AU2015221437A1

AU2015221437A1 - Excess voltage protection apparatus

Info

Publication number: AU2015221437A1
Application number: AU2015221437A
Authority: AU
Inventors: Oliver SCHWEHN; Peter Tugendhat
Original assignee: Thales Management and Services Deutschland GmbH
Current assignee: Thales Management and Services Deutschland GmbH
Priority date: 2014-09-01
Filing date: 2015-08-31
Publication date: 2016-03-17
Anticipated expiration: 2035-08-31
Also published as: AU2015221437B2; DE102014217446B4; PL2991177T3; ES2810758T3; DK2991177T3; EP2991177B1; HRP20201168T1; PT2991177T; EP2991177A1; DE102014217446A1

Abstract

- 17 Abstract An excess voltage protection apparatus (9), in particular for a technical signalling device, for arrangement between an external installation (2) and an internal installation (1), having at least two series terminals (10a, 10b) which are each part of a signal path (12a, 12b), the series terminals (10a, 10b) having connection contacts (13a, 13b, 14a, 14b) for connection to the internal and external installation (1, 2), having a base terminal (11) having a connection for a discharge to earth, and at least one excess voltage protection device (17) which is electrically connected to the series terminals, is characterised in that there is provided a connector housing (23) in which the excess voltage protection device (17) is installed, in that the series terminals (10a, 10b) and the base terminal (11) each have an insertion location (16) for fitting the connector housing (23) of the excess voltage protection device (17) and in that the series terminals (10a, 10b) each have a non-releasable isolating blade (19a, 19b) for temporary separation of the signal paths (12a, 12b). A space saving excess voltage protection apparatus which is simple to operate and has a low failure rate is thereby produced. Fig. 2 14a 24 16 19a 24 13a10Oa F---- ~'13b 1 2b 14 FF ---- 23 9 k---1

Description

Australian Patents Act 1990 - Regulation 3.2 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Invention Title Excess voltage protection apparatus The following statement is a full description of this invention, including the best method of performing it known to me/us:- - 1a Background of the invention The invention relates to an excess voltage protection apparatus for signal and control lines, in particular for a technical signalling device, for arrangement between an external installation and an internal installation, having at least two series terminals which are each part of a signal path, the series terminals having connection contacts for connection to the internal and external installation, having a base terminal having a connection for a discharge to earth, and at least one excess voltage protection device which is electrically connected to the series terminals, wherein there is provided a connector housing in which the excess voltage protection device is installed. Such an excess voltage protection apparatus is known, for example, from Phoenix Contact "Netz & Signal-Qualitat TRABTECH PLUGTRAB PT-IQ Intelligenter Uberspannungsschutz mit System", 2013. ("Network and Signal Quality TRABTECH PLUGTRAB PT-IQ Intelligent Excess Voltage Protection with System").

- 2 Technical railway installations comprise a large number of power-operated elements of external installations, for example, rail signals or points, which are connected by means of lines (signal paths) to an internal installation (for example, a signal box or the electronic control system of the signal box). Although the members of the external installations are generally earthed, as a result, for example, of inductive coupling or potential differences resulting from resistance areas brought about, for example, by means of a remote lightning strike, there may occur an introduction of excess voltage in the control and switching elements (for example, the signal box internal installation) which may lead to damage and operational failures. In order to prevent damage and malfunctions in signal boxes, it is known to use additional excess voltage protection apparatuses. The action of the excess voltage protection is based on the discharge to earth of any excess voltages which occur. It is known to mount excess voltage protection devices on bases which are connected by means of cable connections to isolating blade series terminals, as produced, for example, by Thales Deutschland GmbH using PLUGTRAB elements from Phoenix Contact. A disadvantage of this arrangement is that the excess voltage protection apparatus in addition to the isolating blade series terminal takes up a large amount of space and the discharge is carried out over a relatively long path, which is linked to high levels of discharge inductivity so that, during the discharge operation, large interference fields are - 3 induced and a higher voltage is present at the discharge to earth in the event of an occurrence of an excess voltage. In addition, it is not possible to identify thermal overloads of the excess voltage protection devices. Object of the invention An object of the invention is therefore to provide an excess voltage protection apparatus by means of which the above mentioned disadvantages can be avoided. Description of the invention This object is achieved according to the invention by an excess voltage protection apparatus according to claim 1. According to the invention, the series terminals and the base terminal each have an insertion location for fitting the connector housing of the excess voltage protection device, wherein the series terminals each have a non-releasable isolating blade (which is, for example, pivotable) for temporary separation of the signal paths. Whilst, in the prior art, the excess voltage protection device is fitted on a separate base, and is connected to the isolating blade series terminal by means of cables, in the excess voltage protection apparatus according to the invention the isolating blade series terminals (series terminals with isolating blades) are provided with an insertion location, at which the excess voltage protection device can be fitted. According to the invention, therefore, the excess voltage protection is produced by means of direct - 4 fitting of the excess voltage protection devices to the isolating blade series terminals and the base terminals. In this instance, the connections for individual strands of the technical signalling device are connected to the series terminals and the earth connections are connected to the base terminals. The base terminals are preferably provided with discharge feet which enable a gas-tight contact and current carrying contact to an assembly rail, for example, a DIN rail assembly rail TS 35, on which the series terminals can be assembled. In the excess voltage protection apparatus according to the invention, therefore, isolating blade series terminals are used as a connection member, for example, between the internal and external installation cabling. The series terminals which are intended to be used for the excess voltage protection apparatus according to the invention therefore have to be sized in such a manner that the excess voltage protection device can be fitted without concealing the connection contacts for connection to the internal and external installation. Furthermore, the connector housing and the insertion location have to be configured in such a manner that the excess voltage protection devices can be connected in an impact and vibration-resistant manner in accordance with EN 50125-3; this is particularly the case for the region defined in accordance with EN 50125-3 outside the tracks (spacing of from 1 to 3 m from the track). The connection contacts of the series terminals are connections for individual strands. At the side of the external installation, although cables having many wires can be used, they are then connected as individual strands. The concept according to the invention takes into account that - 5 strands of different current circuits can be connected to the same excess voltage protection device. This is particularly important for technical signalling installations since, as a result of this particular property, the absence of feedback to the safety-related elements of the technical signalling system is maintained. For the use of the excess voltage protection apparatus according to the invention in technical signalling devices for rail operation, the installation components used (series terminal, base terminal) and the excess voltage protection devices have to be permitted for use in installations of control and safety technology. With the excess voltage protection apparatus according to the invention, it is possible to prevent damage and malfunctions in signal boxes which may occur, for example, as a result of excess voltages in the cabling systems to the external installations, caused by remote lightning strikes. At the same time, the excess voltage protection apparatus according to the invention can be assembled in a space-saving manner. It is also advantageous that, as a result of the plug type connection according to the invention between the series terminal and the excess voltage protection device, the discharge and the signal transmission are carried out at the same location, that is to say, without any line connection between the series and base terminal and excess voltage protection device, so that the excess voltage to be discharged can be discharged to earth with the lowest possible level of discharge inductivity. As a result of the short discharge paths, there are produced smaller influences on surrounding components in particular as a result of magnetic fields.

- 6 The excess voltage protection apparatus according to the invention can also be used in installations other than technical rail installations, in particular in installations which are not earthed, since the excess voltage protection apparatus according to the invention is constructed in an insulated manner, and the active components contained cannot be touched. Preferably, the excess voltage protection apparatus according to the invention corresponds at least to the requirements for the protection type IP 20. The excess voltage protection apparatus according to the invention is also particularly suitable for protection for electric circuits in which the absence of feedback is a strict requirement for operation. The excess voltage protection apparatus according to the invention enables installation of different excess voltage protection devices at difference times. It is thereby possible to pre-install series and base terminals so that the installation can also be operated initially without excess voltage protection and a subsequent retrofitting is possible. Preferred embodiments of the invention The series terminals preferably each have on the connections for the input and output lines a test socket for contacting with respect to the signal path, in particular for measuring and testing purposes. The test sockets are preferably provided at both sides (at the internal and external installation), for example, for permanent contacting of a measurement device.

- 7 In a preferred embodiment, there are provided a plurality of excess voltage protection devices which each have a connector housing and the arrangement of the series terminals has a plurality of insertion locations for fitting the connector housings to the excess voltage protection devices. Consequently, a plurality of field elements can be protected with the excess voltage protection apparatus according to the invention. Preferably, the excess voltage protection device comprises at least two discharge paths, wherein each discharge path comprises a series arrangement of an excess voltage discharge and a varistor. The invention thus provides independent discharge elements. For example, a gas discharge may be used as an excess voltage discharge. Using the combination of varistor and excess voltage discharge, it can be ensured that there are no occurrences of feedback in respect of the technical signalling devices during operation. Furthermore, during control operation, the ageing of the structural elements is minimised by the prevention of leakage currents. In particular, signal circuits and inputs/outputs which guide AC or DC voltages can be protected. The combination of varistor and excess voltage discharge in a series arrangement ensures that secondary current is prevented. In a particularly preferred embodiment of the excess voltage protection apparatus according to the invention, a barrier device is arranged between the discharge paths. The barrier device is intended to prevent the discharge paths from being able to touch, and thus brings about a non-releasable separation between both discharge paths. It is thereby possible to connect different circuits to one excess voltage protection device, wherein the absence of feedback to the - 8 operation and the technical signalling safety of the installation are ensured and, at the same time, the spacing between the discharge paths can be kept small. The barrier device prevents the unintentional contact of the components of the discharge paths and is preferably constructed in the form of an insulation plate from a suitable electrically insulating material. Preferably, the dielectric strength of the barrier device is > 10 kV/mm after ageing. The voltage resistance required according to EN 50124-1 between two redirection paths is ensured by means of appropriate sizing of the air gaps and creep paths. As a result of the provision of the barrier device, a plurality of field elements may be connected by means of the same excess voltage protection device. This is particularly advantageous when triple-wire field elements (for example, a dual filament lamp) are intended to be connected to excess voltage protection devices which each have two discharge paths since the remaining discharge path does not then have to remain free as is the case with the excess voltage protection apparatus known from the prior art, but instead can be used for another field element. Furthermore, the planning and testing complexity can be reduced. Preferably, the connector housing is constructed to be at least partially transparent, in particular in the region of the varistor. In this manner, the excess voltage protection devices can be monitored by means of visual examination. Thermal overloads can be identified. In an advantageous embodiment, a monitoring device, in particular an optical detection device, is provided within the excess voltage protection apparatus in order to detect occurrences of excess voltage. The monitoring by means of the - 9 monitoring device enables selective maintenance and thereby improves the availability of the device. Preferably, the excess voltage protection apparatus can be monitored remotely. The monitoring device may be provided with a store which can store a plurality of occurrences of excess voltage discharge. A separate monitoring device may also be provided for each excess voltage protection device. Monitoring of the excess voltage protection devices is particularly advantageous for decentralised technical signalling devices. Other advantages of the invention will be appreciated from the description and the drawings. The features mentioned above and those set out below may also be used according to the invention individually per se or together in any combination. The embodiments shown and described are not intended to be understood to be a conclusive listing but are instead of exemplary character for describing the invention. Detailed description of the invention and drawings Figure 1 shows a technical rail installation which is protected by means of an excess voltage protection apparatus according to the invention; Figure 2 shows the structure of an excess voltage protection apparatus according to the invention; Figure 3 is a perspective view of an excess voltage protection apparatus according to the invention; and Figure 4 shows an excess voltage protection device of an excess voltage protection apparatus according to the invention. Figure 1 shows a technical rail installation having a signal box 1 (internal installation) and a rail signal 2 (external - 10 installation) which is controlled by means of an electronic control system 3 of the signal box 1. The signal box 1 is provided with an external lightning protector 4 which is earthed by means of a foundation ring earth electrode 5. A main potential equalisation unit 6 and internal excess voltage protection apparatuses 7 serve to protect the signal box 1 from direct lightning strike. In order to prevent the introduction of an excess voltage into the electronic control system 3 via components of the external installation 2 (for example, by means of remote lightning strike in the vicinity of the signal 2 or in the vicinity of the lines 8 between the signal 3 and signal box 1), the signal box 1 is provided with an additional excess voltage protection apparatus 9 according to the present invention. Figure 2 shows the structure of the excess voltage protection apparatus 9 according to the invention. Two series terminals 10a, 10b and a base terminal 11 are used to connect the external installation 2 to the internal installation 1, the series terminals 10a, 10b each forming a portion of a signal path 12a, 12b. The terminals (10a, 10b, 11) are arranged in any sequence. The series terminals 10a, 10b are provided with connection contacts 13a, 13b, 14a, 14b (individual strand connectors) for connection to the internal or external installation 1, 2. For earth discharge, the base terminal 11 has a discharge foot 15. An excess voltage protection device 17 is connected to the series terminals 10a, 10b and the base terminal 11 by means of plug type contacts. To this end, the terminals 10a, 10b, 11 have insertion locations 16. The excess voltage protection - 11 device 17 is arranged in a connector housing 23, which is fitted by means of the insertion locations 16 onto the terminals 10a, 10b, 11 and can consequently be electrically and mechanically contacted therewith. By means of the excess voltage protection device, each signal path 12a, 12b is connected to earth. The series terminals 10a, 10b each have a preferably pivotable isolating blade 19a, 19b for temporarily separating the signal paths. Close to the connection contacts 13a, 13b, 14a, 14b for the input and output lines, there are provided test sockets 24 by means of which a test device or measurement device can be contacted with the signal paths 12a, 12b. Figure 3 is a perspective view of an excess voltage protection apparatus 9 according to the invention with two fitted excess voltage protection devices 17. The excess voltage protection apparatus 9 according to the invention may comprise a large number of excess voltage protection devices 17. The excess voltage protection devices 17 are arranged on an assembly rail 22 which, in particular when used in non earthed regions, is in turn fitted on an insulating base plate (conductor guiding plate - not shown). The earth contact can be produced via the assembly rail 22. In order to display discharge events, a display module may, for example, be provided at the lower end of the assembly rail. The basic structure of the excess voltage protection device 17 is shown in Figure 4. The excess voltage protection device 17 comprises two discharge paths 18a, 18b which can be connected to the signal paths 12a, 12b by means of connections 21a, 21b. The two connections 21a, 21b have a spacing di with respect to each other, the spacing di - 12 designating the creep path and air gap which has to be complied with between the connections 21a, 21b of the two discharge paths 18a, 18b of the excess voltage protection device 17. In the discharge paths 18a, 18b, an excess voltage discharge 19 and a varistor 20 are connected in series, respectively. The varistor 19 and the excess voltage discharge 20 may be arranged in any sequence, but they are always in series. Between the two discharge paths 18a, 18b, a barrier device 21 is arranged so that the discharge paths 18a, 18b are electrically insulated from each other. The excess voltage protection apparatus according to the invention makes provision for the excess voltage protection devices to be fitted directly on an isolating blade series terminal, whereby a space-saving excess voltage protection apparatus is produced which is simple to operate and has a low failure rate. Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

- 13 The reference numerals in the following claims do not in any way limit the scope of the respective claims.

- 14 List of reference numerals 1 Signal box/internal installation 2 Rail signal/external installation 3 Electronic control system 4 External lightning protector 5 Foundation ring earth electrode 6 Main potential equalisation unit 7 Internal excess voltage protection apparatuses 8 Lines 9 Excess voltage protection apparatuses 10a, 10b Series terminals 11 Base terminal 12a, 12b Signal path 13a, 13b Connection contacts to the external installation 14a, 14b Connection contacts to the internal installation 15 Discharge foot 16 Insertion locations 17 Excess voltage protection device 18 Connector housing 19 Excess voltage discharge 20 Varistor 21 Barrier device 22 Assembly rail 23 Connector housing 24 Test socket

Claims

1. Excess voltage protection apparatus (9) for signal and control lines, in particular for a technical signalling device, for arrangement between an external installation (2) and an internal installation (1), having: at least two series terminals (10a, 10b) which are each part of a signal path (12a, 12b), the series terminals (10a, 10b) having connection contacts (13a, 13b, 14a, 14b) for connection to the internal and external installation (1, 2), having a base terminal (11) having a connection for a discharge to earth, and at least one excess voltage protection device (17) which is electrically connected to the series terminals, characterised in that there is provided a connector housing (23) in which the excess voltage protection device (17) is installed, in that the series terminals (10a, 10b) and the base terminal (11) each have an insertion location (16) for fitting the connector housing (23) of the excess voltage protection device (17) and in that the series terminals (10a, 10b) each have a non releasable isolating blade (19a, 19b) for temporary separation of the signal paths (12a, 12b).

2. Excess voltage protection apparatus (9) according to claim 1, characterised in that the series terminals (10a, 10b) each have on the connections for the input and output lines a test socket (24) for contacting with respect to the signal paths (12a, 12b).

3. Excess voltage protection apparatus (9) according to either of the preceding claims, characterised in that there - 16 are provided a plurality of excess voltage protection devices (17) which each have a connector housing (23), and in that the arrangement of the series terminals (10a, 10b) has a plurality of insertion locations for fitting the connector housings (23) to the excess voltage protection devices (17).

4. Excess voltage protection apparatus (9) according to any one of the preceding claims, characterised in that the excess voltage protection device (17) comprises at least two discharge paths (18a, 18b), wherein each discharge path (18a, 18b) comprises a series arrangement of an excess voltage discharge (19) and a varistor (20).

5. Excess voltage protection apparatus (9) according to claim 4, characterised in that a barrier device (21) is arranged between the discharge paths (12a, 12b, 18a, 18b).

6. Excess voltage protection apparatus (9) according to any one of the preceding claims, characterised in that the connector housing (23) is constructed to be at least partially transparent, in particular in the region of the varistor (20).

7. Excess voltage protection apparatus (9) according to any one of the preceding claims, characterised in that a monitoring device, in particular an optical detection device, is provided within the excess voltage protection apparatus (9) in order to detect occurrences of excess voltage.