Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
  • H01H9/50—Means for detecting the presence of an arc or discharge

Definitions

• the invention relates to an arrangement for monitoring electrical devices for the occurrence of arcing faults. It is used to detect an arc that may occur during the operation of an electrical device, with the aim of being able to derive a warning signal or a control signal suitable for interrupting an affected circuit from the detected signal.
• arcing can occur, in particular, on lines, cables and / or plug-in devices or contact points via which devices, assemblies or circuit parts are connected to one another. Arcs often occur during switching operations. The arcs can follow the course of the circuit in series within a circuit and / or also, so to speak in parallel, between adjacent circuits. Arcing and breakdowns between or on electrical conductors and metallic housing parts are also possible. Causes of arcing are, for example, chafing or crimping points on the conductors, as well as crushing or cable breaks. Arcing can also occur due to vibrations during operation of the equipment or damage to insulation. Last but not least, improper laying of the ladder can be the cause. Arcs cause faults in neighboring electrical devices and equipment, but can also be the cause for the destruction of affected circuit parts or fires, which can result in severe property damage or even endanger people.
• EP 0 575 932 A1 discloses a device for detecting arcing faults, in which the magnetic field caused by an arcing is detected by means of a Hall element and, in the event of an arc being detected, a switching device for interrupting the circuit concerned is controlled.
• the detection of an arc is additionally provided by detection of the light emanating from it. It is proposed to monitor a plurality of busbars which are guided in parallel, to lay them around an optical waveguide in a loop and to guide the light which is radially entered from the outside in the event of an arc and is therefore subjected to a not inconsiderable attenuation to an optical receiver.
• this solution can only be used to selectively detect arcs selectively at and in the vicinity of individual, possibly particularly vulnerable positions.
• JP 06222097 A discloses an optically based solution for the detection of arcs.
• an optical waveguide arranged in parallel along lines or cables to be monitored. Light is transmitted between a light-emitting transmitter and an optical receiver via the optical waveguide.
• the optical waveguide should melt as a result of the high temperature that occurs, so that the interruption in the connection between the light transmitter and the receiver that then occurs can be evaluated at the latter.
• the disadvantage here is that in individual cases the optical waveguide may not be interrupted in the event of an arc.
• the solution shown in DE 295 13 343 U1 which is also based on the use of an optical waveguide, does not need a light-emitting transmitter, unlike the solution shown above.
• the light coupled into the optical waveguide in the event of an arc is evaluated directly.
• one or more optical waveguides are routed helically around a line or a cable to be monitored.
• a larger number of optical waveguides is preferably required, which are to be arranged in sufficiently narrow coils around the electrical conductor.
• the object of the invention is to reliably detect the occurrence of an arc in electrical devices, namely on their lines, cables and / or contact points.
• comprehensive, spatially all-round monitoring, based on the monitored component is to be guaranteed, the result of which, if an arc occurs, suitable measures can be derived.
• the object is achieved by an arrangement with the features of the main claim.
• Advantageous training and further education are given by the subclaims.
• the proposed arrangement for monitoring electrical devices for the occurrence of arcing faults consists of at least one electrical conductor designed as a single or multi-core line or as a cable, which connects devices, assemblies or circuit parts of the electrical device to one another, from means which are used in the formation of a Lead the arcing light to an optical / electrical converter and a monitoring and evaluation unit that is electrically connected to the converter.
• the means which guide the light emitted by a possible arc to the optical / electrical converter are at least one optical waveguide.
• the optical waveguide envelops one or more cores of the aforementioned electrical conductor and at the same time forms the electrical insulation of a line or the sheath of a cable.
• the optical waveguide is a direct component of a monitored electrical conductor and is also used for its electrical insulation.
• a combination conductor is also referred to below in connection with the invention.
• possible materials suitable for this purpose which are preferably transparent plastics, which on the one hand have good optical properties and on the other hand can be used as flexible electrical insulators.
• the entire electrical conductor is encased by the optical waveguide, i.e. it is almost completely surrounded by the optical waveguide and is not only monitored for arcs in sections, there is the advantage that the encasing of the conductor with the optical waveguide - and thus its electrical insulation - Can be carried out in a known manner in an extrusion process during manufacture.
• the electrical conductor encased by the optical waveguide is a line or a cable for connecting components of an electrical device monitored in the manner described.
• requirements should be understood to mean an electrical device, for example a group of electrical devices connected via corresponding lines or cables sheathed with an optical waveguide, a single electrical device or a special assembly of a device.
• the arrangement responds to an arc which emanates from the electrical conductor itself, which is enveloped by the optical waveguide.
• the light from the arc is coupled in radially from the outside, but directly inside the optical waveguide, in a manner different from that known from the prior art.
• the arrangement can also be designed in such a way that it responds to an arc which arises at a contact point of the electrical conductor designed as a clamp or plug connection with other units of the electrical device.
• the optical waveguide enveloping the electrical conductor is introduced into the contact point.
• the light emanating from the arc is coupled axially into the end face of the optical waveguide.
• the arrangement according to the invention preferably has However, voltage via means for interrupting the current through the circuit parts of the electrical device affected by an arc, said means being actuated or activated by the monitoring and evaluation unit in the event of an arc being detected.
• the means for interrupting an affected circuit can be, for example, relays or semiconductor switches or power semiconductors.
• the invention also includes an arrangement in which the optical waveguide enveloping the electrical conductor, preferably to suppress the influence of extraneous light and / or to increase the dielectric strength, is encased by an additional electrically insulating and opaque jacket.
• the additional outer jacket optically reflective on its inside facing the optical waveguide or to mirror it. This can be done by placing a light reflecting film on the inside.
• An additional measure to suppress the influence of extraneous light is to couple the light into the optical / electrical converter via a corresponding wavelength of the light (daylight and / or room lighting) or only for wavelengths that are typical for arcs.
• the filter can be arranged on the converter or be an integral part of it.
• the electrical conductor enveloped by the optical waveguide can be designed differently.
• a twisted two-wire line can also be used to protect against electromagnetic interference.
• a shielded line can also be surrounded by a jacket designed as an optical waveguide. If the electrical line is a stranded wire, since such an electrical conductor has a comparatively uneven surface, it has proven to be advantageous to apply a preferably, but not necessarily, light-reflecting compensation layer thereon in order to obtain a flat surface, which then surround with the optical fiber This can be done, for example, by a hose method, that is to say by covering the electrical conductor with a hose that forms a corresponding layer.
• a line designed according to the invention or the combination conductor can be a line which can be cut in length in accordance with the application and which, if appropriate, is also only to be coupled to the optical / electrical converter when it is installed.
• the combination conductor is a pre-assembled line, which is then preferably already connected to the converter.
• the converter is advantageously designed with regard to its construction so that it can be coupled as easily as possible by a user, for example a device manufacturer, to the optical waveguide used for monitoring.
• the optical waveguide which, according to the basic idea of the invention, also functions as an insulator or jacket, can be made of a polymer, for example.
• Polymethyl methacrylate (PMMA) and its modifications (e.g. cross-linked and fluoridated), polymethylpentene (PMP), optionally in combination with its copolymers, or polycarbonate (PC) have proven to be suitable materials.
• polycarbonate is characterized by high flexibility and particularly good temperature resistance. In addition, it is impact-resistant and, in the event of an arc caused by flame formation, self-extinguishing.
• Polymethylpentene also has good flexibility and is also suitable for use at high temperatures. It is also very good electrical insulation. All of the aforementioned polymers are characterized by a good transparency, i.e. a high degree of transmission. Silicone elastomers or fluoridated polymers are also suitable as materials for the optical waveguide.
• the optical / electrical converter is designed in accordance with an envisaged embodiment of the invention in the form of a cap that can be plugged onto an axial end of the optical waveguide, or a disc that can be pushed on, the cap or disc optionally being fitted onto the electrical conductor is penetrated.
• an embodiment which can be screwed onto an axial end of the optical waveguide is also conceivable, a ferule possibly being provided for this purpose on the optical waveguide.
• embodiments of the arrangement according to the invention are also possible in which a plurality of optical fibers are routed to an optical / electrical converter.
• the optical / electrical converter is a CCD line, a CCD matrix or a CMOS array.
• the combination of electrical conductor and optical fiber is a pre-assembled cable of fixed length, in which only one axial end of the optical fiber is provided for connection to an optical / electrical converter, while the other end (but not the end of the Optical fiber-coated electrical conductor) remains open after installation in the device to be monitored, the free end is mirrored, according to an advantageous development. This ensures that, for example, the light that arises in the vicinity of this end does not leave the optical waveguide, but is reliably received by the converter and is therefore available for evaluation. If necessary, a mirroring can be realized with a line that can be cut to length, also by closing the open end with a reflective cap.
• the latter variant opens up the possibility of integrating an optical transmitter into such a cap, by means of which a self-test of the arrangement can be carried out by the monitoring and evaluation unit when the monitored electrical device is switched on or in a time-controlled manner. In evaluating a light pulse emitted by the optical transmitter, it can be checked whether the optical waveguide is interrupted or damaged.
• light amplifiers are arranged in sections in optical waveguides with a long cable length, such as are required for monitoring electrical connections in ships.
• the invention is also intended to expressly include such arrangements in which the optical waveguide enveloping the electrical conductor serves both for coupling in the light of any arcing and for transmitting other useful signals within the monitored electrical device.
• measures that are familiar to the person skilled in the art for separating or differentiating a transmitted useful signal from the light of an arc must be taken, that is to say providing light switches or filters, if necessary, or modulate the useful signal in a suitable manner for this.
• Both a light-emitting component when the optical waveguide is used for useful signals and the optical / electrical converter can be designed such that they are coupled to the waveguide from the outside by means of slot / clamp technology for coupling and decoupling light , They are pressed into the waveguide by a claw-like design with protruding optically active elements. If necessary, both the optical coupling with the optical waveguide and the contacting of the electrical conductor are carried out using the slot / clamp technology.
• the distinction between light signals caused by arcing faults and optical useful signals can be made by means of reference curves stored in the monitoring and evaluation unit. Reference curves for different types of arcing faults are preferably stored in the corresponding unit.
• the signal transmission between the optical / electrical converter and the monitoring and evaluation unit can of course also take place via an electrical conductor encased by an optical waveguide, the optical waveguide optionally also being used for the transmission of useful signals, following the previous consideration.
• the signal transmission between the converter and the monitoring and evaluation unit using the so-called “power line technology”, in which the signal transmission takes place via energy supply lines of the monitored device.
• Fig. 1 A basic embodiment of the invention with a line that can be cut to length.
• Fig. 2 The invention shown in Fig. 1 using a pre-assembled line of fixed length.
• Fig. 3 An embodiment of the arrangement according to the invention for monitoring the inside of a plug device.
• Fig. 4 A training form with an attachable optical / electrical converter.
• the arrangement comprises an optical waveguide 2, an optical / electrical converter 3 and a monitoring and evaluation unit 4 for evaluating the signals of the above-mentioned converter 3.
• Another direct component of the arrangement is an electrical conductor 1, which does not show circuit parts, assemblies or devices connects an electrical device and, according to the basic idea of the invention, is encased by the optical waveguide 2 over almost its entire length.
• the electrical conductor 1 forms a non-optical core of the optical waveguide 2.
• there is an electrical line which can be cut to length and which monitors arcs by means of the other arrangement parts and whose insulation is formed by the optical waveguide 2.
• the resulting light is coupled into the optical waveguide 2 directly inside the optical waveguide 2.
• the light is fed through the optical waveguide 2 to the optical / electrical converter 3, the signals of which are processed by the monitoring and evaluation unit 4.
• the evaluation and monitoring unit 4 it can activate a warning signal in the event of an arc or activate a circuit unit comprising a suitable switching element, which interrupts the circuit section affected by the arc.
• the elements and circuit units required for suitable evaluation of the detector signal are known to the person skilled in the art and are not intended to be the subject of further explanations here.
• a line circuit affected by an arc can be switched off, for example, by means of a correspondingly controlled relay.
• optical / electrical converter 3 has a corresponding surface, it is also possible, deviating from the illustration given by FIG. 1, that several optical waveguides 2, each serving as a jacket of electrical conductors, are guided thereon. In the case of complicated constellations, the use of a CCD line or matrix for the optical / electrical converter 3 is also conceivable.
• FIG. 2 shows a slightly modified variant of the arrangement according to FIG. 1.
• the line formed by the electrical conductor 1 and the optical waveguide 2 enveloping it is a prefabricated line with fixed length.
• its ends are guided radially out of the optical waveguide 2 used for monitoring. It is to be regarded as particularly advantageous that such an electrical conductor 1 provided with an optical waveguide 2, irrespective of whether it is variable or fixed in terms of its length, during production in a single extrusion step simultaneously with an electrical insulation and that with it later monitoring serving optical fiber 2 can be sheathed.
• optical / electrical converter 3 may be expedient to provide an additional opaque sheath 7 for a combination conductor designed in this way for reasons of stability or to reduce the influence of extraneous light. Additional measures or special training of the optical / electrical converter 3 may be required for further adaptation. For example, it may be necessary or expedient to couple the optical / electrical converter 3 to corresponding filter elements in order to suppress the influence of the ambient light. A further measure relating to the line consists in the possible mirroring of a possibly free axial end of the optical waveguide 2. This can be done with a view to a reliable evaluation of the arc entered into the optical waveguide 2 Light be advantageous. Finally, with longer cable lengths, for example in shipbuilding, the interposition of light amplifiers in the optical waveguide 2 may be necessary.
• FIG. 3 shows that the line constructed in the manner described, consisting of electrical conductor 1 and optical waveguide 2, following the basic idea of the invention, can also be used for monitoring contact points, such as the inside of plug connections 5.
• the line including the optical waveguide 2 surrounding it, is led directly into the corresponding contact point to be monitored.
• the light emanating from a possible arc is coupled axially via the end face 6 of the optical waveguide 2 and fed to the optical / electrical converter 3.
• the other mode of operation is the same as already described for FIG. 1.
• the optical / electrical converter 3 may also be a complete device, preferably of small dimensions, in its housing the combination conductor according to the invention is introduced for the detection of any arcing faults and is connected there, for example via a clamp connection or a similar connection to the device.
• the optical / electrical converter 3 can also be designed in different ways. According to an advantageous embodiment represented by FIG. 4, the converter 3 can be designed as a cap that can be plugged onto the optical waveguide 2. In the example shown, the cap-shaped converter 3 is penetrated by the electrical conductor 1.
• the line consisting of the electrical conductor 1 and the optical waveguide 2 is encased in the example by an additional insulating and opaque jacket 7.
• an application for detecting wire breaks or indicative wire breaks of electrical control and supply lines that are in motion - for example in automobile construction or in robot technology - is also particularly suitable. Their use is also conceivable in connection with the use of fuel cell technology in hybrid vehicles. Likewise, use in photovoltaic systems in which a possible arcing would burn due to their current source characteristics, possibly until darkness or until the onset of night, makes sense.

Landscapes

• Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
• Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
• Testing Relating To Insulation (AREA)
• Measurement And Recording Of Electrical Phenomena And Electrical Characteristics Of The Living Body (AREA)
• Analogue/Digital Conversion (AREA)
• Remote Monitoring And Control Of Power-Distribution Networks (AREA)
• Led Devices (AREA)
• Cable Accessories (AREA)
• Led Device Packages (AREA)

Applications Claiming Priority (2)

Publications (2)

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Family Cites Families (24)

• 2003
  • 2003-09-09 DE DE10342370A patent/DE10342370B3/de not_active Expired - Fee Related
• 2004
  • 2004-09-09 AT AT04765342T patent/ATE448558T1/de active
  • 2004-09-09 US US10/571,181 patent/US7767957B2/en active Active
  • 2004-09-09 EP EP04765342A patent/EP1665307B1/fr not_active Expired - Lifetime
  • 2004-09-09 DE DE502004010362T patent/DE502004010362D1/de not_active Expired - Lifetime
  • 2004-09-09 WO PCT/EP2004/010449 patent/WO2005027160A2/fr not_active Ceased
  • 2004-09-09 JP JP2006525133A patent/JP4907346B2/ja not_active Expired - Fee Related
  • 2004-09-09 DK DK04765342.3T patent/DK1665307T3/da active

Non-Patent Citations (1)

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