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
  • H01H9/30—Means for extinguishing or preventing arc between current-carrying parts
  • H01H9/34—Stationary parts for restricting or subdividing the arc, e.g. barrier plate
  • H01H9/36—Metal parts
• • 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
  • H01H9/30—Means for extinguishing or preventing arc between current-carrying parts
  • H01H9/46—Means for extinguishing or preventing arc between current-carrying parts using arcing horns

Definitions

• the present invention relates to the general technical field of apparatus for protecting equipment or electrical installations against electrical disturbances, such as short circuits or transient overvoltages due to a lightning strike.
• the present invention more particularly relates to an apparatus for protecting an electrical installation against electrical disturbances, comprising a housing in which are mounted:
• arc generation means formed by two conductive parts between which an electric arc is caused to form when an electrical disturbance of sufficient intensity occurs
• an arc extinguishing chamber comprising a series of fractionation plates spaced apart from each other so as to decompose the electric arc into a plurality of elementary arcs.
• protection devices such as circuit-breakers or arresters are commonly used. These devices have the particular function of protecting the electrical installation, for example by insulating it, so that it is not damaged by the electrical disturbance.
• these protection devices In a manner known per se, these protection devices generally comprise an arc extinguishing chamber (or interrupting chamber) designed to ensure the extinction of an electric arc that may form within the device.
• spark gap arresters that is to say using, as an active protective element, a device comprising two electrodes placed facing each other separated by an insulating zone, formed for example by a blade of In the air, the surge current is evacuated via an electric arc formed between the electrodes when the overvoltage exceeds a threshold value.
• the arc extinction chamber makes it possible to cut off the short circuit current discharged by the network, called the follow-on current, that can be maintained after the discharge of the overvoltage current.
• the formation of the electric arc generally occurs at the moment of opening of the circuit breaker contacts, the electric arc being generated between said contacts.
• the arc extinction chamber makes it possible to extinguish the electric arc thus formed, and to ensure the definitive breaking of the short-circuit current.
• Known arc extinguishing chambers are often formed by a series of splitter plates, spaced apart from each other with a small insulating gap so as to decompose the electric arc into a plurality of elementary arcs, thereby increasing the voltage arc. The final extinction of the electric arc is then obtained when the arc voltage exceeds, in absolute value, the mains voltage.
• the splitter plates are usually very close together and spaced apart by only a few millimeters in order to obtain efficient and fast extinction of the electric arc. For example, it is common to use, for an ac power supply network with a voltage of 230 Volts, an arc quench chamber having about twelve splitter plates. .
• appliances with an arc extinguishing chamber of this type generally give satisfaction.
• abnormal operating conditions can cause damage to the arc extinguishing chamber, especially when the arc extinguishing chamber is applied repeatedly over a short period of time. It is thus possible to observe a deformation of the fractionation plates, under the combined effect of magnetic phenomena and of heating produced by a repetitive or prolonged operation. By deforming, the splitter plates can then approach each other and cause a short circuit in the arc extinguishing chamber. This short circuit, initially local, often propagates very quickly to the entire arc extinguishing chamber, thus causing the complete short circuit of the latter.
• This phenomenon of short-circuiting the extinguishing chamber is also largely favored by the projection on the chamber, under the effect of the displacement of the arc, of hot gases possibly contaminated with metal particles.
• Such projections contribute to deteriorate the splitter plates and may cause, by themselves, short-circuit some or all of the splitter plates.
• the arc extinguishing chamber is then no longer able to effectively interrupt the short circuit current, leading to rapid destruction of the apparatus.
• Failure of the interrupting chamber may also occur when the device is used to protect an electrical installation whose short-circuit current is greater than the maximum current that can be interrupted by the device. This can happen in particular when an error occurs produced in the choice of the device, the latter having insufficient breaking capacity to interrupt the short-circuit current.
• the objects assigned to the invention therefore aim to remedy the various disadvantages listed above and to propose a new protective device for an electrical installation having an improved short circuit breaking capacity.
• Another object of the invention is to provide a new protective device for ensuring the breaking of the short-circuit current, even in case of failure of the arc extinguishing chamber.
• Another object of the invention is to provide a new protective device for slowing the aging of the arc extinction chamber.
• Another object of the invention is to provide a new protective device that is particularly simple to manufacture, and whose structure is robust and compact.
• Another object of the invention is to provide a new protective device with a small footprint.
• Another object of the invention is to provide a new protective device whose arc extinction chamber can, in case of failure, be quickly and permanently isolated from the electrical installation.
• Another object of the invention is to provide a new protective device likely, at the end of life, to be permanently disconnected from the electrical installation.
• the objects assigned to the invention are achieved by means of a device for protecting an electrical installation against electrical disturbances, comprising a housing in which are mounted:
• arc generation means formed by two conductive parts between which an electric arc is caused to form when an electrical disturbance of sufficient intensity occurs
• an arc extinction chamber comprising a series of fractionation plates spaced from each other so as to decompose the electric arc into a plurality of elementary arcs, characterized in that it comprises at least one spark gap; insulation electrically connected in series with the arc extinguishing chamber and having a clean breaking capacity sufficient to ensure, in case of failure of the arc extinction chamber, the definitive extinction of the electric arc when Zeroing of the current in the device by preventing the rebooting of the electric arc.
• a device for protecting an electrical installation against electrical disturbances comprising a housing in which are mounted:
• - Arc generation means formed by two conductive parts defining an angular opening and between which an electric arc is caused to form when an electrical disturbance of sufficient intensity occurs
• an arc extinction chamber comprising a series of fractionation plates spaced from each other so as to decompose the electric arc into a plurality of elementary arcs, characterized in that it comprises at least one spark gap; insulation electrically connected in series with the arc extinguishing chamber, said isolation gap being disposed substantially outside said angular opening.
• FIG. 1 illustrates, in a schematic front view, a protection apparatus according to the invention, the spark gap arrester type.
• Figure 2 is a simplified version of Figure 1, to illustrate more precisely the angular aperture defined by the conductive parts.
• FIG. 3 illustrates, in a schematic front view, an improved version of the protection apparatus shown in Figures 1 and 2, forming a second embodiment of the invention.
• Figure 4 is a simplified version of Figure 3, to illustrate more precisely the angular aperture defined by the conductive parts.
• FIG. 5 illustrates, in a schematic front view, a protection device according to a third embodiment of the invention, spark gap arrester type, in a functional configuration of connection to the electrical installation.
• FIG. 6 illustrates, in a schematic front view, the protection apparatus shown in Figure 5 in a disconnected configuration, wherein it is isolated from the electrical installation.
• the protection apparatus 1 according to the invention is illustrated in FIGS. 1 to 6.
• the apparatus 1 may advantageously consist of an overvoltage protection device, such as a spark gap arrester, as illustrated in FIGS. 1 to 6, or it may consist of a short-circuit protection device of the breaker type. (not shown in the figures). In the remainder of the description, it is considered that the protection apparatus 1 is formed by a spark gap-type overvoltage protection device, mounted in parallel (or in parallel) with an electrical installation (not shown) with a view to protect her.
• an overvoltage protection device such as a spark gap arrester, as illustrated in FIGS. 1 to 6, or it may consist of a short-circuit protection device of the breaker type. (not shown in the figures).
• the protection apparatus 1 is formed by a spark gap-type overvoltage protection device, mounted in parallel (or in parallel) with an electrical installation (not shown) with a view to protect her.
• the invention applies equally to the case of short-circuit protection devices, such as circuit breakers, mounted for example in series with the electrical installation.
• electrical installation refers to any type of equipment or network that can be powered by an electric current.
• the protection apparatus 1 when it is constituted by a spark gap arrester, is advantageously intended to be disposed between a phase of the electrical installation to be protected and earth. It is also conceivable, without departing from the scope of the invention, that the protection device 1, instead of being connected bypass between a phase and the earth, is connected between the neutral and the earth, between a phase and the neutral, or between two phases (case of a differential protection).
• the device 1 of protection according to the invention is advantageously provided with terminals 2, 3 for its connection to the electrical installation.
• terminals designates both the poles of the apparatus 1 and the connection means of the apparatus 1 to the installation electric.
• the connection means can thus be formed, in the case of a plug-in device, by connection pads.
• the electrical installation is advantageously supplied with current and voltage by a generator, and for example an alternating voltage generator, so that the apparatus 1 is traversed, in the conducting state, by the current coming from the generator or a generator. derived current.
• the apparatus 1 comprises a housing 4, forming the external envelope of the apparatus, of electrically insulating material, that is to say non-electrically conductive.
• the apparatus 1 further comprises, mounted within the housing 4, arc generating means 5 formed by two conductive parts 6, 7 between which an electric arc 8 is caused to form when an electrical disturbance sufficient intensity, that is, above a certain threshold, occurs.
• electrical disturbance here refers to all types of disturbances, such as transient overvoltages due to lightning (where the device 1 constitutes a surge arrester) or short-circuit currents (in which case the device 1 constitutes a circuit breaker).
• the term “electrical disturbance of sufficient intensity” refers, in the case where the apparatus 1 constitutes a spark gap-type overvoltage protection apparatus, to the minimum overvoltage necessary to ensure priming (or tripping) 8. In the case where the apparatus 1 is formed by a short-circuit protection device, this expression refers to the minimum current of the short-circuit current. may trigger the opening of the contacts of the device, which is responsible for the formation of the electric arc.
• the apparatus 1 further comprises, mounted within the housing 4, an arc extinguishing chamber 9, designed to extinguish of the electric arc 8.
• Said arc extinguishing chamber 9 is delimited by end plates 10, 11, in particular a first and a second end plate 10, 11, and comprises a series of splitter plates 12, disposed between the end plates 10, 11.
• the series of splitter plates 12 extends between the first and the second end plate 10, 11.
• the splitter plates 12 are spaced apart from each other so as to decompose the electric arc 8 into a plurality of elementary arcs 13.
• the arc extinguishing chamber 9 thus subdivides the electric arc 8 into elementary arcs 13 each having a voltage of foot, the foot voltages of the elementary arcs adding up to increase the arc voltage in the arc extinction chamber 9.
• the electric arc 8 cut into elementary arcs 13, turns off automatically.
• the fractionation plates 12 are advantageously kept motionless relative to each other, within the arc extinguishing chamber 9, by an insulating blade 18 which also ensures a regular spacing between them. More precisely, the fractionation plates 12 are preferably separated from each other by insulating gaps 14 of substantially identical width.
• the arc extinguishing chamber 9 then defines a volume filled with a gas and preferably with air, this gas filling the insulating gaps 14. It is however conceivable, without departing from the scope of the invention, that the Insulating gaps 14 have different widths.
• the electric arc 8 is then transferred in the transfer direction F illustrated in FIGS. 1, 3 and 5 to the arc extinguishing chamber 9, under the action of FIG. his own field electric.
• the arc generating means 5 are preferably arranged in a divergent shape, at V, the arc originating towards the base of the V. Such a measurement technique is well known in the field.
• This transfer of the electric arc 8 is accompanied, as is also well known per se, a flow of hot gas and various residues may include including incandescent particles.
• this stream 200 is channeled by the arc generating means 5, and more particularly by the conductive parts 6, 7, which define an angular aperture 100 delimited by the dashed lines 100A, substantially corresponding to the gas trajectory zone.
• the conductive parts 6, 7 advantageously form a nozzle ejecting to the chamber 9 various gases and residues along a channelized path substantially contained in the angular opening 100.
• the apparatus 1 comprises, mounted within the housing 4, at least one isolation gap 15 electrically connected in series with the arc extinguishing chamber 9 and having a breaking capacity. sufficient to ensure, in case of failure of the arc extinguishing chamber 9, the definitive extinction of the electric arc 8 during the zero crossing of the current in the device 1 by preventing the reboot of the arc 8.
• isolation refers here to an isolation of an electrical nature.
• the short-circuit current likely to flow through the apparatus 1 after the formation of the electric arc 8 comes from the network or the voltage generator associated with the electrical installation.
• the short-circuit current is alternative, it necessarily goes from zero to every half period, thus allowing the rapid and definitive extinction of the electric arc 8 thanks to the intrinsic breaking power of the isolation spark gap 15.
• the isolation spark gap 15 has an insulation resistance and a sufficient regeneration capacity to prevent the electric arc from being re-ignited as soon as the current goes to zero.
• regenerative capacity refers to the ability of the ionizable insulating space to regenerate dielectrically to withstand the voltage of the generator (or network) and prevent rebooting of the electric arc 8.
• insulation resistance here means the resistance measured, under specified conditions, between the electrodes 16, 17.
• failure here means damage to the arc extinguishing chamber 9 leading to the formation of a short -circuit inside the latter, the short-circuit may be local but most often global, causing complete short-circuiting of the arc extinguishing chamber 9. Such damage may for example be due to at least in part to the gaseous and solid material projections mentioned above.
• the spark gap 15 simply contributes to improving the overall breaking power of the device 1, without necessarily necessarily presenting (but only optionally) the function described in the foregoing, namely: presenting a power of clean cut sufficient to ensure, in case of failure of the arc extinguishing chamber 9, the definitive extinction of the electric arc 8 during the zero crossing of the current in the device 1 by preventing the rebooting of the bow 8.
• the isolation gap 15, which is as previously electrically connected in series with the arc extinguishing chamber 9, is disposed substantially outside the angular opening 100 defined by the In other words, the spark gap 15 is positioned outside the fluid path lines defined by the conductive parts 6, 7, trajectory lines which extend inside the zone delimited by the dashed lines 100A in FIGS. 2 and 4. Thanks to this technical measure, the spark gap 15 is not subjected directly, with full force, to the flow 200 and to its deteriorating effects, unlike the chamber 9. Thus, the probability of damage to the spark gap 15 is less than that relative to the chamber 9, which allows the spark gap 15 to play its protective role reliably.
• the isolation spark gap 15 is capable of occupying an ionized state, in which it ensures, in association with the series of fractionation plates 12, the decomposition of the electric arc 8 into the sum of a main arc 8 ', formed within the isolation spark gap 15, and several elementary arcs 13 formed in the arc extinguishing chamber 9.
• the main arc 8 ' is maintained within the isolation spark gap 15 until the current zero in the device 1. Once the zero current reaches, the main arc 8 'turns off and does not reboot, thus permitting the final breaking of the short circuit current in the device 1 protection.
• This arrangement thus makes it possible to guarantee the complete extinction of the short-circuit current even in the event of failure of the arc extinguishing chamber 9.
• the isolation spark gap 15 has a sufficient insulation resistance for prevent the transfer of the electric arc 8 in the arc extinguishing chamber 9 when the energy of the electric arc 8 is less than a predetermined threshold value.
• the electric arc 8 is held between the conductive parts 6, 7 and is not transferred to the chamber of arc extinguishing 9 which is then electrically isolated arc generation means 5 and the electrical installation.
• the isolation spark gap 15 thus makes it possible to avoid soliciting the arc extinction chamber 9 for small short-circuit currents (or currents in succession), thus limiting its aging.
• the triggering threshold value of the isolation spark gap 15 will thus preferably be calculated as a function of the level of protection offered by the device 1. In particular, it will be possible to adjust the isolation distance d between the electrodes 16, 17 of the Isolation gap 15.
• the term "isolation distance" refers here to the minimum distance separating the electrodes 16, 17 constituting the shortest path for the main arc 8 '.
• the isolation distance d between the electrodes 16, 17 is sufficient to prevent, in case of failure of the arc extinguishing chamber 9, the damage and the short-circuiting of the
• the isolation spark gap 15 is thus advantageously designed and dimensioned so that any short circuit formed within the arc extinguishing chamber 9 can not propagate and gain the advantage of Isolation gap 15.
• the isolation spark gap 15 is preferably arranged and designed so that the possible deformation of the fractionation plates 12 under the effect of their heating or magnetic phenomena, is without consequences on the operation of the isolation spark gap 15. Even more preferably, the isolation distance d between the two electrodes 16, 17 of the isolation spark gap 15 is greater than the average distance between the splitter plates 12, that is to say at the average value of the width of the insulating intervals 14.
• the isolation spark gap 15 thus assumes a dual function, namely:
• a protection function for the arc extinguishing chamber 9 in order to prevent the latter from being biased for small short-circuit currents, thus contributing to slowing the aging of the arc extinction chamber 9 .
• the isolation spark gap 15 is connected in series between the arc generation means 5 and the arc extinction chamber 9, and more precisely between one of the conductive parts 6 and the arc extinguishing chamber 9.
• the isolation spark gap 15 extends between one of the end plates 10, 11 of the arc extinguishing chamber 9, hereinafter referred to as the first end plate 10, and the corresponding conductive part 6 closest to the first end plate 10, hereinafter called the first conductive part 6.
• a first electrode 16 of the isolation spark gap 15 is situated at substantially the same potential as the first end plate 10
• a second electrode 17 of the isolation spark gap 15 being situated substantially at the same potential that the first conductive part 6.
• the first electrode 16 is advantageously formed by the first end plate 10 and the second electrode 17 is formed by the first conductive part 6 so that the main arc 8 'is form between the first end plate 10 and the first conductive part 6, for example between the ends facing them.
• the isolation spark gap 15, although connected in series with the arc extinguishing chamber 9, is located at another location of the apparatus 1 , and for example disposed between two series of splitting plates 12 connected in series.
• the apparatus 1 comprises a single isolation gap 15.
• the apparatus 1 comprises two isolation spark gaps 15A, 15B, electrically connected in series with the arc extinction chamber 9 and on the other hand. and other of the latter, so that the current I leaving one of the conductive parts 6 passes successively through a first isolation gap 15A, the arc extinguishing chamber 9, and a second spark gap. 15B isolation before joining the other conductive part 7.
• the arc extinguishing chamber 9 is not electrically connected, either directly or by wiring, to the electrical installation and to the arc generation means 5, so that that in the absence of electrical disturbance, the arc extinction chamber 9 and in particular the end plates 10, 11 are at a floating potential.
• the presence of the two isolation gaps 15A, 15B connected in series with the arc extinguishing chamber 9, is a double security in case of failure of the latter.
• the complementary isolation spark gap could ensure the definitive extinction of the electric arc when the current is switched to zero.
• the apparatus 1 comprises an additional isolation device 20 (FIGS. 5 and 6), mounted within the housing 4 and able to ensure disconnection. , preferably definitive, arc extinguishing chamber 9 vis-à-vis the electrical installation, particularly in the event of failure of said arc extinguishing chamber 9 and more generally in case of failure of the arc extinguishing chamber 9 device 1.
• the isolation device 20 comprises:
• detection means 21 sensitive to the state of the apparatus 1 and able to detect a malfunction of the latter, in particular excessive heating within the housing 4, and insulating means 22, movable and able to come, under the control of the detection means 21, be positioned between the electrodes 16, 17 of the isolation spark gap 15 in order to increase the isolation between the latter and to ensure the simultaneous disconnection of the isolation spark gap 15 and arc extinguishing chamber 9 with respect to the electrical installation.
• malfunction here means a failure of the apparatus 1, which may appear:
• the detection means 21 are advantageously temperature-sensitive, in order to be able to detect heating of the apparatus 1 beyond a predetermined threshold temperature.
• the detection means 21 are preferably located near the components likely, at the end of their life, to be short-circuited, for example the arc generation means 5 and in particular the conductive parts 6, 7 or the arc extinction chamber 9. It is also possible to position. the detection means 22 near the isolation spark gap 15. The positioning of the detection means 21 near the key components of the apparatus 1 makes it possible to rapidly detect an abnormal heating of these components.
• the insulating means 22 are adapted to increase the electrical isolation capacitance of the isolation spark gap 15, and therefore the energy required for the main arc 8 'to start, or reboot between the electrodes 16 , 17. As shown in FIG. 6, the insulating means 22 thus isolate definitively the arc extinguishing chamber 9 with respect to the arc generation means 5 and the electrical installation, thus improving the capacitance of switching off the device 1, in addition to the clean breaking capacity of the isolation spark gap 15.
• the insulating means 22, positioned between the electrodes 16, 17, increase the isolation distance d between the latter, and thus contribute to the final extinction of the electric arc 8, on the one hand by lengthening it and on the other hand by preventing its rebooting, in particular by preventing the reboot of the main arc 8 '.
• the insulating means 22 are formed by an insulating piece 23 that can move, for example by sliding, between the electrodes 16, 17 of the isolation spark gap 15 so as to increase the isolation distance d between them.
• the displacement of the insulating means 22 is advantageously effected in a direction of displacement D, preferably parallel to the transfer direction F.
• Guiding means (not shown), can provide guidance in displacement of the insulating part 23.
• the temperature detection threshold of the detection means 21 is preferably determined as a function of the deformation threshold temperature of the insulating part 23, so as not to hinder the movement of the latter.
• the insulating part 23 is advantageously mounted movably between a first position (illustrated in FIG. 5), in which it allows the free operation of the isolation spark gap 15, and a second position (illustrated in FIG. 6) in which it increases the isolation distance d between the electrodes 16, 17, thus increasing at the same time the path to be traveled by the main arc 8 'to bypass it.
• the insulating part 23 is mounted to move in translation between its first and second positions, under the constraint of an actuating means and preferably under the constraint of an elastic return means 24 of the spring type.
• One of the ends 24A of the elastic return means 24 can thus be fixed to one of the walls 4A of the housing 4, the other end 24B being fixed to or bearing against the insulating part 23 ( Figure 6).
• the insulating part 23 is thus mounted elastically movable between its first and second positions. In its first position illustrated in FIG. 5, the insulating part 23 is advantageously maintained by the detection means 21 which are preferably formed by a fuse element 26 fixed relative to the housing 4 and preferably secured to the latter.
• the fuse element 26 is preferably formed by a tin-lead alloy, calibrated to break or melt beyond the usual operating temperatures of the apparatus 1.
• the fuse element 26 is preferably electrically isolated from the metal parts of the apparatus 1, and in particular conductive parts 6, 7, end plates 10, 11 and fractionating plates 12, for example by interposition of a dielectric material between the metal parts and the fuse element 26.
• the detection means 21, and more precisely the fuse element 26, are mounted within the apparatus 1 so as to release the insulating means 22 (for example the insulating part 23) when a malfunction of the apparatus 1 is detected.
• the detection means 21, in particular the fuse element 26, cooperate with the insulating means 22, in particular with the insulating part 23, in such a way that the melting or breaking of the fuse element 26 causes the release of the insulating part 23. The latter is then propelled, under the stress of the elastic return means 24, to the isolation spark gap 15.
• the detection means 21 and more precisely the fuse element 26 form a stop against the displacement of the insulating means 22.
• the insulating part 23 comes, at the end of the stroke, that is to say in the second position illustrated in FIG. 6, in abutment with the arc extinguishing chamber 9 on the one hand to promote the shearing of the electric arc 8, and more precisely of the main arc 8 ', between the insulating part 23 and the fractionation plates 12 and on the other hand to prevent the rebooting of the electric arc 8 after its extinction.
• the insulating part 23 then forms, in its second position, an additional means of breaking the electric arc.
• the insulating piece 23 In its second position, the insulating piece 23 is advantageously kept in contact with the arc extinguishing chamber 9, and more precisely with the fractionation plates 12 thanks to the restoring force R exerted by the elastic return means 24. The insulating part 23 is then immobilized between the arc extinguishing chamber 9 on the one hand and the elastic return means 24 on the other hand.
• the overall shape of the insulating member 23 is likely to vary.
• the movable insulating part 23 is preferably formed by a U-shaped part comprising two branches 23A, 23B substantially parallel to one another and connected by a connecting bridge 27, so that in the second position shown in Figure 6, the branches 23A, 23B substantially simultaneously position themselves between the respective electrodes 16, 17 of the two isolation gaps 15A, 15B.
• the branches 23A, 23B extend preferably parallel to the direction of displacement D, and perpendicularly to the connecting bridge 27.
• branches 23A, 23B thus advantageously slide against the end plates 10, 11, the latter thus ensuring the guiding the insulating part 23 to its terminal position. It is also possible, without departing from the scope of the invention, that the branches 23A, 23B are not formed by a single piece but by separate parts, mounted on articulated arms (not shown) that can be actuated for positioning the branches 23A, 23B in the ionizable insulating space located between the electrodes 16, 17 of the isolation gaps 15A, 15B.
• the branches 23A, 23B thus form a double insulating barrier capable of electrically isolating the arc extinguishing chamber 9 from the other components of the device 1 and from the other side. -vis the electrical installation.
• the insulating means 22 make it possible to increase the breaking capacity of the short-circuit current and the reliability of the apparatus 1.
• the isolation device 20 thus makes it possible to avoid being taught at an external breaking device for interrupting the short-circuit current in case of failure of the arc extinguishing chamber 9.
• the apparatus 1 also comprises indicating means (not shown) of its state.
• These indication means are preferably operatively connected to the detection means 21 so that when a defective state of the apparatus 1 is detected, this information is transmitted to the indication means so as to warn the user that the Device 1 is damaged and its replacement is necessary.
• the indication means are mechanically connected to the insulating part 23, directly or indirectly, so that the movement of the insulating part 23 towards its second position actuates the indication means.
• the indication means may for example comprise visual means, formed by a separate part of the insulating part 23 and likely, when a malfunction of the apparatus 1 is detected, to move opposite a window formed in the 4.
• the indication means can also be formed directly by the insulating part 23.
• the apparatus 1 comprises an overvoltage protection element, preferably transient, formed by a so-called main spark gap 30, said main spark gap 30 extending between at least two main electrodes 31, 32 formed by the conductive parts 6, 7 so that the device 1 is a surge protection device, preferably transient.
• the main spark gap 30 is formed by an ionizable insulating space, preferably occupied by air, which extends between the conductive parts 6, 7.
• the main spark gap 30 is characterized by a triggering threshold voltage which, when exceeded, leads to the formation of an electric arc 8 between the main electrodes 31, 32.
• the electric arc 8 then makes it possible to evacuate the surge current, for example towards the earth, in order to preserve the electrical installation mounted in parallel with the apparatus 1.
• the main electrodes 31, 32 are arranged relative to each other so as to form a V, the hollow of the V, which has the distance of Isolation of the weakest, then forming the ignition zone 30 'of the electric arc 8.
• the main electrodes 31, 32 preferably extend longitudinally between the priming zone 30 'and the arc extinction chamber 9. Even more preferably, the main electrodes 31, 32 do not extend laterally. , beyond the end plates 10, 11 so as to limit the size of the apparatus 1.
• the first electrode 16 of the isolation spark gap 15 is formed by the first end plate 10, the second electrode 17 of the isolation spark gap 15 being formed by one of the main electrodes 31 of the main spark gap 30.
• the other main electrode 32 is advantageously electrically connected to the second plate end 11, and is at the same potential as the latter.
• the isolation spark gap 15 is advantageously formed by the ends opposite the first end plate 10 and the main electrode 31 situated opposite each other.
• the apparatus 1 comprises two isolation gaps 15A, 15B connected in series with the arc extinction chamber 9
• the main electrodes 31, 32 of the main spark gap 30 each form the second electrode 17 of the isolation spark gaps 15A, 15B
• the end plates 10, 11 then each forming the first electrode 16 of the isolation spark gaps 15A, 15B.
• the isolation device 20 comprises an insulating element 33, able to come, under the control of the detection means 21, to be positioned in an isolation configuration between the conductive parts 6, 7 and for example between the main electrodes 31, 32 to increase the isolation between them when a malfunction of the apparatus 1 is detected.
• the insulating element 33 thus allows, in association with the insulating means 22, and more precisely with the branches 23A, 23B, to ensure the electrical isolation of the apparatus 1 according to three different levels, namely:
• the insulating element 33 is movably mounted between a first configuration, illustrated in FIG. 5, in which it forms a priming aid for the main spark gap 30, and the isolation configuration.
• the insulating element 33 thus allows a better control of the priming level of the main spark gap 30, the electric arc 8 being formed between the main electrodes 31, 32 along the surface of the element insulation 33.
• the insulating element 33 comes, in the isolation configuration illustrated in FIG. 6, in abutment with the arc extinguishing chamber 9, so as, on the one hand, to promote the shearing of the arc electrical, that is to say the reduction of its section, and secondly to prevent its reboot between the conductive parts 6, 7, in particular in the main spark gap 30.
• the insulating element 33 is mechanically connected to the insulating means 22 so that the displacement of the insulating element 33 causes the displacement of the insulating means 22 or vice versa.
• the insulating element 33 is secured to the insulating means 22 and preferably formed by a central branch 34 extending substantially parallel to the branches 23A, 23B of the insulating part 23 from the connection bridge 27. Even more preferably, the insulating element 33 is integral with the part insulating 23, forming with the latter a single piece.
• the insulating element 33 to be dissociated from the insulating means 22 and formed by an independent part, the movement of the insulating element 33 being able in this case to be associated or no to the movement of the insulating means 22.
• the insulating element 33 is held directly by the detection means 21 and is in physical contact with the latter so that heating of the insulating element 33, caused for example by a malfunction of the main spark gap 30, is directly transmitted, by conduction, to the fuse element 26.
• the insulating element 33 is further advantageously maintained in its first configuration under the combined stress of the detection means 21 and the elastic return means 24, which tends to repel it to arc extinguishing chamber 9.
• the device 1 of protection according to the invention constitutes a circuit breaker having contacts, said contacts comprising the conductive parts 6, 7.
• the conductive parts 6, 7 form the contacts of the circuit breaker, the electric arc being, in this case, likely to form during the separation of said contacts.
• the protective apparatus 1 comprises a main spark gap 30 and constitutes a transient overvoltage protection device.
• the operation described hereinafter can nevertheless be transposed in an obvious manner in the case of an overcurrent protection device of the breaker type.
• the contacts of the circuit breaker form, after their separation, electrodes between which an electric arc is likely to be formed, by analogy with the main electrodes 31, 32 of the main spark gap 30.
• the electrical disturbance is not a transient overvoltage but a charging or short-circuit current.
• FIGS. 1 to 6 The operation of the protection device 1 according to the invention illustrated in FIGS. 1 to 6 is as follows.
• the isolation spark gap 15 is advantageously sized according to the breaking capacity intrinsic to the main spark gap 30.
• the insulation resistance of the isolation spark gap 15 is calculated in such a way that the spark gap is only triggered for arc energies higher than a threshold value beyond which the clean breaking capacity of the main spark gap does not, on its own, ensure the final extinction of the electric arc.
• the current I flows through the apparatus 1 between the terminals 2 and 3, passing successively through the main electrode 31, a first spark gap 15A, the arc extinguishing chamber 9 and optionally a second isolation gap 15B before joining, via the other main electrode 32, the terminal 3.
• the extinction of the electric arc 8 is effected in the arc extinguishing chamber 9, as soon as the arc voltage exceeds the voltage of the generator (or network).
• the arc extinguishing chamber 9 is then no longer able to ensure the breaking of the short circuit current.
• the isolation spark gap 1,5, 15A, 15B which ensures, during the zero crossing of the current, the definitive extinction of the electric arc 8, and more precisely of the main arc. 8 'formed within the isolation spark gap 15, 15A, 15B, preventing its rebooting.
• the zero crossing of the current is carried out at each half-period, thus allowing a rapid extinction of the electric arc.
• the temperature within the housing 4 increases abnormally and exceeds a predetermined threshold value, corresponding to the temperature of rupture or melting of the fuse element 26, a triggering of the complementary insulation device 20 occurs, and insulating means 22, formed by the insulating part 23, are positioned between the electrodes 16, 17 the isolation spark gap 15, 15A, 15B.
• the insulating means 22 then provide electrical isolation and permanent disconnection of the arc extinguishing chamber 9 vis-à-vis the electrical installation.
• the isolation device 20 also ensures the disconnection of the main spark gap 30 vis-à-vis the electrical installation, the insulating element 33 coming, under the control of the detection means 21 position between the main electrodes 31, 32 to increase the isolation distance between them.
• the central branch 34 and the branches 23A, 23B located on either side of said central branch 34 are positioned simultaneously between the main electrodes 31, 32 of the spark gap main 30 and between the electrodes 16, 17 of the isolation gaps 15A, 15B.
• the energy required for the formation of a new electric arc is particularly high because of the large isolation distance between the conductive parts 6, 7 (or the main electrodes 31, 32) on the one hand and between the electrodes 16 On the other hand, the apparatus 1 is isolated, effectively and permanently, from the electrical installation.
• the invention thus makes it possible to ensure, in the event of a failure of the arc extinction chamber, the rapid and lasting extinction of the electric arc possibly created within the apparatus 1 and the definitive disconnection of the chamber arc extinguishing vis-à-vis the electrical installation.
• Another advantage of the apparatus 1 according to the invention is that it ensures, in case of malfunction of the apparatus 1, the quick and reliable disconnection of the latter vis-à-vis the electrical installation .
• Another advantage of the device 1 of protection according to the invention and that it allows to report immediately to the user any malfunction, allowing its rapid replacement.
• the invention finds its industrial application in the design, manufacture and use of protective devices for equipment or electrical installations.

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• 2005
  • 2005-01-04 FR FR0500049A patent/FR2880468B1/fr not_active Expired - Fee Related
• 2006
  • 2006-01-04 WO PCT/FR2006/000009 patent/WO2006072737A2/fr not_active Ceased
  • 2006-01-04 EP EP06704666A patent/EP1842269A2/de not_active Withdrawn

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