Electrical circuit protection system

Abstract

The present disclosure relates to a protection system (10) for an electrical circuit (1), the protection system (10) comprising: - a conductor (11, 12, 13) comprising a first conductor portion (11), a second conductor portion (12) and a third conductor portion (13) electrically connecting together the first conductor portion (11) and the second conductor portion (12), and - a ferromagnetic body (14) arranged in the space between the first conductor portion (11) and the second conductor portion (12), the conductor (11, 12, 13) and the ferromagnetic body (14) being configured such that, when a current flowing in the conductor (11, 12, 13) has an intensity I greater than or equal to a threshold intensity IS, a mechanical force in the conductor (11, 12, 13) induced by this current causes the mechanical rupture of the conductor (11, 12, 13). Abstract Figure: Figure 1

Description

Title of the invention: Electrical circuit protection system Technical field

[0001] The present disclosure relates to the field of electrical circuit protection systems, particularly for high DC voltage applications. Prior Art

[0002] In the context of propulsion equipment, in particular aircraft, the electrical power supply to the equipment is carried out by means of an electrical energy storage device in the form of a battery and a battery management device, designated by the acronym BMS in reference to "Battery Management System" in English. The electrical circuit thus defined generally has an electrical protection system in order to protect the various elements of the electrical circuit.

[0003] In particular, high-voltage fuses are conventional electrical protection systems. However, fuses have the disadvantages of being heavy and bulky. In addition, these fuses cannot be controlled and have a response time, of the order of a few ms for the most reactive fuses, which may prove too long to ensure optimal protection of the electrical circuit.

[0004] Another solution consists, for example, in implementing contactors, for example associated with a current measurement or with means for detecting faults in the electrical circuit. The contactors nevertheless have a breaking capacity, i.e. a maximum intensity at which the contactor can perform its current breaking function in the event of a short circuit, which is limited, in particular for high voltage applications. In addition, contactors, similarly to fuses, have a response time, of the order of 25 ms, which may prove too long to ensure optimal protection of the electrical circuit.

[0005] Pyroswitches, also known as pyroswitches, are also known protection systems. Such pyroswitches are based on a principle of triggering, for example by an electrical signal, an explosion that irreversibly damages a conductor and thus ensures the current is cut off. However, these pyroswitches have a limited breaking capacity and a response time that can be long.

[0006] There is therefore a need to improve electrical circuit protection systems, particularly for high DC voltage applications. Summary

[0007] The present disclosure improves the situation.

[0008] A system for protecting an electrical circuit is provided, the protection system comprising a conductor and a ferromagnetic body. The conductor comprises a first conductor portion and a second conductor portion configured in space relative to the first conductor portion such that a direction of a current flowing through the first conductor portion is predominantly opposite in space to a direction of a current flowing through the second conductor portion. The conductor comprises a third conductor portion electrically connecting the first conductor portion and the second conductor portion together. The ferromagnetic body is arranged in the space between the first conductor portion and the second conductor portion.The conductor and the ferromagnetic body are configured so that, when a current flowing in the conductor has an intensity I greater than or equal to a threshold intensity Is, a mechanical force in the conductor, in particular a mechanical tensile force, induced by this current causes the mechanical rupture of the conductor.

[0009] The intensity threshold Is is notably a function of the geometric, electromagnetic and mechanical characteristics of the protection system, and in particular of the conductor and the ferromagnetic body.

[0010] A protection system is understood to mean an electrical protection system for an electrical circuit, which in particular makes it possible to cut off the flow of current in the electrical circuit in an abnormal operating configuration of the electrical circuit.

[0011] Mechanical rupture of the conductor means that the conductor is broken into at least two portions distinct from each other, in particular such that these portions are not in electrical contact with each other. Thus, the flow of current through the conductor is no longer possible.

[0012] The mechanical rupture of the conductor may in particular be irreversible.

[0013] It is understood that a first direction is predominantly opposite in space to a second direction, that the component of the second direction along the first direction is negative.

[0014] In other words, the component of the direction of the current flowing through the second conductor portion according to the direction of the current flowing through the first conductor portion is negative.

[0015] The present disclosure makes it possible to exploit the phenomenon of Laplace forces to which the first conductor portion and the second conductor portion are subjected. In particular, the first conductor portion is subjected to the Laplace forces resulting from the flow of a current in the second conductor portion. In the same way, the second conductor portion is subjected to the Laplace forces resulting from the flow of current in the first conductor portion.

[0016] In addition, the spatial configuration of the first conductor portion and the second conductor part, such that the direction of the current flowing through the first conductor part is predominantly opposite in space to the direction of the current flowing through the second conductor part, advantageously allows the Laplace forces, to which the first conductor part and the second conductor part are respectively subjected, to be predominantly opposite in space. The first conductor part and the second conductor part then tend to move away from each other in space, in particular until the mechanical rupture of the conductor, which is in particular subjected to traction.

[0017] It should be noted that it is generally sought to minimize the Laplace forces in order to avoid the breakage of the conductors. Here, on the contrary, the phenomenon of Laplace forces is exploited in order to stress the conductor until the latter mechanically breaks.

[0018] Furthermore, the implementation of the ferromagnetic body between the first conductor part and the second conductor part advantageously makes it possible to amplify the mechanical force induced by the current flowing in the conductor so as to facilitate the breaking of the conductor.

[0019] Furthermore, said protection system has the considerable advantage of having a high breaking capacity, for example of the order of 10KA, and an improved response time, for example of the order of 100ps. This makes it possible to improve the safety of the electrical circuit.

[0020] The present disclosure is a compact, efficient and rapid solution for the protection of an electrical circuit, in particular for high DC voltage applications.

[0021] Furthermore, the present disclosure advantageously makes it possible to implement a controllable electrical circuit protection system, for example in comparison with high voltage fuses.

[0022] The features set out in the following paragraphs may, optionally, be implemented independently of one another or in combination with one another.

[0023] The protection system advantageously comprises a discharge device electrically mounted in parallel with the conductor. The discharge device is configured to, in an abnormal operating configuration, apply a voltage, hereinafter referred to as the breakdown voltage, to the terminals of the conductor so that the intensity I of the current flowing in the conductor, which results from the application of the breakdown voltage, is greater than or equal to the threshold intensity Is.

[0024] The breakdown voltage is a minimum voltage capable of generating a current of intensity beyond which a mechanical breakdown of the conductor occurs.

[0025] By terminals of the conductor, we mean an input terminal and an output terminal of the driver.

[0026] The terminals may form physical terminals of the conductor or geographical terminals of the conductor. Indeed, said terminals must not necessarily be understood as forming physical objects. The essential thing is that the discharge device is capable of applying the breakdown voltage to the terminals of the conductor.

[0027] More specifically, each of the first conductor portion, the second conductor portion and the third conductor portion may respectively comprise a first end and a second end opposite the first end. The first end of the first conductor portion may form the input terminal of the conductor, the second end of the first conductor portion being electrically connected to or merged with the first end of the third conductor portion, the second end of the third conductor portion being electrically connected to or merged with the first end of the second conductor portion, the second end of the second conductor portion being able to form the output terminal of the conductor.

[0028] The discharge device makes it possible to simply trigger the mechanical rupture of the conductor in the abnormal operating configuration.

[0029] It should be noted that in the absence of the discharge device or when the discharge device does not apply the breakdown voltage to the terminals of the conductor, the mechanical breakdown of the conductor may be caused by the circulation of an abnormally high current, i.e. greater than the threshold intensity Is, within the conductor.

[0030] The conductor may in particular take the form of a set of bars, also called a “busbar” in English.

[0031] Advantageously, the first conductor portion and the second conductor portion may be inclined relative to each other by an angle less than or equal to 40°, for example less than or equal to 20°, preferably less than or equal to 10°, for example substantially equal to 0°. In other words, when said angle is substantially equal to 0°, the first conductor portion and the second conductor portion are substantially parallel to each other. This configuration advantageously makes it possible to increase the mechanical force, induced by the current flowing in the conductor, to which the first conductor portion and the second conductor portion are subjected.

[0032] The first conductor part and the second conductor part may in particular have a bar shape, for example of rectangular section.

[0033] The first conductor part and the second conductor part may have the same length L, for example between 20mm and 60mm, preferably equal to 40mm.

[0034] Advantageously, the length L respectively of the first part of conductor and the second conductor part, a spacing r between the first conductor part and the second conductor part, a magnetic permeability of the ferromagnetic body and a mechanical breaking force Fr necessary for the mechanical breaking of the conductor are determined so that the mechanical breaking force Fr is less than or equal to the mechanical force which is induced by the current flowing through the conductor when the intensity I of said current is greater than the threshold intensity Is, said mechanical force being calculated according to the following equation, in which corresponds to the magnetic permeability of the vacuum:

[0035] F1 = F2 = ~2^-

[0036] This equation advantageously makes it possible to dimension the protection system so that the conductor can break mechanically in the abnormal operating configuration. It can be noted that the mechanical force induced in the conductor by the current flowing in the conductor is proportional to the magnetic permeability of the ferromagnetic body. Consequently, increasing the magnetic permeability of the ferromagnetic body makes it possible to amplify this mechanical force so as to more easily reach the mechanical force for breaking the conductor in the presence of an abnormally high current.

[0037] The spacing r can in particular be between 1 mm and 5 mm.

[0038] In particular, the ferromagnetic body may have a magnetic permeability of between 100 and 1200, preferably between 800 and 1200. This range of values ​​makes it possible in particular to obtain an amplification factor of the Laplace forces, which is of the same order of magnitude as the magnetic permeability, which makes it possible to achieve the mechanical breaking force of the conductor.

[0039] The protection system may comprise a device for detecting faults in the electrical circuit and a device for controlling the discharge device. The control device is configured to, upon receiving fault detection information transmitted by the detection device, control the discharge device so that the discharge device applies the breakdown voltage to the terminals of the conductor. Thus, the protection system can be controlled and therefore triggered when abnormal operation is detected.

[0040] The discharge device may preferably comprise a capacitor capable of applying the breakdown voltage to the terminals of the conductor and a switch, in particular an electronic switch, mounted in series with each other. The switch is configured to allow the application of said breakdown voltage to the terminals of the conductor in the abnormal operating configuration. This electrical assembly is simple and allows an effective discharge on the protection system in the event of an abnormal operating configuration of the electrical circuit. In addition, the switch may be controllable at least in closing. This allows the triggering of the protection system to be controlled.

[0041] The switch may preferably comprise a thyristor.

[0042] The capacitor may in particular comprise an electrochemical capacitor.

[0043] The capacitor may have a capacitance of between 20pF and 1000pF.

[0044] The threshold intensity Is is preferably greater than or equal to 1000A.

[0045] Advantageously, in a nominal operating configuration, the current flowing through the conductor may have an intensity of between 100A and 200A and in which the threshold intensity Is is greater than or equal to 1000A. In the nominal operating configuration, the intensity of the current is in particular insufficient to cause mechanical rupture of the conductor.

[0046] Advantageously, the conductor may be made, at least partially, from a material comprising aluminum. Aluminum has the advantage of being a good conductor while having low tensile strength. However, another material that is a good electrical conductor and has low mechanical strength could be used.

[0047] Advantageously, the conductor may comprise an electrical connector configured so that when the current flowing in the conductor has an intensity I greater than or equal to the threshold intensity Is, the mechanical force in the conductor induced by this current causes the electrical connector to open. In other words, the mechanical rupture of the conductor is achieved by the opening of the electrical connector. The third conductor portion may in particular comprise said electrical connector. This characteristic advantageously makes it possible to better control the mechanical rupture zone of the conductor. In addition, such an electrical connector may advantageously be reclosable and therefore reusable.

[0048] At least two, in particular all three, of the first conductor portion, the second conductor portion and the third conductor portion may advantageously be formed in one piece. This feature makes it easier to implement the conductor.

[0049] The conductor may advantageously have a predetermined zone of weakness configured to break first upon mechanical rupture of the conductor. This characteristic advantageously makes it possible to better control the mechanical rupture of the conductor.

[0050] In particular, the third conductor portion may comprise said weak zone.

[0051] The third conductor part may in particular comprise at least one cavity, for example several cavities, forming said weak zone.

[0052] According to another aspect, there is provided an electrical circuit comprising a system of protection as previously described, an electrical source and a load configured to be supplied with electrical power by the electrical source. The protection system is notably mounted in series with the electrical source and the load. The protection system advantageously makes it possible to protect the electrical circuit in the event of a current overload in the latter, or other abnormal operating configurations of the electrical circuit.

[0053] The load may advantageously include electrical propulsion equipment.

[0054] The electrical source may in particular be configured to supply the electrical circuit with high direct voltage, for example a voltage between 800VDC and 1200VDC. Brief description of the drawings

[0055] Other characteristics, details and advantages will appear on reading the detailed description below, and on analyzing the attached drawings, in which:

[0056] [Fig-1] illustrates a schematic electrical diagram of an electrical circuit comprising a protection system according to one embodiment.

[0057] [Fig.2] illustrates three schematic electrical diagrams respectively a confi nominal operating configuration (Figure 2A), an abnormal operating configuration (Figure 2B) and a failure configuration (Figure 2C) following the abnormal operating configuration of a protection system according to one embodiment.

[0058] [Fig.3] illustrates a schematic electrical diagram of an electrical circuit comprising a protection system according to another embodiment.

[0059] [Fig.4] illustrates three schematic electrical diagrams respectively a confi nominal operating configuration (Figure 4A), an abnormal operating configuration (Figure 4B) and a failure configuration (Figure 4C) following the abnormal operating configuration of a protection system according to one embodiment.

[0060] [Fig.5] schematically illustrates an example of an unfolded conductor for a protection system according to one embodiment.

[0061] [Fig.6] schematically illustrates a graph of the mechanical force to which a first part and a second part of conductor of the protection system are subjected as a function of an angle between the first part of conductor and the second part of conductor. Description of the embodiments

[0062] Reference is now made to Figures 1 and 3 schematically representing an electrical circuit 1 according to one aspect of the present disclosure.

[0063] The electrical circuit 1 comprises a protection system 10 according to a mode of rea According to the present disclosure, an electrical source 2 and a load 3 configured to be supplied with electrical power by the electrical source 2. The protection system 10 is in particular mounted in series with the electrical source 2 and the load 3. The protection system advantageously makes it possible to protect the electrical circuit in the event of a current overload in the latter, or other abnormal operating configurations of the electrical circuit.

[0064] The load 3 can advantageously comprise electrical propulsion equipment.

[0065] The electrical source 2 may in particular be configured to supply the electrical circuit with high direct voltage, for example a voltage between 800VDC and 1200VDC.

[0066] The electrical source 2 may in particular comprise a battery, for example associated with a battery management device.

[0067] By protection system 10 is meant an electrical protection system 10 for an electrical circuit, which in particular makes it possible to cut off the flow of current in the electrical circuit in an abnormal operating configuration of the electrical circuit.

[0068] The protection system 10 comprises a conductor 11, 12, 13 and a ferromagnetic body 14. The protection system may further comprise a discharge device 4 illustrated in dotted lines in [Fig.l]. The protection system may alternatively be without a discharge device.

[0069] Figures 2A, 2B and 2C each respectively illustrate a schematic electrical diagram respectively a nominal operating configuration (figure 2A), an abnormal operating configuration (figure 2B) and a break configuration (figure 2C) following the abnormal operating configuration of the protection system 10.

[0070] In the nominal operating configuration, the current ib i2 passing through the conductor 11, 12, 13 may have an intensity of between 100A and 200A. In the nominal operating configuration, the intensity of the current is in particular insufficient to cause mechanical breakage of the conductor.

[0071] In the abnormal operating configuration, the current ib i2 passing through the conductor 11, 12, 13 may have an intensity greater than or equal to 1000A.

[0072] The conductor 11, 12, 13 comprises a first conductor portion 11 and a second conductor portion 12 configured in space relative to the first conductor portion 11 such that a direction of a current h passing through the first conductor portion 11 is predominantly opposite in space to a direction of a current i2 passing through the second conductor portion 12. The conductor comprises a third conductor portion 13 electrically connecting together the first conductor portion 11 and the second conductor portion 12.

[0073] The ferromagnetic body 14 is arranged in the space between the first conductor part 11 and the second conductor part 12.

[0074] The ferromagnetic body 14 may in particular have a plate shape.

[0075] The ferromagnetic body 14 is advantageously made of a ferromagnetic material, such as for example iron or Mu-metal.

[0076] The conductor 11, 12, 13 and the ferromagnetic body 14 are configured so that, when a current flowing in the conductor has an intensity I greater than or equal to a threshold intensity Is, a mechanical force Fi, F2 in the conductor 11, 12, 13, in particular a mechanical tensile force, induced by this current causes the mechanical rupture of the conductor 11, 12, 13.

[0077] More precisely, in the nominal operating configuration (figure 2A), a current flows through the conductor which remains intact. When an abnormal operating configuration (figure 2B) occurs, for example when the current flowing through the conductor is too high, i.e. greater than the threshold intensity, or when the discharge device is activated, for example following the detection of an anomaly in the circuit, the mechanical force induced by the current mechanically stresses the conductor until the latter mechanically breaks (figure 2C).

[0078] The intensity threshold Is is notably a function of the geometric, electromagnetic and mechanical characteristics of the protection system, and in particular of the conductor and the ferromagnetic body.

[0079] The threshold intensity Is is preferably greater than or equal to 1000A.

[0080] Mechanical rupture of the conductor 11, 12, 13 means that the conductor is broken into at least two portions distinct from each other, in particular such that these portions are not in electrical contact with each other. Thus, the flow of current through the conductor 11, 12, 13 is no longer possible.

[0081] The mechanical rupture of the conductor 11, 12, 13 may in particular be irreversible.

[0082] It is understood that a first direction is predominantly opposite in space to a second direction, that the component of the second direction along the first direction is negative.

[0083] In other words, the component of the direction of the current i2 passing through the second part of conductor 12 according to the direction of the current ii passing through the first part of conductor 11 is negative.

[0084] The present disclosure makes it possible to exploit the phenomenon of the Laplace forces to which the first conductor portion 11 and the second conductor portion 12 are subjected. In particular, the first conductor portion 11 is subjected to the Laplace forces resulting from the flow of a current i2 in the second conductor portion 12. In the same way, the second conductor portion 12 is subjected to the Laplace forces resulting from the flow of current h in the first conductor portion 11 and the second conductor portion 12. driver 11.

[0085] Furthermore, the spatial configuration of the first conductor portion 11 and the second conductor portion 12, such that the direction of the current flowing through the first conductor portion is predominantly opposite in space to the direction of the current flowing through the second conductor portion, advantageously allows the Laplace forces, to which the first conductor portion 11 and the second conductor portion 12 are respectively subjected, to be predominantly opposite in space.

[0086] The first conductor part 11 and the second conductor part 12 then tend to move away from each other in space, in particular until the mechanical rupture of the conductor 11, 12, 13, which is in particular subjected to tensile stress.

[0087] It should be noted that it is generally sought to minimize the Laplace forces in order to avoid the breakage of the conductors. Here, on the contrary, the phenomenon of Laplace forces is exploited in order to stress the conductor until the latter mechanically breaks.

[0088] Furthermore, the implementation of the ferromagnetic body 14 between the first conductor part 11 and the second conductor part 12 advantageously makes it possible to amplify the mechanical force induced by the current flowing in the conductor so as to facilitate the breaking of the conductor.

[0089] Furthermore, said protection system has the considerable advantage of having a high breaking capacity, for example of the order of 10KA, and an improved response time, for example of the order of 100ps. This makes it possible to improve the safety of the electrical circuit.

[0090] The present disclosure is a compact, efficient and rapid solution for the protection of an electrical circuit, in particular for high DC voltage applications.

[0091] Furthermore, the present disclosure advantageously makes it possible to implement a controllable electrical circuit protection system, for example in comparison with high voltage fuses.

[0092] When the protection system 10 comprises the discharge device 4, the discharge device 4 is electrically mounted in parallel with the conductor. The discharge device 4 is configured to, in an abnormal operating configuration, apply a voltage, called the breakdown voltage Vc, to the terminals 15a, 15b of the conductor 11, 12, 13 so that the intensity I of the current flowing in the conductor, which results from the application of the breakdown voltage, is greater than or equal to the threshold intensity Is.

[0093] The breakdown voltage Vc is in particular a voltage high enough to induce mechanical breakdown of the conductor.

[0094] Terminals 15a, 15b of the conductor are understood to mean an input terminal and an output terminal of the conductor.

[0095] The terminals may form physical terminals of the conductor or geographical terminals of the conductor. Indeed, said terminals must not necessarily be understood as forming physical objects. The essential thing is that the discharge device is capable of applying the breakdown voltage to the terminals of the conductor.

[0096] More specifically, each of the first conductor portion 11, the second conductor portion 12 and the third conductor portion 13 may respectively comprise a first end and a second end opposite the first end. The first end of the first conductor portion may form the input terminal 15a of the conductor, the second end of the first conductor portion being electrically connected to or merging with the first end of the third conductor portion, the second end of the third conductor portion being electrically connected to or merging with the first end of the second conductor portion, the second end of the second conductor portion being able to form the output terminal 15b of the conductor.

[0097] The discharge device 4 makes it possible to simply trigger the mechanical rupture of the conductor in the abnormal operating configuration.

[0098] It should be noted that in the absence of the discharge device or when the discharge device 4 does not apply the breakdown voltage to the terminals 15a, 15b of the conductor, the mechanical breakdown of the conductor 11, 12, 13 may be caused by the circulation of an abnormally high current, i.e. greater than the threshold intensity Is, within the conductor 11, 12, 13.

[0099] Furthermore, the conductor 11, 12, 13 may be made, at least partially, from a material comprising aluminum. Aluminum has the advantage of being a good conductor while having low mechanical tensile strength. However, another material that is a good electrical conductor and has low mechanical strength could be used.

[0100] The conductor 11, 12, 13 may in particular take the form of a set of bars, also called a “busbar” in English.

[0101] The first conductor part 11 and the second conductor part 12 may in particular have a bar shape, for example of rectangular section.

[0102] The first conductor part 11 and the second conductor part 12 may have a cross-section of between 1mm2 and 5mm2.

[0103] The first conductor part 11 and the second conductor part 12 may have the same length L, for example between 20mm and 60mm, preferably equal to 40mm.

[0104] Furthermore, the length L respectively of the first conductor part 11 and of the second conductor portion 12, a spacing r between the first conductor portion 11 and the second conductor portion 12, a magnetic permeability of the ferromagnetic body 14 and a mechanical breaking force Fr necessary for the mechanical breaking of the conductor 11,12,13 can be determined so that the mechanical breaking force Fr is less than or equal to the mechanical force Fi,F2 which is induced by the current flowing through the conductor when the intensity I of said current is greater than the threshold intensity Is, said mechanical force being calculated according to the following equation, in corresponds to the magnetic permeability of the vacuum:

[0105] F1 = F2 = ~2^-

[0106] This equation advantageously makes it possible to dimension the protection system so that the conductor can break mechanically in the abnormal operating configuration. It can be noted that the mechanical force induced in the conductor by the current flowing in the conductor is proportional to the magnetic permeability of the ferromagnetic body. Consequently, increasing the magnetic permeability of the ferromagnetic body makes it possible to amplify this mechanical force so as to more easily reach the mechanical force for breaking the conductor in the presence of an abnormally high current.

[0107] The spacing r can in particular be between 1 mm and 5 mm.

[0108] The ferromagnetic body 14 may, preferably, have a magnetic permeability of between 100 and 1200, preferably between 800 and 1200. This range of values ​​makes it possible in particular to obtain an amplification factor of the Laplace forces, which is of the same order of magnitude as the magnetic permeability, which makes it possible to achieve the mechanical breaking force of the conductor.

[0109] The protection system 10 may further comprise a device for detecting faults in the electrical circuit and a device for controlling the discharge device 4. The control device is configured to, upon receipt of fault detection information transmitted by the detection device, control the discharge device so that the discharge device applies the breakdown voltage to the terminals 15a, 15b of the conductor. Thus, the protection system 10 can be controlled and therefore triggered when abnormal operation is detected.

[0110] With reference to figures 3, 4A, 4B and 4C, the discharge device 4 can advantageously comprise a capacitor 41 capable of applying the breakdown voltage Vc to the terminals of the conductor 11, 12, 13 and a switch 42, in particular an electronic switch, mounted in series with each other.

[0111] The switch 42 is configured to allow the application of said breakdown voltage Vc to the terminals 15a, 15b of the conductor 11, 12, 13 in the abnormal operating configuration.

[0112] Figures 4A, 4B and 4C each respectively illustrate a schematic electrical diagram respectively a nominal operating configuration (Figure 4A), an abnormal operating configuration (Figure 4B) and a breakdown configuration (Figure 4C) following the abnormal operating configuration of the protection system 10. In the nominal operating configuration (Figure 4A), a current flows through the conductor which remains intact and the switch 42 is open. When an abnormal operating configuration (Figure 4B) occurs, for example following the detection of an anomaly in the circuit, the switch is closed 42 thus triggering the application of the breakdown voltage Vc to the terminals of the conductor 11, 12, 13. The mechanical force, induced by the current flowing through the conductor and resulting from the application of the breakdown voltage, mechanically stresses the conductor until the latter mechanically breaks (Figure 4C).

[0113] This electrical assembly is simple and allows an effective discharge on the protection system in the event of an abnormal operating configuration of the electrical circuit. In addition, the switch can be controlled at least in closing. This makes it possible to control the triggering of the protection system.

[0114] The switch 42 may preferably comprise a thyristor.

[0115] The capacitor 41 may in particular comprise an electrochemical capacitor.

[0116] The capacitor 41 may have a capacitance of between 20pF and 1000pF.

[0117] Advantageously, the conductor may comprise an electrical connector configured so that when the current flowing in the conductor has an intensity I greater than or equal to the threshold intensity Is, the mechanical force in the conductor induced by this current causes the electrical connector to open. In other words, the mechanical rupture of the conductor is achieved by the opening of the electrical connector. The third conductor portion may in particular comprise said electrical connector. This characteristic advantageously makes it possible to better control the mechanical rupture zone of the conductor. In addition, such an electrical connector may advantageously be reclosable and therefore reusable.

[0118] Furthermore, at least two, in particular all three, of the first conductor portion 11, the second conductor portion 12 and the third conductor portion 13 may be formed in one piece. In other words, at least two, in particular all three, of the first conductor portion 11, the second conductor portion 12 and the third conductor portion 13 may form a single piece. This feature makes it easier to implement the conductor.

[0119] [Fig.5] schematically illustrates an example of an unfolded conductor 11,12,13.

[0120] The conductor 11, 12, 13 may advantageously have a predetermined zone of weakness configured to break first upon mechanical rupture of the conductor 11, 12, 13. This characteristic advantageously allows for better control mechanical breakage of the conductor 11,12,13.

[0121] In particular, the third conductor portion 13 may comprise said weak zone.

[0122] The third conductor part 13 may in particular comprise at least one cavity 16, for example several cavities, forming said weak zone.

[0123] Furthermore, the first conductor portion 11 and the second conductor portion 12 may be inclined relative to each other by an angle less than or equal to 40°, for example less than or equal to 20°, preferably less than or equal to 10°, for example substantially equal to 0°. In other words, when said angle is substantially equal to 0°, the first conductor portion 11 and the second conductor portion 12 are substantially parallel to each other. This configuration advantageously makes it possible to increase the force, induced by the current flowing in the conductor, to which the first conductor portion and the second conductor portion are subjected.

[0124] [Fig.6] schematically illustrates a graph of the mechanical force to which the first conductor part 11 and the second conductor part 12 of the protection system are subjected as a function of said angle between the first conductor part 11 and the second conductor part 12.

[0125] This [Fig.6] clearly illustrates that the higher the angle, the lower the said mechanical force. It is therefore more advantageous to implement the first conductor part 11 and the second conductor part 12 substantially parallel to each other.

Claims

Claims

1. A protection system (10) for an electrical circuit (1), the protection system (10) comprising: - a conductor (11, 12, 13) comprising a first conductor portion (11) and a second conductor portion (12) configured in space relative to the first conductor portion (11) such that a direction of a current (ii) flowing through the first conductor portion (11) is predominantly opposite in space to a direction of a current (i2) flowing through the second conductor portion (12), the conductor comprising a third conductor portion (13) electrically connecting together the first conductor portion (11) and the second conductor portion (12), and - a ferromagnetic body (14) arranged in the space between the first conductor portion (11) and the second conductor portion (12), the conductor (11, 12, 13) and the ferromagnetic body (14) being configured such that, when a current circulating in the conductor (11,12,13) has an intensity I greater than or equal to a threshold intensity Is, a mechanical force (FbF2) in the conductor (11,12,13) ​​induced by this current causes the mechanical rupture of the conductor (11,12,13).,

2. Protection system (10) according to claim 1, comprising a discharge device (4) electrically mounted in parallel with the conductor, the discharge device (4) being configured to, in an abnormal operating configuration, apply a breakdown voltage (Vc) to the terminals (15a, 15b) of the conductor (11, 12, 13) so that the intensity I of the current flowing in the conductor (11, 12, 13), which results from the application of the breakdown voltage (Vc), is greater than or equal to the threshold intensity Is.

3. Protection system (10) according to one of the preceding claims, wherein the first conductor portion (11) and the second conductor portion (12) are inclined relative to each other by an angle less than or equal to 40°, for example less than or equal to 20°, preferably less than or equal to 10°, for example substantially equal to 0°.

4. Protection system (10) according to one of the preceding claims, wherein a length L of the first conductor portion (11) and the second conductor portion (12) respectively, a spacing r between the first conductor portion (11) and the second conductor part (12), a magnetic permeability of the ferromagnetic body (14) and a mechanical breaking force Fr necessary for the mechanical breaking of the conductor (11,12,13) ​​are determined so that the mechanical breaking force Fr is less than or equal to the mechanical force (FbF2) which is induced by the current flowing through the conductor (11,12,13) ​​when the intensity I of said current is greater than the threshold intensity Is, said mechanical force being calculated according to the following equation, in which corresponds to the magnetic permeability of the vacuum: F -F -^L-

5. Protection system (10) according to one of the preceding claims, in which the ferromagnetic body (14) has a magnetic permeability of between 100 and 1200.

6. Protection system (10) according to one of the preceding claims combined with claim 2, wherein the discharge device (4) comprises a capacitor (41) capable of applying the breakdown voltage (V c) to the terminals (15a, 15b) of the conductor (11, 12, 13) and a switch (42) mounted in series with each other, the switch (42) being configured to allow the application of said breakdown voltage (V c) to the terminals (15a, 15b) of the conductor (11, 12, 13) in the abnormal operating configuration.

7. Protection system (10) according to one of the preceding claims, in which, in a nominal operating configuration, the current (ib i2) passing through the conductor (11, 12, 13) has an intensity I of between 100A and 200A and in which the threshold intensity Is is greater than or equal to 1000A.

8. Protection system (10) according to one of the preceding claims, in which the conductor (11, 12, 13) is made, at least partially, from a material comprising aluminum.

9. Protection system (10) according to one of the preceding claims, wherein at least two, in particular all three, of the first conductor part (11), the second conductor part (12) and the third conductor part (13) are formed in one piece.

10. Protection system (10) according to one of the preceding claims, wherein the conductor (11,12,13) ​​has a predetermined zone of weakness configured to break first upon mechanical rupture of the conductor (11,12,13).

11. Electrical circuit (1) comprising a protection system (10) according to any one of the preceding claims, an electrical source (2) and a load (3) configured to be supplied with electrical power by the electrical source (2), the protection system (10) being mounted in series with the electrical source (2) and the load (3).

12. Electrical circuit (1) according to the preceding claim, in which the load (3) comprises electrical propulsion equipment.

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