Non-electrical device for replacing a current sensor in a switching chamber of a load interrupter, and load interrupter having such a non-electrical device

Abstract

This non-electrical device (40) comprises first and second half-cases (41, 42) made of plastic, fixedly joined to one another, defining an axis (X43) along which a passage (43) for an electrical conductor (10) runs through the first and second half-cases, and delimiting between them an internal volume (V40), which is separated from the passage and surrounds the passage all around the axis. The first half-case incorporates, by molding, mechanical reinforcement elements (44) which extend substantially parallel to the axis within the internal volume until they are in contact with the second half-case.

Description

[0001] The present invention relates to a non-electrical device for replacing a current sensor in a breaking chamber of a switch-disconnector. It also relates to a switch-disconnector comprising such a non-electrical device.

[0002] As is known per se, a switch-disconnector is a switch which, in its open position, satisfies the isolation conditions of a disconnector. Thus, the switch-disconnector combines in a single device a load breaking function, typical of a switch, and an isolation function, typical of a disconnector. The isolator-disconnector therefore guarantees the safety of operators who have to work on an electrical circuit connected to the switch-disconnector as soon as the latter is open. Unlike a circuit breaker which integrates an additional function of protection against abnormal conditions that the circuit breaker itself detects, such as overcurrent, short circuit and overvoltage, the switch-disconnector is controlled to open from outside the switch-disconnector, either manually or by an abnormal condition detection unit, external to the switch-disconnector.

[0003] It is common in the field to propose a switch-disconnector that is a version of a circuit breaker, in which the electrical components providing the aforementioned protection function are removed. Such an approach allows for rationalization of device ranges, by using the same components and component assemblies that are found identically in a switch-disconnector version and in a circuit breaker version of the same given device. However, this approach requires adjustments at the level of the arc chute. Indeed, in the circuit breaker version of the device, a current sensor used to detect the aforementioned abnormal conditions is generally present in the arc chute.Such a current sensor is for example disclosed in FR 3 030 763 A1 and comprises a housing inside which are housed electrical elements of the current sensor, this housing comprising two plastic half-housings, which are welded to each other and through which extends a passage for an electrical conductor. In the switch-disconnector version, such a current sensor is unnecessary but cannot be removed as is because this would modify the geometric characteristics of the breaking chamber, with the risk of altering the insulation performance, in particular the capacity of the breaking chamber to allow the extinction of the electric arc forming when the switch-disconnector is opened.

[0004] To overcome this difficulty, it is known in the field to replace the aforementioned current sensor with a "dummy sensor", that is to say a non-electrical device replacing the current sensor in the breaking chamber of the switch-disconnector. This "dummy sensor" comprises a housing, typically made of plastic, which is generally identical to that of the current sensor to be replaced but which is internally devoid of any electrical component in favor of an added insert. This insert is made of a molded and glued resin, and allows the housing to remain intact when the switch-disconnector is opened, by absorbing the overpressure applied to the housing that the electric arc creates in the breaking chamber.Although this resin-inserted "false sensor" is generally effective in preserving the insulation performance of the switch-disconnector version of a given device, compared to the circuit breaker version of this device, it is not completely satisfactory, particularly from an environmental and regulatory point of view.

[0005] The aim of the present invention is to propose a new “false sensor”, which is particularly robust and whose behavior is reliable and controlled.

[0006] To this end, the invention relates to a non-electrical device for replacing a current sensor in a breaking chamber of a switch-disconnector, this non-electrical device being as defined in claim 1.

[0007] One of the ideas underlying the invention is to implement a solution without an added insert, in particular made of resin, in favor of arrangements that are entirely integral with the casing of the non-electric device forming a "false sensor". To this end, the invention provides that the plastic casing of the non-electric device is made up of two half-casings fixedly assembled to each other and that mechanical reinforcement elements are molded with a first of the two half-casings and form a contact support for the second half-casing, these mechanical reinforcement elements extending in the internal volume of the casing in a manner substantially parallel to the axis along which the casing is crossed by a passage for an electrical conductor on which the non-electric device is mounted in service, in particular within a switch-disconnector.The mechanical reinforcement elements make it possible to maintain the integrity of the housing and, therefore, of the non-electrical device according to the invention when the latter are subjected in a breaking chamber of a switch-disconnector to the overpressure created by the formation of an electric arc when the switch-disconnector opens. As the mechanical reinforcement elements are integrated by molding into the first half-housing, their structural specificities can be defined precisely and repeatably and their behavior is controlled. Moreover, the inventors were able to validate and optimize by numerical simulation the characteristics, in particular shape and placement, relating to the mechanical reinforcement elements. In practice, the choice, between the two half-housings, of the first half-housing integrating the mechanical reinforcement elements is advantageously made in connection with rheological considerations of moldability.The non-electric device according to the invention can advantageously be limited to the two half-cases, in particular by dispensing with any added filling in its internal volume. In addition, as detailed below, the effects and advantages of the mechanical reinforcement elements can be reinforced by providing that at least some of these mechanical reinforcement elements are advantageously distributed into one or more groups, each of which preferably consists of at least three mechanical reinforcement elements and in each of which the mechanical reinforcement elements are aligned, advantageously occupying a region of the internal volume, offset from the passage for the electrical conductor. Also as detailed below, the non-electric device according to the invention can provide other arrangements aimed at strengthening its performance.

[0008] Thus, additional advantageous characteristics of the non-electric device according to the invention are specified in claims 2 to 10.

[0009] The invention also relates to a switch-disconnector, as defined in claim 11.

[0010] An additional advantageous characteristic of the switch-disconnector according to the invention is specified in claim 12.

[0011] The invention will be better understood by reading the following description, given solely by way of example and with reference to the drawings in which: There figure 1 is a perspective view of a switch-disconnector according to the invention; The figure 2 is a perspective view according to arrow II of the figure 1 ; There figure 3 is a section along plan III of the figure 2 ; There figure 4 is a perspective view of a non-electrical device according to the invention, belonging to the switch-disconnector of the preceding figures; The figure 5 is a section along plane V of the figure 4 ; There figure 6 is a perspective view of an exploded view of the non-electric device of the figure 4 ; There figure 7 is a view similar to the figure 6 , from a different angle of observation; The figure 8 is a perspective view of a half-case belonging to the non-electric device of the figure 4 ; and The figure 9 is a view similar to the figure 8 , showing a second half-case of the non-electric device.

[0012] On the figures 1 à 3 an air-break switch-disconnector 1 is shown, which makes it possible to isolate electrical systems connected to it. The switch-disconnector 1 is typically a high-power switch-disconnector, in particular a high-intensity switch-disconnector in the sense that, in the normally closed state of the switch-disconnector 1, the latter allows the circulation through it of a permanent current, direct or alternating, the intensity of which is between a few hundred and a few thousand amperes, in particular between 500A and 7500A.

[0013] The switch-disconnector 1 is here multipolar, being intended to be used in an electrical circuit comprising several electrical poles. In the example illustrated in the figures, the switch-disconnector 1 has four independent poles P1, P2, P3 and P4. In a variant not shown, the switch-disconnector 1 has a different number of poles, for example two or three. Also in a variant not shown, the switch-disconnector 1 has only one pole.

[0014] The switch-disconnector 1 comprises an insulating casing 2, which supports the poles P1 to P4. The casing 2 is for example made of a plastic material and comprises several parts fixedly assembled to each other. The casing 2 delimits an internal volume, which is essentially closed and which, here, is divided into four separate compartments, respectively associated with the poles P1 to P4.

[0015] Each of the poles P1 to P4 being identical to the other poles, only one of them is described in detail below, namely pole P2 which is shown in section on the figure 3 The description given for pole P2 applies to each of the other poles P1, P3 and P4.

[0016] The pole P2 comprises two terminal pads 10 and 11 which make it possible to connect the pole P2 to an electrical circuit which it is desired to allow isolation by the switch-disconnector 1. The terminal pads 10 and 11, which are made of an electrically conductive material, generally a metal such as copper, are carried by the casing 2 so as to be electrically connectable from the outside of the casing 2 to the aforementioned electrical circuit. Here, the terminal pads 10 and 11 pass through a dedicated wall of the casing 2, emerging, on either side of this dedicated wall, outside the casing 2 and inside the casing 2, in other words in the internal volume of the latter, more precisely inside the compartment of this internal volume, associated with the pole P2.

[0017] Pole P2 also comprises two contact elements 20 and 21 which are respectively connected to the terminal pads 10 and 11 while being movable relative to each other between a closed position, which is not shown, and an open position, which is shown in the figure 3 . In the closed position, the contact elements 20 and 21 are in direct contact with each other and allow the flow of an electric current between the terminal pads 10 and 11. In their open position, the contact elements 20 and 21 are spaced apart from each other and interrupt the electric flow between the terminal pads 10 and 11.

[0018] In the embodiment considered in the figures, the contact element 20 is fixedly carried by a movable arm 23 which is electrically connected to the terminal pad 10, while the contact element 21 is fixedly carried by the terminal pad 11 and is itself fixedly carried by the casing 2.

[0019] In all cases, the contact elements 20 and 21 are arranged in an extinguishing chamber 24 associated with the pole P2. The extinguishing chamber 24 is delimited inside the casing 2, thus forming a part of the internal volume of the latter, more precisely a part of the compartment of this internal volume, associated with the pole P2. The extinguishing chamber 24 is filled with air and surrounds the contact elements 20 and 21 so as to promote the extinction of the electric arc forming between the contact elements 20 and 21 when the latter pass from their closed position to their open position. Between its formation and its extinction, the electric arc ionizes the air present in the extinguishing chamber 24, which generates gases, called cutting gases, which are partially ionized and which contain suspended particles, such as soot and / or metal particles.The formation of this electric arc creates in the cutting chamber 24 an overpressure generating mechanical forces both on the parts of the casing 2, which delimit the cutting chamber 24, and on the components of the switch-disconnector 1, which are arranged in the cutting chamber 24.

[0020] Pole P2 also includes a mechanism 30 for opening the switch-disconnector 1, i.e. for moving the contact elements 20 and 21 from the closed position to the open position. Mechanism 30 is arranged inside the casing 2, more precisely in the compartment of the internal volume of the latter, associated with pole P2. In practice, mechanism 30 is known per se in the field and will therefore not be described further here. In other words, the specific features of mechanism 30 are not limiting. In the embodiment considered here, mechanism 30 is designed to set in motion movable arm 23 in order to move contact elements 20 and 21 between their closed and open positions.The mechanism 30 is advantageously designed to, when actuated to move the contact elements 20 and 21 from their closed position to their open position, cause the contact elements of the other poles P1, P3 and P4 of the switch-disconnector 1 to open, in particular by means of mechanisms, similar to the mechanism 30 of the pole P2, which belong respectively to the poles P1, P3 and P4.

[0021] The mechanism 30 is controlled in actuation from outside the enclosure 2, in particular either manually or by an ad hoc control unit which is not integrated into the switch-disconnector 1. As a result, the breaking chamber 24 does not have to contain a current sensor which, mounted on one of the terminal pads 10 and 11, would measure the electric current circulating therein to provide information on a potential operating anomaly, such as an overcurrent, a short circuit or an overvoltage.

[0022] Pole P2 also includes a non-electrical device 40, which is visible at figure 3 and which is represented alone on the figures 4 à 9 . This non-electrical device 40 makes it possible to replace the current sensor mentioned just above, by occupying substantially the space that this current sensor would have occupied within the switch-disconnector 1, and this for the reasons explained in detail in the introductory part of this document. In other words, the non-electrical device 40 constitutes a “false sensor” in the sense defined above.

[0023] So, as clearly visible on the figure 3 , the non-electrical device 40 is arranged inside the casing 2, more precisely in the compartment of the internal volume of the latter, associated with the pole P2, being arranged in the cutting chamber 24.

[0024] As shown in the figures 3 à 7 , the non-electric device 40 comprises a housing made up of two half-housings 41 and 42. The half-housing 41 is shown alone in the figure 8 and the half-case 42 is shown alone on the figure 9 . The two half-housings 41 and 42 are made of a molded plastic material. In the embodiment considered in the figures, the non-electric device 40 is advantageously made up of the half-housings 41 and 42, that is to say that the non-electric device 40 does not comprise any other component than the two half-housings 41 and 42.

[0025] In all cases, the half-housings 41 and 42 are fixedly assembled to each other. The embodiment of the fixed assembly connection between the two half-housings 41 and 42 is not limiting, it being noted that this aspect will be discussed in more detail later.

[0026] In the assembled state of the non-electrical device 40, the half-housings 41 and 42 are crossed by a passage 43 along an axis X43 on which the passage 43 is centered. The half-housings 41 and 42 thus follow one another along the axis X43. In the assembled state of the switch-disconnector 1, the terminal pad 10 is received, here in a complementary manner, in the passage 43, extending parallel to the axis X43, or even, as here, being aligned with the axis X43. The housing made up of the half-housings 41 and 42 is thus crossed, via the passage 43, by the terminal stud 10 and is arranged in the breaking chamber 24 so that the half-housing 41 is, along the axis X43, turned and arranged against a part of the casing 2, also crossed by the terminal stud along the axis X43, while the half-housing 42 is turned towards the breaking chamber 24. The half-housing 41 is thus interposed, along the axis X43, directly between the casing 2 and the half-housing 42.

[0027] As clearly visible on the figures 3 And 5 , the half-housings 41 and 42 delimit between them an internal volume V40 which is separated from the passage 43, by surrounding the latter all around the axis X43. In the embodiment considered in the figures, the internal volume V40 is not distributed homogeneously all around the passage 43, and this for reasons linked to the function of “false sensor” of substitution which the non-electric device 40 ensures. More precisely, as indicated in the figure 5 , the internal volume V40 is thus made up of two adjoining sub-volumes, namely an annular sub-volume V40.1, which directly surrounds the passage 43, and an offset sub-volume V40.2, which is further from the axis X43 than the annular sub-volume V40.1. The annular sub-volume V40.1 runs entirely around the axis X43 while the offset sub-volume V40.2 only partially runs around the axis X43.

[0028] According to a practical and simple embodiment to implement, each of the two half-housings 41 and 42 includes a bottom wall 41.1, respectively 42.1, which extends generally transversely, or even perpendicularly, to the axis X43 and which is crossed right through by the passage 43. The bottom walls 41.1 and 42.1 are arranged opposite one another along the axis X43 and each separate the internal volume V40 from the exterior of the non-electric device 40. The half-housing 41 also includes a peripheral side wall 41.2 and a central side wall 41.3, which each extend from the bottom wall 41.1 substantially parallel to the axis X43 towards the half-housing 42, the peripheral side wall 41.2 being further from the axis X43 than the central side wall 41.3. The peripheral side wall 41.2 follows the peripheral contour of the bottom wall 41.1 while the central side wall 41.3 follows the contour of the passage 43 through the bottom wall 41.1. Similarly, the half-housing 42 includes a peripheral side wall 42.2 and a central side wall 42.3, each of which extends from the bottom wall 42.1 substantially parallel to X43 toward the half-housing 41, the peripheral side wall 42.2 being further from the axis X43 than the central side wall 42.3. The peripheral side wall 42.2 follows the peripheral contour of the bottom wall 42.1 while the central side wall 42.3 follows the contour of the passage 43 through the bottom wall 42.1. In the assembled state of the non-electric device 40, the peripheral side walls 41.2 and 42.2 separate the internal volume V40 from the exterior of the non-electric device 40, while the central side walls 41.3 and 42.3 separate the passage 43 from the internal volume V40. Here, the annular sub-volume V40.1 is delimited by, at the same time, the entirety of the central side walls 41.3 and 42.3, a portion of the bottom walls 41.1 and 42.1, and a portion of the peripheral side walls 41.2 and 42.2, while the offset sub-volume V40.2 is delimited by, at the same time, the remainder of the bottom walls 41.1 and 42.1, and the remainder of the peripheral side walls 41.2 and 42.2.

[0029] Whatever the specificities of the half-housings 41 and 42, the non-electric device 40 incorporates arrangements aimed at reinforcing its integrity so that it resists without damage the overpressure created by the formation of an electric arc in the breaking chamber 24 when the contact elements 20 and 21 open. For this purpose, the half-housing 41 integrates by molding mechanical reinforcement elements 44 which each extend substantially parallel to the axis X43 in the internal volume V40 until it is in contact with the half-housing 42 so as to support the latter by contact. According to a preferred embodiment, which is illustrated in the figures, the internal volume V40 is, apart from the mechanical reinforcement elements 44, left substantially empty, in particular by being free of any added resin or, more generally, of any added filling material.

[0030] The mechanical reinforcement elements 44 are thus integral with the rest of the half-housing 41. In the embodiment illustrated in the figures, each of the mechanical reinforcement elements 44 thus projects along the axis X43 from the bottom wall 41.1, and this from one end 44.1 of the mechanical reinforcement element 44, at the junction of the latter with the bottom wall 41.1, to a free end 44.2 of the mechanical reinforcement element 44, which is axially opposite its end 44.1. In the assembled state of the non-electric device 40, the respective free ends 44.2 of the mechanical reinforcement elements 44 are in contact along the axis X43 with the bottom wall 42.1 of the half-housing 42, thus supporting this bottom wall 42.1 by contact.

[0031] According to an advantageous optional arrangement aimed at reinforcing their individual mechanical resistance, each mechanical reinforcement element incorporates by molding ribs 44.3 which each extend from the bottom wall 41.1 over the entire axial extent of the mechanical reinforcement element 44, in other words which each extend from the end 44.1 to the end 44.2 of the mechanical reinforcement element 44. Here, these ribs 44.3 are provided in four copies for each of the mechanical reinforcement elements 44. In addition, the ribs 44.3 of each mechanical reinforcement element 44 are advantageously distributed on the mechanical reinforcement element 44 around the axial direction in which this mechanical reinforcement element 44 extends between its ends 44.1 and 44.2.

[0032] According to a particularly effective arrangement, which is illustrated in the figures, at least some of the mechanical reinforcement elements 44 are distributed into one or more groups, here two groups G1 and G2, in each of which all the mechanical reinforcement elements 44 are aligned in a direction transverse to the axis X43, in particular orthogonal to this axis X43. As clearly visible in the figures 7 And 8 , all the mechanical reinforcement elements 44 of group G1 and all the mechanical reinforcement elements 44 of group G2 are advantageously arranged in the remote sub-volume V40.2. In this way, the mechanical reinforcement elements 44 of groups G1 and G2 act effectively in a region of the internal volume V40, where the mechanical stresses applied by the aforementioned overpressure on the non-electric device 40 are the strongest.

[0033] Various preferred arrangements, which can be combined within them, are conceivable for reinforcing the action of each of the groups G1 and G2. According to one of these preferred arrangements, the groups G1 and G2 are each made up of at least three mechanical reinforcement elements 44, here respectively five and six mechanical reinforcement elements 44, which are distributed in a substantially regular manner along the direction of alignment of the reinforcement elements 44 within each group G1, G2. According to another preferred arrangement, the mechanical reinforcement elements 44 of each of the groups G1 and G2 are made of material directly with each other, in particular by joining two by two of one of their ribs 44.3.

[0034] It will be noted that, in the exemplary embodiment illustrated in the figures, one of the mechanical reinforcement elements 44 does not belong to group G1 or to group G2. This mechanical reinforcement element 44 is here arranged in the annular sub-volume V40.1. In a variant not shown, this mechanical reinforcement element 44 is omitted, which amounts to saying that all the mechanical reinforcement elements 44 then belong to one or other of groups G1 and G2.

[0035] Furthermore, the molded design of the half-housings 41 and 42 is advantageously used with regard to the fixed assembly connection between these half-housings. More precisely, as in the embodiment illustrated in the figures, the half-housing 41 integrates by molding projecting elements 45, which are arranged outside the internal volume V40 and which are in particular integrated into the peripheral side wall 41.2. These projecting elements 45 are designed to, during the assembly of the half-housings 41 and 42, snap into respective hollow reliefs 46, which are complementary to the projecting elements 45 and which are formed outside the internal volume V40 by the half-housing 42, in particular by its peripheral side wall 42.2.

[0036] Finally, various arrangements and variants of the switch-disconnector 1 and the non-electrical device 40, described so far, are conceivable. For example, the different variants mentioned at different points in the description above can be combined with each other, at least partially.

Claims

1. A non-electrical device (40) for replacing a current sensor in a switching chamber (24) of a load interrupter (1), this non-electrical device comprising first and second half-casings (41, 42) which: - are made of plastic, - are securely joined together, - define an axis (X43) along which a passage (43) for an electrical conductor (10) passes through the first and second half-casings, the passage being substantially centred on the axis, and - delimit between them an internal volume (V40), which is separate from the passage (43) and surrounds the passage all around the axis (X43), wherein the first half-casing (41) incorporates, by moulding, mechanical reinforcement elements (44) which extend substantially parallel to the axis (X43) in the internal volume (V40) until they are in contact with the second half-casing (42).

2. The non-electrical device according to claim 1, wherein the non-electrical device (40) consists of the first and second half-casings (41, 42).

3. The non-electrical device according to one of claims 1 or 2, wherein the internal volume (V40), apart from the mechanical reinforcement elements (44), is left substantially empty, in particular free of any added resin.

4. The non-electrical device according to any one of the preceding claims, wherein at least some of the mechanical reinforcement elements (44) belong to at least one group (G1, G2) wherein all the mechanical reinforcement elements are aligned in a direction transverse to the axis (X43).

5. The non-electrical device according to claim 4, wherein the volume (V40) consists of two adjoining sub-volumes, namely: - an annular sub-volume (V40.1) which directly surrounds the passage (43) and runs all around the axis (X43), and - an offset sub-volume (V40.2), which is further from the axis (X43) than the annular sub-volume (V40.1) and which runs only partially around the axis, and wherein all the mechanical reinforcement elements (44) of the or each group (G1, G2) are arranged in the offset sub-volume (V40.2).

6. The non-electrical device according to one of claims 4 or 5, wherein the or each group (G1, G2) consists of at least three mechanical reinforcement elements (44) which are distributed in a substantially regular manner in the said direction transverse to the axis (X43).

7. The non-electrical device according to any one of claims 4 to 6, wherein the mechanical reinforcement elements (44) of the or each group (G1, G2) are integrally formed directly with one another.

8. The non-electrical device according to any one of the preceding claims, wherein the first and second half-casings (41, 42) include respective bottom walls (41.1, 42.1), which are arranged opposite one another along the axis (X43) and which each separate the internal volume (V40) from the outside of the non-electrical device (40), and wherein each mechanical reinforcement element (44) extends projecting along the axis (X43) from the bottom wall (41.1) of the first half-casing (41) to a free end (44.2) of the mechanical reinforcement element, this free end being in contact along the axis with the bottom wall (42.1) of the second half-casing (42).

9. The non-electrical device according to claim 8, wherein each of the mechanical reinforcement elements (44) incorporates ribs (44.3) which each extend from the bottom wall (41.1) of the first half-casing (41) to the free end (44.2) of the mechanical reinforcement element.

10. The non-electrical device according to any one of the preceding claims, wherein the first half-casing (41) incorporates, by moulding, projecting elements (45) which are arranged outside the internal volume (V40) and which are adapted, when the first and second half-casings (41, 42) are assembled, to snap into complementary recessed reliefs (46) formed by the second half-casing (42) outside the internal volume.

11. A load interrupter (1), comprising one or more poles (P1, P2, P3, P4), as well as an insulating enclosure (2), which supports the pole or poles, wherein the or each pole (P1, P2, P3, P4) comprises: - two end terminals (10, 11), which are supported by the enclosure (2) and can be connected from outside the enclosure to an electrical circuit to be isolated by the load interrupter (1), - two contact elements (20, 21), which are arranged in a switching chamber (24) delimited inside the enclosure (2), and which are respectively connected to the end terminals (10, 11) while being movable relative to each other into a closed position, wherein the contact elements (20, 21) are in direct contact with each other, and an open position, wherein the contact elements are moved away from each other, - a mechanism (30), which is arranged inside the enclosure (2) and which is adapted to move the contact elements (20, 21) from the closed position to the open position, being controlled from outside the enclosure, and - a non-electrical device (40), which conforms to any one of the preceding claims and which is arranged in the switching chamber (24) in such a way that one of the two end terminals (10, 11) is received in the passage (43), extending substantially parallel to the axis (X43).

12. The load interrupter according to claim 11, wherein the first half-casing (41) is interposed, along the axis (X43), directly between the enclosure (2) and the second half-casing (42).

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