Electrical contactor with integrated cut-off device
The electrical contactor with an integrated cut-off device, featuring a fuse and insulating enclosure, addresses the challenge of containing electric arcs, ensuring safe operation and managing high currents effectively.
Patent Information
- Application Number
- FR2022012982
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2022-12-08
- Publication Date
- 2025-06-20
- Estimated Expiration
- 2042-12-08
AI Technical Summary
Existing electrical contactors struggle to effectively contain and limit the propagation of electric arcs, particularly when dealing with high currents, which can lead to damage and potential fire hazards.
An electrical contactor with an integrated cut-off device, comprising a fuse and an electrically insulating enclosure, where the fuse is positioned between the arc guides and physically separated from them, allowing the fuse to only conduct when the electric arc leaves the finned breaking module, thus controlling high currents effectively.
The integrated cut-off device effectively contains electric arcs, preventing their propagation and ensuring safe operation by utilizing the fuse to manage high currents within the contactor, thereby reducing the risk of damage and fire.
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Abstract
Description
Title of the invention: Electrical contactor with integrated cut-off device Technical field
[0001] The invention relates to electrical protection equipment, and more particularly to an electrical current cut-off contactor and circuit breaker intended to be mounted on an electrical circuit, for example of an aircraft. Prior art
[0002] Figures 1 to 5 schematically show different sectional views of an electrical contactor 1 according to the state of the art.
[0003] The electrical contactor 1 according to the state of the art comprises two electrically distinct fixed electrical contacts 2, a movable bridge 3, and an arc breaking device 4 for each fixed electrical contact 2, i.e. two arc breaking devices 4.
[0004] Each arc breaking device 4 comprises a first arc guide 5, a second arc guide 6 electrically connected to the fixed electrical contact 2 with which the arc breaking device is associated, and a finned breaking module 7 extending between the first arc guide 5 and the second arc guide 6, at a distance from the movable bridge 3 and the associated fixed electrical contact 2.
[0005] The first two arc guides 5 of the two arc breaking devices 4 are electrically coupled together. And each fin breaking module 7 comprises a series of fins 8 arranged successively one above the other between the second arc guide 6 and the first arc guide 5, each fin 8 being spaced from the other fins by an empty space. The fin 8 at the top of the stack is separated from the first arc guide 5 by an empty space, and the fin at the base of the stack is separated from the second arc guide 6 by an empty space.
[0006] The movable bridge 3 is movable between a first position and a second position.
[0007] In the first position illustrated in [Fig. 1], the movable bridge 3 is in mechanical contact mechanically and electrically with the two fixed electrical contacts 2 and at a distance from the first two arc guides 5, and a second position in contact with the first arc guides 5 and at a distance from the fixed electrical contacts 2.
[0008] In this first position, the two fixed electrical contacts 2 are electrically connected via the movable bridge 3, thus allowing the electric current to flow from one fixed electrical contact 2 to the other via the movable bridge 3 as illustrated by the arrows 9 in dotted lines.
[0009] In the second position illustrated in [Fig.2], the movable bridge 3 is mechanically separated from the two fixed electrical contacts 2 and in mechanically and electrically contact with the first two arc guides 5.
[0010] In this second position, the two fixed electrical contacts 3 are electrically decoupled from each other, and no current can therefore normally flow from one fixed electrical contact 2 to the other.
[0011] However, when separating the movable bridge 3 from the two fixed electrical contacts 2, an electric arc 10 can be formed by ionization of the air at each of the two separation locations as illustrated in [Fig. 3]. An electric current then always flows from one fixed electrical contact 2 to the other via the movable bridge 3 as illustrated by the dot-dash arrows 9.
[0012] As illustrated in Figures 4 and 5, the electric arcs 10 will then move outwards via the first arc guides 5 and the second arc guides 6 thanks to the Laplace force which is created between the electric current 9 and the magnetic field 11. The electric arcs 10, under the effect of the magnetic field 11 created by permanent magnets, bend and come to lick the first and second arc guides 5 and 6.
[0013] As illustrated in [Fig.6], the electric arcs 10 thus move into the finned cut-off modules 7. Once the electric arcs 10 have entered the fins 8 of the finned cut-off module 7, the arc will divide into multiple arcs which will lower the current to zero and cause the network to be cut off.
[0014] However, when the current is too strong, it is possible that the fins 8 of the finned cut-off module 7 are no longer sufficient and that the electric arc passes through them and comes out on the other side. The arc then reforms completely and will not go out as illustrated in [Fig.7].
[0015] An electric arc 10 being a plasma which can reach several thousand degrees Celsius, if it is maintained for too long, it can damage the rest of the electrical contactor and potentially propagate.
[0016] There is therefore a need for an additional protection system to contain and / or limit the propagation of electric arcs.
[0017] There are solutions on high voltage direct current (HVDC) networks in the automotive field in particular. These solutions consist of introducing a fuse or pyrotechnic fuse devices ("pyrofuse" in English) capable of interrupting very high currents in series with the contactors. But these solutions are not contactors. The disadvantage of these solutions is that they are bulky, heavy and not easy to integrate at the input of an electrical contactor.
[0018] These solutions are notably described in documents CN 210837635, FR 3098005, US 11052784, DE 102020006947, and EP 3698419. Statement of the invention
[0019] The invention aims to provide a technical solution offering an electrical contactor capable of containing electric arcs to prevent their propagation to the outside and thus eliminate them.
[0020] In a first object of the invention, an electrical contactor with an integrated electrical cut-off device is proposed, said electrical contactor comprising at least one arc cut-off device comprising a first arc guide, a second arc guide, and a finned cut-off module extending between the first arc guide and the second arc guide.
[0021] According to a general characteristic of the invention, the arc breaking device further comprises a fuse and an electrically insulating enclosure, the fuse being arranged between the first arc guide and the second arc guide and separated from at least one of the arc guides among the first arc guide and the second arc guide by a physical space, and the finned breaking module and the fuse being arranged inside the electrically insulating enclosure.
[0022] The addition of a fuse in the electrical contactor, this fuse being physically separated, in other words distant, from at least one of the two arc guides makes it possible to have an arc breaking device equipped with a fuse which is only conductive when the electric arc leaves the fins of the finned breaking module, for example following a short circuit, so that the rating of the fuse and therefore its size are not necessarily high.
[0023] The finned cut-off module therefore makes it possible to cut the electric arcs generated with a nominal current, and the fuse makes it possible to cut the electric arcs generated with a current greater than the nominal current, the arc then emerging from the fins of the finned cut-off module and forming between the arc guides and the fuse.
[0024] The insulating enclosure allows the cartridge to be isolated from the fuse and blocks the arc so that it catches on the end of the fuse.
[0025] Preferably, the electrical contactor with an integrated electrical breaking device comprises at least two electrically distinct fixed electrical contacts, a movable bridge, and an arc breaking device for each fixed contact, each arc breaking device comprising a first arc guide, a second arc guide electrically connected to the associated fixed contact, and a finned breaking module extending between the first arc guide and the second arc guide, at a distance from the movable bridge and the associated fixed contact, the first arc guides of the different arc breaking devices being electrically coupled together, and the movable bridge being movable between a first position in contact with said fixed contacts and at a distance from the first arc guides, and a second position in contact with the first arc guides and at a distance from said fixed contacts.
[0026] In a first embodiment of the electrical contactor, each device arc interrupter may further comprise an electrically insulating inner wall disposed between the fuse and the finned interrupter module.
[0027] The insulating internal wall thus protects the fuse and prevents an arc from forming between a fin of the finned cut-off module and the fuse.
[0028] In another embodiment of the electrical contactor, each arc breaking device may comprise a first electrical branch having a first end electrically connected to a first of the two terminals of the fuse and a second end electrically connected to the second arc guide, and a second electrical branch having a first end connected to a second of the two terminals of the fuse and a second end disposed opposite the first arc guide while remaining at a distance from said finned module and the first arc guide, the second end of the second electrical branch being separated from the first arc guide by said physical space.
[0029] In a practical implementation of the electrical contactor, for each arc breaking device, the fin breaking module may include first fins located proximate the second arc guide larger than second fins located proximate the first arc guide.
[0030] The extended fins in the lower part of the finned cut-off module make it possible to have a resistance of the electric arc obtained greater than that of the fuse branch, thus promoting the passage of current in the fuse.
[0031] Advantageously, for each arc breaking device, at least a portion of the first arc guide and at least a portion of the second arc guide may be arranged inside the insulating enclosure. Brief description of the drawings
[0032] The invention will be better understood from the reading below, for informational but non-limiting purposes, with reference to the appended drawings in which:
[0033] [Fig-1] [Fig.l], already described, schematically represents a sectional view of a electrical contactor 1 according to the state of the art in a first position.
[0034] [Fig.2] [Fig.2], already described, schematically represents a sectional view of the electrical contactor 1 according to the state of the art in a second position.
[0035] [Fig.3] [Fig.3], already described, schematically represents a sectional view of the state-of-the-art electrical contactor 1 of [Fig.2] with the occurrence of electric arcs.
[0036] [Fig.4] [Fig.4], already described, schematically represents a sectional view of the state-of-the-art electrical contactor 1 of [Fig.2] with the displacement of electric arcs outwards.
[0037] [Fig.5] [Fig.5], already described, schematically represents a sectional view of the state-of-the-art electrical contactor 1 of [Fig.2] with the electric arcs further out.
[0038] [Fig.6] [Fig.6], already described, schematically represents a sectional view of the electrical contactor 1 of the state of the art of [Fig.2] with the electric arcs displaced in the finned cut-off module.
[0039] [Fig.7] [Fig.7], already described, schematically represents a sectional view of the electrical contactor 1 of the state of the art of [Fig.2] with the reformation of the electric arcs outside the finned cutting device.
[0040] [Fig.8] [Fig.8] schematically shows a sectional view of an electrical contactor 10 according to a first embodiment of the invention in a first position.
[0041] [Fig.9] [Fig.9] schematically shows a sectional view of the electrical contactor 10 of [Fig.8] in a second position.
[0042] [Fig. 10] [Fig. 10] schematically shows the direction of the current in the contactor of [Fig.9] when an electric arc forms outside the finned cut-off module 23.
[0043] [Fig. 11] [Fig. 11] schematically shows a sectional view of an electrical contactor 10' according to a second embodiment of the invention. Description of the embodiments
[0044] In [Fig.8] a cross-sectional view of an electrical contactor 10 with an integrated electrical cut-off device according to a first embodiment of the invention is shown schematically.
[0045] In the embodiment illustrated in [Fig.8], the electrical contactor 10 comprises two electrically distinct fixed electrical contacts 12, a movable bridge 13, and, for each fixed contact 12, an arc breaking device 20, in other words two arc breaking devices 20.
[0046] Each arc breaking device 20 comprises a first arc guide 21, a second arc guide 22 electrically connected to the associated fixed contact 12, and a fin breaking module 23 comprising a plurality of fins 24 and extending between the first arc guide 21 and the second arc guide 22. The fin breaking module 23 is arranged at a distance from the movable bridge 13 and the adjacent fixed contact 12.
[0047] The first arc guides 21 of the two arc breaking devices 20 are electrically coupled together.
[0048] The fins 8 of a finned cut-off module 23 are successively superimposed on top of each other between the second arc guide 22 and the first arc guide 21. Each fin 24 is separated from another fin 24 by an empty gap 240, and is therefore not in electrical contact with another fin 24. The fin 24 at the top of the superposition is separated from the first arc guide 21 by an empty gap 241 of top, and the fin at the base of the overlay is separated from the second arc guide 21 by another empty base gap 242.
[0049] As illustrated in Figures 8 and 9, the movable bridge 13 is movable between a first position illustrated in [Fig. 8], in which the movable bridge 13 is in contact with the fixed contacts 12 and spaced from the first arc guides 21, and a second position, illustrated in [Fig. 9], in which the movable bridge 13 is in contact with the first arc guides 13 and spaced from the fixed contacts 12. In the first position, current flows from one fixed contact 12 to the other fixed contact 12 via the movable bridge 13. In the second position, no current is expected to flow from one fixed contact to the other, unless an electric arc forms between the movable bridge and a fixed contact 12.
[0050] Each arc breaking device 20 further comprises a fuse 25 disposed between the first arc guide 21 and the second arc guide 22, a first electrical branch 26 coupled to a first terminal of the fuse 25 and a second electrical branch 27 coupled to a second terminal of the fuse 25.
[0051] The first electrical branch 26 comprises a first end 261 electrically connected to the first terminal of the fuse 25 and a second end 262 electrically connected to the second arc guide 22. The second electrical branch 27 comprises a first end 271 electrically connected to the second terminal of the fuse 25 and a second end 272 arranged opposite the first arc guide 21 but at a distance from the first arc guide 21. The second end 272 of the second electrical branch 27 is thus physically separated from the first arc guide 21 by a physical space 30, and is not in direct electrical contact with any other electrical element.
[0052] Each arc breaking device 20 also comprises an electrically insulating internal wall 28 arranged between the fuse 25 and at least a portion of the finned breaking module 23. The internal wall 28 thus extends over a length greater than that of the fuse 25 but less than that of the finned breaking module 23.
[0053] Each arc breaking device 20 also comprises an electrically insulating enclosure 29 inside which are arranged the finned breaking module 23, the fuse 25, the first electrical branch 26, the second electrical branch 27, and the internal wall 28. The enclosure 29 comprises in this example three external walls 290, 292 and 294. A first wall 290 is arranged opposite a portion of the first arc guide 21, a second wall 292 is arranged opposite the fuse 25, and a third wall 294 is arranged opposite the second arc guide 22. The second wall 292 is integral with the first wall 290 and the third wall 294.
[0054] The physical space 30 provided between the second end 272 of the second electrical branch 27 and the first arc guide 21 thus offers a priority path of management generation of an electric arc, when the electric arc leaves the finned cutting device 23, for example during a short circuit with a non-nominal current. The electric arc is confined inside the electrically insulating enclosure 29 and the shortest and most favorable path for forming by ionization in the air is that through the physical space 30 separating the second end 272 of the second electrical branch 27 from the first arc guide 21.
[0055] As illustrated in [Fig. 10], once an electric arc A is formed between the second end 272 of the second electrical branch 27 and the first arc guide 21 of each of the arc breaking devices 20, a current C flows from one of the contacts 12 to the other contact 12 passing, in a first arc breaking device 20 through the second arc guide 22, the first electrical branch 26, the fuse 25, the second electrical branch 27, the physical space 30, the first arc guide 21, then in the second arc breaking device 20 through the first arc guide 21, the physical space 30, the second electrical branch 27, the fuse 25, the first electrical branch 26, and the second arc guide 22. This continues until one of the fuses 25 blows and thus breaks the electrical circuit.
[0056] In [Fig. 11] is schematically illustrated a sectional view of an electrical contactor 10' according to a second embodiment of the invention.
[0057] The second embodiment illustrated in [Fig.l 1] differs from the first embodiment illustrated in Figures 8 and 9 in that the finned cut-off module 23 of the arc cut-off devices 20 comprise base fins 24' located in the lower portion, i.e. closer to the second arc guide 22 than to the first arc guide 21, which are longer than the other fins 24.
[0058] The base fins 24' which are thus extended in the lower part of the finned cut-off module 23 make it possible to have a resistance of the electric arc obtained which is greater than that of the circuit formed by the fuse 25 and the first and second electrical branches 26 and 27, thus promoting the passage of current in the fuse 25 rather than between the fins 24 or 24'.
Claims
Claims
1. An electrical contactor (10, 10') with an integrated electrical cut-off device, said electrical contactor (10, 10') comprising at least one arc cut-off device (20) having a first arc guide (21), a second arc guide (22), and a fin cut-off module (23) extending between the first arc guide (21) and the second arc guide (22), characterized in that the arc cut-off device (20) further comprises a fuse (25) and an electrically insulating enclosure (29), the fuse (25) being disposed between the first arc guide (21) and the second arc guide (22) and separated from at least one of the arc guides (21, 22) among the first arc guide (21) and the second arc guide (22) by a physical gap (30), and the fin cut-off module (23) and the fuse (25) being arranged inside the electrically insulating enclosure (29).
2. An electrical contactor (10, 10') according to claim 1, comprising at least two electrically distinct fixed electrical contacts (12) each connected to a second distinct arc guide (22), a movable bridge (13), and an arc breaking device (20) for each fixed contact (12), the finned breaking module (23) of each arc breaking device (20) being arranged at a distance from the movable bridge (13) and the associated fixed contact (12), the first arc guides (21) of the different arc breaking devices (20) being electrically coupled together, and the movable bridge (13) being movable between a first position in contact with said fixed contacts (12) and at a distance from the first arc guides (21), and a second position in contact with the first arc guides (21) and at a distance from said fixed contacts (12).
3. An electrical contactor (10, 10') according to claim 2, wherein each arc breaking device (20) further comprises an electrically insulating inner wall (28) disposed between the fuse (25) and the finned breaking module (23).
4. An electrical contactor (10, 10') according to one of claims 2 or 3, wherein each arc breaking device (20) comprises a first electrical branch (26) having a first end (261) electrically connected to a first of the two terminals of the fuse (25) and a second end (262) electrically connected to the second arc guide (22), and a second electrical branch (27) having a first end (271) connected to a second of the two terminals of the fuse (25) and a second end (272) arranged opposite the first arc guide (21) while remaining at a distance from said finned module (23) and the first arc guide (21), the second end (272) of the second electrical branch (27) being separated from the first arc guide (21) by said physical space (30).
5. Electrical contactor (10') according to one of claims 3 to 4, wherein, for each arc breaking device (20), the fin breaking module (5) comprises first fins (24') located near the second arc guide (6) larger than second fins (24) located near the first arc guide (3).
6. Electrical contactor (10, 10') according to one of claims 2 to 5, wherein, for each arc breaking device (20), at least a part of the first arc guide (21) and at least a part of the second arc guide (22) are arranged inside the insulating enclosure (29).