Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H83/00—Protective switches, e.g. circuit-breaking switches, or protective relays operated by abnormal electrical conditions otherwise than solely by excess current
  • H01H83/10—Protective switches, e.g. circuit-breaking switches, or protective relays operated by abnormal electrical conditions otherwise than solely by excess current operated by excess voltage, e.g. for lightning protection

Definitions

• the present invention relates to the general technical field of devices for protecting electrical equipment or installations against overvoltages, and in particular against transient overvoltages such as those due to lightning.
• the present invention relates in particular to the field of surge arresters, and in particular from low voltage surge arresters.
• the present invention relates more particularly to a device for protecting an electrical installation against overvoltages, in particular transient, comprising on the one hand a housing in which is disposed a protection component against overvoltages which comprises at least two electrodes between which an electric arc is likely to form in the event of an overvoltage, and on the other hand two connection terminals intended to electrically connect the electrodes to said installation.
• the invention also relates to a method of manufacturing a device for protecting an electrical installation against overvoltages, in particular transient, in which on the one hand there is, within a housing, a component for protection against overvoltage which comprises at least two electrodes between which an electric arc is liable to form in the event of overvoltage, and in which, on the other hand, the housing is provided with two connection terminals intended to electrically connect the electrodes to said installation.
• a low voltage protection device of the spark arrester type, using the formation of an electric arc between two electrodes to flow the overvoltage current.
• Such a device is generally in the form of a box containing the electrodes forming a spark gap, said box being intended to be connected to the installation to be protected by means of connection terminals.
• This box is generally associated in series with a body.
• additional disconnection capable of isolating the overvoltage protection device from the electrical installation when said device is traversed by a current of too high intensity.
• overcurrent protection devices are most often used, such as commercial fuses or circuit breakers, which are mounted in series with the arrester.
• the impedance of the conductors must be taken into account for the choice of the disconnector, whereas this impedance is often difficult, if not impossible, to calculate precisely. This failure to take impedance into account can lead to errors and an underestimation of the actual level of protection of the electrical installation.
• the distance between the disconnector and the surge arrester does not, moreover, allow for close monitoring of the operating conditions within the surge arrester.
• the objects assigned to the invention therefore aim to propose a new device for protecting an electrical installation against overvoltages which does not have the drawbacks listed above and which provides an excellent level of protection against overvoltage while being susceptible, in the event of failure, to be disconnected from the electrical installation.
• Another object of the invention is to propose a new device for protecting an electrical installation against overvoltages capable of being disconnected from the electrical installation only (when the end-of-life conditions of the device are effectively met.
• Another object of the invention is to propose a new device for protecting an electrical installation against overvoltages of particularly simple and inexpensive design.
• Another object of the invention is to propose a new device for protecting an electrical installation against overvoltages of compact and inexpensive construction.
• Another object of the invention is to propose a new device for protecting an electrical installation against overvoltages having good disconnection reliability.
• a device for protecting an electrical installation against overvoltages, in particular transient comprising on the one hand a housing in which is placed a component for protection against overvoltage which comprises at least two electrodes between which an electric arc is likely to form in the event of overvoltage, and on the other hand two connection terminals intended to electrically connect the electrodes to said installation, said device being characterized in that it comprises, disposed within the housing and electrically mounted in series with said protective component between the terminals, a circuit breaker sensitive to the intensity of the current flowing through it.
• the objects assigned to the invention are also achieved using a method of manufacturing a device for protecting an electrical installation against overvoltages, in particular transient, in which on the one hand there is, within a housing, a component for protection against overvoltage which comprises at least two electrodes between which an electric arc is likely to form in the event of overvoltage, and in which, on the other hand, the housing is provided with two connection terminals intended to electrically connect the electrodes to said installation, said method being characterized in that it comprises a step of mounting a circuit breaker, in which it is mounted electrically in series with said protection component, between the terminals, within the case, a circuit breaker sensitive to the intensity of the current flowing through it.
• a device for protecting an electrical installation against overvoltages, in particular transient comprising on the one hand a housing in which is disposed a component for protection against overvoltages which comprises at least two electrodes between which an electric arc is likely to form in the event of overvoltage, and on the other hand two connection terminals intended to electrically connect the electrodes to said installation, said device being characterized in that it comprises two conductive pads for electrically connecting each terminal respectively to the corresponding electrode, at least one of said pads comprising a fuse zone forming a circuit breaker.
• a device for protecting an electrical installation against overvoltages, in particular transient in which, on the one hand, has, within a housing, a component for protection against overvoltages which comprises at least two electrodes between which an electric arc is likely to form in the event of overvoltage, and in which, on the other hand, the housing is provided with two connection terminals intended to electrically connect the electrodes to said installation, said method being characterized in that it comprises a step of mounting two conductive pads for electrically connecting each terminal respectively to the corresponding electrode, at least one of said pads comprising a fuse zone forming a circuit breaker.
• FIG. 1 illustrates , in a front view, the interior of the housing of a protection device according to the invention.
• Figure 2 illustrates, according to one. perspective view, the components installed in a housing of a protection device according to the invention.
• FIG. 3 illustrates, in a schematic front view, the protection device of Figures 1 and 2 in its operating position.
• - Figure 4 illustrates, in a schematic view, the protection device of Figure 3 in its disconnected position.
• the invention relates to a device 1 for protecting an electrical installation (not shown) against overvoltages, and in particular against transient overvoltages, such as overvoltages generated by a lightning strike.
• the protective device 1 according to the invention therefore advantageously constitutes a surge arrester, and for example a low voltage surge arrester.
• the overvoltage protection device 1 according to the invention is. advantageously intended to be mounted between a phase of the installation to be protected and the earth. It is however conceivable, without departing from the scope of the invention, that the protection device 1, instead of being connected in bypass between a phase and the earth, be connected between the neutral and the earth, between the phase and neutral, or between two phases (case of differential protection).
• FIG. 1 An exemplary embodiment of a protection device 1 in accordance with the invention is illustrated in FIG. 1.
• the protection device 1 comprises a housing 2 in which is placed a component for protection against overvoltages which itself comprises at least two electrodes , for example a first electrode 3 and a second electrode 4, between which an electric arc is likely to form in the event of an overvoltage, to drain said overvoltage to the ground.
• the first and second electrodes 3, 4 delimit an inter-electrode space 5 forming a spark gap.
• the first and second electrodes 3, 4 thus advantageously form the main electrodes of the spark gap.
• said electrodes 3, 4 between which an electric arc is likely to form are therefore part of the main component of overvoltage protection of the device 1, and preferably form the main component of overvoltage protection of the device 1.
• the device 1 within the meaning of the invention is therefore a device whose operating principle is based on the generation of an electric arc in the event of an overvoltage.
• the device 1 is therefore in particular not a varistor protection device as the main protection component against overvoltages.
• the housing 2 is for example made of a rigid plastic material, and is preferably formed of two half-shells (one of which is shown in FIG. 1) added against one another to delimit an enclosed internal volume intended to accommodate the functional part of the device 1.
• the protection device 1 also comprises two connection terminals 6, 7 intended to electrically connect the electrodes 3, 4 to the electrical installation to be protected. More specifically / the device 1 comprises a first terminal 6 electrically connected to the first electrode 3, as well as a second terminal 7 electrically connected to the second electrode 4.
• the terminals 6, 7 can be present in any form known to those skilled in the art.
• the terminals 6, 7 may be in the form of lugs projecting towards and outside the housing 2, said lugs being intended to be inserted in an electrically connected base. to the installation to be protected.
• the terminals 6, 7 are arranged laterally on either side of the housing 2, and each comprise a housing intended to accommodate a connection cable, said cable being secured to the corresponding terminal 6, 7 by screwing with corresponding screws 6A, 7A.
• a connection cable said cable being secured to the corresponding terminal 6, 7 by screwing with corresponding screws 6A, 7A.
• the electric current moves from the first terminal 6 (or from the second terminal 7) to the first electrode 3 (respectively the second electrode 4), and joins the second electrode 4 (respectively the first electrode 3) in the form of an electric arc, for then circulating to the second terminal 7 (respectively the first terminal 6).
• the device 1 can also be provided, as illustrated in FIG. 1, with trigger electronics 8 connected to a priming electrode 9, in order to optimize control of the formation of the electric arc between the main electrodes 3, 4.
• trigger electronics 8 connected to a priming electrode 9, in order to optimize control of the formation of the electric arc between the main electrodes 3, 4.
• the inter-electrode space 5 is filled, at least partially, with a gas, preferably with air, so as to form a dielectric medium between the electrodes 3, 4, as is well known. of the skilled person.
• the inter-electrode space 5 in this case forms an air spark gap.
• the protection device 1 to implement the technology of the encapsulated spark gaps, according to which the air is replaced by another gas, for example a gas rare maintained under controlled pressure.
• the device 1 comprises, disposed within the housing 2 and electrically mounted in series with the protection component (which includes the electrodes 3, 4) between the terminals 6, 7, a - circuit breaker 10 : - • - :: - ... - • - • . -. ••• . • - ; .-.-.
• the circuit breaker 10 is electrically mounted in series with the electrodes 3, 4, so that when an electrical connection is established between said electrodes 3, 4, the current passing through said electrodes also crosses the cut -circuit 10.
• the circuit breaker 10 is designed to pass from a conductive configuration (represented in FIGS. 1 to 3) in which it is capable of conducting the electric current likely to flow between the terminals 6, 7, to a insulating configuration (illustrated in FIG. 4) in which it breaks the passage of current likely to flow between said terminals 6, 7.
• the circuit breaker 10 is capable, in its conductive configuration, of directly ensuring by itself the passage of the electric current capable of flowing between the terminals 6, 7 when an electric arc is formed between the first and second electrodes 3, 4.
• the circuit breaker 10 thus forms part, when it isin its conductive configuration, of the flow circuit between the terminals 6, 7.
• the circuit breaker 10 is. designed to interrupt the flow of current between terminals 6, 7.
• the circuit breaker 10 is of course preferably able to detect by itself a malfunction of the device 1 and to automatically switch to the insulating configuration when such a malfunction is detected.
• a circuit breaker designates an element which has, under normal operating conditions of the device which it equips, a passing character (electrical conductor) and which becomes insulating (circuit break) when an electrical malfunction of the device it equips occurs.
• the general principle of the invention therefore essentially rests on the integration, directly in the housing 2 of the protection device 1, of a circuit breaker 10 interposed directly in the electrical path extending between the first terminal 6 and the second terminal 7, in series connection with the protection component.
• the installer of the protection device 1 does not have to take any particular step (other than connecting the terminals 6, 7 to the installation) to protect the device 1 in the event of a malfunction.
• circuit breaker 10 is. thus sensitive to heat, so that when the temperature reaches a predetermined value (reflecting abnormal operation) at the circuit breaker 10, the latter switches to an insulating configuration.
• the circuit breaker 10 is sensitive to the intensity of the current flowing through it, so that when said intensity reaches a predetermined value reflecting an abnormal operation, the circuit breaker 10 switches to an insulating configuration.
• the circuit breaker 10 is sensitive to. the intensity of the current flowing through it, that is to say that as soon as this intensity reaches a predetermined value preferably corresponding to a malfunction of the protection component (resulting from a short circuit between the electrodes 3, 4 for example) , the circuit breaker 10 changes from its conductive configuration to its insulating configuration.
• circuit breaker 10 sensitive to the intensity which passes through it turns out to be particularly advantageous from the point of view of the simplicity and the cost of manufacture, while bringing a gain in installation safety in the measurement where the predetermined intensity value controlling the tripping of the circuit breaker 10 (that is to say its passage from its passing configuration to its insulating configuration) is chosen to specifically correspond to the characteristics of the protection component.
• the circuit breaker 10 has a fusible character, that is to say that it comprises fusible means so that when the intensity which passes through these fusible means is greater than a predetermined level, thus generating a heat supply by Joule effect, said fusible means melt, thus creating a final electrical break between the first terminal 6 and the second terminal 7.
• the circuit breaker 10 is thus advantageously designed to form at least one insulating empty space 11 in the circuit connecting the first terminal 6 to the second terminal 7.
• This insulating space 11 has a dimension predetermined preferentially designed, with regard to the other characteristics of the device 1, to avoid any untimely reformation of an electric arc at the level of said empty space 11.
• the device 1 comprises two conductive pads 12, 13 for electrically connecting each terminal 6, 7 respectively to the corresponding electrode 3, 4. At least one (and preferably each) of said areas 12, 13 comprises a fuse zone 12A, 13A forming a circuit breaker 10.
• the circuit breaker 10 is thus formed of two fusible elements interposed respectively in the electrical connection connecting the first terminal 6 to the first electrode 3 and in the electrical connection connecting the second terminal 7 to the second electrode 4. It is obviously conceivable that the circuit breaker 10 is formed of a single fusible element , for example connected in series only between the first terminal 6 and the first electrode 3 (or between the second terminal 7 and the second electrode 4). The symmetrical configuration illustrated in the figures is however preferred.
• said area 12, 13 is formed of a single piece, in one piece, having at least one section of reduced section forming said fusible area 12A, 13A.
• connection between each terminal 6, 7 and the corresponding electrode 3, 4 is provided by a unitary metal strip, for example made of stainless steel, a portion of which is located between terminal 6, 7 and the corresponding electrode 3, 4 has a cross section smaller than the cross section of the rest of the tape.
• the invention also relates as such to a protection device 1 of an electrical installation against overvoltages, in particular transient, comprising on the one hand a housing 2 in which is disposed a component for protection against overvoltages which comprises at least two electrodes 3, 4 between which an electric arc is likely to form in the event of an overvoltage, and on the other hand two connection terminals 6, 7 intended to electrically connect the electrodes 3, 4 to said installation, said device 1 comprising two conductive pads 12, 13 for electrically connecting each terminal 6, 7 respectively to the corresponding electrode 3, 4, at least one of said pads 12, 13 comprising a fuse zone 12A, 13A forming a circuit breaker 10 .
• the device 1 also comprises a breaking chamber 14 of the electric arc capable of forming between the electrodes 3, 4.
• the operation of such a breaking chamber 14 is based on the fractionation of the electric arc produced between the electrodes 3, 4.
• the operation of such a chamber 14 is well known as such, and will therefore not be described further here.
• the electrodes 3, 4 are advantageously arranged so that the electric arc is transferred to and in the breaking chamber 14 under the effect of its own electric field.
• the device 1 according to the invention also comprises at least one isolation spark gap 15, 16 electrically mounted in • series between at least one of the electrodes 3, 4 and the breaking chamber 14.
• the breaking chamber (which can also be called arc extinguishing chamber) 14 is delimited by two end plates 17, 18 between which are interposed a series of elementary fractionation plates 19 spaced apart from one another. others so as to decompose the electric arc forming between the electrodes 3, 4 into a plurality of elementary arcs.
• the device 1 comprises two isolation spark gaps 15, 16 interposed respectively between the. first end plate A1 and the first electrode 3 and the second end plate 18 and the second electrode 4.
• Each isolation spark gap 15, 16 is preferably formed by an empty space (filled with air, or another gas, or a dielectric) separating the end of each electrode 3, 4 from the outer plate 17 , 18 correspondent.
• Said isolation spark gaps 15, 16 preferably have a clean breaking capacity sufficient to ensure, in the event of failure of the arc extinguishing chamber 14, the final extinction of the electric arc during the zero crossing of the current in device 1, preventing re-ignition of the electric arc.
• the combination of an isolation spark gap 15, 16 with a circuit breaker is preferably formed by an empty space (filled with air, or another gas, or a dielectric) separating the end of each electrode 3, 4 from the outer plate 17 , 18 correspondent.
• Said isolation spark gaps 15, 16 preferably have a clean breaking capacity sufficient to ensure, in the event of failure of the arc extinguishing chamber 14, the final extinction of the electric arc during the zero crossing of the current in device 1, preventing re-ignition of the electric arc.
• the overall isolation distance of the arrester 1 after operation of the circuit breaker 10 corresponds to the sum e + c + d + f, the dimensions e and f corresponding respectively the dimensions of the free spaces obtained by melting the fuse zones 12A, 13A forming a circuit breaker 10, while the dimensions ç and d correspond respectively to the dimensions of the free space of the isolation spark gaps 15, 16.
• the distances e and f could be between 0.5 and 3 mm, and preferably between 1 and 2 mm, while ç and d could be between 0.5 and 2 -mm, and -preferences equal to 1 mm: - --- ••
• the isolation spark gaps 15, 16 thus makes it possible, in order to obtain a given isolation distance, to reduce the size of the fuse zones 12A, 13A (which contributes to making the device 1 more reliable), compared with a device 1 which would not include an isolation spark gap 15, 16.
• the isolation spark gaps 15, 16 would be short-circuited due to a malfunction of the device 1, or in the absence of such spark gaps 15 , 16, the overall isolation distance obtained after tripping of the circuit breaker 10 would be equal to the sum e + f + a + b to which is added the sum of the interstitial spaces separating each plate from the series of plates 19, the distances a and b corresponding respectively to the distances separating the external plates 17, 18 from the series 19 of elementary plates.
• the invention therefore makes it possible to provide a particularly reliable electrical isolation function of the device 1, in a particularly simple, compact and inexpensive manner.
• a mechanical or electrical display system can be. integrated into the housing 2, said display system (not shown) being functionally connected to the circuit breaker 10 so as to indicate to the user the state of the surge arrester 1, to decide whether or not to replace the latter.
• the invention also relates to a method of manufacturing a device 1 for protecting an electrical installation against overvoltages, in particular transient, such as that which has just been described.
• a component for protection against overvoltages which itself comprises at least two electrodes 3, 4 between which an electric arc is likely to form in overvoltage, to drain the overvoltage current.
• the housing 2 is provided with two connection terminals 6, 7 intended to electrically connect the electrodes 3, 4 to the installation to be protected.
• the method according to the invention also includes a step of mounting a circuit breaker 10, in which one electrically mounts in series with the protection component, between the terminals 6, 7, within the housing 2, a circuit breaker circuit 10 sensitive to the intensity of the current flowing through it.
• the circuit breaker 10 is capable of passing from a conductive configuration in which it is capable of conducting the electric current capable of flowing between the terminals 6, 7, to an insulating configuration in which it breaks the passage of the current likely to flow between said terminals 6, 7.
• the circuit breaker 10 changes from its conductive configuration to its insulating configuration when the intensity of the current which flows through said circuit breaker 10 (but which also passes through the electrodes 3, 4 ) reaches a predetermined value corresponding to a malfunction of the device 1, and more particularly of the protection component.
• the invention also relates as such to a method of manufacturing a device 1 for protecting an electrical installation against overvoltages, in particular transient, in which on the one hand there is, within a housing, a component for protection against overvoltages which comprises at least two electrodes 3, 4 between which an electric arc is likely to form in the event of overvoltage, and in which, on the other hand, the housing 2 is provided with two connection terminals 6, 7 intended to electrically connect the electrodes 3, 4 to said installation, said method comprising a step of mounting two conductive pads 12, 13 to electrically connect each terminal 6, 7 respectively to the corresponding electrode 3, 4, at least the one of said areas 12, 13 comprising a fuse zone 12A, 13A forming a circuit breaker 10.
• the invention finds its industrial application in the design, manufacture and use of devices for protecting electrical equipment or installations against overvoltages.

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• 2005
  • 2005-12-05 FR FR0512313A patent/FR2894383B1/fr not_active Expired - Fee Related
• 2006
  • 2006-12-05 WO PCT/FR2006/002652 patent/WO2007065997A1/fr active Application Filing
  • 2006-12-05 ES ES06841860T patent/ES2396726T3/es active Active
  • 2006-12-05 EP EP06841860A patent/EP1961087B1/de active Active

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