Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H39/00—Switching devices actuated by an explosion produced within the device and initiated by an electric current
  • H01H39/006—Opening by severing a conductor
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H85/00—Protective devices in which the current flows through a part of fusible material and this current is interrupted by displacement of the fusible material when this current becomes excessive
  • H01H85/02—Details
  • H01H85/0241—Structural association of a fuse and another component or apparatus
• • 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
  • H01H9/10—Adaptation for built-in fuses
  • H01H9/106—Adaptation for built-in fuses fuse and switch being connected in parallel
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H39/00—Switching devices actuated by an explosion produced within the device and initiated by an electric current
  • H01H2039/008—Switching devices actuated by an explosion produced within the device and initiated by an electric current using the switch for a battery cutoff

Definitions

• TITLE Electrical circuit breaker
• the present invention relates to an electrical circuit breaker.
• electrical circuit breakers are used to interrupt an electrical current, for example to disconnect an electrical load from an electrical circuit in response to a cut command.
• such a circuit breaker should have a wide operating range, i.e. it should be able to interrupt low current electrical currents (e.g. less than 100 A at 1000 V DC) , or even to open a circuit in the absence of current, as well as to interrupt electrical currents of high intensity (e.g. up to 30 kA), whether in electrical circuits of very low inductance (eg 3 mH or less) or in high inductance electrical circuits (eg 100 mH or more).
• low current electrical currents e.g. less than 100 A at 1000 V DC
• high intensity e.g. up to 30 kA
• the fuse takes longer to completely melt, in particular because the pre-arcing time of the fuse depends on the intensity of the fuse. current to be interrupted.
• the fuse is sized for high currents, it will take longer to completely melt when it is crossed by low currents. All the while, the current will continue to flow at inside the pyrotechnic switch and the electrical load will continue to be supplied, despite the cut-off order.
• the fuse is dimensioned for low intensity currents, there is a risk that the fuse will melt too quickly when it is crossed by high intensity currents, which will not allow the gases present in the switch to cool. and deionize, which can lead to the reestablishment of an electric arc between the cut portions of the conductor in the pyrotechnic switch. The current can then no longer be interrupted, which can damage the electrical load and / or the circuit breaker itself, to the point of leading to the destruction of the circuit breaker.
• a switch configured to separate the first terminal from the second terminal when it is triggered in response to a power cut order
• the arc extinguishing chamber delimited by a body of the circuit breaker, the arc extinguishing chamber being configured to receive, after triggering of the pyrotechnic switch, a portion of the electrical conductor being separated at least from the first terminal or second terminal;
• the circuit breaker comprises a connection device comprising a barrier configured to be broken after tripping of the switch only when at least one or the other of the temperature, or of the pressure inside the chamber arc extinction, or the intensity of an electric arc present in the arc extinguishing chamber exceeds a predefined threshold, the connection device being configured to connect an electrode of the fuse to one of the terminals of the electrical conductor only after the barrier is broken.
• the combination of the fuse and the device provides a rapid response and a wide operating range.
• the barrier allows a threshold to be introduced from which the current is diverted to the fuse.
• the threshold required to break the barrier and thereby connect the fuse indirectly depends on the strength of the electric current to be interrupted and can be controlled by choosing certain characteristics of the barrier when manufacturing the circuit breaker.
• the threshold from which the fuse is connected after tripping of the switch automatically adapts according to the conditions that prevail inside the arc extinguishing chamber. Thanks to this adaptation, for currents below the defined threshold, the switch opens the circuit without the intervention of the fuse; for currents above the defined threshold, the fuse is connected in parallel with the switch.
• the time required for the fuse to melt allows the cooling and deionization of the gases present in the interrupter chamber of the switch. When the fuse blows, an electric arc appears and expands within it, which stops the flow of current. Thanks to this adaptation, the same fuse can be used to interrupt both high intensity and low intensity currents.
• such an electrical circuit breaker can incorporate one or more of the following characteristics, taken in isolation or in any technically admissible combination:
• At least one electrode of the fuse extends inside the arc extinguishing chamber, the barrier being an electrically insulating barrier which separates said at least one electrode from the rest of the arc extinguishing chamber.
• the insulating barrier has a wall which defines a volume around said at least one electrode of the fuse in the arc extinguishing chamber.
• the wall is electrically insulating.
• the wall is configured to melt when the temperature in the arc extinguishing chamber exceeds a preset threshold.
• the wall has a pre-cut area configured to detach and form an opening in the wall when the pressure in the arc extinguishing chamber exceeds a predefined threshold.
• the insulating barrier comprises an electrically insulating coating deposited on said at least one electrode of the fuse in the arc extinguishing chamber, this coating being configured to melt when the temperature in the arc extinguishing chamber exceeds a predefined threshold.
• the wall or coating is covered with at least one electrically conductive outer layer.
• the wall is made of metal.
• the wall is configured to deform when the pressure in the arc extinguishing chamber exceeds a predefined threshold, until it comes into contact against the free end of said at least one electrode.
• the free end of said at least one electrode is configured to perforate the wall when the wall deforms and comes into contact with said free end.
• the wall has a pre-cut area configured to detach and form an opening in the wall when the pressure in the arc extinguishing chamber exceeds a predefined threshold.
• the circuit breaker has a control circuit, a sensor for measuring a condition inside the arc extinguishing chamber, and an auxiliary actuator configured to break the insulating barrier and in which the control circuit is configured to trip. the auxiliary actuator when a physical quantity measured by the sensor exceeds a threshold value.
• the circuit breaker has an additional fuse configured to be electrically connected between the first and second terminals after the switch has tripped, at least one electrode of the additional fuse extending inside the arc extinguishing chamber , the circuit breaker further comprising an additional electrically insulating barrier which separates said electrode of the additional fuse from the rest of the arc extinguishing chamber, said barrier being configured to be broken after tripping of the switch only when minus either of the temperature, or pressure inside the arc extinguishing chamber, or the intensity of an electric arc present in the arc extinguishing chamber exceeds a predefined threshold, this threshold being different from the tripping threshold associated with the insulating barrier of the other fuse.
• the circuit breaker has an additional electrical conductor connected to one of the terminals of the electrical conductor, the additional electrical conductor being isolated from the arc extinguishing chamber and having a free end which opens into the volume delimited by the wall.
• connection device comprises a movable electrically conductive part movable between a rest position and an energized position in which it electrically connects said electrode of the fuse with said terminal, the movable part being slidably mounted in a housing of the circuit breaker, the barrier being arranged to separate the arc extinguishing chamber from the housing and being configured to rupture when the predefined threshold is exceeded.
• the switch is a pyrotechnic switch.
• Figure 1 is a schematic representation, in a sectional view, of an electrical circuit breaker according to a first embodiment of the invention, illustrated in a first state;
• Figure 2 is a schematic representation of the electrical circuit breaker of Figure 1, illustrated in a second state;
• Figure 3 is a schematic representation, in a sectional view, of an electrical circuit breaker according to a second embodiment of the invention.
• Figure 4 is a schematic representation, in a sectional view, of an electrical circuit breaker according to a third embodiment of the invention.
• Figure 5 is a schematic representation, in a sectional view, of the circuit breaker of Figure 4 illustrated in a second state;
• Figure 6 is a schematic representation, in a sectional view, of an electrical circuit breaker according to a fourth embodiment of the invention.
• Figure 7 is a schematic representation, in a sectional view, of an electrical circuit breaker according to a fifth embodiment of the invention.
• Figure 8 is a schematic representation, in a sectional view, of an electrical circuit breaker according to a sixth embodiment of the invention
• Figure 9 is a schematic representation, in a sectional view, of an electrical circuit breaker according to a seventh embodiment of the invention
• Figure 10 is a schematic representation, in a sectional view, of an electrical circuit breaker according to an eighth embodiment of the invention.
• Figure 1 1 is a schematic representation, in a sectional view, of the electrical circuit breaker of Figure 6 according to another embodiment
• Figure 12 is a schematic representation of two electrical circuit breakers connected in series.
• Figures 1 and 2 show an electrical circuit breaker 2.
• the circuit breaker 2 is suitable for use in an electrical system to protect an electrical load connected to an electrical power source.
• circuit breaker 2 is more particularly configured to disconnect an electrical load in response to a control command, for example when an electrical fault is detected in the electrical system.
• the circuit breaker 2 can be used to protect an electrochemical accumulator battery or a photovoltaic panel.
• control command can be provided automatically by a trigger, or by an electronic control system, or manually by an operator.
• Circuit breaker 2 comprises an electrical conductor 10 comprising a first terminal 12 and a second terminal 14, which respectively form input and output terminals of circuit breaker 2.
• conductor 10 is a bar or a tab. made of metallic material, such as copper.
• the circuit breaker 2 is switchable from a first state, also called “closed state” or “armed state”, to a second state, also called “open state” or triggered state ”.
• the circuit breaker 2 allows the flow of an electric current through the electrical conductor 10.
• the first terminal 12 and the second terminal 14 are electrically connected by a main part 16 of the conductor 10.
• Circuit breaker 2 also includes a switch 20.
• the switch 20 is a pyrotechnic switch including a pyrotechnic actuator 22 and a cut-off member 24, housed in a first part of a housing of the device. circuit breaker 2.
• the disconnect device 24 is configured to separate the first terminal 12 from the second terminal 14 in response to the activation of the actuator 22.
• the member 24 comprises, for example, a cutting element, such as a blade or a guillotine or a punch, configured to cut the conductor 10, or a movable body configured to push a precut or weakened portion of the conductor 10.
• a cutting element such as a blade or a guillotine or a punch
• the switch 24 is movable by translation between a retracted position and a deployed position. In the figures, the cut-off member 24 is only visible in its deployed position.
• the actuator 22 comprises a pyrotechnic charge which can be triggered by the application of a control signal and whose operation propels the cut-off device 24 to its deployed position to cut the conductor 10.
• a gasket 26 or other sealing means may be carried by the cutoff member 24 to hermetically seal the first housing part.
• the switch 20 may be an electromechanical electrical switching device, comprising for example moving parts such as separable electrical contacts actuable by means of an actuation mechanism. These moving parts then replace the breaking member 24 and the portion 16 of the electrical conductor 10.
• the circuit breaker 2 also comprises an arc extinguishing chamber 32 partly delimited by a second part 30 of the circuit breaker housing 2.
• the chamber 32 is associated with the electrical conductor 10 and participates in the interruption of the electric current between the first terminal 12 and the second terminal 14 when the circuit breaker 2 is switched from the closed state to the open state.
• the main portion 16 is separated at least from the first terminal 12 or from the second terminal 14 and is located at least in part inside the chamber 32.
• part 16 is detached from terminal 14 but remains attached to terminal 12.
• part 16 could be completely separated from the two terminals 12 and 14.
• the first and second housing parts are joined and aligned in a first direction, for example a vertical direction and the conductor 10 extends in a second direction perpendicular to the first direction, for example in a horizontal direction.
• other configurations can alternatively be used.
• the housing is made of an electrically insulating material, such as a polymer.
• the circuit breaker 2 further comprises a fuse 40 arranged to be electrically connected in series between the first terminal 12 and the second terminal 14 after tripping of the switch, as explained in more detail below.
• fuse 40 In the closed state, fuse 40 remains disconnected from terminal 12. In the example shown, the other end of fuse 40 remains permanently connected to terminal 14.
• the fuse 40 has at least one electrode 42 extending within the internal volume defined by the housing portion 30 delimiting the extinguishing chamber 32.
• a second electrode 44 of the fuse 40 is connected to one of the terminals 12 or 14 of the conductor.
• the free end of the electrode 42 protruding into the chamber 32 here bears the reference "46".
• the free end 46 corresponds to the portion of the electrode 42 which is inside the chamber 32.
• connection of the fuse 40 to the other terminal of the conductor 10 can therefore only be done by means of the extinguishing chamber 32, either by placing the electrode 42 in direct contact with said terminal, or by the intermediate of an electric arc A 'between said terminal 12 and electrode 42.
• the term “fuse” denotes here any component, such as a dipole, capable of dissipating energy to interrupt an electric current. crossing.
• the fuse 40 may include at least one fuse blade arranged in a fuse body.
• the circuit breaker 2 further comprises a connection device comprising an electrically insulating barrier which separates said at least one electrode 42 from the rest of the arc extinguishing chamber 32.
• the electrically insulating barrier comprises a wall 50 which delimits a closed volume 52 within the extinguishing chamber 32.
• the volume 52 is filled. from an electrically insulating medium, such as air or vacuum.
• the barrier can be made differently.
• the barrier is configured to be broken after the triggering of the switch 22 only when at least one or the other of the temperature or the pressure inside the extinguishing chamber.
• the electrode 42 can only be connected to the conductor 10 (in this case, to the terminal 12 in the example of FIG. 2) once the barrier is broken, in particular under the direct or indirect effect of the electric arc A, for example due to heating and / or erosion and / or an increase in pressure of the ionized gases generated by electric arc A.
• the electric arc A disappears and the connection is then made by means of a second electric arc A 'established between the electrode 42 and the end 16 of terminal 12.
• connection device is configured to connect electrode 42 to terminal 12 only after the barrier is broken.
• This connection device implemented by the insulating barrier in the illustrated embodiments, makes it possible to introduce a delay (a delay) between the instant when the actuating device is triggered and the instant when the current to be interrupted is deflected. to fuse 40.
• the value of this delay can be at least partially controlled by choosing barrier construction parameters. In the remainder of this description, this delay may be called "threshold".
• the threshold required to break the barrier and thus connect the fuse 40 indirectly depends on the intensity of the electric current to be interrupted and can be controlled by choosing certain characteristics of the barrier, such as the melting or sublimation temperature of the material used to form the wall 50 and / or the mechanical strength of the wall 50 and / or the dimensional characteristics of the wall 50 and / or the volume 52.
• the threshold from which the fuse is connected after the triggering of the pyrotechnic device automatically adapts according to the conditions prevailing inside the arc extinguishing chamber. Thanks to this adaptation, the same fuse can be used both to interrupt high intensity and low intensity currents.
• the threshold from which the fuse is connected has not been reached.
• the switch operates on its own, the fuse is never connected to terminal 12. This allows for a rapid interruption of the electrical current.
• the threshold from which the fuse is connected has been exceeded.
• the fuse is then sized to have a sufficiently long pre-arcing time, in order to allow the gases in chamber 32 to cool and deionize.
• the wall 50 can be a fusible wall which is destroyed by melting or by sublimation above a predefined temperature, or a wall which deforms or breaks above a predefined temperature. 'a preset pressure.
• the wall 50 is in an electrically insulating material.
• the wall 50 therefore electrically insulates the electrode 42 (for example, at least the portion of the electrode 42 which is inside the chamber 32) from the rest of the chamber 32.
• the insulating properties of the barrier are therefore due the insulating properties of the barrier 50, although the volume 52 of air or vacuum can also participate in this insulation.
• the volume 52 can however be omitted when the wall 50 is sufficiently insulating.
• the electrical insulating properties of the barrier derive from the electrically insulating properties of the volume 52 of air or vacuum, the wall 50 then only serving to contain this volume 52 and to keep it separate. the remainder of the extinguishing chamber 32 until the wall 50 is ruptured.
• the wall 50 may be made of an electrically conductive material, for example of metal, the volume 52 being dimensioned in itself to electrically isolate the electrode 42 from the rest of the chamber 32 and from the wall 50.
• the setting in contact with the electrode 42 is ensured not by breaking the wall 50, but by deforming the wall 50 until it comes into direct contact with the end 46 of the electrode 42 so as to be electrically in contact with the electrode 42. contact with the latter.
• An electrical connection between the fuse 40 and the conductor 10 can then be established by the electric arc A 'which is established between the wall 50 and the terminal 16.
• the fusible wall 50 is made of polymer, for example of polyamide or of polypropylene or of polyimide, or of elastomer, or of polyester, or of silicone, these materials possibly including a mineral filler such as glass fibers or graphene.
• the polymide wall may have a thickness less than 300 ⁇ m, or even less than 100 ⁇ m, or even less than 50 ⁇ m.
• the polypropylene wall may have a thickness of less than 450 ⁇ m, or even less than 300 ⁇ m, or even less than 100 ⁇ m.
• the wall 50 is attached to the interior of the chamber 32.
• the wall 50 can be formed integrally with the walls of the second housing part 30, as illustrated in the insert (b) of FIG. 1, the precise shape of the wall 50 illustrated in this figure is not necessarily limiting. This simplifies the manufacturing process, since the wall 50 can be manufactured at the same time as the rest of the housing 30, for example by molding.
• an attached bottom wall 53 can be used to close the rear of the housing 52.
• the walls of the second housing part 30 may include a housing which opens into the chamber 32 and in which the end 46 of the electrode 42 is placed.
• the wall 50 is arranged in the opening of the housing so as to close this housing.
• the dimensions of the wall 50, and in particular its thickness, depend on the material chosen and on the threshold value adopted for the temperature or for the pressure.
• the wall 50 has a thickness of less than 0.5mm or 0.1mm.
• the volume 52 here has a cylindrical shape with a diameter equal to 3mm and a height equal to 2mm.
• the volume 52 is less than or equal to 50 mm 3 .
• the wall 50 can be replaced by a separation element not necessarily having the shape of a plate, such as a separation membrane, or one or more seals.
• the wall 50 when it is formed of an electrically insulating material, may be covered with an electrically conductive coating on its outer face, c 'that is to say its face directly exposed towards the chamber 32.
• This conductive coating makes it possible to attract the electric arc A as close as possible to the wall 50, which makes it possible to accelerate the rate of degradation of the wall 50.
• Figure 3 shows a circuit breaker 302 according to another embodiment of the invention.
• the circuit breaker 302 is similar to the circuit breaker 2 except that it further comprises a control circuit 310 and a second actuator 312, arranged to break the insulating barrier in response to a control signal emitted by the control circuit 310. .
• the actuator 312 is a pyrotechnic actuator, similar to the actuator 22.
• the actuator 312 can be an electromagnetic actuator or a piezoelectric actuator or use any other suitable motorization means to break the circuit. barrier 50.
• Control circuit 310 includes an electronic processing unit 314 (eg, a processor, such as a microcontroller) and a sensor 316 for measuring at least one physical quantity relating to a condition within chamber 32.
• an electronic processing unit 314 eg, a processor, such as a microcontroller
• a sensor 316 for measuring at least one physical quantity relating to a condition within chamber 32.
• Circuit 310 is configured to trigger second pyrotechnic actuator 312 so as to break said barrier when said measured condition exceeds a predefined threshold.
• the condition is a temperature in the chamber 32, or a pressure in the chamber 32, or the intensity of the current flowing in the conductor 10.
• the sensor 316 is configured to measure the current flowing in the conductor 10 when the electric arc A is established between the terminals 12 and 14. When the measured current exceeds the predefined threshold value, the second actuator 312 is triggered.
• the second actuator 312 is placed outside the chamber 32, being placed opposite the wall 50 by virtue of an opening 318 made in the housing part 30.
• the pressure wave created by the operation of the pyrotechnic charge is at least partly channeled through the passage 318 and reaches the wall 50, causing it to rupture and opening an electrical conduction path between electrode 42 and conductor 10.
• circuit breaker 2 is applicable to circuit breaker 302.
• FIGs 4 and 5 show a circuit breaker 402 according to another embodiment of the invention.
• Circuit breaker 402 is shown in its closed state in Figure 4 and in its open state in Figure 5.
• the circuit breaker 402 is functionally similar to the circuit breaker 2 but differs from the latter in certain construction details and in particular in the way of constructing the insulating barrier of the connection device.
• circuit breaker 402 which are analogous to those of the circuit breaker 2 or which play a role similar to the latter bear the same numerical reference as the latter, increased by the quantity "400".
• the fuse 440 is similar to the fuse 40.
• the description given above of these elements with reference to the embodiments of the circuit breaker 2 can be transposed to the circuit breaker 402.
• the conductor 410 is in the form of a blade or of a tongue comprising terminals 412 and 414 connected together by the central part 416, the latter being able to be precut or weakened compared to terminals 412 and 414.
• the circuit breaker 402 has a body (a housing) having the shape of a cylinder of axis Z402.
• the first part 420 of the housing comprises walls which delimit a central housing 426 centered on the axis Z402 and in which are arranged the pyrotechnic charge 422 of the pyrotechnic switch and a movable body 424 able to move by translation in the housing 426 along the Z426 axis.
• the arc extinguishing chamber 432 is delimited by the walls of the second part 430 of the housing and extends in the extension of the central housing 426.
• the housing 426, the chamber 432 and the movable body 424 have a cylindrical shape.
• the central portion 416 of the conductor 410 extends across the housing 426, perpendicular to the Z402 direction.
• the fuse 440 has a first electrode 442 and a second electrode 444, which are partially inserted into the walls of the second housing part 430 and which open into the extinguishing chamber 432 at ends 446 and 448, respectively.
• the ends 446 and 448 are arranged face to face.
• the insulating barrier comprises an O-ring 450 disposed in the chamber 432 opposite the ends 446 and 448 of the electrodes of the fuse 440.
• the seal 450 is disposed coaxially with the Z402 axis while being pressed against the walls of the chamber 432.
• the seal 450 has a central opening configured to allow the movable body 424 to pass when it is in its deployed position after release. of the pyrotechnic charge 422.
• the seal 450 is made of an elastomeric material, for example of polypropylene, or of PTFE, or of silicone, or any other suitable material.
• a second O-ring 452 is arranged in the chamber 432, above the seal 450, coaxially with the Z402 direction.
• the second seal 452 makes it possible to prevent an electric arc from leaving the chamber 432 when the power is cut off.
• a third O-ring 454 is arranged in the chamber 432, below the seal 450, coaxially with the Z402 direction.
• the third seal 454 makes it possible to prevent, when the power is cut off, an electric arc cannot pass through the main part 16 (the latter having been pushed downwards from the chamber 432 by the mobile body 424 after the triggering. load 422).
• seals 452 and 454 have a higher strength than seal 450, as the latter is configured to rupture when conditions in the chamber require it while seals 452 and 454 must maintain the seal of the chamber. 'extinction during the operation of the circuit breaker.
• the seals 452 and 454 are made of an elastomeric material, for example of PTFE or of silicone, preferably of silicone filled with a mineral material, such as mica.
• at least one vertical seal 456 in the form of a strip connects the seals 450, 452 and 454 by extending along the walls of the chamber 432, for example by extending parallel to the direction Z402. Although only one such vertical seal 456 is visible in FIG. 4, in practice several such seals can be arranged in the chamber 432.
• the vertical seal 456 is made of an elastomeric material, for example of PTFE or of silicone, for example of silicone filled with a mineral material, such as mica, preferably in the same material as the gaskets 452 and 454.
• Figure 6 shows a circuit breaker 502 according to another embodiment of the invention.
• the circuit breaker 502 is similar to the circuit breaker 2 but differs from the latter in that the insulating barrier comprises a metal capsule 550 mounted in a sealed manner around the end 46 of the electrode 42 and which defines a volume 552 comparable to volume 52, as illustrated by insert (a) in figure 6.
• the electrode 42 is isolated from the rest of the chamber 32 by the air or by the vacuum contained in the volume 552.
• the capsule 550 undergoes a deformation which forces it to come into direct contact with the electrode 42, preferably with the free end 46 of the electrode 42, at the level a deformation zone 554, as illustrated schematically by the insert (b) of FIG. 6. In doing so, the electrode 42 is in electrical contact with the capsule 550, even if the latter is not broken and a electrical contact can be established by an electric arc between electrode 42 and conductor 10.
• the end 46 of the electrode 42 has a tip shape and is configured to perforate the capsule 550 when the latter deforms and comes into contact with the end 46. This perforation forms an orifice in the capsule. capsule 550, by which the interior of the volume 552 is placed in communication with the rest of the chamber 32. The insulating barrier is thus broken and an electrical contact can be established by an electric arc between the electrode 42 and the conductor 10.
• the capsule 550 is configured to be ruptured when the pressure in the chamber 32 exceeds the predefined pressure threshold.
• a precut is formed beforehand on one face of the capsule 550. In the event of overpressure, the precut zone is totally or partially detached from the rest of the capsule, thus forming an orifice in the capsule 550, through which the interior of the volume 552 is placed in communication with the rest of the chamber 32. The insulating barrier is thus broken and an electrical contact can be established by an electric arc between the electrode 42 and the conductor 10.
• This variant can advantageously be implemented in the case of a capsule or a wall which is not necessarily metallic or electrically conductive, for example in the case of a membrane or an insulating plastic barrier.
• the capsule 550 can be replaced by one or more metal walls.
• circuit breaker 2 is applicable to circuit breaker 502.
• the wall 30 of the arc extinguishing chamber 32 has a reinforcement zone 560 which protrudes inside the chamber 32 to guide the electric arc A to a particular location. of room 32.
• This reinforcement zone 560 is not essential and can be omitted as a variant. In alternative embodiments, one or more areas of reinforcement 560 could be used in the circuit breakers according to the other embodiments described here.
• Figure 7 shows an electrical circuit breaker 602 according to another embodiment of the invention.
• the circuit breaker 602 is similar to the circuit breaker 2 but differs from the latter in that the insulating barrier has an electrically insulating coating 650 deposited on the end 46 of the electrode 42 and, preferably, on the whole part. of the electrode 42 which extends into the chamber 32.
• the coating 650 isolates the electrode 42 from the rest of the chamber 32 and prevents the establishment of an electrical contact, even by means of an electric arc, between electrode 42 and conductor 10.
• Coating 650 is configured to melt when the temperature in chamber 32 exceeds a predefined temperature. By melting or sublimating, the coating exposes electrode 42 and allows electrical contact to be made with conductor 10.
• the coating 650 is made of polymer, for example of polyamide or of polypropylene or of polyimide.
• the coating 650 is enamel.
• electrode 42 is formed by connecting a portion of enameled wire to fuse 40.
• circuit breaker 2 is applicable to circuit breaker 602.
• Figure 8 shows an electrical circuit breaker 702 according to another embodiment of the invention.
• the circuit breaker 702 is similar to the circuit breaker 2 but differs from the latter in that it has two fuses 710, 720 instead of the fuse 40.
• the first fuse 710 has a first electrode 712 which opens out. inside the chamber 32 and a second electrode 714 connected to the conductor 10, for example here connected to the terminal 14.
• the second fuse 720 comprises a first electrode 722 which opens inside the chamber 32 and a second electrode 724 connected to the conductor 10, for example here connected to the terminal 14 by means of a common electrode with the electrode 714.
• the two fuses 710 and 720 have different ratings.
• fuse 710 has a current rating of 50 A and fuse 720 has a current rating of 150 A.
• a first insulating barrier is associated with the electrode 412 of the first fuse 410 and a second insulating barrier is associated with the electrode 422 of the second fuse 420.
• the first and second insulating barriers are as previously described.
• the first barrier has a wall 730 and volume 732 similar to capsule 550 and volume 552.
• the second barrier has a wall 740 and volume 742 similar to capsule 550 and volume 552.
• walls 730 and 740 can be made in a different fashion.
• it may be walls similar to wall 50.
• the first and second barriers are configured to break under different conditions, in particular so as not to break at the same time.
• the first barrier is configured to rupture before the second barrier when an electric arc A is present after the breaking of the conductor 10 and the temperature and / or the pressure and / or the intensity of the arc increases.
• the barrier being associated with the fuse 410 or 420 having the lower current rating of the two fuses is configured to break before the barrier associated with the other fuse 410 or 420.
• FIG. 7 can be generalized to other embodiments in which more than two fuses 410, 420 are used.
• circuit breaker 2 is applicable to circuit breaker 702.
• Figure 9 shows an electrical circuit breaker 802 according to another embodiment of the invention.
• Circuit breaker 802 is similar to circuit breaker 2 but differs from the latter in that it comprises an additional electrical conductor 860 connected to one of the terminals of conductor 10 (here at terminal 12), the additional electrical conductor 860 being isolated from the arc extinguishing chamber and comprising a free end 862 which opens into the volume 52 delimited by the wall 50.
• the additional electrical conductor 860 is formed outside the body 30 or in a wall of the body 30 (for example by overmolding).
• the additional electrical conductor 860 is made of tungsten.
• the insulation distance between the end 862 of the additional electrical conductor 860 and the end 46 of the electrode 42 is chosen to allow electrical insulation in air for an electrical voltage greater than or equal to at least 1 , 5 times the electrical voltage of the generator used in the electrical circuit to which the circuit breaker 802 is associated.
• the wall 50 can comprise an electrically conductive layer on its outer face, that is to say its face exposed on the side of the chamber 32. This makes it possible to attract the electric arc more easily near the wall. 50 and facilitate its rupture by fusion.
• the wall 50 may include an electrically conductive layer on its inner face, that is to say on its face which is located inside the volume 52. This electrically conductive layer is then capable of ensuring electrical contact between the 2 electrodes 46 and 862 after the barrier has broken.
• circuit breaker 2 is applicable to circuit breaker 802.
• Figure 10 shows an electrical circuit breaker 902 according to another embodiment of the invention.
• the circuit breaker 902 is generally similar to the circuit breaker 2 but differs from the latter in that the connection device does not include a barrier as defined above separating the end 46 from the rest of the extinguishing chamber. bow.
• connection device comprises a housing 910 formed in a wall of the body 30 and in which are arranged a barrier 912 and an electrically conductive movable part 914, for example made of metal, slidably mounted in the housing 910.
• housing 910 is a channel, preferably cylindrical in shape, which opens out to the outside of body 30.
• the end of the electrode 44 of the fuse 40 opens into the housing 910 through its free end 916.
• An additional electrode is connected to the terminal 14 and opens into the housing 910 through its free end 918.
• the ends 916 and 918 are arranged opposite one another.
• the ends 916 and 918 are separated at a distance from each other, for example with an isolation distance as defined above.
• the movable part 914 is movable between a rest position, in which it remains at a distance from the ends 916 and 918, and an energized position in which it electrically connects said electrode of fuse 40 with said terminal 14, by coming into direct contact with the ends. ends 916 and 918.
• the movable part 914 is illustrated in its rest position.
• the position occupied by the moving part 914 in the energized position is represented by the dotted outline 914 '.
• the barrier 912 is arranged to separate the arc extinguishing chamber 32 from the housing 910, for example by closing an entrance to the housing 910.
• Barrier 912 is configured to rupture when the pre-defined threshold in extinguishing chamber 32 is exceeded.
• the barrier 912 can advantageously be a wall similar to the wall 50 or to the capsule 550.
• barrier 912 is configured to rupture when the pressure within arc extinguishing chamber 32 exceeds the predefined threshold.
• part 914 acts like a piston. This movement is illustrated by the arrow F1 in FIG. 10.
• part 914 has a shape complementary to the shape of the section of housing 910.
• the part 914 is mounted in the housing 910 with zero or negative play in order to be able to remain maintained in the rest position as long as the barrier 912 has not been broken and has not been moved by. increased pressure. This limits the risk of the part 914 accidentally moving to the energized position, for example when the circuit breaker 902 is subjected to a shock or to a strong acceleration.
• the part 914 could be mechanically connected with the barrier 912, for example by overmolding.
• the housing 910 includes retaining means 920, such as one or more stops, which limit the movement of the movable part 914 to prevent it from going further than the excited position 914 ’.
• retaining means 920 such as one or more stops, which limit the movement of the movable part 914 to prevent it from going further than the excited position 914 ’.
• part 914 remains held in the excited position 914 ’.
• circuit breaker 902 could include an additional connection device as defined in the embodiments of Figures 1 to 9, associated with the end. 46 of electrode 42.
• the end 46 and the electrode 42 can be omitted and replaced by an electrode 922 which directly connects the end of the fuse 40 to the terminal 12, without necessarily going through the arc extinguishing chamber.
• circuit breaker 2 is applicable to circuit breaker 902.
• the electrode 42 is disposed such in the chamber 32 that the severed part 16 comes into contact against the wall 50 (or the capsule 550) after the cutting of the conductor 10.
• the barrier is broken (for example by destruction of the wall 50 or of the capsule 550)
• the severed part 16 is in direct contact with the electrode 42.
• the breaking devices are described by way of example as being associated with electrode 42 or electrode 44 (and, respectively, terminal 12 or terminal 14), but it is understood that as a variant, these switching devices can be used on the other electrode 44 or 42 of the fuse (and therefore on the other terminal 14 or 12), or even on the two electrodes 42 and 44 at the same time.
• the free end 862 of the additional conductor 860 can open out inside the extinguishing chamber 32, while being outside the volume 52 delimited by the wall 50, the electrode 46 remaining isolated from the rest of the interrupting chamber by the membrane 50
• the free end 862 can thus be placed freely, it is possible to place it at a small distance from the electrode 46, for example at less than 500 ⁇ m, in order to reduce the length of the electric arc, and therefore to reduce the length of the electric arc. 'energy dissipated by this electric arc inside the chamber 52 as well as inside the extinguishing chamber 32.
• the metal capsule 550 may be deformable in a bistable manner, that is to say deformable in a reversible manner between a first state in which the capsule is not. in contact with electrode 46, and a second state in which electrode 46 is in direct contact with metal capsule 550 to establish electrical conductivity.
• the bistable nature of the deformation of the metal capsule can be obtained by virtue of a specific conformation of the upper wall of the capsule, for example by virtue of a convex shape, or a dome shape.
• the convex shape in the first state, is moved away from the electrode 46.
• the convex shape In the second state, the convex shape is inverted and comes into contact with the electrode 46. This favors the contact with the electrode. 'electrode 46 and provides a good threshold effect.
• the circuit breaker 502 comprises an additional conductor similar to the additional conductor 860, and which connects the terminal 12 to the metal capsule, which here bears the reference 1050. This provides the same advantages as those described with reference to the additional conductor 860.
• the free end of the additional conductor can open inside the volume 1052 delimited by the capsule 1050.
• the additional conductor can be connected to the metal capsule even when the capsule is not bistably deformable, like the capsule 550 previously described.
• the movable part 914 is coupled to a return member, such as a helical spring or a pre-stressed spring, configured to push the movable part towards its excited position. .
• a return member such as a helical spring or a pre-stressed spring
• circuit breakers according to one or more of the embodiments described above can be connected together, for example in series or in parallel, by means of their respective terminals 12, 14, to form a device. circuit breaker with increased performance.
• the fuse 40 of one of the circuit breakers can be omitted and replaced by an electrical conductor

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Fuses (AREA)
• Circuit Breakers (AREA)

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• 2019
  • 2019-06-25 FR FR1906892A patent/FR3098006B1/fr active Active
• 2020
  • 2020-06-24 CN CN202080052976.7A patent/CN114144857A/zh active Pending
  • 2020-06-24 EP EP20733663.7A patent/EP3991191B1/de active Active
  • 2020-06-24 JP JP2021577163A patent/JP2022538172A/ja active Pending
  • 2020-06-24 US US17/622,769 patent/US11996252B2/en active Active
  • 2020-06-24 WO PCT/EP2020/067682 patent/WO2020260382A1/fr unknown

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