) used to conduct the current must be electrically insulated from earth potential. At places where the potential difference between the rail earth and earth potential can reach unacceptable levels, voltage flashover fuses are fitted for protection against dangerous body currents. The condition of these fuses must be continuously monitored so that those which have blown may be replaced immediately. This is at present done by regular track patrols. According to the invention, the potential difference between the rail earth (3) and the earth potential (4) is detected by a reporting device (5) and the condition with the appropriate address is transmitted to an evaluation device and stored therein. If a fuse (2) has blown, the reporting device (5) sends an error message to the evaluation device so that the fuse (2) concerned can be properly replaced. The ease of fitting of the reporting device (5) and the use of radio transmission facilities make it possible to apply the system of the invention directly to existing fuses (2), thus permitting the economical and permanent monitoring of the condition of the fuses (2).

Description

Method and apparatus for detecting and reporting the electrical condition of voltage breakdown fuses

Technical field

The invention relates to a method for detecting and reporting the electrical condition of voltage break-through fuses which are placed on rails on direct current along railways for protection against health hazards, in places where the potential difference between the rail potential and the ground can reach unacceptable dangerous values. whereby a voltage breaker fuse directly ensures the potential difference between the rails and the ground as a measure for the condition of the voltage breaker fuse. The invention also relates to an apparatus for implementing this method.

BACKGROUND OF THE INVENTION

In the case of direct-current railways, rails are usually used to guide the current. In order to reduce the risk of corrosion caused by leakage currents, the rails must not conductively connect to devices having grounding effects. The potential of the rails must be insulated from the ground potential. There may be large potential differences between the rail potential and the ground. If these potential differences exceed a certain value, they will become a danger to human health, especially in places where, due to the spatial proximity of the potential-conducting parts, there is a possibility of bridging them by the human body.

This applies in particular to those places where, for example, parts of bridges or alternating current rails are located near the direct current rails. In such places, in order to protect against dangerous currents to human health, at least occasionally conductive connections between the rails and the ground are installed for the duration of the threat. The open grounding of the railway is described in the Warning Cross 4/1999 p.15.

Usually voltage break-through fuses are used between such places with different potentials. When a predetermined voltage, which can cause a dangerous current, is exceeded, it enters into operation and establishes a metallic electrically conductive connection between the DC rails and between the AC rails, or between parts of the bridge. This condition, which is substantially favorable to the risk of corrosion caused by the leakage currents, may, according to existing regulations, only last for a short time. Operators of such direct-current railways have a duty to continuously monitor the status of voltage break-through fuses and, in the event that such a fuse has entered into operation, immediately perform the required separation of potentials, for example by replacing a fuse. Checking the status of voltage break-through fuses is currently carried out visually at regular detours along the line, which is associated with relatively high personnel costs. For the Berlin S-track This is described in the Elektrische Bahnen magazine in the article Power supply of the Berlin S-track, 4/1999 page 191.

Another drawback is that uncontrolled leakage current can flow in the interval between checks.

There are also known devices which, if the predetermined potential difference between the rails and the ground is exceeded, induces a potential equalization by means of quick switches, short-circuiting, and when the preset potential equalizing current drops, the potential separation is again opened by opening the switch. Such devices are very costly and their functionality must be constantly checked. The use of these devices is only possible in exposed areas where increased hazards occur due to short-term increased potential differences, for example at stations.

Also used are devices in which a memory relay current relay, which carries out a fault voltage breaker message to the central unit, is arranged in series with the breakdown voltage fuses operating in a predetermined current region. The disadvantage of these devices is that the reporting is carried out via separate signal lines and the cost of current supplying the memory relay can be large.

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and apparatus which allows to detect at any time the electrical state of voltage break-through fuses which are

controlled at the track or section of a direct current track to protect against human health hazardous currents and evaluate it at headquarters.

According to the invention, this problem is solved in that the potential difference is detected continuously or at certain time intervals and the condition of the breakdown fuses is evaluated and this condition is transmitted at a predetermined time point or at certain time intervals via a coded wireless transmitter. the transmitted state of the breakdown fuse is stored with the appropriate address, and the memory is cleared after evaluation to make it free for further information.

In order to carry out this method according to the invention, a device is provided which consists of a reporting device located immediately next to the breakdown fuse and an evaluation device. The reporting device consists essentially of a detection block, a clock block, a power supply, a clock, and preferably a coded transmitter. The detection block detects the potential difference between the rail potential and the ground potential that is still on the breakdown voltage fuse, if not broken. This potential difference, based on the ground potential, can have both polarities. If a potential difference is detected by the detection block, this difference excites the clock block, which starts to wake up the coded transmitter, which begins to transmit the clocked coded signal with the electrical state and the address of the breakdown fuse to the evaluating device. The handover or transmission is carried out by means of a coded transmitter to an evaluation device in the vicinity which is provided with a receiver. In order to minimize the load on the power supply, preferably the battery, in order to ensure a long operating time, it is controlled by the clock that the potential difference in the breakdown fuse is only detected and transmitted at fixed times or at defined time intervals.

The evaluation device detects and stores the electrical condition and the associated address of a number of breakdown voltage fuses. After evaluation, the memories of the evaluation device are cleared again so that they are free to receive new up-to-date information.

If, as a result of exceeding a predetermined potential difference, the breakdown fuse has been activated, that is, to protect against hazardous currents, an electrical conductive connection between the rail potential and ground, no potential difference in the breakdown fuse is detected by the detection block. This eliminates the need for the signaling device to send a signal to the evaluation device and, as a result of the evaluation, the necessary measures can be taken to remedy the fault immediately. Likewise, the transmission of the signal is eliminated even if only one block of the reporting device, such as the power supply or the clock has been dropped, so that the fault is immediately recognized and can be targeted.

An advantage of this solution according to the invention is that up-to-date information on the electrical state of the breakdown fuse as well as on the functionality of the signaling devices is available at all times. It is furthermore advantageous that due to the easy installation of the reporting device, existing voltage break-through fuses can be used and, in the case of wireless transmission, no additional lines need be laid.

Further features and embodiments of the invention are contained in the subclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in more detail by way of example with reference to the accompanying drawings.

In FIG. 1 shows an apparatus for detecting and reporting the electrical condition of a breakdown fuse.

In FIG. δ The reporting device and the evaluation device at the DC path are shown.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1 A device for detecting and reporting the electrical condition of a breakdown fuse to a mobile pickup and evaluation device is shown. The rails 1 of the direct-current rail are connected by means of a voltage break-through fuse to the earth potential, for example the bridge potential, by means of their grounding S. The reporting device S.J. connected to ground S & ground potential 1 and consists essentially of a detection block g, a power supply g, a clock 11 of the clock block 7 and a transmitter. The detection block g is directly connected to the breakdown fuse a through the grounding ä a. to ground potential 1, and detects the potential difference between the two connections and, when dropped below a predetermined minimum difference in practice, sends a clock command to the clock block 7. If this command persists, the clock block wiring freely oscillates at the base frequency adjustable in fixed range and adjustable clock ratio. The output signal of the clock block 7 activates in this predetermined clockwise advantageously an electronic swirl switch 15, which then clocks the coded heater. By means of its radio antenna 14, the transmitter Q reports the location and electrical status of the voltage breaker fuse to the evaluating device. In order to reduce the power consumption of the reporting device 5, the detection and reporting of the breakdown fuse state ä is not performed continuously, but at fixed times or at defined time intervals for a limited duration. This is achieved in that preferably the electronic clock U, which is powered by its own current supply 10, for example a battery, switches the current supply 6 on and off via the switch 18. also consist of a battery, a reporting device

The evaluating device which receives the signal sent by the quenching device S is equipped with a mobile receiver. It is preferably located on a train running along the tracks along the reporting devices 6. Preferably, the reporting device is connected by a clock 11 at a point in time and for a duration that corresponds to the train travel time along the reporting device 5 and is coordinated with the timetable.

Due to the local proximity of a plurality of reporting devices 5, it may be possible for several reporting devices 5 to be located simultaneously in the receiving area of the mobile receiver of the evaluation device. To prevent simultaneous transmission of several reporting devices 6 which cannot be evaluated by the receiver, £ different.

The multi-channel receiver of the evaluation device assigns the received signals to the respective channel. The signals are stored with their address for further evaluation. Memories are manually cleared after evaluation to make them free for up-to-date information.

If the detection block g of the reporting device 6 detects no potential difference between the rails and the ground, or if the difference lies below the fixed minimum difference, the clock block 7 will not be built by the felting block 6. This also prevents the transmitter 13 from being switched with the switch 13 and the signaling device 6 does not send a signal to the receiver of the evaluation device. The receiver does not announce any signal to the channel. This message status indicates that the respective breakdown fuse S has been operated.

Also, since no signal is emitted in the event of failure of another block of the reporting device 5, such as detection block S or clock 11, such an error with addressing is always detected by the evaluation device, so that a permanent check of the functionality of all the reporting devices is possible. The actual cause of the error detected by the evaluation device can be detected with respect to its location and remedied.

While the switch-on time and switch-on time of the reporting device S are synchronized with the timetable for the respective track corresponding to the programming of the clock ii, the transmit clock frequency is determined by the transmission range, the mobile receiver speed, i.e. train speed and number of selected transmissions.

Advantageously, the state of charge of the power supply S of the reporting device 6 can also be appropriately communicated with the signals of the reporting device S to the evaluation device, so that the current supply H * can be replaced in a timely manner.

Since the evaluation devices with the respective receivers are designed to be adapted for their transport, they are preferably carried by the train at the train operator's station to intercept the reports of the individual reporting devices S located along the track and for this to evaluate the results by the respective personnel. In the event that more reporting devices Si are installed along the track than the memory location evaluation device, more evaluation units may be carried on the train. In this way, it can be ensured that the evaluation devices can be implemented with an optimum number of memory locations, and thus more detecting devices can be sensed while driving.

Another embodiment of the solution according to the invention for detecting the electrical state of the breakdown fuses S will be described with reference to FIG. 8. Reporting equipment 5.1. 5.8 5.5 ... 5.9 distributed along the running track 1 of the direct-current track correspond essentially to their function and construction to the reporting devices 5 according to FIG. 1. Along the track, evaluation devices 41, A8 are installed locally separately, preferably in existing buildings. A5. which are always equipped with a receiver. For each evaluation device A1. A8. A5 is assigned to the evaluation device group 5.1. ... 5.9. so that the evaluation devices are within range of the transmitter S of the respective reporting devices. First group of reporting devices 5.1. 5.8 5.5 is assigned to the evaluation device 51, the second group of evaluation devices 5.4. 5.5 5.s. 5.7 is assigned to the evaluation device A8. and the third group of evaluation devices 5.8. 5.9 is assigned to the evaluation device A5. The signals of the reporting devices are coded so that they are evaluated and stored only by the associated evaluation device. For example, status messages 5.5 or 5.8 are not processed by evaluation device A8. For evaluation devices A1. A8. A5, the transmitters S1, S8, S5 are connected. which have a greater range and which receive the status report of the associated reporting devices 5.1. ... 5.9 and these will be transmitted to control panel £. The handover from the evaluation devices £ 1, £ 2, £ 5 to the control unit £ or to the control unit UZ may be carried out directly or via one or more of the other evaluation devices A1. £ 8, A3. In the exemplary embodiment described, the message of the evaluation device 53 can be transmitted to the evaluation device AS via the transmitter S3 as an additional input message and processed with the messages of the reporting device 5.4 ... 5.7 and again via the transmitter S8 as an additional message to the evaluation device A1. In this way, status reports of all reporting devices 5.1 are transmitted to the SI transmitters. ... .5.9 control panel so that the status of all or individual groups of controlled breakdown fuses can be evaluated in one control panel or in several sub control panels. After evaluation, all reporting device memories 5.1. ·· .5.9 clear again to clear and report new statuses.

Information that is stored in the memories of the stationary evaluation devices £ L, £ 8, £ 3. they may also be sent to the central office, depending on the current situation, also via long-distance or postal lines.

In this embodiment, it is necessary to build transmission networks to slave exchanges and to a master exchange. Since more stationary receivers need to be accommodated according to each track, this embodiment is relatively costly but allows a higher degree of automation.

Claims (4)

PATENT CLAIMS 1. Method for detecting and reporting the electrical condition of voltage break-through fuses which are placed on rails on direct current along railways for protection against health hazards, where the potential difference between the rail potential and the ground can be impermissible at the instantaneous value, the potential breakdown between the rails and the ground as a measure of the breakdown condition, characterized in that the potential difference is detected continuously or at defined time intervals and the condition of the breakdown breaker and predetermined moments or at defined time intervals is transmitted via coded wireless transmitter, an evaluation device that stores the transmitted state of the breakdown fuse with the appropriate address in the memory, while the memory after clears the evaluation so that it is free for new information. this status is evaluated in The apparatus for performing the method of claim 1, wherein a potential difference in the breakdown fuse is detected which is a potential difference between the rails and the ground, characterized in that the detecting device (6) detects the existing potential difference in the detection block (Θ). if, by means of the clock (11), at fixed time points or at defined time intervals, the current supply device (13) of the detector block (6) and the clock block (?) is supplied by the shifter (12). a predetermined potential difference, the clock block (7) is turned on by the detection block (6), whereby the switch (13) clocks the transmitter (8) to the power supply device (9) so that the clocked and coded signal (14) is transmitted to the evaluator. this signal is stored with the appropriate address until evaluated ia and subsequent deletion. The device according to claim 8, characterized in that the evaluation device, which is connected to the receiver and is mobile, is carried on a train which runs on the track and runs along the reporting devices (5) and receives the reports until these are evaluated. stores in memory. Apparatus according to claim 2 and 3, characterized in that the time points and the duration of the detection and the reporting of the electrical condition of the breakdown fuse (2) are so coordinated by means of corresponding programming of the clock (11) with the timetable. of the train carrying the evaluation device and the clock frequency of the clock transmitter (7) is matched to the train speed and range of the transmitter (8). Device according to claim 2, characterized in that one or more evaluation devices (A1, A2, A3) are stably positioned along the track to which one or more several signaling devices (5.1, 5.S, .... 5.9) depending on the range of their transmitter (8), whose messages are always stored by the associated evaluation device (A1 or AS, respectively A3) and by the transmitter (SI) , S3, S3), associated with the respective evaluation device, are transmitted directly or via one or more of the other transmission devices (A1, AS, A3), the control panel (Z) or the control panel (UZ) for further evaluation.