High voltage electric machine equipped with current splitters for cascaded voltage stator modularization

Abstract

The present invention relates to high voltage electric machines equipped with current separation pieces for cascaded voltage stator modularization, and in particular, high voltage electric machines and power distribution systems are provided that include one or more of such electric machines. In one aspect, a high voltage electric machine includes a stator, a rotor, and a housing that encloses at least a portion of the stator and the rotor. The stator is modularized into cascaded voltage stator modules. The stator modules are galvanically isolated from one another by inter-module separation pieces. At least one inter-module separation piece is positioned between each adjacent pair of stator modules. The stator modules are also galvanically isolated from the housing by a housing separation piece. The housing separation piece is positioned between the stator modules and the housing. Each stator module has an associated set of windings that are wound only within its associated stator module.

Description

TECHNICAL FIELD

[0001] The present subject matter relates generally to high voltage electric machines. BACKGROUND

[0002] Electrical power systems, such as those found in aircraft power distribution systems, employ power generation systems or power sources, such as generators, for generating electrical power for providing power to systems and subsystems of an aircraft. Since electrical power is delivered through power cabling to deliver power from the power source to electrical loads, controllable power converters ensure that the power delivered to the electrical loads meets the designed power standards for the loads or distribution system.

[0003] Hybrid electric propulsion systems transfer high voltage electrical power from an engine to a remote location located on an aircraft. On some aircraft, the transmission cable can span a distance of over 50 meters, for example, from a power generator of an engine mounted to a wing to a tail end of the aircraft. The weight of such a cable can be substantial. To reduce the weight of such a cable and, as a result, the weight of the aircraft, high voltage cables can be employed. While the use of high voltage cables can reduce the weight of the transmission cable, high voltage electric machines located on-board the aircraft can be subject to partial discharge inception voltage problems, particularly at altitudes higher than 40,000 ft. To prevent partial discharge problems, additional insulation is required, which adds complexity and weight to such an aircraft electric machine.

[0004] Accordingly, an electric machine and power distribution system that addresses one or more of the challenges identified above would be useful. SUMMARY

[0005] Aspects and advantages of the application will be set forth in part in the following description, or can become apparent to those skilled in the art by practice of the application.

[0006] In one aspect, an electric machine is provided. The electric machine includes a stator having stator modules. The electric machine also includes a housing that surrounds at least a portion of the stator. The electric machine further includes a housing separator that galvanically isolates the housing from the stator modules. Additionally, the electric machine includes an inter-module separator that galvanically isolates the stator modules from one another.

[0007] In another aspect, a power distribution system is provided. The power distribution system includes a high voltage power bus operable to carry high voltage electrical power. The power distribution system also includes power converters electrically coupled with the high voltage power bus and operable to segment the high voltage electrical power. Additionally, the power distribution system includes an electric machine. The electric machine includes a stator having stator modules and a housing surrounding at least a portion of the stator. Moreover, the electric machine includes housing separations electrically isolating the housing from the stator modules and inter-module separations electrically isolating the stator modules from one another. Each of the stator modules is electrically coupled with a respective one of the power converters, and wherein each of the stator modules receives a portion of the segmented high voltage electrical power.

[0008] In another exemplary aspect, an aircraft is provided. The aircraft includes a high voltage power bus operable to carry high voltage electrical power. The aircraft also includes power converters electrically coupled with the high voltage power bus and operable to segment the high voltage electrical power. Additionally, the aircraft includes an electric machine. The electric machine includes a stator having stator modules and a housing surrounding at least a portion of the stator. Moreover, the electric machine includes housing separations electrically isolating the housing from the stator modules and inter-module separations electrically isolating the stator modules from one another. Each of the stator modules is electrically coupled with a respective one of the power converters, and wherein each of the stator modules receives a portion of the segmented high voltage electrical power, and each of the stator modules is at an independent voltage relative to the other stator modules.

[0009] These and other features, aspects, and advantages of the present application will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the application and help to explain the principles of the application. BRIEF DESCRIPTION OF DRAWINGS

[0010] A complete and enabling disclosure of the application, including its best mode, directed to one of ordinary skill in the art, is set forth in the specification which follows, and is illustrated in the accompanying drawings, which are incorporated herein by reference. The following description is made with reference to the accompanying drawings in which:

[0011] Figure 1 A schematic top view of an exemplary aircraft into which various embodiments of the present subject matter can be incorporated is provided;

[0012] Figure 2 A left side view of the aircraft of Figure 1 is provided;

[0013] Figure 3 A schematic view of a power distribution system of the aircraft of Figure 1 and Figure 2 is provided;

[0014] Figure 4 A schematic view of a power distribution system for Figure 1 and Figure 2A schematic diagram of the alternative power distribution system for an aircraft;

[0015] Figure 5 A schematic cross-sectional view of an exemplary motor according to an exemplary embodiment of this subject is provided;

[0016] Figure 6 supply Figure 5 An axial cross-sectional view of the stator and other components of the motor;

[0017] Figure 7 Provide for Figure 6 A schematic diagram of two exemplary winding configurations in the stator module of the stator;

[0018] Figure 8 A schematic cross-sectional view of an axial flux motor according to an exemplary embodiment of this subject is provided;

[0019] Figure 9 supply Figure 8 A schematic cross-sectional view of the first stator of the electric motor; and

[0020] Figure 10 supply Figure 9 The perspective view of the first stator depicted in the figure. Detailed Implementation

[0021] Reference will now be made in detail to present embodiments of the invention, with one or more examples of the invention illustrated in the accompanying drawings. Numerical and alphabetical designations are used to refer to features in the drawings. The same or similar designations in the drawings and description have been used to refer to the same or similar parts of the invention. As used herein, the terms “first,” “second,” and “third” are used interchangeably to distinguish components from each other and are not intended to indicate the location or importance of individual components. As used herein, “high voltage” means 1 kV or greater. Furthermore, as used herein, “electrical coupling” means a direct or indirect electrical connection.

[0022] This disclosure relates to high-voltage rotating electric machines and power distribution systems, the power distribution systems including one or more such high-voltage rotating electric machines. In one aspect, a high-voltage electric machine is provided. The machine is rated for direct current (DC) greater than 1 kV. The machine includes a stator, a rotor, and a housing surrounding at least a portion of the stator and rotor. The rotor can be coupled to a shaft. The shaft and rotor are rotatable about an axis of rotation. The stator is fixed relative to the rotor. For example, the machine can be a radial flux electric machine or an axial flux electric machine. Moreover, the machine can be an electric motor, an electric generator, or a combination motor / generator.

[0023] It is worth noting that the stator modules are cascaded voltage stator modules. The stator modules are electrically isolated from each other via inter-module separators. At least one inter-module separator is located between each adjacent pair of stator modules. Thus, the stator modules are electrically isolated relative to each other. This electrical isolation prevents current flow between stator modules; direct conduction paths are not permitted, but energy can still be exchanged between stator modules by other means such as rotating electromagnetic fields. The stator modules are also electrically isolated from the housing via housing separators. For example, for safety reasons, the housing may be at or nearly at ground potential. For example, a transmission line or cable may be connected to the housing at one end and to the grounding point of a power converter associated with the motor at the other end. As an example, the protective armor of a transmission cable may be electrically connected to the housing at one end and to the grounding point at the other end. As another example, the stranded grounding wire of a transmission cable may be electrically connected to the housing at one end and to the grounding point at the other end. The housing separator is located between the stator module and the housing. In this way, the stator module is electrically isolated from the housing. Furthermore, each stator module has associated groups of windings wound only within its associated stator module.

[0024] The current isolation and winding configuration associated with the stator modules allow the stator modules to "float" on independent, different voltages without negatively impacting motor performance. Because the stator modules float on different independent voltages, the slot ground-wall insulator for each stator module only needs to support the module voltage. Furthermore, since each cascaded voltage stator module has a low voltage across it, many advantages and benefits are realized, especially for high-voltage motors located on aircraft operating at high altitudes (e.g., above 40,000 feet). For example, the cascaded voltage modularity of the stator reduces the voltage between the windings and the stator, allowing each stator module to operate below the partial discharge initiation voltage (PDIV). Moreover, the slot fill factor can be increased by using low-voltage slot ground-wall insulators (such as slot liners). Additionally, the thermal barrier between the conductors and stator iron can be reduced due to lower insulation thermal resistance, making indirect liquid cooling of the high-voltage motor more practical compared to conventional high-voltage machines. Furthermore, more cooling technologies can be used in this motor because a lower level of end winding insulation is required. For example, spray-type end-winding liquid cooling technology can be used to cool components of a motor, a technology that is not yet practical for conventional high-voltage motors due to the required thick end-winding insulation.

[0025] On the other hand, the aforementioned high-voltage motor is a component of the power distribution system for an aircraft. In some embodiments, high-voltage electrical power may be generated by an electric generator operatively connected to the aircraft's engines. This high-voltage electrical power (i.e., exceeding 1 kV) can be transmitted via a power bus to remote electrical loads located on the aircraft. The power bus may include high-voltage transmission cables. In some instances, such transmission cables may, for example, span more than 50 meters from the wing to the tail of the aircraft. For example, the power bus may be a unipolar power bus or a bipolar power bus.

[0026] High-voltage power (i.e., exceeding 1 kV) can be directed to the motor via a power bus. The motor may be associated with or may include multiple power converters. Each stator module of the motor may be electrically coupled to a corresponding power converter. The power converters may be arranged in a cascaded configuration. The power converters are operable to divide the introduced high-voltage power into low-voltage portions and distribute the low-voltage power to their respective stator modules. Each stator module receives the divided portion of high-voltage power. In this way, each stator module has an associated independent low voltage. Current isolation of the stator modules relative to each other and relative to the housing enables cascaded voltage stator modularization of the motor stator.

[0027] Now for reference Figure 1 and Figure 2 , Figure 1 A schematic top view of an exemplary aircraft 10, into which various embodiments of this subject may be incorporated, is provided. Figure 2 supply Figure 1 The aircraft 10 is shown as a port side view. As shown, the aircraft 10 defines a longitudinal direction L1, a lateral direction L2, and a vertical direction V. The aircraft 10 also defines a longitudinal centerline 14 extending along the longitudinal direction L1 through the aircraft 10. Generally, the aircraft 10 extends along the longitudinal direction L1 between its forward end 16 and its rear end 18.

[0028] As depicted, the aircraft 10 includes a fuselage 12 extending longitudinally from the front end 16 of the aircraft 10 to the rear end 18 of the aircraft 10. As used herein, the term "fuselage" generally includes all of the main body of the aircraft 10, including the tail of the aircraft 10. The aircraft 10 also includes a pair of wings 20. The first of such wings 20 extends laterally L2 from the port side 22 of the fuselage 12 relative to the longitudinal centerline 14, and the second of such wings 20 extends laterally L2 from the starboard side 24 of the fuselage 12 relative to the longitudinal centerline 14. Each of the wings 20 includes one or more leading-edge flaps 26 and one or more trailing-edge flaps 28. The aircraft 10 further includes a vertical stabilizer 30 having rudder flaps 32 for yaw control. Figure 2); and a pair of horizontal stabilizers 34, each having elevator flaps 36 for pitch control. Figure 1 The fuselage 12 also includes an outer surface or skin 38. It will be appreciated that the aircraft 10 may include other suitable stabilizers and control surfaces.

[0029] As in Figure 1 and Figure 2 As further shown, the aircraft 10 includes a propulsion system 100. An exemplary propulsion system 100 includes one or more aircraft engines and one or more electric propulsion engines. Thus, in this exemplary embodiment, the propulsion system 100 is a hybrid electric propulsion system. As depicted, the propulsion system 100 includes an electric propulsion engine and a plurality of aircraft engines, each configured to be mounted to the aircraft 10, such as to one of a pair of wings 20. More specifically, for the depicted embodiment, the aircraft engines are configured as gas turbine engines, or more precisely, as turbofans 102, 104 attached under the wings 20 in an underwing configuration.

[0030] Furthermore, the electric propulsion engine is configured to be mounted at the rear end 18 of the aircraft 10, and therefore, the depicted electric propulsion engine may be referred to as the "rear engine." Moreover, the depicted electric propulsion engine is configured to draw in and consume air forming a boundary layer on the fuselage 12 of the aircraft 10. Therefore, the depicted exemplary rear engine may be referred to as a boundary layer inhalation (BLI) fan 106. By drawing in and consuming air forming the boundary layer on the fuselage 12, the BLI fan 106 reduces turbulence and thus reduces drag on the aircraft 10, which ultimately reduces fuel consumption. The BLI fan 106 is mounted to the aircraft 10 at a location aft of the wing 20 and / or the turbofans 102, 104. Specifically, in the depicted embodiment, the BLI fan 106 is connected to the fuselage 12 at the rear end 18, such that the BLI fan 106 is incorporated into or blended with the tail section located at the rear end 18. However, it should be appreciated that in other embodiments, the electric propulsion engine may be constructed in any other suitable manner and may not necessarily be constructed as a rear fan or as a BLI fan.

[0031] In this embodiment, the propulsion system 100 further includes one or more motors, such as an electric generator 108 operatively coupled to a respective turbofan 102, 104. For example, one or both of the turbofans 102, 104 may be configured to provide mechanical power from a rotating shaft (such as a low-pressure shaft or a high-pressure shaft) to the electric generator 108. Although schematically depicted as being located outside the respective turbofans 102, 104, in some embodiments, the electric generator 108 may be located within the respective turbofans 102, 104, for example, coupled to the spool or shaft of its respective turbofan 102, 104. The electric generator 108 may be configured to convert the mechanical power output by its associated turbofan 102, 104 into electrical power. In the depicted embodiment, the propulsion system 100 includes an electric generator 108 for each turbofan 102, 104.

[0032] The propulsion system 100 also includes a power distribution system 110. Generally, the power distribution system 110 is operable to distribute electrical power generated by one or more power sources (such as an electric generator 108) to one or more electrical loads, such as an energy storage device 112, an electric motor 114 operable to drive a BLI fan 106, and / or other aircraft systems. The power distribution system 110 may be included in... Figure 1 Power electronics 116 are schematically represented. Power electronics 116 can regulate, transform, divide, and / or convert electrical power into a desired form. Electrical power can be directed to electrical loads via power bus 118. For example, electrical power can be directed via power bus 118 to energy storage device 112 for storage and / or to electric motor 114, such that electric motor 114 can drive BLI fan 106. Generally, electric generator 108, power electronics 116, energy storage device 112, electric motor 114, and other aircraft systems can be electrically coupled via power bus 118. Power bus 118 may include a transmission line extending from one of the wings 20 to electric motor 114. In some embodiments, such a transmission line may span more than 50 meters.

[0033] Will realize, Figure 1 and Figure 2The aircraft 10 and propulsion system 100 depicted herein are provided by way of example only, and in other exemplary embodiments, any other suitable aircraft 10 may be provided having a propulsion system 100 constructed in any other suitable manner. For example, in other embodiments, the BLI fan 106 may alternatively be located at any suitable location near the rear end 18 of the aircraft 10. Moreover, in other embodiments, the electric propulsion engine may not be located at the rear end of the aircraft 10, and therefore may not be constructed as a "rear engine". For example, the electric propulsion engine may be incorporated into the fuselage of the aircraft 10, and therefore constructed as a "podded engine" or pod-mounted engine. Moreover, in still other embodiments, the electric propulsion engine may be incorporated into the wing of the aircraft 10, and therefore may be constructed as a "combined wing engine". Furthermore, in other embodiments, the electric propulsion engine may not be a boundary layer inlet fan, and instead may be mounted as a free-flow injection fan at any suitable location on the aircraft 10. Additionally, although in Figure 1 and Figure 2 As shown in the diagrams for turbofans 102 and 104, it will be appreciated that this subject matter can also be applied to other types of turbomachinery and aero gas turbine engines. For example, this subject matter can be suitable for use with or in conjunction with turboprop engines, turboshaft engines, turbojet engines, industrial gas turbine engines, and marine gas turbine engines and / or auxiliary power units.

[0034] Figure 3 supply Figure 1 and Figure 2 A schematic diagram of a portion of the power distribution system 110. As noted above, high-voltage electrical power from a power source can be transmitted via a power bus 118 (e.g., via a transmission cable of the power bus 118). For example, electrical power having a voltage greater than 1 kV DC-link can be transmitted via the power bus 118. In this embodiment, the power bus 118 is... Figure 3 The unipolar power bus is represented by the symbols "+VDC" and "0". The unipolar power bus 118 and / or other components of the power distribution system can be electrically grounded via a grounding system 150 (such as an aircraft grounding system). For example, on an aircraft with a highly conductive fuselage (e.g., an aluminum fuselage), the grounding system 150 can be the fuselage itself. On an aircraft with a fuselage that has an insulated fuselage or a low-conductivity fuselage (e.g., a carbon fiber fuselage), an internal metal structure (such as the aircraft's wings, tail cone, or tail fin) located within the fuselage or other components can be used for the grounding system 150. For example, high-voltage power can be supplied by its corresponding turbofans 102, 104 (…). Figure 1 ) Mechanically connected electric generator 108 Figure 1 One or both of them are generated.

[0035] Power electronics 116 may include a plurality of power converters 120A-120F associated with electric motor 114. The power converters 120A-120F associated with electric motor 114 may be components of electric motor 114 or may be components separate from electric motor 114. As depicted, power converters 120A-120F are arranged in a cascaded manner or in a cascaded arrangement. In some embodiments, power converters 120A-120F are components of a single power converter associated with electric motor 114.

[0036] Each power converter 120A-120F is connected in parallel with an associated capacitor. For example, the first power converter 120A is connected in parallel with the first capacitor 122A, the second power converter 120B is connected in parallel with the second capacitor 122B, the third power converter 120C is connected in parallel with the third capacitor 122C, the fourth power converter 120D is connected in parallel with the fourth capacitor 122D, the fifth power converter 120E is connected in parallel with the fifth capacitor 122E, and the sixth power converter 120F is connected in parallel with the sixth capacitor 122F.

[0037] Generally, power converters 120A-120F receive high-voltage power and divide it into low-voltage portions or predetermined amounts. A controller 130 of the power distribution system 110 can control the power converters 120A-120F to divide the high-voltage power into low-voltage portions or predetermined amounts. For example, the controller 130 may include one or more processors and one or more memory devices. The one or more memory devices may include one or more non-transitory computer-readable media. The one or more memory devices may store instructions that, when executed by the one or more processors, cause the one or more processors to perform operations. For example, operations may include monitoring and controlling the power converters 120A-120F. Each power converter 120A-120F may include or be associated with one or more sensors. Sensor outputs may be provided to the controller 130, and the controller 130 may control the power converters 120A-120F at least in part based on the sensor outputs.

[0038] Once the high-voltage power is divided by a given power converter 120A-120F, the power converter (e.g., an inverter) associated with the given power converter can convert the low-voltage portion of the DC power into AC power. For example, a first inverter 124A converts the low-voltage DC power output from a first power converter 120A into low-voltage AC power; a second inverter 124B converts the low-voltage DC power output from a second power converter 120B into low-voltage AC power; a third inverter 124C converts the low-voltage DC power output from a third power converter 120C into low-voltage AC power; a fourth inverter 124D converts the low-voltage DC power output from a fourth power converter 120D into low-voltage AC power; a fifth inverter 124E converts the low-voltage DC power output from a fifth power converter 120E into low-voltage AC power; and a sixth inverter 124F converts the low-voltage DC power output from a sixth power converter 120F into low-voltage AC power. The inverters 124A-124F associated with the electric motor 114 can be components of the electric motor 114 or components separate from the electric motor 114. In some embodiments, inverters 124A-124F are components of a single inverter or power converter associated with electric motor 114.

[0039] It is worth noting that power converters 120A-120F and 124A-124F are each associated with corresponding stator modules 140A-140F of the stator of the electric motor 114. Each stator module 140A-140F has associated groups of stator windings. For example, the first stator module 140A has associated first group of stator windings 142A, the second stator module 140B has associated second group of stator windings 142B, the third stator module 140C has associated third group of stator windings 142C, the fourth stator module 140D has associated fourth group of stator windings 142D, the fifth stator module 140E has associated fifth group of stator windings 142E, and the sixth stator module 140F has associated sixth group of stator windings 142F. The low-voltage portion of the electrical power, divided by power converters 120A-120F and inverted by inverters 124A-124F, is directed to corresponding groups of stator windings 142A-142F. The electrical power directed to the stator windings can ultimately be used to drive the BLI fan 106, which is operatively connected to the electric motor 114.

[0040] As will be explained in detail below, according to an inventive aspect of this disclosure, the grouped stator windings 142A-142F are wound only within their respective stator modules 140A-140F. Furthermore, it is noteworthy that the stator modules 140A-140F are electrically isolated from each other by inter-module current separators. For example, the first inter-module separator 150A-B current-disconnects the first stator module 140A and the second stator module 140B; the second inter-module separator 150B-C current-disconnects the second stator module 140B and the third stator module 140C; the third inter-module separator 150C-D current-disconnects the third stator module 140C and the fourth stator module 140D; the fourth inter-module separator 150D-E current-disconnects the fourth stator module 140D and the fifth stator module 140E; the fifth inter-module separator 150E-F current-disconnects the fifth stator module 140E and the sixth stator module 140F; and, for a radial flux motor, although not shown, the sixth inter-module separator can still current-disconnect the sixth stator module 140F from the first stator module 140A. Additionally, the stator modules are connected via, for example... Figure 3 The housing separator 160 shown is electrically isolated from the housing of the electric motor 114. For example, the housing of the motor 114 may be at or nearly at an electrical ground potential. Since the stator modules 140A-140F are electrically isolated from each other and from the housing of the motor 114, the stator modules 140A-140F are “floating” iron stator modules. Therefore, the stator modules 140A-140F functionally act as independent motors. An exemplary embodiment of a motor equipped with a current separator for cascading voltage stator modules is provided below.

[0041] Figure 4 Provide for Figure 1 and Figure 2 A schematic diagram of the alternative power distribution system 100 for the aircraft. In addition to what is noted below, the power distribution system 100 is compatible with... Figure 3 The power distribution system is configured in the same way. In this embodiment, the power bus 118 is composed of a reference or "0" symbol and... Figure 4 The bipolar power bus is represented by the "+VDC / 2" and "-VDC / 2" transmission line symbols. The bipolar power bus 118 and / or other components of the power distribution system can be electrically grounded via a grounding system 150 (such as an aircraft grounding system). For example, it can be grounded by its corresponding turbofans 102, 104 ( Figure 1 ) Mechanically connected electric generator 108 Figure 1 One or both of these generate high-voltage electrical power. High-voltage electrical power can be supplied to electric motor 114.

[0042] Figure 5A schematic cross-sectional view of a motor 200 according to an exemplary embodiment of this subject is provided. For example, Figure 3 or Figure 4 The electric motor 114 of the power distribution system 110 can be connected with... Figure 5 The motor 200 is configured in the same or similar manner. For reference, the motor 200 is defined in the axial direction A, the radial direction R, and the circumferential direction C. The motor 200 is also defined in the rotation axis AX.

[0043] As described, Figure 5 The motor 200 is a radial flux rotary motor. The motor 200 includes a housing 210. In this exemplary embodiment, the housing 210 is a hollow, substantially cylindrical housing. For safety reasons, the housing 210 may be at or nearly at ground potential. For example, a transmission line or cable may be electrically connected at one end to the housing 210 and at the other end to a power converter associated with the motor 200 (e.g., ...). Figure 3 or Figure 4 The grounding point of (e.g., 120A-120F and 124A-124F) Figure 3 or Figure 4 (Grounding system 150). As an example, the protective outer layer of the transmission cable may be electrically connected to the housing 210 at one end and to the grounding point at the other end. As another example, the stranded grounding wire of the transmission cable may be electrically connected to the housing 210 at one end and to the grounding point at the other end.

[0044] The motor 200 also includes a rotor 212 and a stator 214 enclosed within a housing 210. The rotor 212 is operatively coupled to a shaft 216. The shaft 216 is supported by the housing 210 via one or more bearings 218. The shaft 216 can be any suitable shaft, such as a drive shaft. The shaft 216 is rotatable about an axis of rotation AX. The rotor 212 is rotatable about the axis of rotation AX in conjunction with the shaft 216. The stator 214 is fixed relative to the rotor 212 and the shaft 216. The stator 214 extends along an axial direction A between a first end 232 and a second end 234.

[0045] Stator 214 has associated multiphase AC stator windings 222. Stator windings 222 are axially wound through slots defined by stator 214. End turns or end windings 236 of stator windings 222 are as follows: Figure 5The stator winding 222 is positioned, for example, adjacent to the end surfaces of the stator 214 at the first end 232 and the second end 234, as shown in the diagram. The stator winding 222 is electrically coupled to a power source (such as a power converter). In this way, electrical power can be transferred to the winding 222, and, as will be appreciated, electrical energy can be converted into mechanical energy in motor drive mode, or vice versa in generator mode. The rotor 212 has an associated rotor member 220 for generating a rotor magnetic field to couple to the stator magnetic field, enabling energy conversion. Depending on the type of AC multiphase motor, in the case of a permanent magnet synchronous machine, the rotor member 220 may be a rotor magnet; in the case of an induction machine, the rotor member 220 may be a squirrel cage (sometimes called a squirrel cage winding); or in the case of a field-wound synchronous machine, the rotor member 220 may be a field winding.

[0046] In some embodiments, the motor 200 includes, for example, a cooling system for cooling various components of the motor 200. As an example, the cooling system may include a cooling jacket 224. The cooling jacket 224 may be integrated with the housing 210 or may be a separate component attached to the housing 210. Coolant may flow through conduits disposed within the cooling jacket 224 to cool the components of the motor 200. In other embodiments, the cooling system may be an air cooling system. The air cooling system may include one or more cooling openings defined in endbells of the housing 210. In this way, air may flow through the air cooling components and openings of the motor 200. In addition to or as an alternative to the disclosed exemplary cooling systems, the motor 200 may include other suitable types of cooling systems.

[0047] Although motor 200 has already Figure 5 While described and illustrated in the text as having a specific configuration, it will be appreciated that the inventive aspects of this disclosure are applicable to motors with alternative configurations. For example, in some alternative embodiments, the inventive aspects of this disclosure are applicable to axial flux rotary motors.

[0048] Figure 6 supply Figure 5 An axial cross-sectional view of the stator 214 and other components of the motor 200. As shown, the stator 214 includes a stator core having a core body 226 and a plurality of teeth 228 projecting from the core body 226. In this embodiment, the teeth 228 project inward from the core body 226 along the radial direction R toward the axis of rotation AX. Slots 230 are defined between each of the teeth 228. The slots 230 are sized to receive stator windings (not in...) Figure 6 (as shown in the image).

[0049] It is worth noting that the stator 214 has cascaded voltage stator modules 240A-240F that are electrically isolated from each other by current module separators 250A-B-250F-A. Stator modules 240A-240F are also electrically isolated from the housing 210 by housing separator 260. In this respect, as will be further explained below, stator modules 240A-240F can “float” on independent voltages without negatively impacting the performance of the motor 200. For this embodiment, the stator 214 includes a first stator module 240A, a second stator module 240B, a third stator module 240C, a fourth stator module 240D, a fifth stator module 240E, and a sixth stator module 240F. In other embodiments, the stator 214 may have more or fewer than six modules.

[0050] As noted, the current module separator isolates each adjacent pair of stator modules. For example, as... Figure 6 As shown, the first inter-module separator 250A-B electrically separates the first stator module 240A and the second stator module 240B. The second inter-module separator 250B-C electrically separates the second stator module 240B and the third stator module 240C. The third inter-module separator 250C-D electrically separates the third stator module 240C and the fourth stator module 240D. The fourth inter-module separator 250D-E electrically separates the fourth stator module 240D and the fifth stator module 240E. The fifth inter-module separator 250E-F electrically separates the fifth stator module 240E and the sixth stator module 240F. Finally, the sixth inter-module separator 250F-A electrically separates the sixth stator module 240F and the first stator module 240A. Therefore, the inter-module separators are positioned between consecutive or adjacent stator modules, and each stator module spans between the inter-module separators. The inter-module separator 250A-B-250F-A is positioned between its corresponding stator modules 240A-240F, so that the stator modules 240A-240F are separated from each other along the circumferential direction C.

[0051] In this embodiment, the inter-module separator 250A-B-250F-A is as follows: Figure 6 As shown, each extends radially from the outer surface of the core body 226 to the inner end of one of the teeth 228. Therefore, the inter-module separators 250A-B-250F-A each extend radially along the entire radial length of the stator 214, wherein the radial length is defined as the length extending radially from the outer surface of the core body 226 to the inner end of one of the teeth 228. Additionally, the inter-module separators 250A-B-250F-A each extend radially along the axial direction A (in... Figure 6The stator 214 extends the entire length of the stator (both inside and outside the paper). In this way, each inter-module separator 250A-B-250F-A is applied to the entire surface(s), thereby separating two individual, consecutive stator modules. The inter-module separators 250A-B-250D-E each have a thickness along the circumferential direction C. The inter-module separators 250A-B-250F-A may be in the form of a tape, strip, coating, or deposited as powder, for example, by electrostatic powder deposition (EPD). In some embodiments, the inter-module separators 250A-B-250F-A may be 3D printed together with the conductive stator 214 using a suitable material.

[0052] The inter-module separator 250A-B-250F-A can be formed of any suitable material that allows for current isolation between consecutive or adjacent stator modules. Furthermore, in some embodiments, the inter-module separator 250A-B-250F-A is formed of a ferromagnetic material. Ferromagnetic materials prevent negative impacts on motor performance caused by inter-module separators that create air gaps between stator modules. Air gaps typically result in an undesirable decrease in magnetomotive force (mmF). Additionally, in some embodiments, the inter-module separator 250A-B-250F-A is formed of a dielectric material to withstand high resistivity and voltage differences between two consecutive stator modules, preventing inter-module current flow. Therefore, in some embodiments, the inter-module separator can be formed of barium ferrite. Furthermore, each of the inter-module separators 250A-B-250F-A can have a suitable thickness that allows it to withstand voltage differences between its respective consecutive modules. In some embodiments, the inter-module separators 250A-B-250F-A each have a thickness in the range of 25-250 micrometers (1-10 mils), wherein the thickness is measured for a radial flux motor along the circumferential direction C.

[0053] As noted above, stator modules 240A-240F are electrically isolated from housing 210 via housing separator 260. As noted above, for example, for safety reasons, housing 210 may be at or nearly at ground potential. Figure 5 and Figure 6 As shown, the housing separator 260 extends annularly around the stator 214 along the circumferential direction C and is positioned between the stator modules 240A-240F and the housing 210 along the radial direction R. In some embodiments, such as Figure 5 and Figure 6As shown, housing separator 260 is positioned between stator modules 240A-240F and cooling sleeve 224, which in turn is positioned radially R between housing separator 260 and housing 210. Housing 210 is accessible to cooling sleeve 224, and thus cooling sleeve 224 is also at or nearly at ground potential. Cooling sleeve 224 is accessible to housing separator 260, which in turn is accessible to stator modules 240A-240F. Housing separator 260 may be attached to at least one of stator 214, housing 210, and cooling sleeve 224. In some embodiments, housing separator 260 is assembled between any structures but not attached to any structure. In other embodiments, housing 210 may directly access housing separator 260, which in turn is accessible to stator modules 240A-240F.

[0054] Furthermore, the housing separator 260 may extend along the axial direction A between the first end 232 and the second end 234 of the stator 214. In this way, in some embodiments, the housing separator 260 may have an annular or open cylindrical shape (i.e., a cylinder without ends). In some embodiments, the housing separator 260 has a thickness in the range of 250 micrometers to 2.5 millimeters (10-100 mils), wherein the thickness is measured along the radial direction R for a radial flux motor.

[0055] Generally, the housing separator 260 may be formed of a material having the same or similar properties as the inter-module separators 250A-B-250F-A. In some embodiments, for example, the housing separator 260 is formed of a dielectric material such that it can withstand the voltage difference between each of the floating stator modules 240A-240F and the housing 210. Additionally, in such embodiments, the housing separator 260 is formed of a material with high resistivity to prevent current flow between the stator modules 240A-240F and the housing 210. Therefore, as an example, the housing separator 260 is formed of barium ferrite. The housing separator 260 may also be formed of other suitable materials.

[0056] During operation of motor 200, stator modules 240A-240F may have different independent voltages or "float" on different independent voltages. As an example, assume that a high-voltage DC bus delivers high-voltage power at 1.8kV to motor 200 and its associated power converter. Further assumptions are made that housing 210 may be at or nearly at ground potential. It is also assumed that the DC bus is a unipolar DC bus, such that at least one transmission line is set to "0" or a reference voltage, and at least one transmission line is set to positive (+VDC), for example, as... Figure 3As shown in the diagram. Further assuming that the power converters associated with motor 200 introduce high-voltage power partitioning, such that the first power converter associated with the first stator module 240A partitions the high-voltage power into portions having a voltage range between 0 V and 300 V, the second power converter associated with the second stator module 240B partitions the high-voltage power into portions having a voltage range between 300 V and 600 V, the third power converter associated with the third stator module 240C partitions the high-voltage power into portions having a voltage range between 600 V and 900 V, the fourth power converter associated with the fourth stator module 240D partitions the high-voltage power into portions having a voltage range between 900 V and 1200 V, the fifth power converter associated with the fifth stator module 240E partitions the high-voltage power into portions having a voltage range between 1200 V and 1500 V, and the sixth power converter associated with the sixth stator module 240F partitions the high-voltage power into portions having a voltage range between 1500 V and 1800 V.

[0057] As a result, the first stator module 240A has an associated voltage range between 0 V and 300 V, the second stator module 240B has a voltage range between 300 V and 600 V, the third stator module 240C has a voltage range between 600 V and 900 V, the fourth stator module 240D has a voltage range between 900 V and 1200 V, the fifth stator module 240E has a voltage range between 1200 V and 1500 V, and the sixth stator module 240F has a voltage range between 1500 V and 1800 V. Therefore, in this example, the maximum voltage between the stator module and its windings is a 300V DC link. Additionally, the maximum voltage between the stator module and its associated power converter is a 300V DC link. In this way, particularly when the motor 200 is operating at altitudes higher than 40,000 feet, the voltage associated with the stator modules remains low, which reduces or eliminates partial discharge problems.

[0058] As another example, suppose a high-voltage DC bus delivers high-voltage power at 1.8kV to motor 200 and its associated power converter. Further, suppose that housing 210 may be at or nearly at ground potential. It is also assumed that the DC bus is a bipolar DC bus, such that at least one transmission line is set to negative (-VDC / 2), and at least one transmission line is set to positive (+VDC / 2), for example, as... Figure 4As shown in the diagram. Further assuming that the power converters associated with motor 200 introduce high-voltage power partitioning, such that the first power converter associated with the first stator module 240A partitions the high-voltage power into portions having a voltage range between -900 V and -600 V, the second power converter associated with the second stator module 240B partitions the high-voltage power into portions having a voltage range between -600 V and -300 V, the third power converter associated with the third stator module 240C partitions the high-voltage power into portions having a voltage range between -300 V and 0 V, the fourth power converter associated with the fourth stator module 240D partitions the high-voltage power into portions having a voltage range between 0 V and 300 V, the fifth power converter associated with the fifth stator module 240E partitions the high-voltage power into portions having a voltage range between 300 V and 600 V, and the sixth power converter associated with the sixth stator module 240F partitions the high-voltage power into portions having a voltage range between 600 V and 900 V.

[0059] As a result, the first stator module 240A has an associated voltage range between -900 V and -600 V, the second stator module 240B has a voltage range between -600 V and -300 V, the third stator module 240C has a voltage range between -300 V and 0 V, the fourth stator module 240D has a voltage range between 0 V and 300 V, the fifth stator module 240E has a voltage range between 300 V and 600 V, and the sixth stator module 240F has a voltage range between 600 V and 900 V. Therefore, in this example, the maximum voltage between the stator module and its windings is a 300V DC link. Additionally, the maximum voltage between the stator module and its associated power converter is a 300V DC link. In this way, as noted above, particularly when the motor 200 is operating at altitudes higher than 40,000 feet, the voltage associated with the stator modules remains low, which reduces or eliminates partial discharge problems.

[0060] Furthermore, in this example, it is assumed that housing 210 is electrically grounded and therefore has an associated voltage of 0 V. In such an example, the voltage associated with housing 210 (e.g., 0 V) ​​is the midpoint between the maximum voltage (900 V) associated with the highest voltage stator module (e.g., the sixth stator module 240F) and the minimum voltage (-900 V) associated with the lowest voltage stator module (e.g., the first stator module 240A). The highest voltage stator module may be defined as a stator module having an associated voltage range higher than any other voltage range associated with any of the other stator modules, such as the sixth stator module 240F in the example above, and the lowest voltage stator module may be defined as a stator module having an associated voltage range lower than any other voltage range associated with any of the other stator modules, such as the first stator module 240A in the example above. Therefore, in a bipolar configuration, the difference between housing 210 and any maximum voltage in the stator modules is half the difference between housing 210 and any maximum voltage in the stator modules in a unipolar configuration. In this way, the thickness of the shell modular separator used in the bipolar configuration can be reduced or does not need to be the same as that used in the unipolar configuration, while all other variables remain the same.

[0061] Figure 7 A schematic diagram of an exemplary winding configuration for a first stator module 240A and a second stator module 240B for a motor 200 is provided. It will be appreciated that other stator modules 240C, 240D, 240E, and 240F ( Figure 6 It may have stator windings wound with the same or similar winding configuration shown for the first stator module 240A and the second stator module 240B. Figure 7 In the middle, the first module separator 250A-B (schematically represented by dashed lines) electrically isolates the first stator module 240A and the second stator module 240B from each other.

[0062] Each stator module has associated groups of stator windings. For example, such as Figure 7As shown, the first stator module 240A has associated groups of stator windings 222A, and the second stator module 240B has associated groups of stator windings 222B. Although not shown, stator modules 240C, 240D, 240E, and 240F also each have associated groups of stator windings. It is noteworthy that each group of stator windings is wound only within its corresponding stator module. That is, all windings of a given group of stator windings "go forward" and "go back" within the same stator module. In this way, stator modules 240A-240F are effectively electromagnetically independent motors. Furthermore, since each group of stator windings is wound only within its corresponding stator module, the voltage potential between the windings remains low, and the voltage potential between the winding and its corresponding stator module remains low.

[0063] Through examples, such as Figure 7 As shown, the group of stator windings 222A associated with the first stator module 240A includes one or more first windings 222A-A associated with the first phase A, one or more second windings 222A-B associated with the second phase B, and one or more third windings 222A-C associated with the third phase C. Therefore, in this example, the first stator module 240A acts as an independent three-phase motor. The advancing side of the first winding 222A-A is advanced via a slot marked A+ in the slot 230, turning at the end winding 236A-A, and the returning side of the first winding 222A-A is returned via a slot marked A- in the slot 230. Similarly, the advancing side of the second winding 222A-B is advanced via a slot marked B+ in the slot 230, turning at the end winding 236A-B, and the returning side of the second winding 222A-B is returned via a slot marked B- in the slot 230. Similarly, the advancing side of the third winding 222A-C advances through a slot 230 marked C+, turns at the end winding 236A-C, and the returning side of the third winding 222A-C returns through a slot 230 marked C-. The sequence of stator windings 222A-A, 222A-B, and 222A-C imparts a balanced three-phase winding configuration to the first stator module 240A.

[0064] Similarly, for the adjacent second stator module 240B, the group of stator windings 222B associated with the second stator module 240B includes one or more first windings 222B-A associated with the first phase A, one or more second windings 222B-B associated with the second phase B, and one or more third windings 222B-C associated with the third phase C. Thus, in this example, the second stator module 240B acts as a three-phase motor. The advancing side of the first winding 222B-A turns at the end winding 236B-A via an advancing section marked A+ in slot 230, and the returning side of the first winding 222B-A returns via a returning section marked A- in slot 230. Similarly, the advancing side of the second winding 222B-B turns at the end winding 236B-B via an advancing section marked B+ in slot 230, and the returning side of the second winding 222B-B returns via a returning section marked B- in slot 230. Similarly, the advancing side of the third winding 222B-C advances through a slot 230 marked C+, turns at the end winding 236A-C, and the returning side of the third winding 222B-C returns through a slot 230 marked C-. The sequence of stator windings 222B-A, 222B-B, and 222B-C imparts a balanced three-phase winding configuration to the second stator module 240B.

[0065] For the grouped stator windings 222A, the end windings 236A-A, 236A-B, and 236A-C of the corresponding first winding 222A-A, second winding 222A-B, and third winding 222A-C are each rotated relative to each other in different planes. For example, the end windings 236A-A, 236A-B, and 236A-C can each be rotated relative to each other in different planes along the axial direction A( Figure 5 ) Rotation. Similarly, for the group of stator windings 222B, the end windings 236B-A, 236B-B, and 236B-C of the corresponding first winding 222B-A, second winding 222B-B, and third winding 222B-C are each rotated in different planes relative to each other.

[0066] Furthermore, the associated end windings can be switched from one stator module to the next in different planes. For example, as Figure 7As shown, the end winding 236A-A of the first stator module 240A (associated with phase A) is turned in a different plane than the end winding 236B-A of the second stator module 240B, which is associated with phase A. Similarly, the end winding 236A-B of the first stator module 240A (associated with phase B) is turned in a different plane than the end winding 236B-B of the second stator module 240B, which is associated with phase B. In this respect, the turning planes of the end windings associated with phases A and B allow each stator module to alternate. This facilitates impedance balancing of the end windings.

[0067] Furthermore, since the stator windings are within the same stator module and advance and return in slots separated from each other by more than one slot, the windings in Figure 7 The stator windings are arranged in a distributed configuration. For example, the advancing side of the first winding 222A-A is wound through slot A+, which spans three slots from slot A-. Similarly, the advancing side of the second winding 222A-B is wound through slot B+, which spans three slots from slot B-, and the advancing side of the third winding 222A-C is wound through slot C+, which spans three slots from slot C-. The stator winding 222B is also arranged in a distributed configuration.

[0068] In other embodiments, the stator windings of a group associated with one of the stator modules may be arranged in a toothed or concentrated configuration. In such a configuration, the advancing side of a given winding is wound through a slot, and the returning side of a given winding is wound through an adjacent slot. Thus, in a toothed or concentrated winding configuration, the stator windings advance and return within the same stator module and in slots separated from each other by only a single slot (i.e., they are adjacent slots).

[0069] It will be appreciated that the winding configuration disclosed above is a non-limiting example, and that groups of stator windings associated with their respective stator modules may be wound in other suitable configurations.

[0070] Figure 8 A schematic cross-sectional view of another exemplary motor 200 according to an exemplary embodiment of this subject is provided. As shown, for this embodiment, motor 200 is an axial flux rotary motor. In addition to radial flux motors, the inventive aspects provided herein are also applicable to axial flux motors. Therefore, the advantages and benefits disclosed herein with respect to radial flux machines also apply to axial flux machines.

[0071] like Figure 8As shown, the motor 200 includes a rotor 212 and a stator, the stator including a first stator 214A and a second stator 214B. The rotor 212 is operatively connected to a shaft 216 and is rotatable about a rotation axis AX in conjunction with the shaft 216. The first stator 214A is located on a first side of the rotor 212, and the second stator 214B is located on a second side of the rotor 212 opposite to the first side. The first stator 214A has an associated first stator winding 222A, and the second stator 214B has an associated second stator winding 222B.

[0072] Now for reference Figure 8 , Figure 9 as well as Figure 10 , Figure 9 supply Figure 8 A schematic cross-sectional view of the first stator 214A of the motor 200, and, Figure 10 A perspective view of a first stator 214A is provided. As shown, the first stator 214A includes a stator core having a core body 226 and a plurality of teeth 228 projecting from the core body 226. In this embodiment, the teeth 228 project inwardly from the core body 226 toward the rotor 212 along an axial direction A. Figure 8 Slot 230 is defined between each of the teeth 228. Slot 230 is sized to receive stator windings (not in...). Figure 9 and Figure 10 (as shown in the image).

[0073] It is worth noting that, in this embodiment, the axial flux motor 200 is equipped with a current separator for cascading voltage stator modules. For example... Figure 9 and Figure 10 As illustrated, there are six stator modules with current-ground isolation, including a first stator module 240A, a second stator module 240B, a third stator module 240C, a fourth stator module 240D, a fifth stator module 240E, and a sixth stator module 240F. Each stator module 240A-240F has an associated group of first stator windings 222A. Figure 8 A group of stator windings associated with a given stator module is wound only within that given stator module. For example, a group of first stator windings 222A associated with a first stator module 240A is wound only within the first stator module 240A; none of the windings in this group extend into another module. In some embodiments, the windings in each group of first stator windings 222A and / or the windings in each group of second stator windings 222B may be arranged in a distributed configuration. In some other embodiments, the windings in each group of first stator windings 222A and / or the windings in each group of second stator windings 222B may be arranged in a toothed or concentrated configuration.

[0074] The first inter-module separator 250A-B electrically separates the first stator module 240A and the second stator module 240B; the second inter-module separator 250B-C electrically separates the second stator module 240B and the third stator module 240C; the third inter-module separator 250C-D electrically separates the third stator module 240C and the fourth stator module 240C; the fourth inter-module separator 250D-E electrically separates the fourth stator module 240D and the fifth stator module 240E; the fifth inter-module separator 250E-F electrically separates the fifth stator module 240E and the sixth stator module 240F; and the sixth inter-module separator 250F-A electrically separates the sixth stator module 240F from the first stator module 240A. The inter-module separators 250A-B-250F-A extend generally in a plane orthogonal to the circumferential direction C and have a thickness along the circumferential direction C. Inter-module separators 250A-B-250F-A are positioned between their respective adjacent stator modules 240A-240F, such that the stator modules 240A-240F are separated from each other in the circumferential direction C. This prevents current from flowing circumferentially from one stator module to the next. The inter-module separators 250A-B-250F-A can be dimensioned and formed using the materials indicated herein. It will be appreciated that the second stator 214B can similarly include multiple stator modules that are electrically isolated or separated by corresponding inter-module separators. For example, the second stator 214B can be positioned with... Figure 9 and Figure 10 The first stator 212A shown in the figure is configured in the same or similar manner.

[0075] The first housing separator 260A electrically separates the stator modules 240A-240F of the first stator module 214A from the housing 210 of the motor 200. For example... Figure 8 As shown, a first housing separator 260A may surround the outer surface of the first stator 214A. Specifically, a portion or a first portion 262 of the first housing separator 260A may extend annularly along the axial outer surface of the first stator module 214A, wherein the thickness of the first portion 262 is along the axial direction A. A second portion 264 of the first housing separator 260A may extend annularly around the radially upper outer surface of the first stator module 214A, wherein the thickness of the second portion 264 is along the radial direction R. The first portion 262 and the second portion 264 may be integral or may be distinct separate portions. The first housing separator 260A may be dimensioned and may be formed using materials indicated herein. Figure 8As shown, the first housing separator 260A can directly contact the cooling sleeve 224, which in turn can directly contact the housing 210. In other embodiments, the cooling sleeve 224 may not be present, and the first housing separator 260A can directly contact the housing 210.

[0076] Furthermore, the second housing separator 260B electrically separates the stator module of the second stator module 214B from the housing 210 of the motor 200. The second housing separator 260B can be constructed, oriented, positioned, and / or otherwise arranged relative to the second stator module 214B in the same manner as the first housing separator 260A relative to the first stator module 214A. For example... Figure 8 As shown, the second housing separator 260B can directly contact the cooling sleeve 224, which in turn can directly contact the housing 210. In other embodiments, the cooling sleeve 224 may not be present, and the second housing separator 260B can directly contact the housing 210.

[0077] Although motors equipped with current separators for cascaded voltage stator modules are disclosed herein in the context of aerospace applications, it will be appreciated that such motors are suitable for use in other applications and in other industries. Furthermore, although motors equipped with current separators for cascaded voltage stator modules are disclosed herein in a particular exemplary power distribution system for aircraft, it will be appreciated that such motors are also suitable for use in other suitable high-voltage power distribution systems. For example, such motors can be used in any of the power distribution systems disclosed in U.S. Patent Application 15 / 666173, filed August 1, 2017 and published February 7, 2019 as US2019 / 0044451, which is incorporated herein by reference in its entirety. Additionally, although the windings discussed herein are provided in the context of three-phase windings, it will be appreciated that the inventive aspects of this disclosure are applicable to any multiphase winding arrangement having any suitable number of phases, such as six-phase windings. For example, each stator module may have associated groups of six-phase windings, rather than associated groups of three-phase windings.

[0078] This written description uses examples to disclose the invention (including the best mode) and also enables any person skilled in the art to practice the invention (including making and using any device or system and performing any incorporated methods). The patentability scope of the invention is defined by the claims and may include other examples that would occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they comprise structural elements that are not different from the literal language of the claims, or if they comprise equivalent structural elements that are not substantially different from the literal language of the claims.

[0079] Further aspects of the invention are provided by the subject matter of the following provisions:

[0080] 1. An electric motor comprising: a stator having stator modules; a housing surrounding at least a portion of the stator; a housing separator that electrically isolates the housing from the stator modules; and an inter-module separator that electrically isolates the stator modules from each other.

[0081] 2. The motor of any of the foregoing clauses, wherein the motor defines an axial direction, a radial direction and a circumferential direction, and wherein, for each pair of adjacent stator modules, the inter-module separator is positioned therebetween.

[0082] 3. The motor of any of the foregoing clauses, wherein the stator has a core body and teeth projecting therefrom in a radial direction, the radial length of the stator being defined in a radial direction from the outer surface of the core body to the inner end of one of the teeth, and wherein each of the inter-module separators extends a radial length between its respective adjacent stator modules.

[0083] 4. The motor of any of the foregoing clauses, wherein the stator extends axially between a first end and a second end, and wherein each of the inter-module separators extends axially from the first end of the stator to the second end.

[0084] 5. The motor of any of the foregoing clauses, wherein the motor is defined in an axial direction, a radial direction and a circumferential direction, and wherein the inter-module separator is positioned between the stator modules such that the stator modules are separated from each other in the circumferential direction.

[0085] 6. The motor of any of the foregoing clauses, wherein the motor defines an axial direction, a radial direction and a circumferential direction, and wherein the inter-module separator is positioned between the stator modules such that the stator modules are separated from each other along the axial direction.

[0086] 7. The motor of any of the foregoing clauses, wherein the motor defines an axial direction, a radial direction and a circumferential direction, and wherein the housing separator extends circumferentially around the stator and is positioned radially between the stator module and the housing.

[0087] 8. Any motor in the foregoing clauses, wherein at least one of the housing separator and the inter-module separator is formed of barium ferrite.

[0088] 9. Any motor specified in the foregoing clauses, wherein the inter-module separators each have a thickness in the range of 25-250 micrometers.

[0089] 10. Any motor in the foregoing clauses, wherein the housing separator has a thickness in the range of 250 micrometers to 2.5 millimeters.

[0090] 11. Any of the foregoing provisions of the motor, wherein each of the stator modules has an associated group of stator windings, and wherein each group of stator windings is wound only within its respective stator module.

[0091] 12. Any of the foregoing provisions of an electric motor, wherein the stator windings of each group are arranged in a distributed configuration.

[0092] 13. The motor of any of the foregoing provisions, wherein each set of stator windings includes a first winding associated with a first phase, a second winding associated with a second phase and a third winding associated with a third phase, and wherein the first winding, the second winding and the third winding each have end windings that are turned relative to each other in different planes.

[0093] 14. Any motor in the foregoing clauses, wherein the stator module has a successively varying associated voltage range.

[0094] 15. A power distribution system comprising: a high-voltage power bus operable to carry high-voltage electrical power; a power converter electrically coupled to the high-voltage power bus and operable to divide the high-voltage electrical power; and a motor comprising: a stator having stator modules; a housing surrounding at least a portion of the stator; a housing separator electrically isolating the housing from the stator modules; and an inter-module separator electrically isolating the stator modules from each other, wherein each of the stator modules is electrically coupled to a corresponding one of the power converters, and wherein each of the stator modules receives a portion of the divided high-voltage electrical power.

[0095] 16. Any power distribution system specified in the foregoing clauses, wherein the high-voltage power bus is a unipolar high-voltage power bus.

[0096] 17. Any power distribution system specified in the foregoing clauses, wherein the high-voltage power bus is a bipolar high-voltage power bus.

[0097] 18. A power distribution system according to any of the foregoing provisions, wherein the stator module includes a highest voltage stator module having an associated voltage range higher than any other voltage range associated with any other stator module and a lowest voltage stator module having an associated voltage range lower than any other voltage range associated with any other stator module, and wherein the voltage associated with the housing is the median between the maximum voltage associated with the highest voltage stator module and the minimum voltage associated with the lowest voltage stator module.

[0098] 19. Any power distribution system of the foregoing clauses, wherein the stator module is electrically coupled to its corresponding cascaded power converter.

[0099] 20. An aircraft comprising: a high-voltage power bus operable to carry high-voltage electrical power; a power converter electrically coupled to the high-voltage power bus and operable to divide the high-voltage electrical power; and a motor comprising: a stator having stator modules; a housing surrounding at least a portion of the stator; a housing separator electrically isolating the housing from the stator modules; and an inter-module separator electrically isolating the stator modules from each other, wherein each of the stator modules is electrically coupled to a corresponding one of the power converters, and wherein each of the stator modules receives a portion of the divided high-voltage electrical power, and each of the stator modules is at an independent voltage relative to each other.

Claims

1. An electric motor, comprising: The stator has a stator module; A housing that surrounds at least a portion of the stator; A housing separator that electrically isolates the housing from the stator module; as well as Inter-module separators that electrically isolate the stator modules from each other; Each of the stator modules is associated with a different voltage range.

2. The motor according to claim 1, characterized in that, The motor defines an axial direction, a radial direction, and a circumferential direction, and wherein, for each pair of adjacent stator modules, an inter-module separator is positioned therebetween.

3. The motor according to claim 2, characterized in that, The stator has a core body and teeth protruding therefrom along the radial direction, the radial length of the stator being defined from the outer surface of the core body along the radial direction to the inner end of one of the teeth, and wherein each of the inter-module separators extends the radial length between its respective adjacent stator modules.

4. The motor according to claim 3, characterized in that, The stator extends along the axial direction between a first end and a second end, and each of the inter-module separators extends from the first end of the stator along the axial direction to the second end.

5. The motor according to claim 1, characterized in that, The motor defines an axial direction, a radial direction, and a circumferential direction, and wherein the inter-module separator is positioned between the stator modules such that the stator modules are separated from each other along the circumferential direction.

6. The motor according to claim 1, characterized in that, The motor defines an axial direction, a radial direction, and a circumferential direction, and wherein the inter-module separator is positioned between the stator modules such that the stator modules are separated from each other along the axial direction.

7. The motor according to claim 1, characterized in that, The motor defines an axial direction, a radial direction, and a circumferential direction, wherein the housing separator extends circumferentially around the stator along the circumferential direction and is positioned between the stator module and the housing along the radial direction.

8. The motor according to claim 1, characterized in that, At least one of the housing separator and the inter-module separator is formed of barium ferrite.

9. The motor according to claim 1, characterized in that, Each of the inter-module separators has a thickness in the range of 25-250 micrometers.

10. The motor according to claim 1, characterized in that, The housing separator has a thickness in the range of 250 micrometers to 2.5 millimeters.

11. The motor according to claim 1, characterized in that, Each of the stator modules has an associated group of stator windings, wherein each group of stator windings is wound only within its respective stator module.

12. The motor according to claim 11, characterized in that, The stator windings of each group are arranged in a distributed configuration.

13. The motor according to claim 12, characterized in that, Each group of stator windings includes a first winding associated with a first phase, a second winding associated with a second phase, and a third winding associated with a third phase, wherein the first winding, the second winding, and the third winding each have end windings that are turned relative to each other in different planes.

14. The motor according to claim 1, characterized in that, The stator module has a successively changing associated voltage range.

15. A power distribution system, comprising: High-voltage power bus, which can be operated to carry high-voltage electrical power; A power converter electrically coupled to the high-voltage power bus and operable to divide the high-voltage power; An electric motor, comprising: The stator has a stator module; A housing that surrounds at least a portion of the stator; A housing separator that electrically isolates the housing from the stator module; and Inter-module separators that electrically isolate the stator modules from each other, and Each of the stator modules is electrically coupled to a corresponding one of the power converters, and each of the stator modules receives a portion of the divided high-voltage power. Each of the stator modules is associated with a different voltage range.

16. The power distribution system according to claim 15, characterized in that, The high-voltage power bus is a single-pole high-voltage power bus.

17. The power distribution system according to claim 15, characterized in that, The high-voltage power bus is a bipolar high-voltage power bus.

18. The power distribution system according to claim 17, characterized in that, The stator module includes a highest voltage stator module having an associated voltage range higher than any other voltage range associated with any other stator module, and a lowest voltage stator module having an associated voltage range lower than any other voltage range associated with any other stator module. The voltage associated with the housing is the median between the maximum voltage associated with the highest voltage stator module and the minimum voltage associated with the lowest voltage stator module.

19. The power distribution system according to claim 15, characterized in that, The stator module is electrically coupled to its corresponding cascaded power converter.

20. An aircraft comprising: High-voltage power bus, which can be operated to carry high-voltage electrical power; A power converter electrically coupled to the high-voltage power bus and operable to divide the high-voltage power; An electric motor, comprising: The stator has a stator module; A housing that surrounds at least a portion of the stator; A housing separator that electrically isolates the housing from the stator module; and Inter-module separators that electrically isolate the stator modules from each other, and Each of the stator modules is electrically coupled to a corresponding one of the power converters, and each of the stator modules receives a portion of the high-voltage power, and each of the stator modules is associated with a different voltage range.

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