Smart electric motor with electrical redundancy and integrated fault detection

Abstract

The present invention relates to a smart motor (10) comprising a permanent magnet electromechanical converter (12) and an electronic control unit, wherein the electromechanical converter (12) comprises a permanent magnet rotor (121) and a stator (122) comprising a first assembly having at least three phases electrically coupled to each other in a star configuration, a second assembly having the same number of phases as the first assembly, wherein the phases of the second assembly are electrically coupled to each other in a star configuration, and impedances between the star neutral points of the first and second assemblies, and the electronic control unit (18) comprises a control inverter having the same number of independent control arms as the phases of the first assembly and the same number of independent control arms as the phases of the second assembly, wherein the control inverter is configured to control each phase of the first assembly and each phase of the second assembly via its own control arms, and the electronic control unit is configured to measure the voltage difference across the star neutral points of the first and second assemblies with respect to a voltage reference common to the first and second assemblies.

Description

Technical Field

[0005]

[0001] The present invention discloses an electrical architecture of a smart electric motor, particularly for aircraft, and more particularly, a smart electric motor with multiple electrical channels with integrated fault detection to improve its operational safety.

Background Art

[0002] Electric motors have become attractive in recent years for vehicle applications, particularly in aerospace, due to their usage, flexibility of their implementation, their efficiency (only the necessary energy is consumed), their reliability (limited maintenance), and the potential mass and volume reduction they offer compared to conventional propulsion systems (which are thermal and involve hydraulic or pneumatic power distribution), as well as their low carbon footprint.

[0003] Therefore, it is easy to understand that the mechatronic integration constraints (mass and volume) of electric motor assemblies, controllers (power electronics and control electronics), filtering and cooling systems, as well as operational safety, are important issues in this change, particularly to obtain a low mass and footprint propulsion assembly. <​​​​​There is also a known smart motor that has two groups of three coils electrically coupled in a star configuration, with the neutrals of the two groups electrically connected to each other to provide an electrical common point and balance the current. This configuration is relatively inexpensive to implement. However, in this configuration, a failure in one group can disrupt the operation of the other group.

[0006] French Patent Application Publication No. 3089715 discloses a motor comprising two three-phase assemblies in which the stators are electrically decoupled from each other. The object of the following disclosure is, conversely, to demonstrate that well-designed electrical coupling can improve the ability to detect faults or anomalies in the behavior of the stator assemblies. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] French Patent Application Publication No. 3089715 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] This disclosure is intended to provide an architectural solution for a smart motor that ensures the supply of mechanical torque in the event of a complete or partial failure of the voltage-type inverter arm of the stator, or even in the event of a complete failure of the stator, and also enables the detection of a failure in one of the stars of the stator.

[0009] A given control arm of an inverter controls only one phase of a single assembly. [Means for solving the problem]

[0010] In a first object of this disclosure, a smart motor is proposed comprising an electromechanical permanent magnet converter and an electronic control unit. The electromechanical converter comprises a permanent magnet rotor and a stator. The stator comprises a first assembly having at least three phases electrically coupled to each other in a star configuration, a second assembly having the same number of phases as the first assembly, the phases of which are electrically coupled to each other in a star configuration, and impedances between the star neutral points of the first and second assemblies. The electronic control unit comprises a control inverter having the same number of independent control arms as the phases of the first assembly and the same number of independent control arms as the phases of the second assembly. The control inverter is configured to drive each phase of the first assembly and each phase of the second assembly by its own control arms. The electronic control unit is configured to measure the voltage difference between the star neutral points of the assemblies with respect to a voltage reference common to the first and second assemblies.

[0011] The electrical coupling of the star neutral points of the first and second assemblies, as well as the measurement of the voltage between them, allows the motor to detect stator faults (complete or partial short circuits, motor phase failures, conductor degradation, open circuits, open-circuit transistor losses, open faults, etc.). If a fault is detected early enough, it may even be possible to alter the motor's operation to prevent overheating and / or damage to its components (e.g., stator conductors).

[0012] Impedance not only generates a voltage difference when current exists between the neutral points of an assembly, but it can also help limit this current. An electronic control unit can be configured to measure the voltage across an impedance terminal.

[0013] In the smart motor described herein, the two star assemblies can be wound sequentially rather than simultaneously, which takes longer than simultaneous winding, but allows for magnetic and / or electrical decoupling, and / or enables the mechanical separation of the coils of the two assemblies. The torque generated by the control current is balanced by the way each coil assembly is wound separately. The winding must therefore be more complex than in a configuration where the two coil assemblies are wound simultaneously (because two independent windings are created instead of a single winding with two wires electrically insulated from each other).

[0014] In the smart motor described herein, coils from different assemblies can be distributed around the rotation axis of the smart motor rotor so as to be geometrically separated from one another. Geometric separation, or mechanical separation, can limit or even prevent the propagation of a fault in one assembly to another via electrical conduction and / or induction and / or heat transfer.

[0015] The motors can be configured to isolate the stars of the first and second assemblies from each other in response to a voltage between them exceeding a threshold.

[0016] Therefore, the faulty assembly is no longer driven, while the motor continues to drive the non-faulty assembly.

[0017] The motor may be configured to measure the voltage at each terminal of each phase of the first and second assemblies, and to signal a fault in a given assembly in response to a deviation threshold being exceeded by the voltage difference between its two phases. In addition or alternatively, the motor may be configured to measure the voltage at each terminal of each phase of the first and second assemblies, as well as the current in each coil supply, to detect a fault in a given assembly in response to a voltage threshold being exceeded by the voltage between the star neutral points of the first and second assemblies.

[0018] Therefore, the motor can identify which assembly is faulty, even if the stator has only two assemblies. However, the motor can be configured in this way regardless of the number of assemblies in the stator.

[0019] The stator may comprise at least one assembly other than the first and second assemblies, each having the same number of phases as the first assembly, electrically coupled to one another in a star configuration. The inverter may further comprise the same number of independent control arms as there are phases in the (set of) assemblies other than the first and second assemblies. The inverter may further be configured to drive each phase of the (set of) assemblies other than the first and second assemblies by its own control arms. The electronic control unit may further be configured to measure the voltage difference between the star neutral point of the first assembly and the star neutral point of the assemblies other than the first and second assemblies, and between the star neutral point of the second assembly and the star neutral point of the assemblies other than the first and second assemblies.

[0020] If the smart motor has three or more assemblies, it can measure at least the voltage difference between the neutral point of one assembly and those of the other two assemblies, or even the voltage difference between the neutral points of all assemblies in pairs.

[0021] A smart motor does not need to have a gearbox inside its housing; the housing, or casing, accommodates the electromechanical converter and control unit. This can lead to increased reliability and maintenance in addition to savings in volume and mass.

[0022] An electromechanical converter can be a synchronous machine.

[0023] The stator of an electromechanical converter may comprise a series of teeth arranged circumferentially on the stator. For example, the series of teeth may be implemented as a stack of thin plates having radially projecting teeth circumferentially separated from each other by toothed rings and / or radial cutouts. Each phase may comprise a coil wound around a single tooth of the stator, or a series of several coils wound around a single tooth of the stator. The term "tooth of the stator" refers to the teeth of the toothed ring or the radially projecting teeth of the stack of laminations.

[0024] Therefore, each of the coils of each assembly can be wound around a single tooth of the toothed ring, and the size of the stator, particularly the size of the coil head, can be minimized.

[0025] The rotor may include magnets arranged in a Halbach array configuration, which can increase the mass torque of the smart motor.

[0026] The stator of an electromechanical converter can be divided into separate angular ranges, the number of angular ranges of the stator corresponding to the number of three-phase assemblies of the stator, and the angular ranges extending over an angle corresponding to 360° divided by the number of assemblies of the stator, or an integer multiple of the number of assemblies of the stator.

[0027] In the case of a stator with two assemblies, the coils of the first assembly will thus be arranged over a first angular range of the stator that mechanically extends over 180°, and the coils of the second assembly can be arranged over a second angular range of the stator that mechanically extends over 180°, the first angular range being separate from the second range.

[0028] The first coil assembly and the second coil assembly are thus located in two separate parts around the circumference of the circle. This can facilitate mechanical, magnetic, electrical, and / or thermal separation between the two coil assemblies so that a fault that may exist in one coil of an assembly does not propagate to and / or damage another part of the other assembly.

[0029] The control unit may further include a current adjustment module and / or a rotor speed adjustment module for each coil assembly, independent of the other coil assembly.

[0030] The control unit may be configured to operate with and / or without a sensor for the mechanical position of the rotor. The mechanical position sensor may provide the angular mechanical position (relative to the stator) of the rotor to which the sensor is connected. This can allow the control unit to have this position information to regulate the current in the two stator winding assemblies. If the motor is equipped with a rotor position sensor, this sensor may include a measurement channel used by all assemblies—or one sensor per assembly.

[0031] If a position sensor is not installed, or if position information from the sensor is lost, the control module of the control unit can implement a position estimation process to ensure the function of adjusting the current in the two stator windings.

[0032] The electronic control unit may also be advantageously provided with a connection interface that connects a high-voltage DC power bus to each of the inverter arms and includes a capacitive decoupling stage equipped with differential mode capacitors.

[0033] Other features and advantages of the technology described herein will become apparent after reading the following descriptions of some embodiments of the technology described herein, which are given with reference to the accompanying drawings as examples. [Brief explanation of the drawing]

[0034] [Figure 1] An aircraft with several propulsion rotors equipped with an electric propulsion system according to one embodiment is schematically illustrated. [Figure 2] A schematic representation of a fixed-wing aircraft with multiple propulsion rotors equipped with an electric propulsion system according to one embodiment. [Figure 3] A schematic cross-sectional view of the smart motor in the propulsion system shown in Figure 1 is shown according to the first embodiment of the smart motor. [Figure 4] This is a schematic representation of the circumferential arrangement of at least three-phase two assemblies. [Figure 5] This is a schematic representation of the circumferential arrangement of at least three-phase two assemblies. [Figure 6] This is a schematic representation of the circumferential arrangement of at least three-phase two assemblies. [Figure 7] Figure 3 shows a schematic representation of the electrical architecture of the electromechanical converter of the smart motor according to the first embodiment. [Figure 8] Figure 3 schematically illustrates the electrical architecture of the electromechanical converter of the smart motor according to the second embodiment. [Figure 9] Figure 3 schematically illustrates the electrical architecture of the electromechanical converter of the smart motor according to the third embodiment. [Modes for carrying out the invention]

[0035] Figure 1 schematically illustrates an aircraft 7 with several propulsion rotors equipped with a propulsion system 9 according to one embodiment. In the example illustrated in Figure 1, the propulsion system 9 comprises four propulsion rotors 1-4 distributed across a dotted propulsion rotor circle concentrically arranged around a center of symmetry 8. The propulsion rotors 1-4 form two pairs of propulsion rotors. The propulsion rotors within the same pair of propulsion rotors face each other symmetrically with respect to the center of symmetry 8. The first pair of propulsion rotors consists of rotors 1 and 4, and the second pair of propulsion rotors consists of rotors 2 and 3. It is also possible to have five or more rotors. As can be seen in Figure 1, in the case of eight rotors 1, 1a, 2, 2a, 3, 3a, 4, 4a, rotors 1, 2, 3 and 4 are grouped with rotors 1a, 2a, 3a and 4a respectively, with rotors 1a and 4a facing each other symmetrically with respect to the center of symmetry 8, and rotors 2a and 3a facing each other symmetrically with respect to the center of symmetry 8. Furthermore, the propulsion system 9 includes smart motors for each propulsion rotor 1, 1a, 2, 2a, 3, 3a, 4, 4a. It is also assumed that the aircraft 7 has a single pair of propulsion rotors, or more precisely, three pairs of propulsion rotors, or at least four pairs of propulsion rotors. Furthermore, the smart motor 10 disclosed herein may be used in an aircraft with a single propulsion motor, or in an aircraft with an even or odd number of propulsion motors.

[0036] While the propulsion rotor configuration illustrated in Figure 1 is suitable for vertical takeoff and landing and / or rotary-wing applications, Figure 2 schematically illustrates a fixed-wing aircraft 7a with one, two, three, four, five or more propulsion rotors 1, 2, 3, ..., X-1, X. Each engine may be identical to one of the engines illustrated in Figure 1.

[0037] Those skilled in the art will understand that the engine described herein may be used in any propulsion / motor application or otherwise in any aircraft / vehicle or non-vehicle machine.

[0038] For applications involving proximity to the ground, such as non-aircraft applications, the common voltage reference for smart motor assemblies is the ground. For applications not involving proximity to the ground, such as aircraft applications, the common voltage reference for smart motor assemblies is the reference voltage used in the aircraft's (or other applications') electrical system.

[0039] Figure 3 schematically shows a cross-sectional view of the smart motor 10 according to the first embodiment.

[0040] The smart motor 10 illustrated in Figure 3 includes an electromechanical converter 12 with a rotating section that defines the axial DA and radial DR. Figure 3 is a cross-sectional view along a plane with the axial DA and radial DR.

[0041] The drive shaft 13 is installed in the axial direction DA toward the first end 201 of the motor 10.

[0042] The smart motor 10 includes an impeller 14 mounted on a cooling rotor 9 that surrounds a cooling stator 99. The cooling rotor 9 and cooling stator 99 are positioned axially DA toward the second end 202 of the smart motor 10.

[0043] The smart motor 10 comprises an electrical filtering means 16, an electronic control unit 18, and a housing 20 or casing, which houses the electromechanical converter 12, the electronic control unit 18, and the filtering means 16.

[0044] In the embodiment illustrated in Figure 3, the housing 20 is hollow and substantially cylindrical or frustoconical in shape with a circular cross-section. The axis of rotation of the housing 20 may coincide with the axis of rotation of the electromechanical converter 12, which coincides with the axis of rotation of the drive shaft 13.

[0045] The rotation axis of the transmission shaft 13 may coincide with the rotation axis of the foreign wheel 14.

[0046] In the axial direction DA, the housing 20 is closed at the first end 201 by the cover 22 and at the second end 202 by the impeller 14.

[0047] The smart motor 10 includes a cooling device 24 that works in cooperation with the impeller 14 and housing 20 to cool various components of the smart motor 10, and in particular the electromechanical converter 12.

[0048] The cooling device 24 comprises a cooling casing 245 positioned around the housing 20, thereby defining a radially positioned cooling channel 248 between the outer radial surface 203 of the housing 20 and the inner radial surface of the cooling casing 245. The terms “inside” and “outside,” as well as “internal” and “external,” are used here in reference to the radial DR in the smart motor 10.

[0049] The rotation of the impeller 14 generates and supplies an airflow F to the cooling channel 248. For example, the flow may enter the duct 248 through the second end 202 of the smart motor 10, pass through the blades 140 of the impeller 14, exit the duct through the first end 201 of the smart motor 10, and pass through the cover 22.

[0050] The cooling device 24 includes a pair of fins 240 extending radially outward from the outer radial surface 203 of the housing 20 at a position in the axial direction DA between the first end 201 and the second end 202. The fin assembly 240 forms a radiator that enables heat exchange between the fins 240 and the airflow F passing through the fins 240 of the cooling device 24. In this case, the fin assembly is located on the stator 122 of the smart motor 10, thereby enabling the stator 122 to be cooled.

[0051] In one modification, the smart motor may not include an impeller and cooling casing in order to reduce the mass of the smart motor. The smart motor would therefore be an aircraft propulsion rotor, which is cooled by the airflow generated by the propulsion rotor, and typically consists of a propeller mechanically connected to the rotating shaft of the smart motor. In another modification, the smart engine may include a water turbine driven directly by shaft 13, without the need for a cooling rotor torque and a cooling stator.

[0052] In the embodiment illustrated in Figure 3, the so-called "shaft" configuration of the smart motor 10 is shown, which comprises a housing 20 with a cooling device 24, a drive unit comprising an electromechanical converter 12 and a drive shaft 13, and an electronic unit comprising, in particular, an electrical filtering means 16 and a control unit 18. The electronic unit is positioned between the electromagnetic converter 12 and the second end 202, for example, between the impeller 14 and the drive unit in the axial direction DA.

[0053] The drive unit is supported in the housing 20 by a conical structure 98 that extends axially from a first end 201 to a second end 202 and radially from the shaft 13 toward the inner radial surface 204 of the housing 20. On the shaft 13, the structure 98 comprises one or more bearings 97A, 97B.

[0054] Structure 98 separates the drive unit from the electronic unit. However, as shown in Figure 3, structure 98 may include one or more perforations to reduce its weight.

[0055] The smart motor 10 includes an inner wall 15 that extends axially from the cooling stator 99 toward the first end 201 and radially from the cooling stator 99 toward the inner radial surface 204 of the housing 20. A first portion 15A of the inner wall 15 is mounted on the inner radial surface 204 of the housing 20, enclosing the disk and extending radially toward the axial direction DA. A second portion 15B of the inner wall 15 is installed inside the cooling stator 99 and mounted on the first portion 15A of the inner wall 15. The electromechanical converter 12 is installed inside the housing 20 downstream of the first portion of the inner wall 15. The electrical filtering means 16 and electronic control unit 18 of the electronic section are installed upstream of the electromechanical converter 12. The terms “upstream” and “downstream” are used here with respect to the flow direction of the cooling airflow, which is represented by arrow F in Figure 3.

[0056] The electronic control unit 18 includes a static electrical converter 180 configured to supply power to the electromechanical converter 12.

[0057] The electrical converter 180 is mounted on the first portion 15A of the inner wall 15 and is installed between the disk and the second end 202.

[0058] In the embodiment shown in Figure 3, the electrical converter 180 comprises six power electronic units 1800 arranged together in a first portion 15A of the inner wall 15, forming a hexagonal-bottomed hollow cylinder coaxial with the shaft 13.

[0059] In variations where the electrical converter has three, four, five, seven, or eight, or even more, power electronic units 1800, they form a regular polygon coaxial with the axis 13. If it has two power electronic units 1800, they would be on either side of the axis and coplanar with its axis of rotation.

[0060] The smart motor 10 is equipped with the same number of cooling devices 25 as there are electronic power units 1800. The cooling devices 25 are positioned in the first portion 15A of the inner wall at the same location as the electronic power units 1800 in the axial direction DA, such that their fins extend into the flow path 248.

[0061] The filtering means 16 includes a filtering electronic circuit board 160 on which a capacitor 162 is mounted. The filtering electronic circuit board 160 is mounted on the disk and positioned between the disk and the structure 98.

[0062] In the embodiment illustrated in Figure 3, the capacitors 162 are arranged to create a polygonal shape that allows them to be inserted between the housing 20 and the shaft 13. The same applies if the motor 10 has two capacitors (diametrically opposed with respect to the axis of rotation of the shaft 13), or three, four, five, six, seven, eight, or more (a regular polygonal shape coaxial with the shaft 13).

[0063] In addition, the electronic control unit 18 includes an electronic control board 182 configured to control the operation of the electromechanical converter 12.

[0064] The smart motor 10 includes an electronic management board 26 housed inside the housing 20 and communicating with an electronic control board 182. The electronic management board extends in a radial plane that includes the radial direction DR and is perpendicular to the axial direction DA. The electronic management board 26 is installed between the electrical converter 180 and the second portion 15B of the inner wall 15, facing the second portion 15B of the inner wall 15.

[0065] In this axial configuration, the cooling device 24 is shared between the electromechanical converter 12 and the electronics of the smart motor 10 (for example, between the electromechanical converter 12, the filtering means 16, and the electronic control unit 18). The cooling airflow F, delivered by the blades 140 of the impeller 14, circulates along the outer radial surface 203 of the housing 20 and is in fluid communication with the fins of the cooling devices 24 and 25. The housing 20 recovers heat generated by the electromechanical converter 12 and heat generated by the electronics, particularly by the power converter 180, and transfers the heat to the cooling airflow F, especially via the cooling devices 24 and 25. The airflow F then removes heat from the smart motor 10.

[0066] The electromechanical converter 12 of the smart motor 10 may be a synchronous machine. The electromechanical converter 12 comprises a permanent magnet rotor 121 and a stator 122. As illustrated in Figure 7, the stator is equipped with a first assembly 123 having at least three phases, in which coils 1230 are electrically coupled in a star configuration, and a second assembly 124 having the same number of phases as the first assembly 123, in which coils 1240 are electrically coupled in a star configuration.

[0067] The electronic control unit 18 of the smart motor 10 comprises a control inverter 184 equipped with the same number of independent control arms 1840 as there are phases in the stator of the electromechanical converter. Each control arm 1840 is configured to drive phases 123 and 124 of the stator 122 of the electromechanical converter 12. The inverter 184 is configured to drive each phase of the stator by its own control arms.

[0068] To ensure mechanical separation between stator assemblies 123 and 124, the coil 1230 of the first assembly 123 can be wound first, and then the coil 1240 of the second assembly 124 can be wound after the coil 1230 of the first assembly 123 has been wound.

[0069] The stator 122 is equipped with a toothed ring. Each coil 1230, 1240 of the stator can be wound around a single tooth of the toothed ring, minimizing the size of the stator 122, in particular the size of each head of the coils 1230 and 1240, each wound around a single tooth of the toothed ring, or a series of several coils.

[0070] The rotor 121 has magnets arranged in a conventional radial configuration or a Halbach configuration to increase the mass torque of the smart motor 10.

[0071] If the motor 10 comprises only two assemblies 123 and 124, the coil 1230 of the first assembly 123 may be positioned over a first angular range P1 of the stator extending over a mechanical 180°, and the coil 1240 of the second assembly 124 may be positioned over a second angular range P2 of the stator extending over a mechanical 180°. Such angular range arrangements are schematically illustrated in Figure 4. In order to minimize or even avoid magnetic coupling between the phases of the different assemblies 123 and 124, and / or to ensure mechanical isolation / geometric separation between the phases of the different assemblies 123 and 124, the first angular range P1 is distinct from the second angular range P2, and each angular range P1, P2 thus extends over a semicircle. More generally, if the motor comprises N assemblies, there will be N distinct angular ranges, each extending over a mechanical (360 / N)°, forming a circle overall. For example, N may be an integer greater than or equal to 3.

[0072] It is also conceivable to have several angular ranges for each assembly. For example, in Figure 5, angular ranges P1a, P1b, P2a, and P2b each extend over a mechanical 90°, with ranges P1a and P1b corresponding to the first assembly interspersed with ranges P2a and P2b corresponding to the second assembly. Figure 6 illustrates a similar arrangement where three angular ranges P1a, P1b, and P1c corresponding to the first assembly are interspersed with three angular ranges P2a, P2b, and P2c corresponding to the second assembly, with each of the six ranges extending over a mechanical 60°. More generally, if M ranges are provided for each assembly, they each extend over (180 / M)°, and as a result, the ranges corresponding to the first and second assemblies form a circle overall. For example, M can be an integer greater than or equal to 3.

[0073] More generally, the range may extend over (360 / (N*M))° mechanical degrees, where N is the number of assemblies and M is the number of ranges per assembly.

[0074] The electronic control unit 18 includes a current adjustment module and a rotor speed adjustment module 121 in each assembly 123, 124, which are independent of the other assembly 124, 123 (and other components).

[0075] The smart motor 10 includes a connection interface for connecting a high-voltage DC power bus to each of the arms 1840 of the inverter 184 of the electronic control unit 18. The connection interface includes a filtering means 16 in the form of a capacitive decoupling stage equipped with a differential mode capacitor. In the embodiment illustrated in Figure 3, the connection interface is combined with an electronic filtering board 160.

[0076] The electronic control unit 180 is configured to measure the voltage difference between the star neutral point of the first assembly 123 and the star neutral point of the second assembly 124. For this purpose, the motor 10 may include an impedance Z12 (e.g., resistance, capacitance, inductance, or a combination thereof) that electrically couples the star neutral points of the first assembly 123 and the second assembly 124, and the electronic control unit 180 may be configured to measure the voltage VD12 across this impedance. The placement of the impedance Z12 between the neutral points limits the current between the stars of the assemblies. The impedance Z12 may be directly connected to the stator conductors or indirectly connected to the stator conductors via wires or other conductors.

[0077] Generally, when two identical assemblies are driven in the same way, they are expected to behave similarly. Deviations in their behavior typically mean a problem with one or both assemblies when driven similarly, but can be detected by the presence of a voltage difference VD12 between the neutral points of their stars that exceeds a predetermined voltage threshold. This predetermined voltage threshold is higher than the normal voltage fluctuations that may exist when similarly driven assemblies behave similarly.

[0078] The motor 10 may be configured (for example, in its electronic control unit 180) to isolate the first assembly 123 and the second assembly 124 from each other when it detects that the voltage difference VD12 exceeds a predetermined voltage threshold. For example, the predetermined threshold may correspond to deviations in behavior that may occur in a given assembly, such as a break or open fault in the bridge arm supplying the coil, an open circuit, open-circuit transistor loss, a short circuit, and / or significant deterioration of the conductor, or even a failure of the assembly may generate a signal that exceeds the threshold, thereby sending a fault signal.

[0079] For example, in the context of aircraft propulsion engines, the neutral point voltages of two assemblies may differ by only about 7 volts or less, while a fault in one assembly can result in a difference of about 30-50 volts, or even more. Thresholds can therefore be set between 7 and 50 volts, or between 7 and 30 volts, or between 10 and 30 volts, or between 13 and 25 volts, or between 13 and 20 volts, or between 13 and 17 volts. Relatively low thresholds may allow faults to be detected in their early stages of progression, while relatively high thresholds may allow false alarms to be ruled out. Those skilled in the art will understand that such threshold ranges may also be used in contexts other than aircraft.

[0080] The motor 10 can continue to drive shaft 13 using a non-fault assembly.

[0081] Figure 8 schematically illustrates the electrical architecture of a second embodiment of the motor shown in Figure 3. This architecture differs from that shown in Figure 7 in that the stator 122 has three or more assemblies.

[0082] If the motor 10 comprises three or more assemblies (each having the same number of phases as the first assembly 123), the star neutral point of the first assembly 123 is electrically coupled to the star neutral point of the assemblies other than the second assembly 124, and the electronic control unit is configured to measure the voltage difference between the star neutral points of the first assembly 123 and the other assemblies other than the second assembly. The star neutral point of the second assembly 124 is electrically coupled to the star neutral point of the assemblies other than the first assembly 123, and the electronic control unit is configured to measure the voltage difference between the star neutral points of the second assembly 124 and the other assemblies other than the first assembly.

[0083] For example, in Figure 8, if the stator has three assemblies, and the third assembly 125 has the same number of phases (and coils 1250) as the first assembly 123, then the star neutral point of the third assembly 125 is electrically coupled to the star neutral points of the first assembly 123 and the second assembly 124, and the electronic control unit is configured to measure the voltage VD13 between the star neutral points of the first assembly 123 and the third assembly 125, and the voltage VD23 between the star neutral points of the third assembly 125 and the second assembly 124. There are also impedances Z13 and Z23 between these neutral points to facilitate the detection of these respective voltages VD13 and VD23.

[0084] Generally, the inverter 184 comprises the same number of independent control arms 1840 as there are phases in the stator assembly.

[0085] More generally, as shown in Figure 9, if the stator 122 comprises at least three assemblies, each neutral point of each star in each assembly is electrically coupled to two neutral points of two stars in at least two other assemblies of the stator 122, and the electronic control unit 18 is configured to measure the voltage difference between the neutral point and each of the neutral points to which it is coupled.

[0086] If the motor 10 has at least three assemblies, it is sufficient to measure the voltage difference between the star neutral points of the assemblies to determine which assembly is affected by a fault, in order to determine a deviation in behavior between two assemblies driven in the same way. This is because when an assembly is affected by a fault, a voltage will be detected between its star neutral point and the star neutral point to which that neutral point is electrically coupled, and these voltages will exceed a selection threshold.

[0087] If the motor 10 comprises only two assemblies, voltage difference measurements may be supplemented by other measurements to determine differences in behavior when the assemblies are driven in the same manner. For example, an electronic control unit may be configured to measure the voltages at each terminal of each phase of the first assembly 123 and the second assembly 124, and to compare them to a deviation threshold. If the voltage between the neutral points exceeds the voltage threshold, and the voltage between two phases of the same assembly exceeds the deviation threshold, the motor 10 may send a fault signal for the assembly corresponding to the diverging phase.

[0088] While it is conceivable to do the same for each phase of each assembly if the motor 10 has three or more assemblies, this is not necessary if the motor 10 has at least three assemblies in order to detect a fault in a given assembly.

[0089] This disclosure provides an architectural solution for smart motors that improves the power-to-weight ratio of motors for applications requiring lightweight, powerful motors with their own power and control electronics, and also ensures the supply of mechanical torque in the event of a failure of the voltage-type inverter arm of the statoster for smart motors.

[0090] The motor 10 is presented with its control unit located inside the housing; however, for example, to facilitate the integration of the motor 10 into a limited space, it is also conceivable that the control unit be located outside the housing.

[0091] Motor 10 is presented in the context of an aircraft propulsion motor. It is also conceivable that motors such as those described herein could be used as electromechanical flight control actuator motors, electromechanical landing gear actuator motors, pumps or fan motors—for example, for critical applications (cockpit ventilation, hydraulic pumps, fuel pumps), or for any other applications where operational safety is a critical feature.

[0092] Furthermore, it is conceivable that such motors could be used outside the aerospace sector. Many other applications can be envisioned, while remaining within the scope of this disclosure. [Explanation of Symbols]

[0093] 1, 1a, 2, 2a, 3, 3a, 4, 4a propulsion rotor 7 Aircraft 7a fixed wing aircraft 8 Centers of Symmetry 10 Smart Motors 12 Electromechanical Converter 13 Drive shaft 14 Impeller 15 Inner wall 15A Part 1 15B Part 2 16 Electrical filtering means 18 Electronic control unit 20 Housing 22 Cover 24, 25 Cooling device 26 Electronic management board 97A, 97B bearings 98 Conical structure 99 Cooling Stator 121 Permanent Magnet Rotor 122 stata 123 First Assembly 124 Second Assembly 125 Third Assembly 140 feathers 160 Filtering Electronic Circuit Boards 162 Capacitors 180 Static Electrical Converter 182 Electronic control board 184 Control Inverter 201 First end 202 The second end 203 Outer radial surface 204 Inner radial surface 240 fins 245 Cooling casing 248 cooling channels 1230, 1240, 1250 coils 1800 Power Electronic Unit 1840 Control Arm DA axis direction DR Radial direction F Airflow P1, P1a, P1b, P1c First angular range P2, P2a, P2b, P2c Second angular range VD12, VD13, VD23 Voltage Z12, Z13, Z23 Impedance

Claims

1. Electromechanical permanent magnet converter (12), Electronic control unit (18) and Equipped with, The electromechanical converter (12) Permanent magnet rotor (121) and The stator (122) is, A first assembly (123) having at least three phases electrically coupled to each other in a star configuration, A second assembly (124) having the same number of phases as the first assembly, wherein the phases of the second assembly are electrically coupled to each other in a star configuration, The impedance between the neutral points of the star in the first assembly and the second assembly and A stator (122) is provided, Equipped with, The electronic control unit comprises a control inverter (184) having the same number of independent control arms (1840) as the number of phases in the first assembly and the same number of independent control arms as the number of phases in the second assembly. The control inverter is configured to drive each phase of the first assembly and each phase of the second assembly by its own control arm. A smart motor (10) wherein the electronic control unit is configured to measure the voltage difference (VD12) between the star neutral points of the first assembly and the second assembly with respect to a voltage reference common to the first assembly and the second assembly.

2. The smart motor (10) according to claim 1, configured to isolate the first assembly and the second assembly from each other in response to the voltage between the neutral points of the stars of the first assembly and the second assembly exceeding a voltage threshold.

3. The smart motor (10) according to claim 2, wherein the voltage threshold is 7, 10, or 13 volts or more and 50, 30, 25, 20, or 17 volts or less.

4. The smart motor (10) according to claim 2 or 3, configured to measure the voltage at each terminal of each phase of the first assembly and the second assembly, and to send a fault signal for a given assembly in response to a deviation threshold being exceeded by the difference between the voltages of the two phases.

5. The stator comprises at least one assembly other than the first and second assemblies, each having the same number of phases as the first assembly, which are electrically coupled to each other in a star configuration, and the voltage reference is common to the first and second assemblies, and to the other assemblies. The inverter further comprises the same number of independent control arms as there are phases in the (set of) assemblies other than the first and second assemblies, The inverter is further configured to drive each phase of the assembly other than the first and second assemblies by its own control arm, The aforementioned electronic control unit, with respect to the common standard, The voltage difference between the neutral point of the star of the first assembly and the neutral point of the star of the assemblies other than the first assembly and the second assembly is measured. A smart motor (10) according to any one of claims 1 to 4, further configured to measure a voltage difference between the neutral point of the star of the second assembly and the neutral point of the star of the assemblies other than the first assembly and the second assembly.

6. The smart motor (10) according to any one of claims 1 to 5, wherein the stator (122) comprises a series of teeth arranged circumferentially to the stator, and each phase comprises a coil or a series of several coils wound around a single tooth of the stator.

7. The smart motor (10) according to any one of claims 1 to 6, wherein the rotor (121) comprises Halbach-constituent magnets.

8. The smart motor (10) according to any one of claims 1 to 7, wherein the stator (122) is divided into separate angular ranges, the number of angular ranges of the stator is equal to the number of stator assemblies, and the angular range extends over an angle corresponding to the result of dividing 360° by the number of stator assemblies or by an integer multiple of the number of stator assemblies.

9. The smart motor (10) according to any one of claims 1 to 8, wherein the electronic control unit (18) further comprises a current control module configured to control the currents in the assembly independently of each other, and a rotor speed control module (121).

10. A smart motor (10) according to any one of claims 1 to 9, further comprising a connection interface for connecting a high-voltage DC power bus to each of the arms (1840) of the inverter (184) of the electronic control unit (18), the connection interface further comprising a capacitive decoupling stage (16) equipped with a differential mode capacitor.

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