POWER ELECTRONIC MODULE WITH CURRENT LIMITER MADE OF SUPERCONDUCTING MATERIAL

Abstract

The invention relates to an electronic power module (10) comprising: - a ceramic substrate (11), - at least one electrical connection track (12) arranged on one face of the ceramic substrate (12), - at least one electronic component (13) electrically connected to the electrical connection track (12), and - a current limiter (14) consisting of a superconducting electrical track (23) made of a material having superconducting properties in a very low temperature range of between 0K and 200K, and preferably between 0K and 90K, and more preferably between 20K and 90K, - said superconducting electrical track (23) being arranged on the ceramic substrate (11) so as to define a plurality of turns (24.1-24.4) in which the current of a given turn flows in a direction opposite to that in which a current of an adjacent turn flows to obtain a current limiter (14) not inductive. Figure for short: Figure 1

Description

Title of the invention: ELECTRONIC POWER MODULE WITH CURRENT LIMITER MADE OF SU MATERIAL DRIVER

[0001] The present invention relates to an electronic power module with current limiter made of superconducting material.

[0002] The invention finds a particularly advantageous, but not exclusive, application in the field of power electronics, in particular with power electronic modules for electrical conversion systems, such as inverters or rectifiers for rotating electrical machines associated with the electrification of aircraft.

[0003] Climate change is a major concern for many legislative and regulatory bodies around the world. Indeed, various restrictions on carbon emissions have been, are being, or will be adopted by various states. In particular, an ambitious standard applies both to new types of aircraft and those currently in circulation, requiring the implementation of technological solutions to make them compliant with current regulations. Civil aviation has been mobilizing for several years now to make a contribution to the fight against climate change.

[0004] Technological research efforts have already made it possible to significantly improve the environmental performance of aircraft. The Applicant takes into consideration the impact factors in all phases of design and development to obtain less energy-intensive, more environmentally friendly aeronautical components and products whose integration and use in civil aviation have moderate environmental impacts with the aim of improving the energy efficiency of aircraft.

[0005] Consequently, the Applicant is constantly working to reduce its climate impact by using methods and operating virtuous development and manufacturing processes that minimize greenhouse gas emissions to reduce the environmental footprint of its activity.

[0006] This sustained research and development work covers new generations of aircraft engines, the lightening of aircraft, particularly through the materials used and lighter on-board equipment, the development of the use of electrical technologies to ensure propulsion, and, as essential complements to technological progress, aeronautical biofuels.

[0007] Electrification and hybridization of the propulsion chain of future generation aircraft nation require high electrical power to generate the thrust necessary for the aircraft to take off and maintain flight condition. All types of aircraft can be affected, namely vertical takeoff and landing (VTOL) aircraft, short takeoff and landing (STOL) aircraft or conventional takeoff and landing (CTOL) aircraft, commercial or military aircraft, helicopters or drones.

[0008] The development of increasingly powerful electrical systems (in the order of megawatts) for electric or hybrid propulsion requires the design of power electronics with the highest possible specific power.

[0009] Furthermore, the development of numerous propulsion and storage devices based on the use of liquid hydrogen (at a temperature of the order of 20K) implies the availability of a significant source of cryogenic cooling that can be used for cooling power electronic components. In this context, the use of superconducting materials is an interesting potential route to achieve high power densities and efficiencies while taking advantage of the available cryogenic environment.

[0010] Recent studies on the development of power electronic modules suitable for superconducting systems have shown that a number of semiconductor components have improved their electrical performance at cryogenic temperature compared to room temperature. For example, a MOSFET-Si transistor has a minimum on-state resistance at 77 K reduced by a factor of 5 compared to its value at room temperature. In this context, operation at very low temperatures is envisaged for the production of electrical converters having improved performance in a cryogenic environment.

[0011] Current protection in a power electronic module requires the addition of numerous specifically dedicated components, such as current measuring devices (shunt, Rogowski loop, or other) associated with a processing system for controlling the electrical parameters of a switching component. This addition of components impacts the volume, cost and reliability of the power electronic module.

[0012] The invention aims to effectively remedy the aforementioned drawbacks by proposing an electronic power module comprising: - a ceramic substrate made of a ceramic material, - at least one electrical connection track arranged on one face of the substrate ceramic, - at least one electronic component electrically connected to the electrical connection track, - said electronic power module further comprises a current limiter consisting of a superconducting electrical track made of a material having superconducting properties in a very low temperature range between OK and 200K, and preferably between OK and 90K, and more preferably between 20K and 90K, - said superconducting electrical track being arranged on one face of the substrate so as to adhere to said face of the ceramic substrate, said superconducting electrical track being arranged on the ceramic substrate so as to define a plurality of turns in which the current of a given turn flows in a direction opposite to that in which a current of an adjacent turn flows to obtain a non-inductive current limiter.

[0013] The invention thus makes it possible to intrinsically integrate a current limiter function into the electrical power module in order to protect it by limiting the amplitude of the currents appearing in particular in the event of a short circuit. Indeed, in normal operation, the superconducting track of the current limiter has almost zero inductance and resistance, so that the current limiter has no impact on the electrical performance of the power module. On the other hand, when the current exceeds an admissible level, the current limiter becomes active so that the superconducting track of the current limiter has a significant resistance, thus limiting the magnitude of the current. The intrinsic torque limiter functionality also makes it possible to do without a component dedicated to current limitation and thus to reduce the mass, cost, and size of the electronic power module while improving its reliability.Furthermore, in applications with powers too low to consider the integration of a dedicated current limiter, having an electrical module integrating this function intrinsically makes it possible to provide additional electrical protection that would not have been present otherwise.

[0014] According to one embodiment of the invention, the current limiter is arranged upstream of the electronic component.

[0015] According to one embodiment of the invention, the current limiter is arranged downstream of the electronic component.

[0016] According to one embodiment of the invention, a width of the superconducting electrical track of the current limiter is fixed so as to define from which critical current, a current limitation is triggered.

[0017] According to one embodiment of the invention, a length of the superconducting electrical track- The current limiter's conductive resistance is set to define a desired current limiter resistance during a short circuit.

[0018] According to one embodiment of the invention, the superconducting electrical track of the current limiter is made from at least one material belonging to the "Rare Earths-Barium-Copper-Oxygen" family.

[0019] According to one embodiment of the invention, at least one interface layer is arranged between the substrate and the superconducting electrical track of the current limiter to improve the adhesion of the superconducting track to the substrate.

[0020] According to one embodiment of the invention, the electrical connection track is a superconducting electrical track made of a material having superconducting properties in a very low temperature range between 0K and 200K, and preferably between 0K and 90K, and more preferably between 20K and 90K.

[0021] According to one embodiment of the invention, the electrical connection track is covered by a metallization layer on which the electronic component is assembled.

[0022] According to one embodiment of the invention, an insulating layer partially covers the electronic component and the electrical connection track to allow a connection between at least one upper electrode of the electronic component to another electrical connection track deposited at least partially on the insulating layer and an upper face of the electronic component.

[0023] According to one embodiment of the invention, the substrate is made of a ceramic material containing at least one material chosen from the following materials: sapphire, aluminum oxide (A1O), magnesia (MgO), silicon carbide (SiC), or silicon monoxide (SiO).

[0024] According to one embodiment of the invention, the substrate comprises fins arranged on a lower face intended to come into contact with a cooling fluid.

[0025] According to one embodiment of the invention, the substrate internally comprises at least one channel for circulating a cooling fluid having a cooling fluid inlet and outlet.

[0026] According to one embodiment of the invention, the cooling fluid is chosen from gaseous dihydrogen (H2), liquid dihydrogen (H2), gaseous helium (He), or liquid nitrogen (N2).

[0027] The present invention will be better understood and other characteristics and advantages will become apparent upon reading the detailed description which follows, comprising embodiments given by way of illustration with reference to the appended figures, presented as non-limiting examples, which may serve to complete the understanding of the present invention and the description of its embodiment and, where appropriate, contribute to its definition, in which:

[0028] [Fig-1] [Fig.l] is a schematic perspective view of an electronic module power device provided with a current limiter according to the present invention;

[0029] [Fig.2] [Fig.2] is a cross-sectional view of the electronic module of power of [Fig.l];

[0030] [Fig.3] [Fig.3] is a graphical representation of the evolution, as a function of the temperature, of a thermal conductivity of different materials which can constitute the substrate of an electronic power module according to the invention;

[0031] [Fig.4] [Fig.4] is a graphical representation of the evolution, as a function of the temperature, of a critical current density of a superconducting material constituting electrical tracks of an electronic power module according to the invention;

[0032] [Fig.5] [Fig.5] is a top view of the superconducting electrical track of a A current limiter according to the present invention describing a plurality of turns;

[0033] [Fig.6] [Fig.6] is a graphical representation of an evolution as a function of the time of a current flowing in the electronic power module respectively without and with a current limiter according to the present invention;

[0034] [Fig.7a][Fig.7b] Figures 7a and 7b are schematic sectional views of different embodiments of a cooling circuit of a power electronic module according to the invention.

[0035] It should be noted that the structural and / or functional elements common to the different embodiments have the same references. Thus, unless otherwise stated, such elements have identical structural, dimensional and material properties.

[0036] [Fig.l] and 2 are schematic perspective and sectional views of a power electronic module 10 comprising a ceramic substrate 11 made of a ceramic material. The substrate has a mechanical support function for at least one electronic component 13 as well as for electrical connection tracks 12.1-12.4. The substrate also has a heat transfer function towards a cooling system. The substrate 11 may also have a function of receiving a protective cover and / or a function of receiving an encapsulation solution.

[0037] The substrate 11 is made of a ceramic material containing at least one material chosen for example from the following materials: sapphire, aluminum oxide (A1O), magnesia (MgO), silicon carbide (SiC), or silicon monoxide (SiO). This list is not exhaustive; these are only examples of potential materials. As illustrated in [Fig. 3], these materials have thermal conductivity properties X (expressed in Wm *.K *) that are increased tenfold in a very low temperature range Temp between 20K and 90K.

[0038] The electrical connection tracks 12.1-12.4 are arranged on one face of the substrate 11. The electrical connection tracks 12.1-12.4 are made of a material having superconducting properties in a very low temperature range between OK and 200K, and preferably between OK and 90K, and more preferably between 20K and 90K. The superconducting properties are characterized by the absence or near absence of electrical resistance at very low temperatures.

[0039] An electrical track 12.1-12.4 is preferably made of at least one material belonging to the Rare Earth (RE)-Barium (Ba)-Copper (Cu)-Oxygen (O) family. [Fig.4] illustrates the fact that the critical current density Dec (expressed in A / mm2) of an electrical track 12.1-12.4 made of Gd (gadolinium)-Ba-Cu-O increases when the temperature Temp is lower than 90K. A superconducting electrical track 12 can be made of several materials chosen from the RE-Ba-Cu-O family.

[0040] The superconducting electrical tracks 12.1-12.4 are screen-printed on the substrate 11. For this purpose, masking may be carried out before deposition to ensure correct location of the superconducting electrical tracks 12.1-12.4 on the substrate 11. The superconducting electrical tracks 12.1-12.4 may be produced by pulsed laser ablation deposition known as "PLD" (Pulsed Laser Deposition) or any other technique suitable for depositing superconducting electrical tracks on the substrate 11 made of ceramic. A superconducting electrical track 12.1-12.4 preferably has a thickness of a few microns.

[0041] As can be seen in [Fig.2], at least one interface layer 19 can be arranged between the substrate 11 and a superconducting electrical track 12.1-12.4 to improve the adhesion of the superconducting track to the substrate 11. The interface layer 19 is for example made of magnesia (MgO).

[0042] The electronic component 13 is electrically connected to a superconducting electrical track 12.1. The electronic component 13 may for example take the form of a power semiconductor component, such as a power diode or a switching element which may for example be constituted by a transistor (IGBT for "Insulated Gate Bipolar Transistor", HEMT for "High Electron Mobility Transistor", MOSFET for "Metal Oxide Semiconductor Field Effect Transistor" or other) with or without a freewheel diode in parallel.

[0043] The superconducting electrical track 12.1 is covered by a metallization layer 15 on which the electronic component 13 is assembled. In order to limit the electrical resistance of the assembly, the metallization layer 15 is a layer partially covering the superconducting electrical track 12.1 only at the location where the electronic component 13 is assembled. The connection between the electronic component 13 and the metallization layer 15 can be made by soldering, sintering, bonding or any other technique suitable for the application. In [Fig.2], a solder zone 16 obtained with a filler metal is arranged between the electronic component 13 and the metallization layer 15 deposited on the superconducting electrical track 12.1.

[0044] An insulating layer 18 partially covers the electronic component 13 and the superconducting electrical track 12.1 to allow a connection between at least one upper electrode of the electronic component 13 to another superconducting electrical track 12.3 deposited at least partially on the insulating layer 18 and an upper face of the electronic component 13. The insulating layer 18 extending at least partially between the superconducting tracks 12.1 and 12.3 thus makes it possible to avoid short circuits between two superconducting electrical tracks 12.1 and 12.3 connected to different electrical potentials.

[0045] As can be seen in [Fig. 1], a current limiter 14 is constituted by a superconducting electrical track 23 made of a material having superconducting properties in a very low temperature range between 0K and 200K, and preferably between 0K and 90K, and more preferably between 20K and 90K. The superconducting electrical track 23 is arranged on one face of the substrate so as to adhere to said face of the ceramic substrate 11. The superconducting electrical track 23 of the current limiter 14 is made of at least one material belonging to the "Rare Earths-Barium-Copper-Oxygen" family.

[0046] As illustrated in [Fig. 5], the superconducting electrical track 23 is arranged on the ceramic substrate 11 so as to define a plurality of turns 24.1-24.4 in which the current of a given turn flows in a direction opposite to that in which a current of an adjacent turn flows to obtain a non-inductive current limiter 14. In [Fig. 5], the direction of the current inside the turns 24.1-24.4 is indicated by the arrows F. The number of turns of the current limiter 14 may vary depending on the application.

[0047] In order to obtain the circular shape of the turns 24.1-24.4, the superconducting electrical track 23 can be screen-printed on the substrate 11. Masking can be carried out before deposition to ensure correct location of the superconducting electrical track 23 on the substrate 11. Like the connection tracks 12.1-12.4, the superconducting electrical track 23 can be produced by pulsed laser ablation deposition known as "PLD" ("Pulsed Laser Deposition") or any other technique suitable for depositing a superconducting electrical track on a substrate 11 made of ceramic. The superconducting electrical track 23 preferably has a thickness of a few microns. An interface layer may be arranged between the substrate 11 and the superconducting electrical track 23 to improve the adhesion of the superconducting track 23 to the substrate 11. The interface layer is for example made of magnesia (MgO).The superconducting electrical track 23 of the current limiter 14 may be deposited at the same time as some or all of the superconducting electrical tracks. conductive 12.1-12.4.

[0048] The current limiter 14 can be arranged upstream or downstream of the electronic component 13. Thus, the current limiter 14 can be arranged between the electrical track 12.2 and the electrical track 12.4 as shown in [Fig.l] or alternatively between the electrical track 12.4 and the electrical track 12.1.

[0049] In normal operation, the current in the electrical track 23 of the current limiter 14 is less than a critical current of the current limiter 14 which therefore has neither inductance nor resistance and is therefore invisible on the electrical network. During a short circuit, the current in the current limiter 14 exceeds the critical current, so that the resistance of the current limiter 14 increases, which limits the amplitude of the short circuit making it easier to extinguish quickly by a cut-off device, such as an electrical power contactor or a fuse.

[0050] [Fig.6] thus shows that from the instant t1 of appearance of a short circuit in the power module 10, the current I observable inside the power module 10 equipped with the current limiter 14 (see curve C1) is much lower than the current observable inside a similar power module without a current limiter (see curve C2).

[0051] A width of the superconducting electrical track 23 of the current limiter 14 is set so as to define from which critical current, a current limitation is triggered. A length of the superconducting electrical track 23 of the current limiter 14 is set so as to define a desired resistance of the current limiter 14 when a short circuit occurs. The resistance of the current limiter 14 during a short circuit is proportional to the length of the electrical track 23.

[0052] The electronic power module 10 may comprise a cooling system 20 which may have different shapes. In the embodiment of [Fig.7a], the substrate 11 comprises fins 21 arranged on a lower face intended to come into contact with a cooling fluid 22. The fins 21 are arranged on the face opposite the face carrying the electronic component(s) 13. The fins 21 may be made in one piece with the rest of the substrate 11 or added and fixed to the substrate 11.

[0053] In the embodiment of [Fig.7b], the substrate 11 comprises internally, that is to say in the mass of the substrate 11, at least one channel 25 for circulation of a cooling fluid having an inlet 26 into which the cooling fluid 22 enters according to the arrow F1 and an outlet 27 from which the cooling fluid 22 leaves according to the arrow F2. The shapes of the substrate 11, such as the fins 21 or the channel(s) 25 for circulation of the cooling fluid can be obtained by an additive manufacturing process or by machining

[0054] The cooling fluid 22 is chosen from gaseous dihydrogen (H2), di- liquid hydrogen (H2), gaseous helium (He), or liquid nitrogen (N2). According to a particular embodiment, the electronic module 10 can be equipped with two cooling systems (with fins and with an internal circulation channel for a cooling fluid).

[0055] The assembly thus formed can be embedded in an encapsulation material making it possible to protect the electronic components against attacks caused by an environment in which the power module is located. Conventionally, the encapsulation material can take the form of a gel, an epoxy resin and / or a coating of an insulating material suitable for being applied to the electronic components. The encapsulation material is also known by the English term "coating".

[0056] A protective cover (not shown) may close the assembly thus formed. The protective cover may carry part of the power terminals and / or the control terminals of the electronic power circuit.

[0057] Alternatively, the electrical tracks 12.1-12.4 are made of a metallic material, such as copper or aluminum.

[0058] Of course, the various features, variants and / or embodiments of the present invention may be combined with each other in various combinations to the extent that they are not incompatible or mutually exclusive.

[0059] Furthermore, the invention is not limited to the embodiments described above and provided solely by way of example. It encompasses various modifications, alternative forms and other variants that may be envisaged by those skilled in the art within the scope of the present invention and in particular all combinations of the different operating modes described above, which may be taken separately or in association.

Claims

Claims

1. Power electronic module (10) comprising: - a ceramic substrate (11) made of a ceramic material, - at least one electrical connection track (12.1-12.4) arranged on one face of the ceramic substrate (11), - at least one electronic component (13) electrically connected to the electrical connection track (12.1-12.4), characterized in that said power electronic module (10) further comprises a current limiter (14) constituted by a superconducting electrical track (23) made of a material having superconducting properties in a very low temperature range between 0K and 200K, and preferably between 0K and 90K, and more preferably between 20K and 90K, - said superconducting electrical track (23) being arranged on one face of the substrate so as to adhere to said face of the ceramic substrate (11), said superconducting electrical track (23) being arranged on the ceramic substrate (11) so as to define a plurality of turns (24.1-24.4) in which the current of a given turn flows in a direction opposite to that in which a current of an adjacent turn flows to obtain a non-inductive current limiter (14).

2. Electronic power module according to claim 1, characterized in that the current limiter (14) is arranged upstream of the electronic component (13).

3. Electronic power module according to claim 1, characterized in that the current limiter (14) is arranged downstream of the electronic component (13).

4. Power electronic module according to any one of claims 1 to 3, characterized in that a width of the superconducting electrical track (23) of the current limiter (14) is fixed so as to define from which critical current, a current limitation is triggered.

5. Power electronic module according to any one of claims 1 to 4, characterized in that a length of the superconducting electrical track (23) of the current limiter (14) is fixed so as to define a desired resistance of the current limiter (14) during a short circuit.

6. Electronic module according to any one of claims 1 to 5, characterized in that the superconducting electrical track (23) of the current limiter (14) is made of at least one material belonging to the "Rare Earths-Barium-Copper-Oxygen" family.

7. Power electronic module according to any one of claims 1 to 6, characterized in that at least one interface layer is arranged between the substrate (11) and the superconducting electrical track (23) of the current limiter (14) to improve the adhesion of the superconducting track to the substrate (11).

8. Power electronic module according to any one of claims 1 to 7, characterized in that the electrical connection track (12.1-12.4) is a superconducting electrical track made of a material having superconducting properties in a very low temperature range between 0K and 200K, and preferably between 0K and 90K, and more preferably between 20K and 90K.

9. Electronic power module according to claim 8, characterized in that the electrical connection track (12.1-12.4) is covered by a metallization layer (15) on which the electronic component (13) is assembled.

10. Electronic power module according to claim 8 or 9, characterized in that an insulating layer (18) partly covers the electronic component (13) and the electrical connection track (12.1) to allow a connection between at least one upper electrode of the electronic component (13) to another electrical connection track (12.3) deposited at least partly on the insulating layer (18) and an upper face of the electronic component (13).

11. Power electronic module according to any one of claims 1 to 10, characterized in that the substrate (11) is made of a ceramic material containing at least one material chosen from the following materials: sapphire, aluminum oxide (A1O), magnesia (MgO), silicon carbide (SiC), or silicon monoxide (SiO).

12. Electronic power module according to any one of claims 1 to 11, characterized in that the substrate (11) comprises fins (21) arranged on a lower face intended to come into contact with a cooling fluid (22).

13. Electronic power module according to any one of claims 1 to 12, characterized in that the substrate (11) internally comprises at least one channel (25) for circulation of a cooling fluid having an inlet (26) and an outlet (27) for cooling fluid. dissement.

14. Power electronic module according to claim 12 or 13, characterized in that the cooling fluid (22) is chosen from gaseous dihydrogen (H2), liquid dihydrogen (H2), gaseous helium (He), or liquid nitrogen (N2).

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