EP2261942A2 - Short circuit switch with improved security - Google Patents

Abstract

The switch has a liberation element (7) mounted between an actuating rod (5) and an attachment point (8) fixed relative to a fixed contact (2) to block the rod in translation. A pyrotechnic isolator (12) is provided with a cutting tool for cutting the liberation element. The tool is moved in translation from a retracted state to a triggering state when the isolator is ignited, the rod is released and displaced, an elastic element (9) is triggered, and the switch is closed. An independent claim is also included for an electric circuit comprising electronic components associated to a switch.

Description

TECHNICAL AREA

The present invention relates to an improved safety short circuit switch. Such short circuit switches can be used in particular in high voltage direct current equipment known as HVDC for High Voltage Direct Current. These short circuit switches are called fast, which means that they can close in milliseconds after the order has been given.

The equipment comprises a transmission line and at both ends a rectifier type conversion device on one side and inverter type on the other. They are inserted in an AC transmission system. To transport over long distances very large powers, often greater than 1,000 MW, it is preferable for technical and economic reasons to adopt a DC link to the detriment of a conventional AC link. One reason is that beyond a certain distance, about 50 to 100 km for submarine links, 500 to 1,000 km for overhead power lines, voltage drops along a power line. in AC power are too important to allow transmission.

Generally the rectifiers and inverters are symmetrical and reversible so as to be able to change role. A conversion device is realized today with electronic components, semiconductor power switches such as thyristors, GTO type thyristors, Gate Turn-Off thyristor, that is to say thyristor blockable by the trigger, IGCT type thyristors, Integrated Gate-Commutated Thyristor, ie integrated trigger gate thyristor, IGBT type transistors, Insulated Gate Bipolar Transitor, that is to say insulated gate bipolar transistor.

The short-circuit switch is designed to short-circuit an electronic component very quickly. The reason is that this electronic component takes an open state when it fails. In this application, the electronic component is a power switch. The short circuit of the faulty power switch isolates said power switch from other power switches which are connected in series with it and to avoid its degradation which could for example cause a fire and a reaction. in chain on all the components of the conversion device.

STATE OF THE PRIOR ART

These short-circuit switches generally comprise a vacuum enclosure containing a pair of electrical contacts with a fixed contact relative to the enclosure and a movable contact relative to the fixed contact. In the rest position, pair contacts are open. The occurrence of a fault on one of the associated power switches sends an electrical pulse to an actuator of the movable contact to bring it into electrical contact with the fixed contact.

There are short-circuit switches that use devices for triggering the displacement of the electromagnetic coil moving contact and others of the pyrotechnic type. Short circuit switches with pyrotechnic trip devices are faster than those with an electromagnetic coil.

A pyrotechnic trip short-circuit switch is described for example in the patent application EP 1,514,287 . A vacuum enclosure contains a pair of electrical contacts with a fixed contact and a movable contact with respect to the fixed contact. The movable contact is secured to an operating rod accessible from outside the enclosure, it is extended by a tube which is surrounded by a spring. The spring in the compressed position keeps the moving contact away from the fixed contact. The short circuit switch is in the open position.

The tube houses an explosive cartridge. To actuate the short-circuit switch, the explosive cartridge is exploded and the explosion breaks the tube into pieces, the spring relaxes and translates the actuating rod in such a way that the moving contact comes into electrical contact with the fixed contact. The short circuit switch closes. During the explosion, debris from the tube can damage the spring and even the vacuum envelope. The short circuit switch may be damaged and may not close. Such a short circuit switch is unreliable and requires very expensive maintenance. In addition, this short-circuit switch presents risks for an operator as well as for the electrical circuit containing the electronic components to be short-circuited. As a result, additional constraints are added when handling, transporting or marketing the short circuit switch.

Another pyrotechnic trigger short-circuit switch is described in the patent application WO 2007/095873 . In a first configuration presented in this document, the short-circuit switch comprises a pair of electrical contacts with a fixed contact with respect to a support and a movable contact relative to the fixed contact. The movable contact is secured to an operating rod, the operating rod slides in a fixed tube relative to the support and a spring is housed at the bottom of the tube. The operating rod is provided with a notch. A needle is housed in the notch and blocks the actuating rod in translation, the spring being compressed. The electrical contacts are open in this locked position in translation of the operating rod, the short-circuit switch is open. The needle is connected to a propellant cartridge placed in a sealed enclosure. When the propellant cartridge explodes, the needle backs up and frees itself from the maneuvering rod. It is no longer locked in translation. The spring relaxes and the spring expansion causes the actuating rod in translation so that the movable contact comes into electrical contact with the fixed contact. In another, simpler configuration, the propellant cartridge instead of translating a needle, translates directly in translation the operating rod whose free end forms the movable contact. Before the explosion of the propellant cartridge, the operating rod is away from the fixed contact and after the explosion it comes into electrical contact with it.

A disadvantage of the first configuration is that it is extremely sensitive to vibrations. In case of severe vibrations, the needle may escape from the notch and switching of the short-circuit switch from the open position to the closed position may be unwanted. In the second configuration, particular weather conditions may cause the operating rod to shift slightly or retract and its free end no longer makes a correct electrical contact or no electrical contact at all with the fixed contact. When passing the short-circuit current between the operating rod and the fixed contact, a repulsive force appears between the operating rod and the fixed contact. The repulsive force can be a few kilo Newtons with short-circuit electrical currents of several kilo amps.

STATEMENT OF THE INVENTION

The object of the present invention is precisely to propose a short-circuit switch which does not have the drawbacks mentioned above. More particularly, the present invention provides a short circuit switch which is more reliable and safer than short circuit switches of the prior art.

An object of the invention is in particular to provide a short circuit switch whose maintenance is simple, the elements to be changed after the explosion do not concern the pair of electrical contacts.

To achieve these aims, the invention proposes to sever a release member which holds locked in translation an operating rod of a movable contact, the latter being at a distance from a fixed contact of the short-circuit switch, the sectioning making free movement of the actuating rod and triggering the extension of an elastic member for manipulating in translation the operating rod so that the movable contact comes into electrical contact with the fixed contact.

More specifically, the invention is a short-circuit switch for short-circuiting an electronic component comprising at least one pair of electrical contacts with a fixed contact and a movable contact with respect to the fixed contact, the switch being open when the Pair contacts are remote and closed when the contacts are in electrical contact. It also includes a actuating rod connected to the movable contact, an elastic element coupled to the operating rod to move it in translation when it expands so as to close the switch, a release element mounted between the actuating rod and a fixed fixing point relative to the fixed contact, to lock in translation the operating rod, the switch being open, and to maintain compressed the elastic element. It further comprises a pyrotechnic disconnector provided with a cutting tool for cutting the release element, the cutting tool being able to move in translation from a retracted state to a relaxed state when the pyrotechnic disconnector is set to traffic light. The sectioning causes the unlocking of the operating rod, the expansion of the elastic element, the displacement in translation of the operating rod and the closing of the switch.

The release member is interchangeable and is removably mounted between the operating rod and the attachment point.

The release member may be a cable, a rod or a wire.

The release member has a major axis, the displacement of the cutting tool is preferably substantially perpendicular to the main axis of the release member so as to improve the efficiency of the cutting.

The elastic member may be a spring that surrounds the operating rod, the spring having one end abutting against a fixed stop relative to the fixed contact and the other end is coupled to the operating rod.

To simplify assembly, the stop can serve as a support for the pyrotechnic disconnector.

The short circuit switch may comprise a vacuum chamber in which is placed the pair of electrical contacts, the fixed contact being secured to the enclosure, the operating rod being accessible from outside the vacuum chamber.

So that the sectioning does not risk damaging either the vacuum chamber or the elastic element, the elastic element is located between the vacuum chamber and the release element.

The release member has a sectional area, the elastic member is shifted along the major axis of the release member relative to the sectional area, and the elastic member is not likely to be damaged. during sectioning.

The pyrotechnic disconnector preferably comprises, in a tubular body, an anvil, the cutting tool, a propellant cartridge intended to manipulate the cutting tool towards the anvil when it is fired, the body being provided with a light for engaging the release member, the light being between the anvil and the cutting tool in the retracted position.

The present invention also relates to an electrical circuit comprising a plurality of electronic components connected in series, each of the components having two terminals and being associated with a short-circuit switch thus characterized, the pair of electrical contacts of the short-circuit switch being connected in parallel to the terminals of the electronic component. The circuit further comprises means for detecting a failure of the electronic component and for triggering the firing of the pyrotechnic disconnector of the associated short-circuit switch in case of failure.

The electrical circuit is advantageously of the inverter or rectifier type, the electronic components being semiconductor power switches.

BRIEF DESCRIPTION OF THE DRAWINGS

• les figures 1A, 1B montrent respectivement en position ouverte et fermée un commutateur de court-circuit selon l'invention ;
• les figures 2A, 2B montrent un sectionneur pyrotechnique utilisé dans le commutateur de court-circuit selon l'invention respectivement en position de repos et après mise à feu ;
• la figure 3 montre un commutateur de court-circuit selon l'invention en position ouverte monté aux bornes d'un composant électronique ;
• la figure 4 montre un circuit électrique selon l'invention dont les composants électroniques sont équipés chacun d'un commutateur de court-circuit selon l'invention.

The present invention will be better understood on reading the description of exemplary embodiments given purely by way of indication and in no way limiting, with reference to the appended drawings in which:

• the Figures 1A, 1B respectively show in open and closed position a short circuit switch according to the invention;
• the Figures 2A, 2B show a pyrotechnic disconnector used in the short circuit switch according to the invention respectively in the rest position and after firing;
• the figure 3 shows a short-circuit switch according to the invention in the open position mounted at the terminals of an electronic component;
• the figure 4 shows an electrical circuit according to the invention, the electronic components of which are each equipped with a short-circuit switch according to the invention.

Identical, similar or equivalent parts of the different figures described below bear the same numerical references so as to facilitate the passage from one figure to another.

The different parts shown in the figures are not necessarily in a uniform scale, to make the figures more readable.

DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS

We will refer to Figures 1A, 1B which show an example of a short-circuit switch respectively in an open position and in a closed position. The short-circuit switch comprises at least one pair of electrical contacts 2, 3 with a fixed contact 2 and a movable contact 3 with respect to the fixed contact 2. The electrical contacts 2, 3 can be housed in a vacuum enclosure 4 when voltage levels require it. In this case, the fixed contact 2 is secured to the vacuum chamber 4. In these figures, there is no electronic component that the short-circuit switch according to the invention is intended to short-circuit. The short circuit switch according to the invention can take an open position in which the electrical contacts 2, 3 are disjoint and a closed position in which the electrical contacts 2, 3 are in electrical contact with each other.

The movable contact 2 is extended by an operating rod 5 accessible from outside the vacuum chamber 4, in the configuration where there is a vacuum chamber 4. The operating rod 5 extends along an axis XX '. The vacuum chamber 4 may be equipped with sealing means 6 in an area where the operating rod leaves the enclosure 4. The operating rod 5 is removably connected to one end of a release element 7, this release element 7 having another end removably connected to an attachment point 8 fixed with respect to the fixed contact 2. The release element 7 is built around a main axis which coincides with the 20 'axis of the operating rod 5. An elastic element 9 is coupled to the operating rod 5. It may be a spring that surrounds the operating rod 5. The elastic element 9 is preferably more close to the release element 7 than it is to the movable contact 3. It is outside the vacuum enclosure 4.

The release element 7 cooperates at its two ends with detachable fixing means 10 distributed on the one hand on the release element 7 and on the other hand on one side at the attachment point 8 and on the other side 5. The fixing means 10 may comprise at the level of the release element 7, an opening 10.1 for example an eyelet.

They may comprise at the attachment point 8 and the operating rod 5 a substantially U-shaped part 10.2 having two branches each provided with at least one opening 10.3, two openings on different branches facing each other, the two openings 10.3 to accommodate a pin 10.4, the opening 10.1 being housed between the two arms of the U-shaped piece 10.2 and being traversed by the pin 10.4. The fastening means 10 are easily detachable, they make it easy to change the release element 7 when the latter has been cut.

The elastic member 5 may be a spring. The elastic element 5 has one end connected to the operating rod 5, on the side of the moving contact 2 and the other end, located on the side of the release element 7, which abuts against a stop 11 fixed relative to in the fixed contact 2. The elastic element 9 can take a compressed state in which it stores energy and a relaxed state. When the release member 7 is mounted between the attachment point 8 and the operating rod 5, the elastic member 9 is in its compressed state. The release member 7 holds the elastic member 9 in its compressed state.

The short circuit switch further comprises a pyrotechnic disconnector 12 for severing the release element 7. It comprises a cutting tool 12.1 operated by a propellant cartridge 12.2. Details of the pyrotechnic disconnector 12 are shown on the Figures 2A, 2B . The pyrotechnic disconnector 12 can also take two states, in the first said at rest, the cutting tool 12.1 is retracted, without contact with the release element 7. In the other said struck state, the cutting tool 12.1 is in extension. The pyrotechnic disconnector 12 has been actuated, it has moved the cutting tool 12.1 in translation until reaching the release element 7 and section.

In the configuration of the Figure 1A as already mentioned, the movable contact 3 is moved away from the fixed contact 2, the elastic element 9 is compressed, the pyrotechnic disconnector 12 is at rest, the cutting tool 12.1 is retracted, the release element 7 is whole, it has not been sheared. The short circuit switch is open.

In the configuration of the Figure 1B the movable contact 3 is in electrical contact with the fixed contact 2, the elastic element 9 is in extension, the pyrotechnic disconnector 12 has been fired and the cutting tool 12.1 has expanded, it has struck the release element 7 at a sectioning zone 7.1. It has severed the release element 7. The release element 7, even when it is cut, remains integral on the one hand with the attachment point 8 and on the other hand with the operating rod 5 of the movable contact 3. The operating rod 5 has penetrated a little more in the vacuum chamber 4 and the movable contact 3 is in electrical contact with the fixed contact 2, thus closing the short circuit switch according to the invention. The elastic element is shifted along the axis XX 'with respect to the sectioning zone 7.1.

We will now, referring to Figures 2A, 2B , detail the structure of the pyrotechnic disconnector 12. Such a pyrotechnic disconnector 12 is a product sold in the trade.

It comprises a tubular body 12.3 containing from one end a propellant cartridge 12.2 coupled to a cutting tool 12.1 and terminating at the other end an anvil 12.4. The cartridge propulsive 12.2 is apt to be fired by an electrical pulse. Conductors for supplying the electrical pulse are referenced 12.5. When firing the propellant cartridge 12.2, the cutting tool 12.1 is driven with a translational movement to bring it closer to the anvil 12.4 and thus to the release element 7. In fact, the body tubular 12.3 is provided with a light 12.6 allowing the introduction of the release element 7 that is to be sectioned. The lumen 12.6 is close to the anvil 12.4, so that during the firing of the pyrotechnic disconnector 12, the release element 7 will be caught between the anvil 12.4 and the cutting tool 12.1. When the propellant cartridge 12.2 is fired, the cutting tool 12.1 moves from a retracted position to an extended position, in which it approaches the anvil 12.4 and cuts off the release element 7 which he finds on his way to the anvil 12.4. The sectioning is done at a portion 7.1 of the release element 7 placed in the light 12.6. This portion 7.1 of the release element 7 is wedged against the anvil 12.4. The release member 7 may be a rod or preferably a cable or even a wire. The pyrotechnic disconnector 12 is fixed relative to the fixed contact 2.

The abutment 11 can serve as a support for the pyrotechnic disconnector 12. It is further possible that the stop 11 takes the form of a protective wall of the elastic element 9, the operating rod 5, the vacuum chamber 4, if it exists, against any debris from the release member 7 when it has been severed. It is shown substantially normal to the direction of movement of the operating rod 5. Moreover, it has a hole 11.1 and the operating rod assembly 5, release element 7 passes through the hole 11.1.

We will now study the process to move from the configuration of the Figure 1A to that of the Figure 1B . When the pyrotechnic disconnector 12 receives an electric firing pulse indicating that the electronic component (not shown) that it must short circuit fails, the propellant cartridge 12.2 explodes and propels the cutting tool 12.1 in translation to the anvil 12.4. The cutting tool 12.1 on its path meets the release element 7. It cuts it. The cutting tool 12.1 moves substantially perpendicularly to the main axis of the release element 7.

Once the release element 7 has been cut off, the operating rod 5 is free in translation and the elastic element 9 is no longer held in compression. The elastic element 9 relaxes and gives energy to the operating rod 5. Here the effects of gravity are not exploitable. The orientation of the short circuit switch does not matter. The expansion of the elastic element gives it a much greater speed than it would have in the absence of elastic element. The closing speed is advantageously greater than or equal to about 1.2 m / s.

The movable contact 3 comes into electrical contact with the fixed contact 2. The short-circuit switch closes. The direction of movement of the movable contact 3 is substantially along the axis XX 'of the operating rod 5.

We refer to the figure 3 which schematically shows the short circuit switch according to the invention cooperating with an electronic component 13 which it must bypass. The latter comprises two terminals 13.1, 13.2. The fixed contact 2 is electrically connected to one of the terminals, referenced 13.1 of the electronic component 13 and the movable contact 3 to the other terminal 13.2. The short-circuit switch is connected in parallel with the electronic component 13. In the closed position, the short-circuit switch bypasses the electronic component.

To reset the short circuit switch according to the invention, once it has moved from the open state to the closed state as illustrated in FIGS. Figures 1A and 1B it is sufficient to remove the pyrotechnic disconnector 12 and replace it with a new one and to remove the pieces of the release element 7 which are still fixed on one side of the attachment point 8 and on the other hand of the rod 5 and replace them with a new release element 7. The fixing means 10 of the release element 7 are easily dismountable and reassemblable, for example by removing the pin 10.4. This rearmament can be done particularly easily. The parts on which one intervenes are easy to reach.

Maintenance costs are moderate because these parts are inexpensive. The parts to be changed do not touch the electrical contacts 2, 3 of the short-circuit switch, they can remain under vacuum in the vacuum chamber 4. The vacuum chamber 4 containing the electrical contacts 2, 3, it does not risk not be damaged by the ignition of the pyrotechnic disconnector 12. It is removed on the one hand, and secondly, the explosion of the propellant cartridge 12.2 is in a confined area, inside the 12.3 body of the pyrotechnic disconnector 12. There is no risk of pollution due to splinters formed during the explosion of the propellant cartridge 12.2.

Such a short circuit switch is not as sensitive to vibrations as that of the prior art described in the patent application. WO 2007/095873 . It can not be triggered unintentionally in case of vibration. Release of the movable contact so that it comes into contact with the fixed contact can not be done unintentionally. The material of the release element 7 is chosen so that the cutting is done in a clean manner, without debris, which reduces the risk of projection and does not take a risk to a user. But what matters mainly is its strength which must be sufficient for the open position, a minimum space is maintained between the fixed contact 2 and the movable contact 3, the elastic member 9 being in the compressed state. This minimum space depends on the voltage across the two contacts 2, 3. Typically, for a voltage of 12.5 kV, a space of the order of 4 mm must exist.

The release element 7 may be metallic, for example, made of steel. But it is understood that other non-metallic materials may be suitable if they have the required robustness properties.

It has an elongated shape and may be formed of a rod, a cable, a wire for example.

The pyrotechnic disconnector 12 can be installed only when the connection of the short circuit switch is made to the terminals of the electronic component. The transport and installation of the short circuit switch can be done in the absence of the propellant cartridge. The short circuit switch is safe and maintains its integrity before, during and after switching.

Compared to the short-circuit switches in which the switching is initiated electromagnetically, the short-circuit switch object of the invention has a significantly reduced number of parts and therefore has a lower cost. Reducing the number of parts increases the security of the switch. By cons, it is necessary to change the used parts after switching as already mentioned.

We have shown on the figure 4 an electrical circuit 100 with electronic components 13 each equipped with a short circuit switch 101 according to the invention. In the example described, the electrical circuit 100 is a device for converting electric current partially represented. It comprises several branches B1, B2, B3 ... each comprising several electronic components 13 to short circuit connected in series, branches B1, B2, B3 ..... being mounted in parallel. A short circuit switch 101 is associated with each of the electronic components 13. Each electronic component 13 to be short-circuited can be mounted with other electronic components (not shown) to form a module 104 (shown in FIG. figure 4 by a rectangle in solid lines). These other components, for example capacitor diodes, bipolar transistors, if they are in default, go into a closed state and let current flow. These other components do not need to be associated with a short circuit switch according to the invention.

The short-circuit switch 101 is connected in parallel with the associated electronic component 13 and is located between the input and the output of the module 104. Means 102 are shown for detecting a failure of one of the electronic components 13 and for triggering the firing of the pyrotechnic disconnector of the associated short-circuit switch 101 in case of failure. This has been done at only one of the electronic components 13 for the sake of clarity, but of course each of the electronic components 13 is associated with such means 102. Switching a short circuit switch 101 to close it allows a flow of current in the branch B1, B2, B3 in which the faulty electronic component 13 is located without go through this faulty electronic component 13. The conductor 103 terminating in a triangle is a conductor for setting a reference potential of the module 104. It is connected to one of the terminals of the electronic component 13 and to a contact of the short-circuit switch 101. the ground of the electronic component 13 is connected to the earthed contact of the short-circuit switch.

The means 102 for detecting a failure may comprise an ultra-fast fault detection device which following a failure of the electronic component 13 controls the firing of the pyrotechnic disconnector leading to the short circuit of the defective electronic component. The failure of the electronic component causes it to go into an open state. If no short-circuit switch was provided, this open state would prevent the flow of current in the branch in which the faulty electronic component is located. The short circuit switch according to the invention restores the flow of current in this branch.

In the described application of a rectifier or inverter type current conversion circuit, the electronic components 13 are semiconductor power switches such as, for example, thyristors, GTO type thyristors, IGCT type thyristors. , transistors of the IGBT type.

Although several embodiments of the present invention have been described in detail, it will be understood that various changes and modifications can be made without departing from the scope of the invention.

Claims (12)

Short-circuit switch, for short-circuiting an electronic component (13), comprising: at least one pair of electrical contacts (2, 3) with a fixed contact (2) and a movable contact (3) with respect to the fixed contact (2), the switch being open when the contacts (2, 3) of the pair are remote and closed when the contacts (2, 3) are in electrical contact, an operating rod (5) connected to the movable contact (3), an elastic member (9) coupled to the operating rod (5) to move it in translation when it expands so as to close the switch, a release element (7) mounted between the actuating rod (5) and a fixing point (8) fixed relative to the fixed contact (2), to lock in translation the operating rod (5), the switch being open and to keep the elastic element (9) compressed, characterized in that it further comprises a pyrotechnic disconnector (12) provided with a cutting tool (12.1) for severing the release element (7), cutting tool (12.1) being able to move in translation from a retracted state to a relaxed state when the pyrotechnic disconnector (12) is ignited, the disconnection causing the unlocking of the operating rod (5), the detent of the elastic element (9), the translation displacement of the operating rod (5) and the closing of the switch. Short-circuit switch according to claim 1, wherein the release member (7) is interchangeable and is removably mounted between the operating rod (5) and the attachment point (8). Short-circuit switch according to claim 2, wherein the release element (7) is a cable, a rod or a wire. Short-circuit switch according to one of the preceding claims, in which the release element (7) has a main axis (XX '), the displacement of the cutting tool (12.1) being substantially perpendicular to the main axis of the release element (7). Short-circuit switch according to one of the preceding claims, in which the elastic element (9) is a spring which surrounds the operating rod (5), the spring having one end abutting against a fixed stop (11). relative to the fixed contact (3) and whose other end is coupled to the operating rod (5). Short-circuit switch according to claim 5, wherein the stop (11) serves as a support for the pyrotechnic disconnector (12). Short-circuit switch according to one of the preceding claims, comprising a vacuum chamber (4) in which is placed the pair of electrical contacts (2, 3), the fixed contact (2) being secured to the enclosure (4). ), the operating rod (5) being accessible from outside the vacuum enclosure (4). Short-circuit switch according to one of the preceding claims, in which the elastic element (9) is situated between the vacuum enclosure (4) and the release element (7). Short-circuit switch according to one of the preceding claims, in which the release element (7) has a main axis (XX ') and a sectioning area (7.1), the elastic element (9) being offset by along the main axis (XX ') of the sectioning zone (7.1). Short-circuit switch according to one of the preceding claims, in which the pyrotechnic disconnector (12) comprises, in a tubular body (12.3), an anvil (12.4), the cutting tool (12.1), a propellant cartridge ( 12.2) for operating the cutting tool (12.1) towards the anvil (12.4) when ignited, the body (12.3) being provided with a lumen (12.6) for engaging the release member therein (7), the lumen (12.6) between the anvil (12.4) and the cutting tool (12.1) in the retracted position. Electrical circuit comprising several electronic components (13) connected in series, each of the components (13) having two terminals (13.1, 13.2), characterized in that each of the electronic components (13) is associated with a short-circuit switch according to the one of the preceding claims 1 to 10, the pair of electrical contacts (2, 3) of the short-circuit switch being connected in parallel to the terminals (13.1, 13.2) of the electronic component (13) and in that it comprises further means (102) for detecting a failure of the electronic component (13) and for initiating the firing of the pyrotechnic disconnector (12) of the associated short circuit switch in the event of a failure. Electrical circuit according to Claim 11, characterized in that it is of the inverter or rectifier type, the electronic components being semiconductor power switches.

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