ELECTRICAL PROTECTION DEVICE

Abstract

The invention relates to an electrical protection device comprising main electrical contacts, a switching mechanism, a solid-state power switch connected in series with the main electrical contacts, a safety device connected in parallel with the main electrical contacts, the safety device comprising secondary electrical contacts, and a control unit. The control unit is adapted to control the power switch and the switching mechanism. The safety device is adapted to activate the switching mechanism when a current exceeding a predetermined value flows through the safety device, thereby switching the main and secondary electrical contacts to the open state. Figure 2:

Description

Title of the invention: ELECTRICAL PROTECTION DEVICE Technical field

[0001] The present invention relates to the technical field of electrical protection devices and systems, such as electrical circuit breakers. More particularly, the invention relates to the technical field of so-called "solid state circuit breaker" electrical circuit breakers. STATE OF PRIOR ART

[0002] Many electromechanical electrical switching devices, such as air circuit breakers, and in particular miniature circuit breakers (MCBs), generally include an arc chute. The arc chute is configured to extinguish an electric arc that appears in the air between the electrical contacts of the device when electrical contacts are separated following tripping of the device.

[0003] The breaking chamber typically comprises, in addition to at least one moving part allowing the circuit to be opened, a stack of metal plates superimposed on top of each other to lengthen and extinguish the electric arc which may appear when the circuit is opened.

[0004] However, in order to improve the performance of these electrical protection devices (hereinafter "protection device"), it has been proposed to replace the breaking chamber with an electronic breaking device comprising power switches based on semiconductor components. Such circuit breakers are called "solid state" circuit breakers.

[0005] French patent application FR3123141 published on November 25, 2022 presents such electrical protection devices.

[0006] The improved performance of these electrical protection devices is, for example, advantageous in direct current (DC) electrical systems comprising electrochemical accumulator batteries, for which the electrical protection devices must be capable, in the event of an electrical fault occurring, of interrupting high intensity currents with a very rapid reaction time.

[0007] These semiconductor electrical protection devices must be capable of interrupting the electric current with at least as much reliability and safety as electromechanical protection devices. These reliability and safety requirements are defined in standards, for example the “UL 489i” standard managed by the Underwriters' Laboratories (UL) certification body.

[0008] This standard includes requirements to be met for solid state molded-case circuit breakers (or solid state hybrid molded-case circuit breakers (SSCB)).

[0009] These requirements cover circuit breakers with a rating of up to 1000 V for alternating current and 1500 V for direct current that switch using semiconductors in 2023. These protective devices are intended, for example, to protect service entrances, feeders and branch circuits. These devices may require an auxiliary control power supply.

[0010] This standard defines that a disconnector must be capable of cutting a current of an intensity equal to six times the nominal current on closing and opening in the event of failure of the cutting electronics.

[0011] The object of the present invention is to propose an electrical protection device comprising a cut-off mechanism in the event of failure of the cut-off electronics. Statement of the invention

[0012] The above-mentioned objectives are, at least in part, achieved by an electrical protection device comprising two connection terminals, main electrical contacts, separable and connected between the two connection terminals, the main electrical contacts being switchable between an open state, in which the electrical contacts are separated, and a closed state, in which the electrical contacts are in contact, a switching mechanism, the switching mechanism being adapted to switch the main electrical contacts to the open state, a semiconductor power switch connected in series with the main electrical contacts, the power switch being adapted to switch between an open state, blocking the flow of current, and a closed state, allowing the flow of current and a safety device connected in parallel with the main electrical contacts.The safety device comprises secondary electrical contacts, the secondary electrical contacts being separable and movable between an open state and a closed state. The switching mechanism is adapted to switch the secondary electrical contacts to the open state. The electrical protection device comprises a control unit, the control unit being adapted to switch the electrical protection device between an open state, in which the power switch, the main electrical contacts and the secondary electrical contacts are in an open state, and a closed state, in which the power switch, the . main electrical contacts and the secondary electrical contacts are in a closed state. The control unit is adapted to control the power switch and the switching mechanism, and to, when closing the electrical protection device, close the secondary electrical contacts of the safety device before the main electrical contacts and the power switch, and, when opening the electrical protection device, open the main electrical contacts and the power switch before opening the secondary electrical contacts of the safety device. The safety device is adapted to, when a current of an intensity greater than a predetermined value flows in said safety device, activate the switching mechanism in order to switch the main electrical contacts and the secondary electrical contacts to the open state.

[0013] Advantageously, the electrical protection device is protected against a possible fault in the power switch which would allow a current to pass despite the fact that the current switch is assumed to be in an open state.

[0014] Indeed, when closing the electrical protection device - when the electrical protection device changes from an open state to a closed state - the secondary electrical contacts of the safety device are closed first. In the event that the power switch, although in the open state, would nevertheless allow a current to pass, then the safety device activates the switching mechanism to immediately open the main electrical contacts and the secondary electrical contacts, possibly in the process of closing, thus interrupting the current in the electrical protection device.

[0015] Similarly, when opening the electrical protection device - when the electrical protection device changes from a closed state to an open state - the secondary electrical contacts of the safety device are opened last. In the event that the power switch, although switched to the open state, would still allow a current to pass, then the safety device activates the switching mechanism to immediately open the main electrical contacts and the secondary electrical contacts, thus interrupting the current in the electrical protection device.

[0016] According to one embodiment of the invention, the safety device comprises a first striker adapted to, when current of an intensity greater than a predetermined value flows in said safety device, activate the switching mechanism in order to switch the main electrical contacts and the secondary electrical contacts to the open state.

[0017] Advantageously, any current passing through the striker makes it possible to trigger said striker and activate the switching mechanism.

[0018] According to one embodiment of the invention, the switching mechanism being adapted to switch the separable main electrical contacts and the separable secondary electrical contacts to the open state and to the closed state, the safety device is further adapted to, when current of an intensity greater than a predetermined value flows in said safety device, and after activating the switching mechanism in order to switch the separable main electrical contacts and the separable secondary electrical contacts to the open state: block the switching mechanism in order to prevent the switching of the main electrical contacts and the secondary electrical contacts to the closed state.

[0019] Advantageously, the safety device, in the event of triggering following a possible failure of the power switch, then blocks any possibility of closing the separable main electrical contacts and the secondary electrical contacts, making the electrical protection device safe.

[0020] According to one embodiment of the invention, the first striker comprises a blocking element adapted to keep the switching mechanism blocked once the striker is struck.

[0021] Advantageously, the striker, once triggered, is locked in its triggered position, which makes it possible to keep the switching mechanism locked, thus preventing any possibility of closing the separable main electrical contacts and the secondary electrical contacts.

[0022] According to one embodiment of the invention, the safety device further comprises a current limiting element connected in series with the secondary electrical contacts.

[0023] Advantageously, if an electric arc forms when the secondary electrical contacts are opened, the current limiting element makes it possible to reduce the intensity of the current passing through the safety device and thus to cut the electric arc between the secondary electrical contacts in the open position. This is particularly advantageous for direct current and / or high voltage (for example, for a voltage greater than 750Vdc).

[0024] According to one embodiment of the invention, the current limiting element connected in series with the secondary electrical contacts is a fuse.

[0025] Advantageously, the fuse makes it possible to cut off the current in the safety device permanently depending on the size of the fuse.

[0026] According to one embodiment of the invention, the safety device further comprises a movable screen, the movable screen being made of an electrically insulating material and adapted to be moved between a first position and a second position, the movable screen being placed by default in the first position and being placed between the main electrical contacts in order to prevent contact between the main electrical contacts in the second position. The safety device comprises a second striker, the second striker being adapted to, when current of an intensity greater than a predetermined value flows in said safety device, move the movable screen into the second position.

[0027] Advantageously, in the event of a possible failure of the power switch, an insulating screen is put in place, physically preventing any closure of the main electrical contacts. Thus, in combination with the presence of a fuse - effectively cutting off the safety device - this feature prevents any closure of the main electrical contacts and makes the cutting of the current for the protection device independent of any possible action of the switching mechanism.

[0028] According to one embodiment of the invention, the first striker and the second striker being the same striker.

[0029] Advantageously, the architecture of the protection device is simplified and made more compact by the use of the same striker to activate the switching mechanism and place the insulating screen between the main contacts. BRIEF DESCRIPTION OF THE FIGURES

[0030] Other characteristics and advantages of embodiments of the electrical protection device according to the invention will appear in the following description, given as non-limiting examples, with reference to the appended figures in which:

[0031] [Fig.l] [Fig.l] illustrates a protection device according to the state of the art as disclosed in French patent application FR3123141 published on November 25, 2022.

[0032] [Fig.2] [Fig.2] schematically illustrates the protection device according to the state of the art.

[0033] [Fig.3] [Fig.3] schematically illustrates the invention according to a first embodiment.

[0034] [Fig.4] [Fig.4] schematically illustrates the invention according to a second embodiment.

[0035] [Fig.5] [Fig.5] illustrates a method of securing the protection device according to an embodiment of the invention, implemented when the protection device is opened.

[0036] [Fig.6] [Fig.6] illustrates a method of securing the protection device according to an embodiment of the invention, implemented when closing the protection device.

[0037] [Fig.7] [Fig.7] schematically illustrates an architecture for implementing the invention according to a first embodiment, making it possible to manage the shift kinematics between the main contact and the arcing contact.

[0038] [Fig.8] [Fig.8] schematically illustrates an architecture for implementing the invention according to a second embodiment, making it possible to manage the kinematics offset between the main contact and the arcing contact.

[0039] [Fig.9] [Fig.9] schematically illustrates an implementation architecture of the invention according to a third embodiment, making it possible to manage the shift kinematics between the main contact and the arcing contact.

[0040] [Fig. 10] [Fig. 10] schematically illustrates an architecture for implementing the invention according to a fourth embodiment, making it possible to manage the shift kinematics between the main contact and the arcing contact.

[0041] [Fig. 11] [Fig. 11] schematically illustrates an architecture of an actuator comprising a locking element in its activated position according to a first embodiment.

[0042] [Fig. 12] [Fig. 12] schematically illustrates an architecture of an actuator comprising a locking element in its activated position according to a second embodiment.

[0043] [Fig. 13] [Fig. 13] schematically illustrates an architecture of an actuator comprising a locking element in its activated position according to a third embodiment.

[0044] [Fig. 14] [Fig. 14] schematically illustrates an architecture of an actuator comprising a locking element in its activated position according to a fourth embodiment.

[0045] [Fig. 15] [Fig. 15] schematically illustrates an architecture of an actuator comprising a locking element in its activated position according to a fifth embodiment.

[0046] DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

[0047] [Fig. 1] illustrates a protection device 20 according to the state of the art as disclosed in French patent application FR3123141 published on November 25, 2022. [Fig. 1] corresponds to [Fig. 2] of patent application FR3123141 amended to remove unnecessary references. A detailed description of this protection device 20 is provided in document FR3123141, particularly from paragraph

[0032] and up to paragraph

[0097] of document FR3123141. The operating mode of the protection device 20 is detailed from paragraph

[0098] of document FR3123141. The references used in the description of [Fig. 1] correspond to the references used in document FR3123141.

[0048] The protection device 20 illustrated in [Fig.l] comprises two pairs of connection terminals 6 and 8: a first input terminal 6 connected to a first output terminal 8 via a first connection line (at the top of [Fig.l]), and a second input terminal 6 connected to a second output terminal 8 via a second connection line (at the bottom of [Fig.l]).

[0049] The protection device 20 illustrated in [Fig.l] comprises contacts separable electrical devices 10 connected between the connection terminals 6 and 8, and a switching mechanism 12 comprising a control member 14 (also called a control handle or operating lever in the following). The operating lever 14 is for example a pivoting lever accessible from outside the housing 4 and intended to be manipulated by a user.

[0050] The separable electrical contacts 10 are movable between an open state, in which the separable electrical contacts 10 are separated, and a closed state, in which the separable electrical contacts 10 are in contact. In the open state, the separable electrical contacts 10 are, for example, separated from each other by a volume of ambient air acting as an electrical insulator, which prevents the flow of an electric current. The switching mechanism 12 makes it possible to switch the separable electrical contacts 10 between the open state and the closed state. The switching mechanism 12 is configured to move the electrical contacts 10 to an open state in response to a switching command. The switching command may be sent by a trigger (“automatic triggering”) or result from an action by a user on the operating lever 14 (“manual triggering”).

[0051] The protection device 20 also comprises an electronic cut-off module which is configured to interrupt an electric current between the connection terminals 6 and 8. The electronic cut-off module, also called a static cut-off module, comprises electronic components, in particular semiconductor components, such as power transistors. The protection device 20 differs from electromechanical air-break protection devices which comprise an arc-breaking chamber (arc extinguishing chamber).

[0052] The protection device 20 thus comprises at least one power switch 22 connected in series with the separable electrical contacts 10. Each power switch 22 is switchable between an electrically blocking state and an electronically conducting state. In the example illustrated in [Fig.l], the protection device 20 comprises four power switches 22, identified by the references T1, T2, T3 and T4. According to an alternative embodiment of the invention, the protection device 20 may comprise a different number of power switches 22. Thus, the number of power switches 22 may vary, depending on the topology of the device and in particular the number of poles (single-phase, polyphase, with or without neutral line) but also depending on the current rating of the device.Each power switch 22 can, in practice, be implemented by several components (such as transistors) connected in parallel depending on the rating of the circuit breaker that one wants to produce.

[0053] The protection device 20 further comprises an electronic control circuit 24 coupled with said at least one power switch 22 (i.e., with each power switch 22). In other words, the electronic control circuit 24 makes it possible to control each of the power switches 22 in order to switch them between the electrically blocking state and the electronically conducting state. In many embodiments, the electronic control circuit 24 comprises a processor, such as a programmable microcontroller or a microprocessor. The processor is advantageously coupled to a computer memory, or to any computer-readable data recording medium, which comprises executable instructions and / or software code intended to implement a method for detecting an electrical fault when these instructions are executed by the processor.In particular, this process makes it possible to detect an electrical fault such as an overload current fault, a short-circuit fault, a differential current fault, a series (or differential) arc presence fault on the line to be protected, but also overvoltages or undervoltages.

[0054] The electronic control circuit 24 is configured to switch the power switches 22 to an open state when an electrical fault is detected, for example by a measuring circuit such as the measuring circuit 30.

[0055] The protection device 20 comprises a synchronization system intended to synchronize the switching of the power switches 22 with the opening of the contacts 10, in order to avoid the occurrence of electric arcs when the electrical contacts 10 open and to provide electrical insulation when the protection device 20 opens. Thus, during an opening phase of the protection device 20, the electronic control circuit 24 controls the switching of the power switches 22 to their blocking state before the electrical contacts 10 are separated, which prevents the occurrence of an electric arc and thus makes it possible to interrupt the current safely. On the other hand, once the electrical contacts 10 are in the open position, the electrical contacts 10 make it possible to create electrical insulation in the air (“air gap” in English).This prevents an electric current, such as a leakage current from the power switches 22, or a current resulting from a failure of these power switches 22, from being able to flow again between the terminals after the protection device 20 has been triggered.

[0056] [Fig.2] schematically illustrates a protection device 200 known to those skilled in the art similar to the protection device 20 previously described.

[0057] The protection device 200 comprises two connection terminals 201 and 202. The two connection terminals 201 and 202 are similar to the connection terminals 6 and 8 of [Fig.l] described previously.

[0058] The protection device 200 comprises main electrical contacts 230, separable and connected between the two connection terminals 201 and 202, the main electrical contacts 230 being switchable between an open state, in which the electrical contacts are separated to block the flow of a current, and a closed state, in which the electrical contacts are in contact to allow the flow of a current. The main electrical contacts 230 are similar to the separable electrical contacts 10 of [Fig.l] described previously.

[0059] The protection device 200 comprises a switching mechanism 240, the switching mechanism being adapted to switch the main electrical contacts 230 between the open state and the closed state. The switching mechanism 240 is adapted to switch the main contacts 230 to the open state. The switching mechanism 240 is similar to the switching mechanism 12 of [Fig.l] described previously.

[0060] The protection device 200 comprises a solid-state power switch 210 connected in series with the main electrical contacts 201 and 202, the power switch being adapted to switch between an open state, blocking the flow of current, and a closed state, allowing the flow of current. The power switch 210 is similar to the power switch 22 of [Fig.l] described previously.

[0061] The protection device 200 comprises a control unit 220, the control unit 220 being adapted to switch the electrical protection device 200 between an open state, in which the power switch 210 and the main electrical contacts 230 are in the open state, and a closed state, in which the power switch 210 and the main electrical contacts 230 are in the closed state. The control unit 220 is adapted to control the power switch 210 and the switching mechanism 240, and to: • when closing the protection device 200, close the main electrical contacts 230 before the power switch 210, and, • when opening the protective device 200, open the power switch 210 before opening the main electrical contacts 230.

[0062] The control unit 220 is similar to the electronic control circuit 24 of [Fig.l] described previously.

[0063] Thus, when the protection device 200 is closed, the main electrical contacts 230 are closed before the power switch 210. That is to say, in the absence of a fault on the power switch 210, the main electrical contacts 230 are closed while no current flows through the protection device 200.

[0064] Similarly, when opening the protection device 200, the power switch 210 is opened before opening the main electrical contacts 230. That is to say, in the absence of a fault on the power switch 210, the contacts main electrical devices 230 are open while no current flows through the protection device 200.

[0065] In the two previous cases of closing or opening of the protection device 200, and in the absence of a fault in the power switch 210, the main electrical contacts 230 are open or closed without any risk of an electric arc appearing between the main contacts 230.

[0066] Conversely, in the case of a fault in the power switch 210, a fault current can flow in the main contacts 230. This can be problematic when opening the protection device 200 because the main contacts 230 are generally not designed to ensure the breaking of an electric arc.

[0067] This is a problem that the invention as described below aims to solve.

[0068] [Fig. 3] schematically illustrates the invention according to a first embodiment.

[0069] The protection device 300 according to this first embodiment of the invention differs from the protection device 200 in that it includes a safety device 350.

[0070] The principle of the invention is to ensure that the safety device 350 of the protection device 300 is opened last when the protection device 300 is opened, and closed first when the protection device 300 is closed. In these two situations, and in the absence of a fault in the power switch 310, no current passes through the safety device 350. Conversely, in the event of a fault in the power switch 310, a fault current then passes through the safety device 350, which makes it possible to trigger the reopening and / or possibly the blocking in the open position of the protection device 300.

[0071] The protection device 300 comprises two connection terminals 301 and 302. The connection terminals 301 and 302 are similar to the connection terminals 6 and 8, and 201 and 202, of FIGS. 1 and 2 previously described.

[0072] The protection device 300 comprises main electrical contacts 330, separable and connected between the two connection terminals 301 and 302, the main electrical contacts being switchable between an open state, in which the electrical contacts are separated, and a closed state, in which the electrical contacts are in contact. The main electrical contacts 330 are similar to the main electrical contacts 10 and 230 of FIGS. 1 and 2 previously described.

[0073] The protection device 300 comprises a switching mechanism 340. The switching mechanism is adapted to switch the main electrical contacts 330 from the open state to the closed state and from the closed state to the open state. The switching mechanism 340 is similar to the switching mechanisms 12 and 240 of FIGS. 1 and 2 described previously. The switching mechanism 340 is adapted to switch the main electrical contacts 330 from the closed state to the open state after activation by a striker, for example the striker 354 described below.

[0074] According to one embodiment of the invention, the switching mechanism 340 comprises an operating lever (not shown) similar to the operating lever 14 of the protection device 20 described in the document FR3123141. The operating lever may be associated with a mechanical position sensor of said operating lever. This mechanical position sensor is adapted to detect the start of an opening operation of the switching mechanism 340 and then issue an electrical command to the control unit 320 indicating that a mechanical opening command is in the process of occurring. The entire protection device 300 is configured so that the static cut-off (i.e. by the power switch 310 described below) takes place before the actual opening of the main electrical contacts 330 and the secondary electrical contacts 352.

[0075] The protection device 300 comprises a solid-state power switch 310 connected in series with the main electrical contacts 330, the power switch 310 being adapted to switch between an open state, blocking the flow of current, and a closed state, allowing the flow of current. The power switch 310 is similar to the power switches 22 and 210 of FIGS. 1 and 2 described previously.

[0076] The protection device 300 comprises, unlike the protection device 200 described previously, a safety device 350 connected in parallel with the main electrical contacts 330, as illustrated in [Fig. 3]. The main electrical contacts 330 and the safety device 350 are both placed in series with the power switch 310.

[0077] The ratio between the impedance of the main electrical contacts 330 and the impedance of the safety device 350 is configured so that, when the protection device 300 is closed, a nominal current flowing through the protection device 300 passes mainly through the main electrical contacts 330 (or "main circuit"), the residual current flowing through the safety device 350 being, relative to this nominal current, negligible. Thus, for this, the impedance of the safety device 350 is significantly greater than the impedance of the main circuit, the main circuit being the circuit formed by the main electrical contacts 330 in the closed position.

[0078] According to one embodiment of the invention, the impedance of the safety device 350 is of an order of magnitude one hundred times greater, preferably one thousand times greater, even more preferably more than one thousand times greater, than the impedance of the main circuit. For example, a ratio between the two impedances of the order of one thousand makes it possible to obtain good operation of the protection device 300.

[0079] The safety device 350 comprises secondary electrical contacts 352, the secondary electrical contacts 352 being separable and movable between an open state, preventing the flow of a current, and a closed state, allowing the flow of a current. The switching mechanism 340 is adapted to switch the secondary electrical contacts 352 to the open state. According to one embodiment, the switching mechanism 340 is adapted to switch the secondary electrical contacts 352 from the open state to the closed state and from the closed state to the open state.

[0080] The safety device 350 comprises a control unit 320, the control unit 320 being adapted to switch the electrical protection device 300 between an open state, in which the power switch 310, the main electrical contacts 330 and the secondary electrical contacts 352 are in an open state, blocking the passage of a current through the electrical protection device 300, and a closed state, in which the power switch 310, the main electrical contacts 330 and the secondary electrical contacts 352 are in a closed state, allowing the passage of a current through the electrical protection device 300.

[0081] The control unit 320 is adapted to control the power switch 310 and the switching mechanism 340, and to: • when closing the electrical protection device 300, close the secondary electrical contacts 352 of the safety device 350 before closing the main electrical contacts 330 then the power switch 310, and, • when opening the electrical protection device 300, open the power switch 310 then the main electrical contacts 330 before opening the secondary electrical contacts 352 of the safety device 350.

[0082] The safety device 350 is adapted to, when a current flows in said safety device 350, activate the switching mechanism 340 in order to switch the main electrical contacts 330 and the secondary electrical contacts 352 to the open state.

[0083] According to one embodiment of the invention, the safety device 350 comprises a striker 354 adapted to, when a current flows in said safety device 350, activate the switching mechanism 340 in order to switch the main electrical contacts 330 and the secondary electrical contacts 352 to the open state. A striker is here a mechanism which, when crossed by an electric current, is adapted to set in motion a movable element in order to strike a triggering element of the switching mechanism 340. A striker is for example an electromagnetic trigger, typically comprising a coil excitation coil coaxially surrounding a tubular insulating sheath, inside which is slidably mounted a movable ferromagnetic core. The ferromagnetic core can be set in motion when a current flows through the excitation coil and then strike the trigger element of the switching mechanism 340. According to an alternative embodiment of the invention, the striker 354 is a vane actuator. More generally, the striker 354 can be an electromagnetic actuator of another type.

[0084] In the case of the protection device 300, when the protection device 300 is opened, the main electrical contacts 330 and the power switch 310 are opened before opening the secondary electrical contacts 352 of the safety device 350. Thus, in the event of a fault in the power switch 310, the fault current present flows through the safety device 350 alone. The safety device 350 is then adapted to cut off the fault current.

[0085] According to one embodiment of the invention, the secondary electrical contacts 352 are adapted to cut off any possible fault current.

[0086] According to one embodiment of the invention, the impedance of the safety device 350 is adapted in order to reduce the intensity of a possible fault current passing through the safety device 350.

[0087] Similarly, when closing the protection device 300, the secondary electrical contacts 352 of the safety device 350 are closed before the main electrical contacts 330 and the power switch 310. Thus, in the event of a fault in the power switch 310, a fault current flows through the safety device 350, the safety device 350 is then adapted to activate the switching mechanism 340 in order to switch the main electrical contacts 330 and the secondary electrical contacts 352 to the open state. Any attempt to close a protection device 300 comprising a defective power switch 310 is thus prevented.

[0088] [Fig.4] schematically illustrates the invention according to a second embodiment.

[0089] The protection device 400 of [Fig.4] differs from the protection device 300 illustrated in [Fig.3] in that the protection device 400 further comprises a current limiting element 355, connected in series with the secondary electrical contacts 352, and a movable screen 331.

[0090] The movable screen 331 is made of an electrically insulating material and is adapted to be moved between a first position and a second position, the movable screen 331 being placed by default in the first position and being placed between the main electrical contacts in order to prevent contact between the main electrical contacts 330 in the second position.

[0091] According to an alternative embodiment of the invention, the protection device 400 comprises, in addition to the first striker 354, a second striker. The second striker is adapted to move the movable screen 331 into the second position when a current flows in the safety device 350.

[0092] According to one embodiment, the movable screen 331 can move from the first to the second position, and from the second position to the first position, depending on the position of the second striker.

[0093] According to another embodiment, the movable screen 331 remains in place once it is in the second position, permanently blocking the main electrical contacts.

[0094] According to the embodiment illustrated in [Fig.4], the first striker 354 and the second striker are the same striker 354, the latter being adapted to both activate the switching mechanism 340 and place the screen 331 in the second position when a fault current flows through it.

[0095] Advantageously, in the event of a fault in the power switch 310, the insulating screen 331 is placed in the second position, physically preventing the main electrical contacts 330 from closing.

[0096] Advantageously, the current limiting element 355 makes it possible to increase the arc voltage (in addition to the arc voltage of the secondary contacts 352).

[0097] According to one embodiment of the invention, the current limiting element 355 is a resettable fuse with a positive temperature coefficient (PTC) (polymeric positive temperature coefficient device (PPTC) in English).

[0098] Advantageously, when the current limiting element 355 is a fuse, the striker 354 comprises a blocking element in order to possibly provide for the replacement of the damaged component, for example the damaged power switch and / or the fuse.

[0099] According to another embodiment of the invention, the current limiting element 355 is a fuse. In this other embodiment, the installation of the screen 331 between the main electrical contacts 330 and the melting of the fuse 355 make it possible to guarantee that the protection device 400 is permanently cut off in the event of a fault in the power switch 310.

[0100] [Fig.5] illustrates a method for securing the protection device 300 or 400 (hereinafter protection device) as described previously according to an embodiment of the invention, implemented when the protection device is opened.

[0101] Step 500 corresponds to the closed state of the protection device. In this closed state, the power switch 310, the main electrical contacts 330 and the secondary electrical contacts 352 are closed, a nominal current can flow through the protection device.

[0102] In a step 505, a command to open the protection device is received, for example by an action of a user on the operating lever of the switching mechanism 340. This opening command may correspond to a manual command carried out by a user using a control member of the protection device (for example an operating lever associated with the switching mechanism 340) or to an automatic triggering controlled by the control unit 320 following the detection of an electrical fault.

[0103] According to an embodiment of the invention, during this step 505, the switching mechanism 340 is activated in order to initiate the switching of the main electrical contacts 330 and the secondary electrical contacts 352 to the open state, the switching mechanism 340 being adapted so that the main electrical contacts 330 are only open in step 515 and the secondary electrical contacts 352 only in step 530. In other words, the switching mechanism 340 is adapted so that the opening of the secondary contacts 352 (step 530) only takes place once the main contacts 330 are actually open (step 515). In other words, the main contacts 330 must be sufficiently open so that there is no appearance of an electric arc between the main contacts 330 when an arc voltage appears on the secondary contacts 352 when they open.There is therefore a predetermined time lag between steps 515 and 530, depending for example on the opening speed of the main contacts 330. Figures 7 to 10 illustrate examples of switching mechanisms making it possible to obtain a time lag between the switching of the main electrical contacts 330 and the switching of the secondary electrical contacts 352. In a following step 510, the control unit 320 switches the power switch 310 to the open state.

[0104] In a step 515, starting later than or simultaneously with step 510, the control unit 320 switches the main electrical contacts 330 to the open state, possibly via the switching mechanism 340. The faster switching time of the power switch 310 ensures that step 510 is completed before step 515. In other words, in the absence of a fault in the power switch 310, the main electrical contacts 330 are open without voltage, the power switch 310 having previously cut off the current.

[0105] Following steps 510 and 515, in a step 520, a fault current may nevertheless be present in the event of a fault in the power switch 310.

[0106] In the case where there is no fault current, i.e. the power switch 310 does not have a fault, in a step 530, the control unit 320 switches the secondary electrical contacts 352 to the open state, possibly via the switching mechanism 340.

[0107] In a following step 540, the protection device is then in an open state. In this open state, the power switch 310, the main electrical contacts 330 and the secondary electrical contacts 352 are open, no current can flow through the protection device.

[0108] In the case where there is a fault current, that is to say that the power switch 310 has a fault, in a step 550, the safety device 350, being crossed by the fault current, activates the switching mechanism 340 in order to switch the main electrical contacts 330 and the secondary electrical contacts 352 to the open state. For this, the safety device 350 may comprise a striker 354 adapted to, when a fault current flows in said safety device 350, activate the switching mechanism 340 in order to switch the main electrical contacts 330 and the secondary electrical contacts 352 to the open state.

[0109] According to one embodiment of the invention, the striker 354 comprises a blocking element adapted to keep the switching mechanism 340 blocked once the striker 354 has been struck. Thus, advantageously, during step 550, the switching mechanism 340 is blocked, preventing any subsequent closing of the protection device 300.

[0110] According to one embodiment of the invention, the striker 354 does not comprise a blocking element. The activation of the switching mechanism 340 in order to switch the main electrical contacts 330 and the secondary electrical contacts 352 to the open state is redundant with the step 505 of initiating the switching to the open state of the main electrical contacts 330 and the secondary electrical contacts 352. This remains, however, advantageous because it allows for a simple technical architecture making it possible to protect the protection device 300 and operating both when opening and closing the protection device 300.

[0111] In a subsequent step 570, the secondary electrical contacts 352 are opened. According to one embodiment of the invention, the impedance of the safety device 350 reduces the power of any electric arc appearing when the secondary electrical contacts 352 open, allowing effective breaking of the fault current. This impedance can be adapted thanks to the presence of a current limiting element 355.

[0112] In an optional step 560, present if the protection device comprises a current limiting element 355 of the fuse type, then said fuse melts, cutting off the current in the safety device 350.

[0113] In addition, and in an optional step not shown, and if the safety device comprises a second striker, possibly the same as striker 354, and a movable screen 331 as described previously, the second striker then moves the movable screen 331 into the second position, thus preventing a future closing of main electrical contacts 330.

[0114] In a following step 580, the protection device is then in an open state. In this open state, the power switch 310, the main electrical contacts 330 and the secondary electrical contacts 352 are open, no current can flow through the protection device 300.

[0115] According to one embodiment of the invention, if the safety device 350 comprises a current limiting element 355, a second striker, possibly the same as the striker 354, and a movable screen 331 as described previously, the protection device 300 cannot be returned to its closed state, the safety device 350 being cut off by the melting of the fuse 355 and the main electrical contacts 330 blocked by the placement of the screen 331 in the second position.

[0116] According to an embodiment of the invention, the safety device 350 is further adapted to, when a current flows in said safety device 350, and after activating the switching mechanism 340 in order to switch the main electrical contacts 330 and the secondary electrical contacts 352 to the open state, block the switching mechanism 340 in order to prevent the switching of the main electrical contacts 330 and the secondary electrical contacts 352 to the closed state. According to this embodiment, the switching mechanism 340 is blocked by the striker 354 and can no longer switch the main electrical contacts 330 and the secondary electrical contacts 352 to the closed state.

[0117] According to one embodiment of the invention, the striker 354 comprises a blocking element adapted to keep the switching mechanism 340 blocked once the striker is struck.

[0118] [Fig.6] illustrates a method for securing the protection device 300 or 400 (hereinafter protection device) as described previously, according to an embodiment of the invention, implemented when closing the protection device.

[0119] Step 600 corresponds to the open state of the protection device. In this open state, the power switch 310, the main electrical contacts 330 and the secondary electrical contacts 352 are open, no current can flow through the protection device.

[0120] In a step 605, a command to close the protection device is received. This closing command may correspond to a manual command carried out by a user using a control member of the protection device (for example an operating lever associated with the switching mechanism 340) or to an automatic closing controlled by the control unit 320.

[0121] In a subsequent step 610, the control unit 320, possibly via the switching mechanism 340, switches the secondary electrical contacts 352 to the closed state.

[0122] In a step 615, a fault current may appear in the protection device in the event of a fault in the power switch 310.

[0123] In the absence of fault current, in steps 620 and 630, possibly simultaneously, the control unit 320 switches the main electrical contacts 330 and the power switch 310 to the closed state.

[0124] In a following step 640, the protection device is then in a closed state. In this closed state, the power switch 310, the main electrical contacts 330 and the secondary electrical contacts 352 are closed, a nominal current can flow through the protection device.

[0125] In the presence of a fault current, in a step 650, the safety device 350, being crossed by the fault current, activates the switching mechanism 340 in order to switch the main electrical contacts 330 and the secondary electrical contacts 352 to the open state.

[0126] In an optional step 670, if the safety device comprises a second striker, possibly the same as striker 354, and a movable screen 331 as previously described, the second striker then moves the movable screen 331 into the second position, thereby physically preventing the main electrical contacts 330 from closing.

[0127] In a step 680, the secondary electrical contacts 352 are in the open state.

[0128] In an optional step 660, present if the protection device comprises a fuse-type current limiting element 355, then said fuse blows, cutting off the current in the safety device 350.

[0129] According to one embodiment of the invention, if the safety device comprises a current limiting element 355, a second striker, possibly the same as the striker 354, and a movable screen 331 as described previously, the protection device cannot be returned to its closed state, the safety device being cut by the fuse and the main electrical contacts 330 blocked by the screen 331.

[0130] According to one embodiment of the invention, the safety device 350 is further adapted to block the switching mechanism 340 in order to prevent the switching of the main electrical contacts 330 and the secondary electrical contacts 352 to the closed state. According to this embodiment, the switching mechanism 340 is blocked by the striker 354 and can no longer switch the main electrical contacts 330 and the secondary electrical contacts 352 to the closed state.

[0131] According to one embodiment of the invention, the striker 354 comprises a blocking element adapted to keep the switching mechanism 340 blocked once the striker 354 is struck.

[0132] In a following step 690, the protection device is then in an open state. In this open state, the power switch 310, the electrical contacts main 330 and secondary 352 electrical contacts are open, no current can flow through the protective device.

[0133] Figures 7, 8, 9 and 10 schematically illustrate architectures for implementing the invention according to different embodiments. In these different embodiments, the switching mechanism 340 makes it possible to mechanically manage a time shift kinematics between the switching of the main electrical contacts 330 and the secondary electrical contacts 352. This time shift kinematics is suitable for: • when activating the switching mechanism 340 to open the protection device 300, allow the main electrical contacts 330 to be opened before the secondary electrical contacts 352, and, • when activating the switching mechanism 340 to close the protection device 300, allow the secondary electrical contacts to be closed before the main electrical contacts 330.

[0134] [Fig.7] schematically illustrates an architecture for implementing the invention according to a first embodiment.

[0135] [Fig. 7] comprises the three figures 7A, 7B and 7C, illustrating the same architecture for implementing the invention in a protection device 700 according to the first embodiment. Each figure 7A, 7B and 7C illustrates the protection device 700 and corresponds to a different position of a contact element 740A (hereinafter element 740A) included in a switching mechanism 740 similar to the switching mechanism 340 described previously

[0136] The protection device 700 comprises two connection terminals 701 and 702. The connection terminals 701 and 702 are similar to the connection terminals 301 and 302 of [Fig.3] previously described.

[0137] The protection device 700 comprises a power switch 710 similar to the power switch 310 of the protection device 300 described previously.

[0138] The protection device 700 comprises main electrical contacts 730. The main electrical contacts 730 are switchable between an open state, in which the electrical contacts are separated, and a closed state, in which the electrical contacts are in contact. The main electrical contacts 730 are similar to the main electrical contacts 330 of [Fig. 3] previously described.

[0139] The protection device 700 comprises secondary electrical contacts 752. The main electrical contacts 752 are switchable between an open state, in which the electrical contacts are separated, and a closed state, in which the electrical contacts are in contact. The main electrical contacts 752 are similar to the main electrical contacts 352 of [Fig. 3] previously described.

[0140] The protection device 700 comprises a switching mechanism 740 (referenced "COMMUT" in [Fig.7]). The switching mechanism 740 is adapted to switch the main electrical contacts 730 and the secondary electrical contacts 752 from the open state to the closed state and from the closed state to the open state. The switching mechanism 740 is similar to the switching mechanisms 340 of [Fig.3] described previously.

[0141] In this first embodiment of the invention, the switching mechanism 740 comprises the contact element 740A, this contact element 740A comprising an upper part of the main contacts 730 and an upper part of the secondary contacts 752. The element 740A is made of an electrically conductive material and allows electrical continuity between the connection terminals 701 and 702 when the upper part of the main contacts 730 or the upper part of the secondary contacts 752 is in contact with the lower part of the respective contacts.

[0142] The element 740A is rotatably mounted on an axis 740B, the switching mechanism 740 being adapted to pivot the element 740A about this axis 740B, between a high position, illustrated in FIG. 7A and a low position, illustrated in FIG. 7C. The high position corresponds to the open position of the protection device 700. The low position corresponds to the closed position of the protection device 700.

[0143] The protection device 700 is adapted so that, when the element 740A passes from its high position to its low position, and vice versa, the element 740A passes through an intermediate position illustrated in FIG. 7B. In this intermediate position, the secondary contacts 752 are closed while the main contacts 730 are open. For this, as illustrated in [Fig. 7], the lower part of the secondary contacts 752 can be raised relative to the lower part of the main contacts 730, the lower part of the secondary contacts 752 being able for example to be mounted on a spring.In this way, when moving from the high position to the low position of the element 740A, the element 740A first comes into contact with the lower part of the secondary contacts 752, then, for example thanks to the elasticity of the spring on which the lower part of the secondary contacts 752 is mounted, the element 740A can continue to descend to reach its low position illustrated in FIG. 7C in which the main contacts 730 and the secondary contacts 752 are both closed. This offset arrangement of the contacts makes it possible to introduce a time lag between the main and secondary contacts when making contact (closing) and when opening the protection device 700 in accordance with the closing and opening methods described previously and illustrated in FIGS. 5 and 6.

[0144] The protection device 700 comprises a striker 754 similar to the striker 354 of the protection device 300 described previously. This striker, when it is crossed by a fault current, can activate a trigger (reference "TRIP", for "tripping" in English or "triggering" in French), of the switching mechanism 740), then triggering the upward pivoting of the element 740A, by a rotation around the axis 740B, first opening the main contacts 730 (intermediate position illustrated in figure 7B) then the secondary contacts 752 (open position illustrated in figure 7A).

[0145] In other words, the protection device 700 comprises a safety device similar to the safety device 350 of the protection device 300 described previously. The safety device of the protection device 700 comprises the secondary contacts 752, the striker 754, adapted to be able to trigger the switching mechanism 740 and to be able to put the screen 721 in place, and the current limiting element 755.

[0146] In the embodiment illustrated in [Fig.7], the striker 754 is adapted to be able to trigger the switching device 740 and put in place the screen 721 when a fault current of an intensity greater than a predetermined value flows in the protection device.

[0147] The protection device 700 may comprise a screen 721, similar to the screen 321 of the protection device 300 described previously. In the embodiment illustrated in [Fig.7], the screen 721 is adapted to be able to be pushed by the striker 752 towards the left of the figure, to come and be interposed between the lower part and the upper part (on the element 740A) of the main contacts 730, thereby preventing the possible closing of the main contacts 730.

[0148] The protection device 700 may comprise a current limiting element 755, similar to the element 355 of the protection device 300 described previously.

[0149] The protection device 700 is adapted to implement the safety method implemented when opening a protection device described previously and illustrated in [Fig.5].

[0150] The protection device 700 is adapted to implement the safety method implemented during the closing of a protection device described previously and illustrated in [Fig.6].

[0151] [Fig.8] schematically illustrates an architecture for implementing the invention according to a second embodiment, making it possible to manage the shift kinematics between the main contact and the arcing contact.

[0152] [Fig. 8] comprises the three figures 8A, 8B and 8C, illustrating the same architecture of implementation of the invention in a protection device 800 according to the second embodiment. Each figure 8A, 8B and 8C illustrates the protection device 800 and corresponds to a different position of a contact element 840A (hereinafter element 840A) included in a similar switching mechanism 840 to the switching mechanism 340 described previously.

[0153] The protection device 800 corresponds to an alternative embodiment of the protection device 700 described above and differs from it in that it does not comprise a spring supporting the lower part of the secondary contacts 752 and making it possible to generate a time shift, during the lowering or raising movement of the element 740A, between the openings and closings of the main and secondary contacts.

[0154] The protection device 800 comprises an element 840A, substantially similar to the element 740A, comprising two sub-elements 840Ap and 840As. The sub-element 840Ap comprises an upper portion of the main contacts 830. The sub-element 840As comprises an upper portion of the secondary contacts 852 and is flexible. The sub-element 840As is for example a spring blade. The mechanical offset between the position of the two sub-elements 840Ap and 840As in the open position (illustrated in FIG. 8A), the sub-element 840As then being under the sub-element 840Ap, as well as the elasticity of the element 840As, makes it possible to generate the time offset previously described in the methods illustrated in FIGS. 5s and 6 during the closing of the secondary 852 and main 830 contacts.

[0155] The protection device 800 is adapted to implement the safety method implemented when opening a protection device described previously and illustrated in [Fig.5].

[0156] The protection device 800 is adapted to implement the safety method implemented during the closing of a protection device described previously and illustrated in [Fig.6].

[0157] [Fig.9] schematically illustrates an architecture for implementing the invention according to a third embodiment, making it possible to manage the shift kinematics between the main contact and the arcing contact.

[0158] [Fig. 9] comprises the three figures 9A, 9B and 9C, illustrating the same architecture for implementing the invention in a protection device 900 according to the third embodiment. Each figure 9A, 9B and 9C illustrates the protection device 900 and corresponds to a different position of a contact element 940A (hereinafter the element 940A) included in a switching mechanism 940 similar to the switching mechanism 340 described previously.

[0159] In this alternative embodiment, the time shift, during the lowering or raising movement of the element 940A, between the openings and closings of the main 930 and secondary 952 contacts, is obtained by a cantilever between a guide point 940B of the element 940A by the switching mechanism 940 and an elastic pivot means, for example a spring 925.

[0160] The protection device 900 comprises a firing pin 954 similar to the firing pin 354. The striker 954 is adapted to trigger the switching mechanism 940, and possibly put in place the screen 921, when a fault current of an intensity greater than a predetermined value flows in the protection device 900.

[0161] The protection device 900, as for the other embodiments, may comprise a current limiting element 955, possibly a fuse, and / or a screen 921, similar respectively to the current limiting element 355 and the screen 321.

[0162] The protection device 900 is adapted to implement the safety method implemented when opening a protection device described previously and illustrated in [Fig.5].

[0163] The protection device 900 is adapted to implement the safety method implemented during the closing of a protection device described previously and illustrated in [Fig.6].

[0164] [Fig. 10] schematically illustrates an architecture for implementing the invention according to a fourth embodiment, making it possible to manage the shift kinematics between the main contact and the arcing contact.

[0165] [Fig. 10] comprises Figures 10A and 10B, illustrating the same architecture of a protection device 1000 in three different positions (positions 1, 2 and 3, the three references corresponding to these three positions being boxed in Figures 10A and 10B) of a contact element 1040A (hereinafter element 1040A) included in a switching mechanism 1040 (open position 1 being illustrated in both Figures 10A and 10B). The switching mechanism 1040 comprises the contact element 1040A, the element 1040A being shown individually in Figures 10A and 10B to clarify its operation.

[0166] Figures 10A and 10B illustrate connection terminals 1001 and 1002 similar to connection terminals 301 and 302, as well as a power switch 1010 similar to power switch 310 (referenced “SS CB” for “Solid State Circuit Breaker” in English). A striker 1052 is illustrated, the dotted lines illustrating that the activation of this striker 1052 is adapted to trigger the switching mechanism 1040 (illustrated in Figures 10A and 10B by the reference “TRIP”, for “tripping” in English, or “triggering” in French) and, possibly, to put in place a movable screen 1021 similar to the movable screen 321 (movable screen 1021 not shown in Figure 10B for simplification). A current limiting element 1055, possibly a fuse, is also shown. This current limiting element 1055 is similar to current limiting element 355.

[0167] Main electrical contacts 1030 and secondary electrical contacts 1052 are illustrated. The main electrical contacts 1030 are similar to the contacts main electrical contacts 330. Secondary electrical contacts 1052 are similar to secondary electrical contacts 352. As illustrated, a portion of each of the main and secondary electrical contacts is included on the same element 1040A.

[0168] The element 1040A is an electrical conductor. The element 1040A comprises two hinged rods, a spring-like element maintaining a bent shape to the element 1040A so that, when the element 1040A is lowered, as illustrated in position 2, the end of the element 1040A, comprising a portion of the secondary electrical contacts 1052, first contacts the fixed portion of the secondary electrical contacts 1052.

[0169] A fixed stop 1025 is adapted so that the lowering of the element 1040A causes a tilting effect on the end of the element 1040A, the contact between the secondary electrical contacts 1055 being broken, and the main electrical contacts 1030 being closed, as illustrated by position 3 of FIG. 10B.

[0170] Advantageously, in this embodiment illustrated in [Fig.10], the main electrical contacts 1030 and the secondary electrical contacts 1052 are not in the closed position at the same time.

[0171] When closing the protection device 1000, and similarly to the method illustrated in [Fig. 6], the secondary electrical contacts 1052 are thus closed (step 610) before the main electrical contacts 1030 are closed (step 620). If a fault current is present, this activates the striker 1054 and causes the switching mechanism 1040 to be triggered, the element 1040A being raised, which opens the protection device. In this case, the element 1040A is possibly raised before it can even come into contact with the main electrical contacts 1030.

[0172] When opening the protection device 1000, and in a similar manner to the method illustrated in [Fig. 5], the secondary electrical contacts 1052 are thus well opened (step 530; corresponding to the passage of the element 1040A from position 2 to position 1) after the main electrical contacts 1030 are (step 515, corresponding to the start of the passage of the element 1040A from position 3 to position 2). A particularity of the embodiment illustrated in [Fig. 10] is that an intermediate step of closing the secondary electrical contacts 1052 is carried out immediately after the opening of the main electrical contacts 1030 by the rocking of the end of the element 1040A around the stop 1025 when the element 1040A is raised (end of the passage from position 3 to position 2 of the element 1040A).

[0173] [Fig. 11] schematically illustrates an architecture of a firing pin comprising a blocking element in its activated position according to a first embodiment.

[0174] The firing pin illustrated corresponds to the firing pin 354 described previously. Figure 11A illustrates the firing pin 354 in a non-activated, so-called rest, position. The figure 1 1B illustrates the striker 354 in an activated position. The striker 354 here comprises a blocking element 354A preventing any return to the rest position illustrated in FIG. 11A of the striker after the striker 354 has passed into its activated position illustrated in FIG. 1 1B. The striker 354 is thus maintained in its struck position (FIG. 1 1B) and is adapted to thus keep triggered (or activated) a switching mechanism such as the switching mechanism 340 described previously. The switching mechanism 340 is thus kept blocked once the striker 354 has been activated, preventing switching to the closed state of the protection device 300. In other words, once the striker 354 has been activated, it maintains an action on the trigger mechanism (reference "TRIP" in the preceding figures) of the switching mechanism, keeping said switching mechanism in its open position.The blocking element 354A makes the passage of the firing pin 354 from its rest position (figure 11 A) to its activated position (figure 11B) irreversible.

[0175] [Fig. 12] schematically illustrates an architecture of a firing pin comprising a locking element in its activated position according to a second embodiment.

[0176] [Fig. 12] illustrates an alternative embodiment of the locking element 354A. In this embodiment of the invention, the locking element 354A takes a conical shape, allowing the passage of the firing pin in one direction, but preventing its return to the rest position.

[0177] [Fig. 13] schematically illustrates an architecture of a firing pin comprising a blocking element in its activated position according to a third embodiment.

[0178] [Fig. 13] illustrates an alternative embodiment of the locking element 354A. In this embodiment of the invention, the locking element 354A takes the form of a flexible lug, making it possible to retain the firing pin in its activated position, preventing it from returning to the rest position.

[0179] [Fig. 14] schematically illustrates an architecture of a firing pin comprising a locking element in its activated position according to a fourth embodiment.

[0180] [Fig. 14] illustrates an alternative embodiment of the blocking element 354A. In this embodiment of the invention, the blocking element 354A takes the form of a flexible rod comprising a thickness at its end, making it possible to retain the firing pin in its activated position (position illustrated in FIG. 14C), preventing it from returning to the rest position (position illustrated in FIG. 14A). The flexibility of the blocking element 354A allows the firing pin to be activated (illustration of the flexibility of the rod of the blocking element 354A in FIG. 14B, corresponding to the passage from the rest position to the activated position), but then the end of the flexible rod prevents it from returning to the rest position. The flexibility of the spring blade advantageously allows the firing pin to be kept in the rest and retracted position.

[0181] [Fig. 15] schematically illustrates an architecture of an actuator comprising a locking element in its activated position according to a fifth embodiment.

[0182] [Fig. 15] illustrates a firing pin similar to the firing pin 354 and comprising a blocking element 354A. The firing pin illustrated corresponds to an alternative embodiment to the firing pin illustrated in [Fig.l 1]. The conical shape of the end of the firing pin makes it possible to maintain the firing pin in the retracted position at rest, in fact the force of the spring of the blocking element 354A is converted into a force for maintaining the retracted position by the contact of the end of the blocking element 354A on the conical shape. This principle advantageously replaces a spring normally present in the firing pin to maintain the rest position of the firing pin.

Claims

1. Claims Electrical protection device (300) comprising: - two connection terminals (301, 302), - main electrical contacts (330), separable and connected between the two connection terminals, the main electrical contacts being switchable between an open state, in which the electrical contacts are separated, and a closed state, in which the electrical contacts are in contact, - a switching mechanism (340), the switching mechanism being adapted to switch the main electrical contacts to the open state, - a semiconductor power switch (310) connected in series with the main electrical contacts, the power switch being adapted to switch between an open state, blocking the flow of current, and a closed state, allowing the flow of current, - a safety device (350) connected in parallel with the main electrical contacts, the safety device comprising: • secondary electrical contacts (352), the secondary electrical contacts being separable and movable between an open state and a closed state, the switching mechanism being adapted to switch the secondary electrical contacts to the open state, - a control unit (320), the control unit being adapted to switch the electrical protection device between an open state, in which the power switch, the main electrical contacts and the secondary electrical contacts are in an open state, and a closed state, in which the power switch, the main electrical contacts and the secondary electrical contacts are in a closed state, the control unit being adapted to control the power switch and the switching mechanism, and to: • when closing the protective device electrical, close the secondary electrical contacts of the safety device (610) before the main electrical contacts (620) and the power switch (630), and, • when opening the electrical protection device, open the main electrical contacts (515) and the power switch (510) before opening the secondary electrical contacts (530, 570) of the safety device, the safety device being adapted for, when a current of an intensity greater than a predetermined value flows in said safety device: - activating the switching mechanism (650) to switch the main electrical contacts (330) and the secondary electrical contacts (352) to the open state (680).

2. Electrical protection device (300) according to the preceding claim, the safety device comprising a first striker (354) adapted to, when the current of an intensity greater than a predetermined value flows in said safety device (350), activate the switching mechanism (340) in order to switch the main electrical contacts (330) and the secondary electrical contacts (352) to the open state.

3. Electrical protection device (300) according to one of the preceding claims, the switching mechanism being adapted to switch the separable main electrical contacts and the separable secondary electrical contacts to the open state and to the closed state, the safety device being further adapted to, when current of an intensity greater than a predetermined value flows in said safety device, and after activating the switching mechanism in order to switch the separable main electrical contacts and the separable secondary electrical contacts to the open state: blocking the switching mechanism (340) to prevent the switching of the main electrical contacts and the secondary electrical contacts to the closed state.

4. An electrical protection device according to claims 2 and 3, the first striker (354) comprising a blocking element (354A) adapted to keep the switching mechanism (340) blocked once the striker is struck.

5. An electrical protection device according to one of the preceding claims, the safety device further comprising a current limiting element (355) connected in series with the secondary electrical contacts (352).

6. Electrical protection device according to the preceding claim, the current limiting element (355) connected in series with the secondary electrical contacts being a fuse.

7. An electrical protection device according to one of the preceding claims, the safety device further comprising a movable screen (321), the movable screen being made of an electrically insulating material and adapted to be moved between a first position and a second position, the movable screen being placed by default in the first position and being placed between the main electrical contacts in order to prevent contact between the main electrical contacts in the second position, the safety device comprising a second striker, the second striker being adapted to, when current of an intensity greater than a predetermined value flows in said safety device: - move the movable screen into the second position.

8. Electrical protection device according to claims 4 and 7, the first striker (354) and the second striker being the same striker (354).

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