FR2980273A1 - Electric cable assembly for use in electrical distribution system in railway, has detection device provided with processing unit to determine presence of cut of cable from detection of modification in optical signal - Google Patents

Abstract

The assembly (4) has an optical fiber (6) attached with a cable. A detection device detects cut of the cable and includes an emission unit (32) and a reception unit (33) for receiving an optical signal from the fiber, where the assembly is configured such that the cut of the electric cable generates modification of the optical signal from the fiber. The detection device is provided with a processing unit to determine presence of the cut of the cable from detection of the modification in the optical signal. Independent claims are also included for the following: (1) an electrical distribution system (2) a method for detecting a cut of an electric cable.

Description

The present invention relates to an assembly of an electric cable, an optical fiber associated with said cable and a device for detecting an interruption of an electric cable, as well as a current distribution system, particularly a railway system. detection of at least one break in the cable. It also relates to a corresponding rail power distribution system. The invention is more particularly concerned with the field of electric cables used in the railway sector for the power supply of catenaries or for the transport of railway signaling information. These electric cables are more and more often the target of thieves who do not hesitate to cut entire sections of cables in order to recover copper. These flights are constantly increasing due in particular to the increase in the price of this metal.

Unfortunately, such cable cuts cause great damage in the railway sector. In addition to the cost of replacing the cable, the resulting power cut causes a paralysis of the traffic train lines concerned during the time required for repair, may last several hours.

It can also be noted that this repair time is currently lengthened by the fact that a cut of an electric power cable of a catenary is not identified immediately. Indeed, the reason for the power failure of the catenary is known only after investigation. Faced with the upsurge of these malevolent acts, the public authorities and the railway companies concerned have reinforced rail monitoring devices, including the deployment of CCTV cameras and overflights of the rails by gendarmerie helicopters. These solutions, besides the fact that they are very expensive, do not make it possible to monitor the entire railway network to prevent the cutting of the cables. The present invention aims to improve the situation. For this purpose, the present invention firstly relates to a set of an electrical cable, an optical fiber associated with this cable, and a device for detecting at least one cut of this cable, said device detection device comprising transmitting means and means for receiving an optical signal in the fiber, said assembly being configured so that the breaking of the electrical cable causes a modification of the optical signal in the fiber, said detection device further comprising processing means for determining the presence of the cable break from detection of the change in the optical signal.

Thanks to this set, the detection and identification of a cable break and its probable flight are immediate. There is in fact information specifically related to the cut of the cable from the modification of the optical signal, namely the interruption or at least the attenuation of said signal. This makes it possible to implement the appropriate repairs quickly so as to restore the electrical connection in a very short time. It also allows to give the alert without delay in order to stop the perpetrators of the offense. Advantageously, the optical fiber is inserted into the cable. Thanks to this integration of the optical fiber in the cable, for example by means of a tube of synthetic or metallic material, a cut of the cable causes a cut in the optical fiber, resulting in a loss of the optical signal. Preferably, the optical fiber is a multi-stranded fiber, comprising at least one emitter and one receiver strand.

In one embodiment, the cable comprises an electrically insulating sheath and the optical fiber is inserted into the electrically insulating sheath. In another embodiment, the cable comprises a mechanical protection sheath and the optical fiber is inserted into the mechanical protection sheath.

In yet another embodiment, the cable comprises a core and the optical fiber is inserted into the core. More specifically, the cable may comprise a bundle of strands, for example copper, the optical fiber being inserted into the bundle, in particular in place of one of the copper strands. Preferably, the transmitting means comprises a light emitting diode and the receiving means comprises a photodiode. Advantageously, the transmission means and / or the means for receiving the optical signal are located at a distance from ends of electrical connection points of the cable. In other words, they are remote from the ends of the cable which will protect said transmitting means and / or the means for receiving the optical signal independently of the cable.

Preferably, the detection device further comprises means for triggering an alarm when the presence of at least one cable break is determined. This makes it possible to immediately warn a person in charge of monitoring the cable of the occurrence of the cut. In one embodiment, the cable is a power supply cable of a catenary. This is, for example, a 1500 V DC power supply or 25 kV AC power cable for railway electric traction.

In another embodiment, the cable is a railway signal cable. This is, for example, a traction return cable such as a 750 V insulated cable. It can be a buried cable, especially in a gutter. Indeed, these cables are more exposed than overhead cables to theft attempts.

The present invention also relates to a current electrical distribution system, including rail, comprising an assembly as mentioned above. Said distribution system comprises, for example, electrical distribution members such as switches, transformers and / or circuit breakers, and control means of said electrical members. Advantageously, the distribution system comprises means for transmitting cable cutoff information to a network connected to a remote monitoring unit. This network is separate from the catenary power distribution network. It includes information transmission lines. The system may be configured to transmit through said network both electrical device monitoring information and cable cutoff information. It may also be configured so that the control means of the electrical organs and the detection device are powered by the same source of electric current. Preferably, the processing means are capable of providing an identification of the cut cable to the information transmission means, in particular when the system comprises several sets of an electrical cable, an optical fiber and a detection device. . According to one aspect of the invention, the distribution system comprises a power station in which are arranged the electrical distribution members, the control means of said electrical organs and said detection device, the electric cable being arranged at least in part outside said feed station. Advantageously, the processing means are able to identify the power station to which a cut cable is connected, in particular when the system comprises several feed stations connected to the same remote monitoring unit. Said station may comprise a frame enclosing at least all or part of the control means of the electrical distribution members as well as the transmitting means, the receiving means and / or the processing means of the detection device. "Built" means a closed building and out of water. Said frame may also be equipped with an alarm, possibly connected to said remote monitoring unit, for example by the same network as that connected to the cable cutoff information transmission means. The present invention also relates to a method of detecting at least one cut of an electrical cable to which an optical fiber is associated, comprising the steps of: - transmitting an optical signal in the fiber by an optical transmitter; - receiving said optical signal by an optical receiver; and determining the presence of at least one cable break from detection of a change in the optical signal by the receiver. Advantageously, the method further comprises the step of identifying the cut cable and / or a feed station equipped with said cut cable. Exemplary embodiments of the invention will now be described in a more precise but nonlimiting manner, with reference to the appended drawings in which: FIG. 1 is a diagram showing an electrical distribution system according to an embodiment of the invention; invention; FIG. 2 is a diagram showing the structure of the electrical distribution members of the feed station of FIG. 1 according to a first embodiment of the invention; FIG. 3 is a diagram showing the structure of the electrical distribution members of the feed station of FIG. 1 according to a second embodiment of the invention; FIG. 4 is a diagram illustrating a first example of insertion of an optical fiber in an electric cable; FIG. 5 is a diagram illustrating a second example of insertion of an optical fiber in an electric cable; FIG. 6 is a diagram illustrating a third example of insertion of an optical fiber in an electric cable; and Fig. 7 is a flowchart illustrating the operation of the cut detection method of the present invention. FIG. 1 shows the architecture of a rail current electrical distribution system 2 according to a preferred embodiment of the invention.

This distribution system 2 comprises an electric cable 4. According to the invention, this cable 4 is associated with an optical fiber 6 which is here inserted into the cable 4 in one of the ways described with reference to FIGS. 4 to 6. distribution system 2 further comprises a power station 8, also called substation, providing power to one or more catenary (s) from an electrical network. The supply station 8 also provides electrical protection and control of the system 2. The distribution system 2 also comprises a central substation 10 for remote management of the supply station 8.

A power station is provided along a railway line, for example, for a stretch of several kilometers or tens of kilometers and a central substation manages several power stations. The central substation 10 here comprises at least one operator station 12 connected to an optical control board 14, called TCO, and a remote control 16. These equipment 12, 14, 16 allow a regulating agent to manage, monitor and ensure the operation of the distribution system 2. From its operator station 12, the agent monitors the information displayed, in particular by means of optical indicators, on the optical control board 14 and relating to the central area of action. substation 10. In addition, the agent transmits commands with the remote control 16 to the power supply station (s) 8. For this purpose, an information transmission network 18 formed of transmission lines , connects the remote control 16 of the central substation 10 to a remote control 20 of the supply station 8. According to the invention, the supply station 8 also comprises an optical transceiver 31.

The optical transceiver 31 comprises, for example, a light-emitting diode 32 for transmitting an optical signal in the optical fiber 6 and a photodiode 33 for receiving the optical signal. In general, the reception means are able to detect a modification, in particular loss and / or attenuation, of the optical signal. Power supply means 34, 36 are provided for supplying the various devices of the supply station 8 and the substation central station 10 respectively from the same respective current source having a voltage of 230 V AC, for example. example.

The feed station 8 also comprises electrical distribution members whose architecture is detailed with reference to FIGS. 2 and 3. In the embodiments illustrated in FIGS. 2 and 3, the cable 4 is either a conductive cable allowing the supply of a catenary is a cable of return of traction. Figure 2 relates to the case of an electrification at 25 kV AC. This is more particularly a so-called 2 * 25 kV supply. This power supply makes it possible to increase the distance separating two substations. The supply station 8 comprises, in this case, a first portion 40 formed of switches providing the interface with the very high voltage electrical network THT, for example 225 kV. A second part 42, comprising transformers, produces a voltage of 25 kV from the voltage THT. A third portion 44, including switches and circuit breakers, provides the voltage of 25 kV to a catenary 46. Conductive cables 48, 50, 52, 54 provide the connection between the third portion 44 and the catenary 46. This is medium voltage copper cables, said HTA cables provided, according to the invention, optical fibers Two rails 56, 57 are also shown in Figure 2. They correspond to the rails of the rails or rails fed. They allow the return of traction current. They are connected to the transformers of the second part 42 via 750 V insulated low voltage cables 58, 59 provided with optical fibers, according to the invention.

Figure 3 relates to the case of an electrification at 1500 V DC.

The supply station 8 comprises, in this case, a first portion 60 formed of high-voltage circuit breakers providing the interface with the high-voltage electrical network HT, for example 20 to 90 kV. A second portion 62 includes a three-phase triangle / star transformer for lowering the voltage. A third portion 64, including a rectifier, provides the voltage of 1500 V to a fourth portion 66 formed of circuit breakers and disconnectors for supplying catenaries. Conductive cables 68, 70, 72, 74 provide the connection between the fourth portion 66 and the catenaries. These are medium voltage copper cables, called HTA cables provided, according to the invention, with optical fibers. A rail 76 is also shown in FIG. 3. It corresponds to the rails of the feeder track or rails. It allows the return of traction current. It is connected to the rectifier of the third part 64 by means of a 750 V insulated low voltage cable 78 provided with optical fiber, according to the invention. FIGS. 4 to 6 illustrate various examples of insertion of the optical fiber 6 into the cable 4, this cable being one of the cables 48, 50, 52, 54, 58, 59, 68, 70, 72, 74 or 78 Figures 2 and 3.

The cable 4 is a multi-strand cable comprising a core 82 in which are inserted several strands 83 copper (Figure 6). An insulating sheath 84 surrounds the core 82 and a mechanical protective sheath 86 envelopes the assembly. The optical fiber 6 is a multi-strand fiber comprising, for example, a transmitting strand 88 intended to be connected to the light emitting diode 32 and a receiving strand 90 intended to be connected to the photodiode 33. It is here integrated into a tube 92 made of synthetic or metallic material. The tube 92 is inserted, according to the first example, illustrated in FIG. 4, into the insulation sheath 84.

According to a second example, illustrated in FIG. 5, the tube 92 is inserted into the mechanical protection sheath 86. According to a third example, illustrated in FIG. 6, the tube 92 is inserted into the core 82 instead of a strand 83 of copper. Referring again to FIG. 1, the remote control 20 makes it possible to receive information from the supply station 8, transmitted to at least one automation unit 24. The latter controls the operation of at least one or more electrical devices. 22 with which he is connected. As mentioned with reference to FIGS. 2 and 3, these are, for example, circuit breakers, switches and / or rectifiers of the first 40, 60, third 44, 64 or fourth parts 66 of the corresponding electrical distribution systems. In other words, the automation 24 is arranged to control the or the electrical organs 22. It may be able to receive information about their status. According to one embodiment of the invention, the automation 24 is connected to the optical transceiver 31 to process the optical signal received and thus determine the presence of a possible cut of the cable 4. It is then able to transmit this information of breaking the cable to the remote control 20. Preferably, the distribution system 2 also comprises at least one sensor 26 connected to at least one protection 28 and the automation 24. The sensor 26 is arranged to detect electrical faults at the level of the or bodies 22, in particular by means of measurements. The protection 28 is in charge of issuing electrical cut-off instructions in the event of detection of such a fault by the sensor 26. In addition, the power supply station 8 here comprises a local optical control panel 30 on which are displayed information relating to the electrical member 22 and / or the cutting of the cable 4. Here, the circuit breakers, switches, transformers and / or other electrical members 22 traversed by the current used to feed the catenary are outside of a closed frame 9 used to house the devices for controlling them. It is possibly the same sensors 26 associated.

In other words, the remote control 20, the automation 24, the protection 28 and the local control panel 30 are located inside the frame 9, in particular at an electronic bay. The same is true of the optical transceiver 31. In a variant, the circuit breakers, switches, transformers and / or other electrical components 22 traversed by the current used to feed the catenary are partially or wholly integrated into the optical transceiver. the closed frame 9, particularly in the case of power stations or substations 1500 V. They can then be separated from devices for their control by a partitioning.

The processing means for determining the presence of the cable cutoff from the detection of a change in the optical signal are integrated, for example, at the optical transceiver 31 and / or the automation 24. The flow chart of FIG. 7 illustrates the operation of the method for detecting a cut in the cable 4.

During a step 104, an optical signal is emitted from the light-emitting diode 32 in the strand 88 of the optical fiber 6. This optical signal is then received, during a step 106, by the photodiode 33 from the strand 90 of the optical fiber. The received optical signal then corresponds to the transmitted optical signal delayed by the propagation time in the optical fiber.

In the event of a break in the cable 4, in step 108, the optical fiber is also cut off. The optical signal received by the photodiode 33 is then strongly degraded, or even lost. This loss of the optical signal triggers, in step 110, a specific alarm signal. The alarm signal is then transmitted, in step 112, from the supply station 8 to the central substation 10 via the information transmission network 18. The agent present at the position of Operator 12 is thus immediately alerted of the occurrence of a cable break and initiates the appropriate repair procedure. Of course, other embodiments are possible.

For example, when the distribution system 2 comprises several supply stations 8 associated with the same central substation 10, each supply station being connected to one or more electric cables provided with optical fibers and cut-off detection devices, the processing means associated with the cables send, in this case, on the network, at the same time as the cut-off information of one or more cables, identification information of the supply station and / or of the cable or cables; damaged.

Claims (17)

REVENDICATIONS1. Assembly of an electric cable (4), an optical fiber (6) associated with this cable (4), and a device for detecting at least one cut of this cable (4), said detection device comprising transmission means (32) and means (33) for receiving an optical signal in the fiber (6), said assembly being configured so that the interruption of the electric cable (4) causes a modification of the optical signal in the fiber (6), said detection device further comprising processing means for determining the presence of the cut-off of the cable (4) from a detection of the modification of the optical signal. 2. The assembly of claim 1, wherein the optical fiber (6) is inserted into the cable (4). 3. An assembly according to claim 1 or 2, wherein the cable (4) comprises an electrically insulating sheath (84) and the optical fiber (6) is inserted into the electrically insulating sheath (84). 4. The assembly of claim 1 or 2, wherein the cable (4) comprises a mechanical protective sheath (86) and the optical fiber (6) is inserted into the mechanical protective sheath (86). 5. The assembly of claim 1 or 2, wherein the cable (4) comprises a core (82) and the optical fiber is inserted into the core (82). An assembly according to any one of the preceding claims, wherein the transmitting means (32) and / or the receiving means (33) of the optical signal are located at a distance from ends of electrical connection points of the cable ( 4). 7. An assembly according to any one of the preceding claims, further comprising means for triggering an alarm when the presence of at least one cut of the cable (4) is determined. 8. An assembly according to any one of the preceding claims, wherein the cable (4) is a power supply cable (48, 50, 52, 54; 68, 70, 72, 74) of a catenary (46) and or a railway signal cable (58, 59; 78). 9. Electrical distribution system (2) current, including rail, 5 comprising an assembly according to any one of the preceding claims. 10.Distribution system according to claim 9, comprising means for transmitting information (20, 24) for cutting the cable to a network (18) 10 connected to a remote monitoring unit (10). 11.Distribution system according to any one of claims 9 or 10, comprising electrical distribution members (22, 40, 42, 44; 60, 62, 64, 66) and control means (24, 26, 28) of said electrical members. 12.Distribution system according to claim 11, the distribution system being configured to transmit monitoring information of electrical components and cable cutoff information (4) to the same network (18) 20 and / or for the means control device and the detection device are powered by the same power source (34). 13.Distribution system according to any one of claims 11 or 12, comprising a feed station (8) in which are arranged the electrical distribution members (22, 40, 42, 44; 60, 62, 64, 66), the control means (24, 26, 28) of said electrical components and said detection device, the electric cable (4) being arranged at least partly outside said supply station (8). 30 14.Distribution system according to claim 13, wherein said station comprises a frame (9) enclosing at least all or part of the control means (24, 26, 28) of the electrical distribution members (22, 40, 42, 44). 60, 62, 64, 66) as well as the transmitting means (32), the receiving means (33) and / or the processing means of the detection device. 35 15.Distribution system according to any one of claims 13 or 14, wherein the processing means are adapted to provide an identification of the cut cable and / or the feed station equipped with said cut cable to the information transmission means ( 20,24). 16.Procedure for detecting at least one break in an electrical cable (4) to which an optical fiber (6) is associated, comprising the steps of: - emitting (104) an optical signal in the fiber (6) by an optical transmitter (32); - receiving (106) said optical signal by an optical receiver (33); and - determining the presence of at least one cut of the cable (4) from a detection of a modification of the optical signal by the receiver (33). 17. The detection method according to claim 16, further comprising the step of identifying the cut cable and / or a feed station equipped with said cut cable.