Inverter device

Abstract

Inverter device (OD) for converting a three-phase DC voltage into a polyphase AC voltage at a predetermined frequency, the inverter device (OD) comprising three single-phase inverters (O1, O2, O3), each of the three single-phase inverters (O1, O2, O3) being capable of delivering one of the three phases. Figure for the abbreviation: Fig. 2

Description

Title of the invention: Inverter device

[0001] The invention relates to the field of generating a fixed-frequency three-phase voltage on board an aircraft from the mechanical energy generated by an engine of a nacelle of the aircraft fixed to the body of an aircraft. The invention also relates to the cooling of such generators.

[0002] From US patent US 3,579,143 a combined device is known which is installed in a nacelle of an aircraft and comprises a gearing system configured to transform the rotation of a motor shaft of the aircraft engine into a rotation at constant speed of a secondary shaft to which is coupled in rotation an electric machine operating as a generator and configured to deliver a three-phase voltage (for example 115 Vac, 230 Vac) at a fixed frequency (400 Hz) from the rotation of the secondary shaft at constant speed. The gearing system comprises a hydraulic system, a differential epicyclic gear train and a hydraulic pump.

[0003] However, this device is very expensive. Furthermore, due to its mechanical complexity, it has reliability problems resulting in high maintenance costs and requiring its regular replacement.

[0004] One solution to limit these drawbacks consists of providing a generation device comprising a generator intended to be mechanically coupled to the motor shaft, a rectifier for rectifying an alternating voltage delivered by the generator, a device for controlling the generation device so that the direct voltage delivered by the rectifier is fixed and an inverter receiving the fixed voltage as input and capable of delivering a three-phase alternating voltage of fixed frequency. The inverter is usually installed outside the nacelle in an avionics bay housed in the volume delimited by the body of the aircraft. The inverter is water-cooled.

[0005] However, the inverter is unavailable as soon as a power switch of the inverter fails.

[0006] One aim of the invention is to limit at least one of the aforementioned drawbacks.

[0007] To this end, the invention relates to an inverter device intended to convert a three-phase direct voltage from a polyphase alternating voltage at a predetermined frequency, the inverter device comprising three single-phase inverters, each of the three single-phase inverters being capable of delivering one of the three phases.

[0008] Advantageously, the inverter device comprises a support radially surrounding a cooling channel extending longitudinally along an axis x and in which a cooling liquid is intended to circulate along the axis x, electronic components of the inverter device being mounted on the support around the cooling channel so as to be able to be cooled by the cooling liquid when the latter circulates in the cooling channel.

[0009] Advantageously, all of the electronic components mounted on the support around the cooling channel so as to be able to be cooled by the cooling liquid when the latter circulates in the cooling channel or a subset of these electronic components is supported on a radial surface of a solid tubular support. The solid tubular support radially delimits the cooling channel.

[0010] Advantageously, the inverter device comprises toroidal output inductors mounted on the support so as to radially surround the cooling channel.

[0011] Advantageously, the toroidal output inductances are juxtaposed along the x axis.

[0012] Advantageously, each of the three single-phase inverters comprises power switches mounted on the support around the cooling channel so as to be able to be cooled by the cooling liquid when the latter circulates in the cooling channel.

[0013] Advantageously, the support comprises a tubular support for switches surrounding the x axis and is delimited radially by a first surface delimiting the cooling channel and by a second surface radially surrounding the first surface, the power switches being arranged around the tubular support bearing on the second surface.

[0014] Advantageously, the second surface has six flat faces distributed around the x axis, two of the power switches resting on each flat face.

[0015] The invention also relates to a generation assembly intended to be mechanically coupled to a motor shaft of an aircraft engine and intended to deliver the three phases of the single-phase alternating voltage when the motor shaft is rotated at variable speed, the generation assembly comprising a generator intended to be engaged with the shaft so as to generate an alternating voltage at a fixed initial frequency, a rectifier intended to rectify the alternating voltage and an inverter device according to the invention.

[0016] Other characteristics, details and advantages of the invention will emerge from reading the description given with reference to the appended drawings given by way of example and which represent, respectively:

[0017] [Fig-1] [Fig.l] is a block diagram of a generation system according to the invention,

[0018] [Fig.2] [Fig.2] is an electrical diagram of the inverter device according to the invention,

[0019] [Fig.3] [Fig.3] schematically represents a side view of an internal part of an inverter device according to the invention and of the cooling circuit of this inverter device,

[0020] [Fig.4] [Fig.4] schematically represents in front view (left) and in view of side (right) an individual support on which is mounted a first toroidal output inductance,

[0021] [Fig.5] [Fig.5] schematically represents in front view (left) and in view of side (right), the first output inductance mounted on its individual support,

[0022] [Fig.6] [Fig.6] schematically represents in perspective (left), in side view (middle) and in section in a section plane perpendicular to the x axis (right), a support for power switches,

[0023] [Fig.7] [Fig.7] schematically represents in side view (left) and in section in a section plane AA (right), the power switch support and the power switches fixed to the switch support,

[0024] From one figure to another, the same elements are identified by the same references.

[0025] The invention relates to a generation system as shown in the diagram. tically in [Fig.l]. The generation system comprises a generator assembly EG intended to be installed in a nacelle N of an aircraft.

[0026] The generator assembly EG is intended to be mechanically engaged with a motor shaft AR and to deliver three phases of a three-phase alternating voltage at a predetermined fixed frequency when the motor shaft AR is driven in rotation at variable angular speed by a motor M arranged in the nacelle N.

[0027] The motor is, for example, intended to drive the motor in rotation in a speed range from 4500 rpm to 9000 rpm.

[0028] The generator assembly EG comprises a generator G intended to be mechanically engaged with the motor shaft AR and capable of delivering a polyphase alternating voltage having the same predetermined effective voltage, whatever the rotation speed of the motor shaft AR when the latter is driven in rotation by the motor M.

[0029] The generation system comprises a generator control device CG configured to control the generator G so that the polyphase alternating voltage delivered by the generator G has the predetermined effective voltage regardless of the rotational speed of the motor shaft AR. The generator control device CG comprises, for example, a power converter and a power converter control member. The control member is configured to control the power converter so that it electrically supplies the generator G so that it delivers the desired polyphase alternating voltage at the predetermined effective voltage, the frequency of which depends on the rotational speed of the shaft.

[0030] Generator G is conventional for those skilled in the art. It is, for example, a synchronous generator with a brushless wound rotor. It then comprises a main electrical machine, an exciter and a rotating rectifier bridge connecting the main electrical machine and the exciter.

[0031] Advantageously, the generator G is three-stage. It comprises a brushless synchronous auxiliary generator comprising a rotor, coupled to the common shaft, comprising permanent magnets and a stator comprising stator windings. Alternatively, the generator G is two-stage.

[0032] The generator assembly EG also comprises a rectifier RG configured to deliver a substantially constant direct voltage UE when it is subjected, at input, to the polyphase alternating voltage generated by the generator G.

[0033] Advantageously, the generator control device is configured to control the generator so that it delivers a direct voltage of 540 V.

[0034] The generator assembly EG also comprises an inverter device DO intended to transform the output voltage of the rectifier RG into three phases of a three-phase alternating voltage having a fixed predetermined frequency. The invention also relates to the inverter device DO.

[0035] The three phases are generated by the inverter device DO in differential mode.

[0036] According to the invention, the inverter device DO comprises three independent inverters Oi, O2, O3, for example voltage inverters, each having an input connected to the output of the RG rectifier so as to be subjected to the direct voltage delivered at the output of the RG rectifier. Each voltage inverter Oi, O2, O3 is intended to deliver a single-phase voltage, corresponding to one of the phases of the three-phase alternating voltage at fixed frequency, from the direct voltage delivered at the output of the RG rectifier.

[0037] The generator assembly EG comprises a device for controlling the inverter device CO configured to control the inverters Ob O2, O3, and more particularly controllable electronic switches of the inverters Ob O2, O3, so that each inverter Ob O2, O3 delivers one of the phases of the three-phase alternating voltage of fixed frequency and the three inverters Ob O2, O3 deliver the three phases of the three-phase voltage. This type of control is conventional for those skilled in the art.

[0038] The control device is, for example, configured so that each inverter provides an alternating voltage at 400 Hz with an effective voltage of 300 V, the three alternating voltages being phase-shifted so as to form the phases of a three-phase alternating voltage, from the direct output voltage of the rectifier of 540 V.

[0039] This configuration makes it possible to provide partial availability of the DO inverter device in the event of a failure of one of the inverters.

[0040] Furthermore, the fact that the inverter device DO has three independent single-phase inverters allows good thermal and mechanical integration and easy assembly. Indeed, the power components of the different inverters can be separated from each other.

[0041] The CO control device advantageously comprises three devices of individual controls, each individual control device being configured to control only one of the three inverters. The control device is then configured to synchronize the controls of the three individual control devices. Synchronization is, for example, achieved using an "open collector" type priority bus composed of three logic signals. The three inverters generate three synchronization signals at a predetermined frequency, phase-shifted by 120°. These signals are shared via this logic bus: the first of the inverters to switch to the low state synchronizes the other two inverters.

[0042] The generation system advantageously comprises a transformer T configured to provide galvanic isolation between the inverter device DO and a distribution network DL of the three-phase voltage on board the aircraft.

[0043] The transformer T is advantageously configured to generate phases having a predetermined effective distribution voltage different from that of the phases delivered by the inverters. The inverter device DO is, for example, configured to deliver an alternating voltage at 400 Hz having an effective voltage of 115 V or 230 V.

[0044] The transformer T is advantageously configured to transform the phases delivered by the inverters in differential mode into a three-phase voltage in common mode (three phases and neutral).

[0045] In the advantageous embodiment of [Fig.l], the generator G and the inverter device DO are arranged in an aircraft nacelle N.

[0046] The transformer T and the generator control device CG are housed in a volume delimited by the body of the aircraft on which the nacelle N is mounted.

[0047] [Fig.2] represents an electrical diagram of the voltage inverters Oi, O2, O3 (or O; with i = 1 to 3) of the inverter device DO. Each inverter O; is subjected between its input terminals En and Ei2, to the output voltage UE of the rectifier RG.

[0048] Each inverter Oi, O2, O3 comprises power components.

[0049] Each inverter Oi comprises an input filter comprising two input capacitors Cy (with j = 1 to 2) connected in parallel between the input terminals En and Ei2 of the inverter O; considered. The capacitors Cy have a low impedance making it possible to obtain a fixed voltage at the output of the input filter. The value of the output voltage of the input filter does not vary as a function of a variation in the current draw.

[0050] Each voltage inverter O; (with i= 1 to 3) further comprises four power switches Tik (with k= 1 to 4) mounted in H bridge at the output of the input filter Cy (with j = 1 to 2).

[0051] Each switch Tik comprises, for example, a transistor TR connected in parallel with a diode D. The transistor is, for example, an insulated gate bipolar transistor or IGBT in reference to the Anglo-Saxon expression “Insulated Gate Bipolar Transistor”, for example a PNP IGBT.

[0052] The H-bridge of each inverter O; comprises two branches Bu and Bi2 each comprising two switches connected in series.

[0053] Each voltage inverter O; comprises a first output filter LC comprising an output inductance Lf; and an output capacitor Cf; connected in series between the two midpoints of the two branches B^ and Bi2 of the H-bridge. This LC filter is a low-frequency filter making it possible to obtain a sinusoidal voltage having a zero average voltage value. The function of the output inductance Lf; is to smooth the voltage so as to obtain a sinusoidal voltage at the output of the inverter O; and the function of the output capacitor Cf; is to eliminate any voltage offset so as to obtain an output voltage with a zero average value.

[0054] For this purpose, the resonant frequency of the LC filter is very low compared to the switching frequency of the power switches.

[0055] Each inverter O; also comprises a current sensor CT; for measuring the output current of the inverter O;.

[0056] The control device of the inverter device CO uses the measurement of the output current delivered by the current sensors CT; of the inverters O; to control the power switches in order to limit the output current during an overload.

[0057] Advantageously, each inverter O; comprises a second low-pass HF output filter; mounted across the output capacitor Cf; of the inverter O;. The second HF output filter; is configured to filter the high-frequency parasitic signals generated in particular at the switching frequency of the switches and at frequencies of its harmonics.

[0058] This low-pass filter is, for example, a series LC filter having a resonance frequency of the order of the switching frequency.

[0059] The output voltage U; of each inverter O; is the voltage measured at the output of the HF low-pass filter;

[0060] We will now describe the mechanical and thermal architecture of the inverter device DO according to the invention.

[0061] [Fig. 3] schematically represents in side view, an internal part of an inverter device DO according to the invention and of the cooling circuit CR of this inverter device.

[0062] The inverter device DO comprises a support S radially surrounding a channel CA elongated along an axis x, and in which a cooling liquid is intended to circulate along the axis x.

[0063] The coolant is intended to circulate in the cooling circuit CR in a closed loop. This cooling circuit CR comprises the cooling channel- AC system, a PP pump and an ET heat exchanger.

[0064] The support S advantageously comprises an outlet connector Cg intended to convey a cooling liquid, for example oil or water, leaving a cooling channel CA towards the heat exchanger ET, intended to cool the cooling liquid, then towards the pump PP configured to circulate the cooling liquid towards an inlet connector Cd, of the support S, in the direction of the arrows in [Fig. 3], to inject the cooling liquid into the cooling channel CA and circulate it along the x axis to the connector Cg. The direction of circulation of the liquid could of course be reversed compared to that of [Fig. 1].

[0065] Advantageously, electronic components, in particular power components of the inverter device DO, are mounted on the support S around the cooling channel CA so that these power components are capable of being cooled by the cooling liquid when the latter circulates in the cooling channel CA.

[0066] The cooling channel CA advantageously extends longitudinally along the x axis.

[0067] This assembly is compact and easy to carry out. It allows for assembly in the nacelle N, which reduces the mass of the assembly.

[0068] This assembly allows cooling of the power components mounted around the AC cooling channel with the same coolant as that used to cool the electrical machine of the generator.

[0069] The fact that the AC cooling channel extends linearly favors the integration of the DO inverter device.

[0070] Advantageously, electronic components Lf;, Tik of each of the three inverters O; are mounted on the support S around the cooling channel AC so that these power components are capable of being cooled by the coolant when the latter circulates in the cooling channel AC. This makes it possible to mount the components of three inverters on the nacelle and to cool the components of the three inverters by means of the same cooling loop.

[0071] These components advantageously include the output inductances Lf; and the power switches Tik. Indeed, these are the components of the inverters which dissipate the most heat.

[0072] For this purpose, the support S comprises a support for inductances SB, on which the output inductances Lf are mounted and a support SI for switches on which the power switches Tik are mounted.

[0073] These supports are integral with each other.

[0074] Advantageously, the electronic components Lf;, Tik mounted on the support S are intended to be mounted on the nacelle via the S bracket. This allows easy mounting of the three inverters on the nacelle.

[0075] Advantageously, each of these electronic components Lf;, Tik rests on a radial surface of a solid tubular body SB;, SI having a tubular shape radially delimiting the cooling channel CA. By radial surface of the tubular body is meant a surface radially delimiting the tubular body.

[0076] As we will see in the rest of the text, each of this or these tubular bodies SB;, SI is advantageously delimited radially by an internal surface delimiting the cooling channel CA and by an external surface completely surrounding, radially, the internal surface. This makes it possible to obtain a good heat exchange between each component resting on the tubular body and the coolant circulating in the cooling channel CA delimited radially by the tubular body SB;, SI.

[0077] Advantageously, each of this or these tubular bodies is metallic. Metals have the advantage of being good thermal conductors.

[0078] The metal body is, for example, made of aluminum, which has the advantage of being light, or of steel.

[0079] In [Fig.4], one of the three individual supports SBi on which the first output inductance Lfp is mounted is shown schematically in front view (left) and in side view (right). The individual supports on which the other output inductances are mounted are identical to this individual support.

[0080] The individual inductance support SBi delimits a cylindrical internal volume V) corresponding to an axial portion of the cooling channel CA.

[0081] The individual support comprises a tubular base EBi of axis x and a plate Pi extending in a transverse plane perpendicular to the axis x. The plate Pi is adjacent to the tubular base EBi along the axis x.

[0082] The plate Pi adjacent to the tubular base EBi has a disc shape comprising an opening having a diameter substantially identical to that of the internal diameter of the tubular base EBb.

[0083] The tubular base EBi and the plate Pi surround and radially delimit the individual portion of the cooling channel CA.

[0084] The individual support SBi is, advantageously, provided with first cooling fins Al extending within the internal volume Vp

[0085] For example, the first fins Al are produced in the form of plates extending radially within the cooling channel CA and more particularly within the volume Vj.

[0086] In [Fig.5], the first output inductance Lfi mounted on its support in is shown schematically in front view (left) and in side view (right). individual SBp The structure of each of the other two output inductances Lf2>Lf3 and their mounting are not shown in detail because they are identical to the structure of the output inductance Lfi and respectively to its mounting on its individual support SBp

[0087] The first output inductance Lfi is toroidal and comprises a toroidal magnetic circuit CMi and a winding Bi made around the toroidal magnetic circuit CMb. The winding Bi is a winding of an electrically conductive wire, for example, made of copper, made around the toroidal magnetic circuit CMb. As visible in [Fig.3], this is the case for each output coil Lf;: it comprises a toroidal magnetic circuit CM; and a winding B; made around the toroidal magnetic circuit CM;.

[0088] The first output inductance Lfi radially surrounds the channel CA and more particularly the tubular base EBL

[0089] Advantageously, each toroidal output inductor completely radially surrounds the AC cooling channel.

[0090] The toroidal power inductance Lfi forms a crown surrounding the x axis and the AC cooling channel.

[0091] The EBi tubular base is massive.

[0092] Advantageously, the power inductance Lfi is radially supported on the tubular base EBi.

[0093] The power inductance Lf; may be in direct or indirect physical contact with the tubular base EB;.

[0094] This arrangement of the power inductors is particularly compact and allows efficient cooling of the power inductors by a liquid circulating in the AC cooling channel.

[0095] Advantageously, as shown in [Fig.3], the toroidal output inductances Lf; are arranged adjacently along the x axis, i.e. next to each other along the x axis. This arrangement is particularly compact.

[0096] The volumes delimited by the different individual supports SB; are then adjacent along the x axis.

[0097] As visible in [Fig.3], the individual supports SB; are joined to each other along the x axis so that the tubular bases of two consecutive individual supports SBi and SB2 (respectively SB2 and SB3) are separated by a plate Pi (respectively P2) of one of the two individual supports.

[0098] The support S also comprises an end plate Pg contiguous to the tubular base EBi of the first individual support SB.

[0099] Each power inductance Lfb respectively Lf2, respectively Lf3 is interposed axially between two plates Pg, Ph respectively Ph P2, respectively P2, P3, so as to be maintained in a substantially fixed axial position relative to the S support.

[0100] Advantageously, each power inductance Lfb respectively Lf2, respectively Lf3 is axially separated from each of the two plates Pg, Pi; respectively Pi, P2; respectively P2, P3 between which it is interposed, by a thermal interface I.

[0101] Advantageously, each thermal interface I is attached to one of the toroidal output inductances and to a plate Pg. The thermal interfaces I are electrically insulating and promote heat exchange between the toroidal output inductance and the cooling channel CA via the plates P, Pg.

[0102] The thermal interface I, attached to one of the toroidal output inductors and to a Pg plate P; has, for example, a blade shape having a central opening surrounding one of the bases. It can be formed from an electrically insulating material having a high heat transfer coefficient, for example a polymer, such as, for example, Kapton or polypropylene. Alternatively, the thermal interface I is multilayer. It comprises, for example, layers of the same electrically insulating material separated by a change-of-state material changing state when a threshold temperature is exceeded so that the thickness of the thermal interface decreases when the temperature exceeds this threshold temperature. This allows the thermal interface to take up the axial expansion of a power inductor when the temperature increases and therefore to limit vibrations at low temperature.

[0103] Preferably, as shown in [Fig.3], the power switches Tik are arranged around a second zone of the AC cooling channel adjacent, along the x axis, to a first zone of the cooling channel along the x axis around which the toroidal output inductances Lf are arranged; so that the switches Tik are cooled by the coolant circulating in the AC cooling channel. This makes it possible to arrange the power switches Tik close to the toroidal output inductances Lf; while ensuring efficient cooling of these switches.

[0104] For this purpose, the support SI for power switches is adjacent to the support for inductances SB along the x axis.

[0105] In [Fig.6], the support for power switches SI is shown schematically in perspective (left), in side view (middle) and in section in a section plane perpendicular to the x axis (right). The fins A2 with which the support SI is equipped are not shown on the left.

[0106] The support for power switches SI is tubular and solid. The tubular support SI surrounds the axis x and is radially delimited by a first surface SI delimiting the volume VI which is an axial portion of the cooling channel CA, and by a second surface S2, radially surrounding the first surface S1 and on which the Tik power switches are fixed.

[0107] Advantageously, the second surface S2 comprises at least one planar face SPm (m = 1 to 6).

[0108] In the advantageous embodiment of [Fig.6], the second surface S2 has a generally hexagonal shape in a plane perpendicular to the x axis so as to have six flat faces SPm distributed around the x axis.

[0109] The flat faces SPm extend longitudinally along the x axis.

[0110] The support for power switches SI is advantageously provided with second cooling fins A2 projecting from the first surface SI so as to extend within the cooling channel CA.

[0111] For example, the second fins A2 are produced in the form of plates extending radially within the cooling channel CA.

[0112] In [Fig.7], there is shown schematically in side view (on the left) and in section in the plane AA (on the right), the support for power switches SI and the power switches Tik fixed to the support for switches SL

[0113] Advantageously, the set of power switches Tik is arranged radially around the support for switch SI, bearing on the second surface S2.

[0114] Advantageously, the Tik power switch assembly comprises power switches distributed radially around the SI power switch support. This allows good cooling of the various Tik power switches.

[0115] Advantageously, the power switches Tik are supported on different flat faces SPm of the second surface S2 or on the different flat faces of the second surface S2. This makes it possible to ensure effective cooling of the power switch by placing a flat face of the power switch or of a support on which the power switch is mounted against one of the axial flat faces of the support SL.

[0116] In the non-limiting embodiment of the figures, the inverter device DO comprises power modules Mm. Each power module Mm comprises a substantially flat base SOm (m = 1 to 6) and two power switches Tik.

[0117] At least one flat face of each switch Tikest is attached to a flat surface of one of the bases SOm, itself resting on one of the flat faces SPm so as to present a large heat exchange surface between the switch and the support SI, which promotes the cooling of the switch by the cooling liquid circulating in the channel CA.

[0118] Each module Mm advantageously comprises a cover CAPm. The two switches of the module Mm are interposed between the cover CAPm and the base of the module SOm.

[0119] In the advantageous embodiment of the figures, two power switches are in support on each of the six flat faces of the second surface S2.

[0120] In other words, each power module Mm rests on one of the flat faces SPm of the second surface S2.

[0121] Advantageously, as visible in [Fig.7], each power module Mm comprises the two switches of the same arm of the bridge of one of the three inverters. This makes installation and connections easier.

[0122] Each power module Mm extends longitudinally along the x-axis and the two power switches of the power module are adjacent along the x-axis. Only the switches T32 and T34 are, therefore, not visible in [Fig.7].

[0123] Therefore, in the particular embodiment of the figures, the power switches are distributed radially around the AC channel and axially along the AC channel.

[0124] Alternatively, the power switches are distributed only axially around the x axis. This promotes uniformity of cooling of each of the switches.

[0125] More generally, the second surface S2 comprises at least one planar face and at least one power switch is fixed against the planar face. The number of planar faces of the second surface visible in the figures is not limiting. It is possible, for example, to envisage a second surface having overall a polygon shape having a number of sides other than six in the plane perpendicular to the x axis.

[0126] For example, it is possible to envisage a second surface having a general dodecagon shape so as to have twelve flat faces. A switch can then be placed on each of the faces. Alternatively, it is possible to envisage a second surface having a general triangle shape so as to have three flat faces. Four switches can then be placed on each of the faces.

[0127] Generally, the second surface S2 advantageously comprises different flat faces distributed around the axis x. Power switches rest on at least a subset of these flat faces.

[0128] The number of power modules and the number of power switches per power module. It is possible to envisage several intermediate supports per power switch or one or more than two switches per intermediate support.

[0129] Advantageously, all the electronic components of the inverter device DO are mounted on the support S and arranged around the cooling channel CA in a cylindrical volume shown in dotted lines in [Fig.3], the axis of which is the x axis of the cooling channel CA. This facilitates the integration of the inverter device DO in the N nacelle and its mounting on the nacelle. This assembly is particularly compact.

[0130] The cylindrical volume is delimited axially by the plate Pg and by another end plate Pd perpendicular to the x axis.

[0131] Advantageously, the control device of the CO inverter device is advantageously integrated into this cylindrical volume.

[0132] .In the non-limiting embodiment of [Fig.3], the support S comprises a tubular end support ST radially delimiting the cooling channel and contiguous to the support for switches SI but could, as a variant, be contiguous to the support for inductances SB.

[0133] The electronic components other than the switches and the toroidal output inductors may be arranged radially around the ST end tubular support and / or around the power switches. This makes it possible to limit the diameter of the cylindrical volume occupied by the components of the inverter device.

[0134] Alternatively, the components of the inverter device DO other than the output switches and the output inductors may be arranged radially around the end tubular support ST and / or around the switches and / or around the output inductors.

[0135] The support S can be a single piece or be an assembly of parts assembled in a sealed manner so as to prevent liquid from flowing from the cooling channel towards the electronic components.

[0136] The inverter device DO advantageously comprises a housing enclosing the electronic components of the inverter device in a sealed manner. I

[0137] The housing comprises, for example, a tubular cover sealed to the end plates Pg and Pd.

[0138] The cooling channel surrounds the x-axis.

[0139] Advantageously, the cooling channel CA is rotationally symmetrical around the x axis.

[0140] Advantageously, at least one of the tubular supports is rotationally symmetrical around the x axis.

Claims

Claims

1. An inverter device (DO) for converting a three-phase DC voltage to a polyphase AC voltage at a predetermined frequency, the inverter device (DO) comprising: - three single-phase inverters (Oi, O2, O3), each of the three single-phase inverters (Oi, O2, O3) being capable of delivering one of the three phases in differential mode, - a support (S) radially surrounding a cooling channel (CA) extending longitudinally along an x-axis and in which a cooling liquid is intended to circulate along the x-axis, electronic components of the inverter device (DO) being mounted on the support (S) around the cooling channel (CA) so as to be capable of being cooled by the cooling liquid when the latter circulates in the cooling channel (CA), - toroidal output inductors mounted on the support (S) so as to radially surround the cooling channel (CA).

2. Inverter device (DO) according to the preceding claim, in which the support (S) comprises a solid tubular support radially delimiting the cooling channel (CA), at least a subset of the electronic components mounted on the support (S) around the cooling channel (CA) so as to be able to be cooled by the cooling liquid when the latter circulates in the cooling channel (CA) is supported on a radial surface of the solid tubular support, the solid tubular support radially delimiting the cooling channel (CA).

3. Inverter device (DO) according to one of the preceding claims, in which the toroidal output inductances are juxtaposed along the x axis.

4. Inverter device (DO) according to any one of claims 1 to 3, wherein each of the three single-phase inverters comprises power switches mounted on the support (S) around the cooling channel so as to be capable of being cooled by the coolant when the latter circulates in the cooling channel.

5. Inverter device (DO) according to claim 4, wherein the support (S) comprises a tubular support for switches (SI) surrounding the x axis and being radially delimited by a first surface (SI) delimiting the cooling channel (CA) and by a second surface (S2) radially surrounding the first surface (SI), the power switches being arranged around the tubular support resting on the second surface (S2).

6. Inverter device (DO) according to claim 5, in which the second surface (S2) has six flat faces distributed around the x axis, two of the power switches resting on each of the flat faces.

7. Generation assembly (EG) intended to be mechanically coupled to a motor shaft (AR) of an aircraft engine and intended to deliver the three phases of the polyphase alternating voltage when the motor shaft is rotated at variable speed, the generation assembly (EG) comprising a generator (G) intended to be engaged with the shaft so as to generate an alternating voltage at a fixed initial frequency, a rectifier intended to rectify the alternating voltage and the inverter device (DO) according to any one of the preceding claims.

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