DE20310680U1 - Device for remote monitoring of point machines - Google Patents

Description

WEICKMANN SWlEICfGMANK*

Patent attorneys
European Patent Attorneys ■ European Trademark Attorneys

Our reference: 31146G DE/HGmo

Applicant:

VAE Railway Systems GmbH
Alpinestrasse 1
8740 Zeltweg
Austria

DIPL.-ING. H. WEICKMANN (up to 3l.l.oi) DIPL.-1NO. FA WEICKMANN

DIPL-CHEM. B. HUBER

DR.iNG. H. LISKA

DIPL-PHYS. DR. J. PRECHTEL DIPL.-CHEM. DR. B. BÖHM DIPL.-CHEM.DR. W. WEISS

DIPL.-PHYS. dr. J. TIESMEYER

DIPL-PHYS. DR. M. H ERZO G

DiPL-PHYS. B. RUTTENSPERGER

DIPL.-PHYS. DR.-DJG. V.JORDAN

DIPL.-CHEM. DR. M. DEY DIPL.-FORSTW. DR. J. LACHNlT

Wed 2m

VAE GmbH Rotenturmstrasse 5-9 1010 Vienna Austria

Device for remote monitoring of switch drives

P.O. Box 860 820, 81635 Munich, Germany, Tel. (089) 45563 0, Fax (089) 45563 999, email@weickmann.de

VAE Railway Systems GmbH

in Zeltweg (Austria) and VAE GmbH in Vienna (Austria)

Device for remote monitoring of switch drives

The invention relates to a device for remote monitoring of, for example, three-phase current operated switch drives or a monitoring circuit operated via four lines with contacts switched depending on the position of the switch, via which a monitoring circuit guided via the four lines for, for example, a switch monitor powered by direct current is closed after the respective end position has been reached, wherein a plurality of test levels arranged offset in the longitudinal direction of the rails are provided and in each test level at least four switching contacts are interconnected and interact with moving parts of the switch drive or the switch, e.g. a test rod, in such a way that in an end position two switching contacts are in the closed switching position and two switching contacts are in the open switching position and the switching position of each switching contact is changed once when switching to the other end position.

A device of the type mentioned at the beginning can be found, for example, in EP 0 052 759 A2. This known device is based on an electronic signal box for feeding and remotely monitoring a switch drive operated with four three-phase current lines. Contacts controlled by the drive are arranged in the star point connections of the motor windings, via which the motor windings can be connected to the three-phase current network when switching contacts are closed, and via which a monitoring circuit is closed after the drive has rotated and the new end position has been reached, which is led over the four lines and the three windings of the drive for a switch control circuit that is usually fed with direct current. The motor windings are fed symmetrically during rotation when operating correctly and asymmetrically at least when running out. The monitoring device reacts via assigned diodes and via

· i
> · t

Final contacts of a direction selector on the monitoring currents, whereby when the switch assumes one of the two end positions, the control current is switched off and the monitoring voltage is switched on. After the drive has rotated and the new end position has been reached, the monitoring circuit, which is led over two of the four end position contacts, the three motor windings and the four three-phase lines, closes, so that a circuit formed in this way signals the correct function of the end position switches. Other devices of the type mentioned at the beginning can be found, for example, in DE 36 38 681 A1, in which remote monitoring of three-phase switch drives is carried out by two current direction-sensitive indicators that are connected in parallel to one another via connection contacts of a direction selector. A monitoring DC voltage source supplies a control potential to the two indicators via the three-phase line, the motor windings of the drive and the end position contacts, provided the drive assumes one of its end positions.

DE 198 19 162 A1 describes another device of this type for a switch with several switch drives. The end positions of the switch drives are monitored by combining the corresponding end position messages from the other individual switch drives into a total message. The circuit is intended to ensure that the monitoring circuit is only created when all of the drives being monitored together are in the same end position. In the case of split switch drives, the basic position of all stop relays is monitored.

In the device mentioned above, known from EP 0 052 759 A2, a number of additional monitoring measures were carried out and recorded centrally. What the known devices have in common is that if the training is to be used for a number of test levels without fundamentally changing the wiring, the signals combined to form a summary message are not suitable for monitoring all switches in certain special cases and therefore incorrect positions of a switch can lead to an over-

• · · ϕ

·

5 -

monitoring circuit can still be established and the corresponding error message does not occur or cannot be evaluated.

Based on the device described at the beginning for supplying and remotely monitoring three-phase current operated switch drives via four lines, the present invention now aims to ensure reliable monitoring of several test levels of the same switch without increasing the cable complexity and without significant adaptation work and to be able to carry out reliable control of all switches of a plurality of test levels of the same or several switches with a single monitoring unit. To solve this problem, the device according to the invention essentially consists in the switching contacts of several test levels being connected to one another in such a way that in the respective end positions all closed switching contacts of the interconnected test levels are connected in series to form a monitoring circuit. While in the known designs only some of the switches were connected in series and other switches were connected in parallel, the design according to the invention, whereby the switching contacts of several test levels are connected to one another in such a way that all closed switching contacts, i.e. all conductive connections for the formation of the test circuit, are connected in series, actually creates a sum signal which only closes the monitoring circuit and thus enables the test voltage in the monitoring circuit to be measured if all switches of several test levels have actually been detected by the control. In order to enable such a circuit arrangement, a number of boundary conditions must be observed, whereby the wiring of the first test level for the complete series connection, regardless of the respective position, requires particular attention. The design can either be such that a separate, self-monitoring test unit is arranged in a first of the interconnected test levels, or it can be such that the signals assigned to a first of the interconnected test levels

6 -

Switch contacts are cross-connected to each other. In both cases, the first test level ensures that no undesirable shunts can occur and that the series connection for all closed contacts of a plurality of test levels is actually always guaranteed.

For correct functioning and the required testing, not only the switch position itself but also the time required by the three-phase motor for the changeover process must be evaluated as an essential criterion for the correct functioning of the switch and its safety. As is known, the design is such that motor windings of a three-phase motor are connected in series with the switching contacts and can be connected to the three-phase network via these, whereby the design is particularly advantageously such that the monitoring circuit corresponding to one end position and the monitoring circuit corresponding to the other end position are connected to one another, so that the monitoring circuits are connected to a star point connection in at least one test level if a malfunction of at least one switching contact occurs or if the switch is incorrectly changed. If a malfunction of a switching contact occurs, a new star point connection can be created in this circuit arrangement, whereby the correct functioning or a malfunction can be determined directly from the parameters of the changeover time and current consumption of the three-phase drive.

In both the reporting and the actuating modes, absolute potential separation between the logic and the power range must be ensured. As already mentioned at the beginning, the voltage in the monitoring circuit is usually a direct current voltage, whereas the power range is usually fed by a three-phase current source. During an actuating process, it must be ensured that the drive is switched off when the end position is reached in order to ensure the appropriate potential separation for the subsequent check. If the end position is not reached, the drive must be switched off after a

7 -

maximum permissible running time, whereby an error can then be immediately detected or evaluated by checking the sum signals.

The circuit arrangement according to the invention, which connects a plurality of test levels to one another, can be implemented with conventional switches or switching contacts or controlled contacts, so that the only effort is limited to connecting the contacts in the correct way to enable the desired series connection in every position. The design is advantageously such that two switching contacts of a test level, which have different switching positions from one another, are combined in one switch component and interact with a common actuating element. In principle, switching contacts of a test level do not necessarily have to be redundant. In order to ensure the redundancy required for the series connection according to the invention in these cases too, the total number of switching contacts must meet the redundancy criteria. For this purpose, the design is such that the sum of the switching contacts of all test levels corresponds to an integer multiple of 8. With such a number of switching contacts and the corresponding cross-connection or self-monitoring design in a first test level, it is possible to safely avoid shunts or parallel connections in all switching positions, so that the required series connection, with which a sum signal can be correctly determined for all switches to be monitored, is actually always guaranteed.

In the preferred embodiment, the device according to the invention is further developed in such a way that at least two switching contacts are connected in series in the same switching position and the same end position, wherein further preferably two switching contacts with different switching positions of a switching element for the same end position are linked to one another. This ensures improved failure detection.

Finally, the design can also be such that the switching element consists of three switching contacts,

which have different switching positions from one another, are combined in one switching element and interact with a common actuating element. In this case, not two but three switching contacts are integrated in one component and actuated together, whereby two such switching elements can be arranged in the test plane so that a total of six switching contacts are arranged.

The invention is explained in more detail below using embodiments of the various switching states shown schematically in the drawing. In this, Fig. 1 to 8 show a monitoring device according to the prior art, Fig. 9 shows a schematic structure of the monitoring device according to the invention and Fig. 10 to 15 show circuit diagrams of the monitoring device according to the invention in the various states of the switch.

Fig. 1 shows a schematic representation of a switch drive 1 which is fed via four supply lines 2, 3, 4 and 5 and can be controlled and monitored from a signal box. The drive 1 has a three-phase motor with windings U, V and W, which are connected in a known manner to the switching contacts 6, 7, 8 and 9. A three-phase network with phases Ll, L2, L3 and the common center conductor Mp serves as the power supply device for changing over the drive. Furthermore, a switch direction selector (not shown in detail) is connected in or between two of the three outer conductors Ll, L2 and L3, via which, for example, the phase position of the currents flowing on the outer conductors Ll and L2 can be exchanged for clockwise or anti-clockwise rotation of the drive. In Fig.l, the contact switches with the switching contacts 6, 7, 8 and 9 are connected in such a way that the phases Ll, L2 and L3 are connected together to form a star point 10 so that the three-phase motor can be operated at full power.

In Fig. 2, switching elements 11 and 12 are shown as examples, in each of which two switching contacts are combined. The switching element 11 has the switching contacts 6 and 7, the switching element 12 has the switching contacts 8 and 9. The switching contacts 6, 7 arranged in a switching element 11 or 12

t
·«

t··

or 8, 9 is assigned a common actuating member 13 which interacts, for example, with grooves 15 and 16 formed in a test rod 14. In Fig. 2, the actuating member 13 of the switching element 12 engages in the groove 15 and is therefore in the relaxed position. The switching element 11, on the other hand, is in the tensioned position. The switch positions shown in Fig. 2 correspond to one of the two end positions of the switch tongue or a movable frog. In the other end position, the switching element 12 is in the tensioned position and the switching element 11 is in the relaxed position. During the switching movement, both switching elements 11, 12 are tensioned. The two switching contacts 6, 7 and 8, 9 of the switching elements 11 and 12 are in different switching positions from one another.

In the right end position, the circuit diagram shown in Fig. 3 is obtained. In this right end position, the supply lines 2, 3, 4, 5 are connected together on the signal box side in such a way that a monitoring circuit can be formed via the four supply lines 2, 3, 4, 5 and the three motor windings U, V, W. The monitoring circuit is designed as a direct current circuit with a supply voltage of 60 volts. When the right end position is correctly assumed, the monitoring circuit is closed and runs via the supply line 2, the motor winding V, the switching contact 8, the supply line 3, the monitoring relay Wü, the supply line 4, the motor winding U, the switching contact 7, the motor winding W and the supply line 5.

In Fig.4 it is assumed that the signal box's control computer has issued the control command to reverse the switch, thus opening the monitoring circuit on the signal box side and closing the supply circuit for the drive motor. The V winding of the drive motor is connected to the phase voltage, the U and W windings are connected to the linked phase voltage between phases L2 and L3. The drive motor begins to rotate without, however, the switch contacts 6, 7, 8, 9 being switched over first. In this start-up phase the motor starts with a torque of approx. 70%. In the start-up phase

10 -

the switching contacts 8, 9 are now switched over, since the actuating member 13 of the switch element 12 is pressed out of the groove 15 of the test rod. The result is the connection shown in Fig.l, in which the motor windings are connected in star.

Fig.5 shows the drive supply circuits in the run-down phase shortly before the drive motor is switched off. In this phase, the switching contacts 6, 7 have also changed their switching position and thus separated the star point connection of the motor windings. The motor is now excited asymmetrically via the phase voltage and the linked phase voltage, whereby the motor continues to run with approx. 70% of the torque. The signal box recognizes that the changeover is complete via the center conductor Mp. In the signal box, the supply voltage for the three-phase motor is therefore disconnected and the monitoring voltage for the left end position is applied. This creates a monitoring circuit as shown in Fig.6 via the supply line 4, the motor winding U, the switching contact 6, the supply line 3, the monitoring relay Wü, the supply line 2, the motor winding V, the switching contact 9, the motor winding W and the supply line 5.

The illustration in Fig. 7 shows the situation in which the switch was opened, i.e. it was approached from the blunt side, opposite to the position defined by the last switching order carried out. The two switching contacts 6 and 7 have changed their switching position. As a result of the contact change, the previously existing monitoring circuit has been interrupted, with the monitoring relay Wü dropping out and the drive relay WA energizing. When the supply voltage is applied, the phases Ll, L2, L3 are again connected in a star connection, so that the three-phase current can be applied for another changeover.

The illustration in Fig.8 shows a circuit as provided in accordance with the state of the art in a testing device which takes into account several test levels arranged offset in the longitudinal direction of the rail. Each of the test levels 17, 18 and 19 has a test circuit with

- 11 -

two contact switches, each with two switching contacts, which are connected in a cascade. In the illustration according to Fig.8, the monitoring voltage for the right end position is applied and it is clear that a malfunction of individual contact switches is not detected. If all switching contacts are functioning correctly, with switching contact 20 being open and switching contact 21 being closed, the test circuit should run via switching contact 21, as indicated by the dashed line. If the switching contacts 20 and 21 combined to form a switching element according to switching elements 11 or 12 malfunction (as shown in Fig. 8), however, switching contact 20 is closed and switching contact 21 is open, so that the monitoring circuit is still closed via switching contact 20. A malfunction is not detected by the signal box because the individual switching contacts are connected in parallel, so that no sum signal is available which would also indicate the malfunction of a single switching contact.

According to the invention, it is therefore proposed that the switching contacts of several test levels are interconnected in such a way that in the respective end positions all closed switching contacts of the interconnected test levels are connected in series. A schematic representation of a monitoring device according to the invention is shown in Fig. 9. The individual test levels are designated 17, 18 and 19 and switching elements A, B, C and D can be seen, each of which comprises two switching contacts with different switching positions. In the following figures, the switching contacts of the individual switching elements are designated Al/2, A3/4, Bl/2, B3/4, Cl/2, C3/4 and Dl/2, D3/4. The drive motor is designated M and the signal box is designated St. Fig. 10 shows the interconnection of the individual switching contacts, with three further test levels 17, 18 and 19 being lined up and connected in series based on a first drive end position monitor 22. In the end position shown in Fig.10, the monitoring circuit is closed and optically highlighted. It is clear that all the

12 -

closed switching contacts are connected in series, with the monitoring circuit running via the switching contacts Al/2, Bl/2, C3/4 and D3/4 of the individual test levels. In the other end position, a monitoring circuit would result via the switching contacts Cl/2, Dl/2, A3/4 and B3/4 of the individual test levels, as indicated by the dashed line. It can be seen that the monitoring circuit connects all of the closed switching contacts in series, so that the malfunction of a single switching contact in the series causes an interruption in the monitoring circuit, so that the malfunction of a single switching contact can be detected at any time. The monitoring circuits corresponding to the two end positions (shown in Fig. 10 with a solid line and a dashed line) are connected via connections 23, so that if one of the switching contacts malfunctions, a star connection results, so that the three-phase motor continues to run during the changeover and the fault is detected by the signal box when the specified changeover time is exceeded. Fig. 11 shows the situation in which the switching element, which includes the switching contacts Bl/2 and B3/4 in the test level 19, does not indicate that the desired end position has been reached, so that the monitoring circuit is interrupted and a star point connection with the star point 10 results, so that the three-phase motor continues to run at full power. This shifts the connection point for the star point of the first test level with conventional four-wire technology, including the individual test levels, and thus enables the monitoring current path to be routed through the individual star points of the test levels.

In the lowest interconnection level 22, either a self-monitoring monitoring unit must be provided or a crosswise interconnection of two contact elements, as is indicated for example for the contact elements B and D in Fig. 10. Such a crosswise interconnection ensures that all subsequent contacts can be continuously checked in the respective end position after the test circuit has been applied.

13 -

An external additional device, such as a collision detection device 32, can be integrated into this device for remote monitoring of switches.

The test device according to the invention can also be integrated into a separate four-wire monitoring circuit. Fig. 12 shows a contact circuit which includes a monitoring relay 23 which works in both directions. If just one of the numerous switching contacts fails, the monitoring current fed in, for example 48 volts, cannot flow and the switch system must be checked. In contrast to the illustration in Fig. 12, in which the monitoring circuit is closed and therefore no error message is displayed, the switching element A is not switched when the desired end position is reached during the changeover in Fig. 13, so that the monitoring relay is short-circuited and this is displayed as an error message in the signal box.

Overall, it is advantageous if a number of switching contacts are interconnected in the testing device according to the invention, which corresponds to an integer multiple of 8, and it is therefore necessary that, when only two contact switches are arranged in a test plane, a group of four contact switches each are combined so that a group of two contact switches are arranged in a relaxed position and two contact switches are arranged in a tensioned position, as is the case in Figs. 9 to 11 in the test plane 19. A test plane can be arranged in the drive plane or within the extension of the tongue or the movable frog.

In Fig.14, another type of switching element 25, 2 6 is shown, in which three switching contacts are combined. The switching element 25 has the switching contacts 27, 28 29. The switching contacts 27, 28, 29 and 24, 30, 31 arranged in a switching element 25 or 26 are assigned a common actuating member 13, which interacts, for example, with grooves 15 and 16 formed on a test rod 14.

The switching element 26 engages with the actuating member 13 in the groove 15 and is in the relaxed position, with the switching contact 30 closed and the contacts 24 and 31 open. The switching element 25, on the other hand, is in the tensioned position, with the switching contacts 27 and 28 closed and the switching contact 29 open. The switch positions shown in Fig. 14 correspond to one of the two end positions of the switch tongue or the movable frog.

The test device according to the invention can be constructed using switching elements as described in Fig. 14. It can be seen that all switching contacts closed in the end position are connected in series and a monitoring circuit is closed as shown in Fig. 15, which runs via the switching contacts All/12 and C4/3 and C13/14 of the individual test levels.

Claims (10)

1. Device for remote monitoring of, for example, three-phase operated point drives or a monitoring circuit operated over four lines with contacts switched depending on the position of the point, via which contacts a monitoring circuit led over the four lines for, for example, a point monitor fed with direct current is closed after the respective end position is reached, wherein a plurality of test levels ( 17 , 18 , 19 ) arranged offset in the longitudinal direction of the rails are provided and in each test level at least four switching contacts (A 1/2, A 3/4, C 1/2, C 3/4) are interconnected and thus connected to moving parts of the point drive or the point, e.g. B. a test rod, such that in one end position two switching contacts (A 1/2, C 3/4 or C 1/2, A 3/4) are in the closed switching position and two switching contacts (C 1/2, A 3/4 or A 1/2, C 3/4) are in the open switching position and the switching position of each switching contact (A 1/2, A 3/4, C 1/2, C 3/4) is changed once when switching to the other end position, characterized in that the switching contacts (A 1/2, A 3/4, C 1/2, C 3/4) of several test levels (17, 18, 19) are interconnected in such a way that in the respective end positions all closed switching contacts (A 1/2, C 3/4 or C 1/2, A 3/4) of the interconnected test levels ( 17 , 18 , 19 ) are connected in series to form a monitoring circuit. 2. Device according to claim 1, characterized in that a separate, self-monitoring inspection unit is arranged in a first of the interconnected inspection levels. 3. Device according to claim 1, characterized in that the switching contacts (B1/2, B 3/4, D 1/2, D 3/4) assigned to a first ( 22 ) of the interconnected test levels are cross-connected to one another. 4. Device according to claim 1, 2 or 3, characterized in that motor windings (U, V, W) of a three-phase motor are connected in series with the switching contacts (A 1/2, A 3/4, C 1/2, C 3/4) and can be connected to the three-phase network via these. 5. Device according to one of claims 1 to 4, characterized in that the monitoring circuit corresponding to one end position and the monitoring circuit corresponding to the other end position are connected to one another, so that the monitoring circuits are connected to form a star point connection in the event of a malfunction of at least one switching contact or incorrect switching of the switch in at least one test level. 6. Device according to one of claims 1 to 5, characterized in that two switching contacts (A 1/2, A 3/4 or B 1/2, B 3/4 or C 1/2, C 3/4 or D 1/2, D 3/4) of a test level ( 17 , 18 , 19 ), which have different switching positions from one another, are combined in a switching component (A, B, C, D) and interact with a common actuating element. 7. Device according to one of claims 1 to 6, characterized in that the sum of the switching contacts of all test levels ( 17 , 18 , 19 ) corresponds to an integer multiple of eight. 8. Device according to one of claims 1 to 7, characterized in that at least two switching contacts (A 1/2, B 1/2) are connected in series in the same switching position and the same end position. 9. Device according to one of claims 1 to 8, characterized in that two switching contacts (A 1/2, A 3/4) with different switching positions of a switching element (A) are linked together for the same end position. 10. Device according to one of claims 1 to 5 and 9, characterized in that the switching element ( 25 ) consists of three switching contacts ( 27 , 28 , 29 ) which have different switching positions from one another, are combined in a switching element ( 25 ) and interact with a common actuating member ( 13 ).