Power system

Abstract

A power system is provided. The power system includes: an electric machine including a first multi-phase winding and a second multi-phase winding, the first multi-phase winding and the second multi-phase winding being electrically opposite in phase with respect to each other; and a power converter system having: a first switching element electrically connected to the first multi-phase winding and having a DC side and an AC side; a second switching element electrically connected with the second multi-phase winding and having a DC side and an AC side; a plurality of capacitors coupled to the first switching element at a DC side of the first switching element and coupled to the second switching element at a DC side of the second switching element; and means for reducing the common mode current of the AC side of the first switching element and the AC side of the second switching element.

Description

[0001] Priority information

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 585,039, filed on September 25, 2023, the entire contents of which are incorporated herein by reference in their entirety for all purposes. Technical Field

[0003] The present subject matter relates generally to electrical power systems, such as electrical power systems for aircraft. Background Art

[0004] Conventional commercial aircraft typically include a fuselage, a pair of wings, and a propulsion system that provides thrust. The propulsion system typically includes at least two aircraft engines, such as turbofan jet engines. Each turbofan jet engine is typically mounted to a corresponding one of the wings of the aircraft, such as in a suspension position below the wing that is separate from the wing and the fuselage.

[0005] Hybrid electric propulsion systems are being developed to improve the efficiency of conventional commercial aircraft. Some hybrid electric propulsion systems include one or more electric machines, each of which is mechanically coupled to a rotating component of one of the aircraft engines. The electric machines may each have an associated power converter electrically connected thereto. The inventors of the present disclosure have developed various systems and methods to improve hybrid electric propulsion systems, and more generally, power systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] A full and enabling disclosure of the present disclosure, including the best mode thereof, to one of ordinary skill in the art is set forth in the specification with reference to the accompanying drawings, in which:

[0007] Figure 1 A schematic top view of an aircraft having a hybrid electric propulsion system according to various exemplary embodiments of the present disclosure is provided;

[0008] Figure 2 Provided Figure 1 A schematic cross-sectional view of one of the hybrid electric propulsion systems of an aircraft;

[0009] Figure 3 A schematic diagram of a power system according to an example embodiment of the present disclosure is provided;

[0010] Figure 4 Provided Figure 3 Schematic diagram of a multi-phase winding of a motor;

[0011] Figure 5 Provides Figure 3 A schematic diagram of a first switching element of a power converter system electrically coupled to a first multi-phase winding of a power system;

[0012] Figure 6 Provided Figure 3 The topology of the control system of the power system;

[0013] FIG. 7A to FIG. 7D Various graphs depicting voltage signals as a function of time are provided;

[0014] Fig. 8A and Figure 8B Provides a description that can be generated with Figure 3 A graph of an exemplary embodiment of a pulse width modulation signal associated with a first multi-phase winding of an electric machine;

[0015] Fig.9A and Fig. 9B Provides a description that can be generated with Figure 3 A graph of an example embodiment of a pulse width modulation signal associated with a second multi-phase winding of an electric machine;

[0016] Fig.10 depicts simplified graphs depicting various signals as functions of time;

[0017] Fig.11 A schematic diagram of a power system according to an example embodiment of the present disclosure is provided;

[0018] Fig.12 Provided Fig.11 The topology of the control system of the power system;

[0019] Fig.13 A schematic diagram of a power system according to an example embodiment of the present disclosure is provided;

[0020] Fig.14 A schematic diagram of a power system according to an example embodiment of the present disclosure is provided;

[0021] Fig.15 A schematic diagram of a power system according to an example embodiment of the present disclosure is provided;

[0022] Fig.16 A schematic diagram of a power system according to another example embodiment of the present disclosure is provided;

[0023] Fig.17 A schematic diagram of a power system according to yet another example embodiment of the present disclosure is provided;

[0024] Fig.18 A schematic diagram of a power system according to yet another example embodiment of the present disclosure is provided;

[0025] Fig.19 A schematic diagram of a power system according to yet another example embodiment of the present disclosure is provided;

[0026] Fig. 20 A schematic diagram of a power system according to yet another example embodiment of the present disclosure is provided;

[0027] Fig.21 A schematic diagram of a power system according to yet another example embodiment of the present disclosure is provided;

[0028] Fig. 22 A schematic diagram of a power system according to yet another example embodiment of the present disclosure is provided;

[0029] Fig.23 A schematic diagram of an electric power system is provided, which may include and may operate according to one or more exemplary aspects of the present disclosure;

[0030] Fig.24 providing a graph of exemplary common mode emission reduction; and

[0031] Fig.25 An example computing system is provided according to example embodiments of the present disclosure. DETAILED DESCRIPTION

[0032] Reference will now be made in detail to the present embodiments of the present disclosure, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and letter references to refer to features in the drawings. Like or similar reference numbers in the drawings and description have been used to refer to like or similar parts of the present disclosure.

[0033] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations. In addition, unless expressly stated otherwise, all embodiments described herein should be considered exemplary.

[0034] As used herein, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another, and are not intended to indicate the position or importance of each component.

[0035] The terms "front" and "rear" refer to relative positions within a gas turbine engine or vehicle and refer to the normal operating attitude of the gas turbine engine or vehicle. For example, for a gas turbine engine, front refers to a position closer to the engine inlet, while rear refers to a position closer to the engine nozzle or exhaust.

[0036] The terms "upstream" and "downstream" refer to the relative directions of flow in a path. For example, for fluid flow, "upstream" refers to the direction from which the fluid is flowing, and "downstream" refers to the direction toward which the fluid is flowing. However, the terms "upstream" and "downstream" as used herein may also refer to electric current.

[0037] The singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

[0038] Here and throughout the specification and claims, range limitations are combined and interchanged, and unless context or language indicates otherwise, such ranges are identified and include all sub-ranges contained therein. For example, all ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other.

[0039] The term "ground connection" refers to an electrical connection established between a point in an electrical system and a reference point. The reference point may be the chassis or frame of the engine or a dedicated ground structure. The ground connection may regulate voltage levels, provide a path for fault currents, stabilize electrical noise, and / or ensure the safety and proper functioning of the system by preventing unexpected voltage potentials.

[0040] Power systems, such as those found in aircraft hybrid electric propulsion systems, may employ electric machines and power converter systems electrically connected thereto. As the demand for increased distribution voltages, increased power levels and consequent transmission paths, and the use of efficient and high-speed power semiconductors in aviation power systems continues to increase, the need to reduce common-mode emissions is also increasing. Common-mode emissions may introduce voltage stresses and parasitic currents via electromechanical interfaces.

[0041] For example, in power systems for aviation applications, common-mode currents originating from power converters can cause electromagnetic interference (EMI), reduced system efficiency, and / or potential damage to equipment. Conventional systems, especially those employing multi-phase windings, are often particularly susceptible to these interferences due to inherent design limitations or insufficient filtering capabilities. Additionally, in advanced engine architectures, including robust EMI filters may be weight and / or space constrained.

[0042] The present disclosure provides an electric power system equipped with an electric machine having a first multi-phase winding and a second multi-phase winding. These windings are constructed to be electrically opposite in phase with respect to each other, which can inherently cancel out some common-mode interference. The system also incorporates an electric power converter system utilizing a first switching element and a second switching element. In addition, a control method implemented via one or more processors is introduced to generate dedicated pulse width modulation (PWM) signals for the first and second switching elements, which further helps to eliminate the effects of common-mode current. However, operating the first and second switching elements according to one or more PWM schedules may not itself reduce common-mode emissions to a desired level.

[0043] Therefore, the system also incorporates a power converter system that couples the first and second switching elements with a plurality of capacitors on the DC side and has means for reducing common mode current on the AC side. The present disclosure provides various embodiments and configurations for reducing common mode current, including the use of filter capacitors, dv / dt filters and LC filters connected to each other or to ground.

[0044] By systematically arranging and controlling these components, the system achieves a significant reduction in common-mode current, thereby improving system efficiency, reducing EMI, and enhancing overall system reliability. In addition, this construction can significantly reduce weight by eliminating dedicated EMI filters.

[0045] Referring now to the drawings, in which like numerals refer to like elements throughout, Figure 1 A schematic top view of an exemplary aircraft 100 is provided that may incorporate one or more inventive aspects of the present disclosure. Figure 1 As shown, for reference, the aircraft 100 defines a longitudinal direction L1 and a transverse direction L2. The transverse direction L2 is perpendicular to the longitudinal direction L1. The aircraft 100 also defines a longitudinal centerline 114 extending therethrough along the longitudinal direction L1. The aircraft 100 extends, for example, along the longitudinal direction L1 between a front end 116 and a rear end 118.

[0046] As shown, the aircraft 100 includes a fuselage 112 that extends longitudinally from a front end 116 of the aircraft 100 to a rear end 118 of the aircraft 100. The aircraft 100 also includes a tail 119 at the rear end 118 of the aircraft 100. In addition, the aircraft 100 includes a wing assembly that includes a first port wing 120 and a second starboard wing 122. The first and second wings 120, 122 each extend laterally outward relative to the longitudinal centerline 114. The first wing 120 and a portion of the fuselage 112 together define a first side 124 of the aircraft 100, and the second wing 122 and another portion of the fuselage 112 together define a second side 126 of the aircraft 100. For the depicted embodiment, the first side 124 of the aircraft 100 is configured as the port side of the aircraft 100, and the second side 126 of the aircraft 100 is configured as the starboard side of the aircraft 100.

[0047] Aircraft 100 includes various control surfaces. For this embodiment, each wing 120, 122 includes one or more leading edge flaps 128 and one or more trailing edge flaps 130. Aircraft 100 further includes, or more specifically, the tail 119 of aircraft 100 includes: a vertical stabilizer 132, which has a rudder flap (not shown) for yaw control; and a pair of horizontal stabilizers 134, each horizontal stabilizer has an elevator flap 136 for pitch control. Fuselage 112 additionally includes an outer surface or skin 138. It should be understood that in other exemplary embodiments of the present disclosure, aircraft 100 may additionally or alternatively include any other suitable configuration. For example, in other embodiments, aircraft 100 may include any other control surface configuration.

[0048] Figure 1 The exemplary aircraft 100 also includes a hybrid electric propulsion system 150. For this embodiment, the hybrid electric propulsion system 150 has a first propeller 200A and a second propeller 200B, both of which are operable to generate thrust. The first propeller 200A is mounted to the first wing 120 and the second propeller 200B is mounted to the second wing 122. In addition, for the depicted embodiment, the first propeller 200A and the second propeller 200B are both configured as underwing mounting configurations. However, in other exemplary embodiments, one or both of the first and second propellers 200A, 200B can be mounted in any other suitable location in other exemplary embodiments.

[0049] The first thruster 200A includes a gas turbine engine 210A and one or more motors, such as a motor 300A mechanically coupled to the gas turbine engine 210A. The motor 300A can be a generator, an electric motor, or a combined generator / motor. For this example embodiment, the motor 300A is a combined generator / motor. In this way, when operating as a generator, the motor 300A can generate electricity when driven by the gas turbine engine 210A. When operating as a motor, the motor 300A can drive or start the gas turbine engine 210A.

[0050] Likewise, the second propeller 200B includes a gas turbine engine 210B and one or more motors, such as a motor 300B mechanically coupled to the gas turbine engine 210B. The motor 300B may be a generator, an electric motor, or a combined generator / motor. For this example embodiment, the motor 300B is a combined generator / motor. In this way, when operating as a generator, the motor 300B can generate electricity when driven by the gas turbine engine 210B. When operating as a motor, the motor 300B can drive or start the spool of the gas turbine engine 210B. The motor 300B may be constructed and operated in a manner similar to the motor 300A described herein.

[0051] The hybrid electric propulsion system 150 also includes an energy storage unit 180, which can be electrically connected to the motors 300A, 300B, and in some embodiments, can be electrically connected to other electrical loads. In some exemplary embodiments, the energy storage unit 180 may include one or more batteries. Additionally or alternatively, the energy storage unit 180 may include one or more supercapacitor arrays, one or more ultracapacitor arrays, or both. For the hybrid electric propulsion system 150 described herein, the energy storage unit 180 is configured to store a relatively large amount of electricity. For example, in certain exemplary embodiments, the energy storage unit 180 can be configured to store at least about fifty kilowatt-hours of electricity, such as at least about sixty-five kilowatt-hours of electricity, such as at least about seventy-five kilowatt-hours of electricity, and up to about one thousand kilowatt-hours of electricity.

[0052] The hybrid electric propulsion system 150 also includes a power management system having a controller 182 and a power bus 184. The motors 300A, 300B, the energy storage unit 180, and the controller 182 can each be electrically connected to each other via one or more wires 186 of the power bus 184. For example, the power bus 184 can include various switches or other power electronic devices that can be moved to selectively electrically connect various components of the hybrid electric propulsion system 150. Specifically, as shown in FIG. Figure 1 As shown, a first power converter 188A of the power bus 184 is electrically coupled or connectable to the motor 300A via one or more wires 186, and a second power converter 188B of the power bus 184 is electrically coupled or connectable to the motor 300B via one or more wires 186. The power bus 184 may include other power electronics (e.g., inverters, converters, rectifiers, etc.) for conditioning or converting power within the hybrid electric propulsion system 150.

[0053] The controller 182 is configured to control the power electronics to distribute power between the various components of the hybrid electric propulsion system 150. For example, the controller 182 can control the power electronics of the power bus 184 to provide power to or draw power from the various components (e.g., the motors 300A, 300B) to operate the hybrid electric propulsion system 150 between various operating modes and to perform various functions. This is schematically depicted as wires 186 of the power bus 184 extending through the controller 182.

[0054] The controller 182 may form part of a computing system 190 of the aircraft 100. The computing system 190 of the aircraft 100 may include one or more processors and one or more memory devices embodied in one or more computing devices. Figure 1 As shown, computing system 190 includes controller 182 and other computing devices, such as computing device 192. Computing system 190 may also include other computing devices, such as an engine controller (not shown). The computing devices of computing system 190 may be communicatively coupled to each other via a communication network. For example, computing device 192 is located in the cockpit of aircraft 100 and is communicatively coupled to controller 182 of hybrid electric propulsion system 150 via a communication link 194 of the communication network. Communication link 194 may include one or more wired or wireless communication links.

[0055] exist Figure 1 In the illustrated embodiment, the computing device 192 is configured to receive and process input and / or other information, such as from a pilot or other crew member. Thus, as an example, one or more processors of the computing device 192 may receive input indicating a command to change the thrust output of the first and / or second thrusters 200A, 200B, and may cause the controller 182 to control the power drawn from or delivered to one or both of the motors 300A, 300B in response to the input to ultimately change the thrust output of one or both of the thrusters 200A, 200B.

[0056] The controller 182 and other computing devices of the computing system 190 of the aircraft 100 may be configured to communicate with the following references: Fig.25 The exemplary computing devices of the described computing system 950 are constructed in substantially the same manner.

[0057] Figure 2 Provided Figure 1 Schematic diagram of a first propeller 200A of a hybrid electric propulsion system 150 of an aircraft 100. Although a first propeller 200A is shown, it should be understood that a second propeller 200B may be used in conjunction with a Figure 2 The first thruster 200A depicted in FIG. 1 is constructed in the same or similar manner. Figure 2 The exemplary gas turbine engine of is configured as a single non-ducted rotor engine 210A defining an axial direction A, a radial direction R, and a circumferential direction C. The engine 210A also defines a central longitudinal axis 214 .

[0058] like Figure 2As shown, the engine 210A takes the form of an open rotor propulsion system and has a rotor assembly 212 that includes an array of airfoils arranged about a central longitudinal axis 214 of the engine 210A. More specifically, the rotor assembly 212 includes an array of rotor blades 216 arranged about the central longitudinal axis 214 of the engine 210A. In addition, as will be explained in more detail below, the engine 210A also includes a non-rotating blade assembly 218 (i.e., does not rotate relative to the longitudinal axis 214) positioned behind the rotor assembly 212. The non-rotating blade assembly 218 includes an array of airfoils also arranged about the longitudinal axis 214. More specifically, the blade assembly 218 includes an array of blades 220 arranged about the central longitudinal axis 214.

[0059] The rotor blades 216 are arranged in a generally equally spaced relationship about the central longitudinal axis 214, and each blade has a root 222 and a tip 224 and a span defined therebetween. Similarly, the buckets 220 are also arranged in a generally equally spaced relationship about the central longitudinal axis 214, and each bucket has a root 226 and a tip 228 and a span defined therebetween. The rotor assembly 212 also includes a hub 245 located forward of the plurality of rotor blades 216.

[0060] In addition, the engine 210A includes a turbine 230 having a core 232 (or a high pressure / high speed system) and a low pressure / low speed system. It should be understood that as used herein, the terms "speed" and "pressure" may be used interchangeably with respect to the high pressure / high speed system and the low pressure / low speed system. In addition, it should be understood that the terms "high" and "low" are used in the same context to distinguish between the two systems and are not meant to imply any absolute speed and / or pressure values.

[0061] The core 232 generally includes a high-speed compressor 234, a high-speed turbine 236, and a high-speed shaft 238 extending between and connecting the high-speed compressor 234 and the high-speed turbine 236. The high-speed compressor 234, the high-speed turbine 236, and the high-speed shaft 238 may be collectively referred to as a high-speed spool 253 of the engine. In addition, a combustion section 240 is located between the high-speed compressor 234 and the high-speed turbine 236. The combustion section 240 may include one or more configurations for receiving a mixture of fuel and air and providing a flow of combustion gases through the high-speed turbine 236 to drive the high-speed spool 253.

[0062] The low-speed system includes a low-speed turbine 242, a low-speed compressor 244 or a supercharger, and a low-speed shaft 246 extending between and connecting the low-speed compressor 244 and the low-speed turbine 242. The low-speed compressor 244, the low-speed turbine 242, and the low-speed shaft 246 may be collectively referred to as a low-speed spool 255 of the engine.

[0063] Although engine 210A is depicted as having a low-speed compressor 244 positioned in front of high-speed compressor 234, in certain embodiments, compressors 234, 244 may be in an interdigitated arrangement. Additionally or alternatively, although engine 210A is depicted as having a high-speed turbine 236 positioned in front of low-speed turbine 242, in certain embodiments, turbines 236, 242 may similarly be in an interdigitated arrangement.

[0064] In order to support the rotating components of the engine 210A, the engine 210A includes a plurality of bearings that couple the rotating components to various structural components. Figure 2 As shown, bearing 290 supports and facilitates rotation of low speed shaft 246. In addition, bearing 292 supports and facilitates rotation of high speed shaft 238. Although bearings 290, 292 are shown as being generally located at the front and rear ends of their associated shafts 246, 238, bearings 290, 292 may be located at any desired location along their associated shafts. In addition, in some embodiments, in addition to Figure 2 One or more additional bearings other than the bearing 290 shown in FIG. 2 may be used to support the low speed shaft 246. For example, in some embodiments, an additional bearing may be positioned in the center or mid-span region of the low speed shaft 246 to provide support therefor. Figure 2 One or more additional bearings other than the bearing 290 shown in FIG. 2 may be used to support the high speed shaft 238. The bearings 290, 290 may be any suitable type of bearing, such as an air bearing, an oil-lubricated bearing, or the like.

[0065] Still reference Figure 2 , the turbine 230 is generally enclosed in a shroud 248. In addition, it should be understood that the shroud 248 at least partially defines an inlet 250 and an exhaust port 252, and includes a turbomachinery flow path 254 extending between the inlet 250 and the exhaust port 252. For the illustrated embodiment, the inlet 250 is an annular or axisymmetric 360-degree inlet 250 located between the rotor assembly 212 and the fixed or stationary bucket assembly 218 in the axial direction A, and provides a path for the incoming atmospheric air to enter the turbomachinery flow path 254 (and the compressor 244, 234, the combustion section 240, and the turbine 236, 242) in the radial direction R inside the guide vanes 220. Such a location may be advantageous for various reasons, including management of icing performance and protecting the inlet 250 from various objects and materials that may be encountered during operation. However, in other embodiments, the inlet 250 may be located in any other suitable location, for example, arranged behind the bucket assembly 218 in a non-axisymmetric manner, etc.

[0066] As shown, the rotor assembly 212 is driven by the turbine 230, and more specifically, by the low speed spool 255 of the turbine 230. More specifically, for this embodiment, the engine 210A includes a power gearbox 256. The rotor assembly 212 is driven by the low speed spool 255 of the turbine 230 across the power gearbox 256. In this manner, the rotating rotor blades 216 of the rotor assembly 212 can rotate about the central longitudinal axis 214 and generate thrust to propel the engine 210A, and thus propel the aircraft 100 associated therewith, in a forward direction F ( Figure 1 ). The power gearbox 256 may include a gear set for reducing the rotational speed of the low-speed spool 255 relative to the low-speed turbine 242 , so that the rotor assembly 212 can rotate at a slower rotational speed than the low-speed spool 255 .

[0067] As briefly described above, engine 210A includes a bucket assembly 218. Bucket assembly 218 extends from shroud 248 and is positioned rearward of rotor assembly 212. Buckets 220 of bucket assembly 218 may be mounted to a stationary frame or other mounting structure and do not rotate relative to central longitudinal axis 214. For reference purposes, Figure 2 The forward direction is depicted by arrow F, which in turn defines the front and rear of the engine 210A. Figure 2 As shown, the rotor assembly 212 is located in front of the turbine 230 in a "puller" configuration, and the exhaust port 252 is located behind the guide vanes 220. The vanes 220 of the vane assembly 218 are aerodynamically shaped to smooth the airflow from the rotor assembly 212 (e.g., reduce vorticity in the airflow) to improve the efficiency of the engine 210A. For example, the size, shape and configuration of the vanes 220 can be designed to impart a counteracting swirl to the airflow from the rotor blades 216, so that in the downstream direction behind the two rows of airfoils (e.g., blades 216, vanes 220), the degree of airflow vortex is greatly reduced, which may translate into an increase in the level of induced efficiency.

[0068] In some embodiments, it may be desirable to incorporate a pitch-changing mechanism in rotor blades 216, vanes 220, or both, so that airfoils (e.g., blades 216, vanes 220, etc.) may be rotated independently or in conjunction with one another relative to a pitch axis of rotation. Such pitch changes may be used to change thrust and / or swirl effects under various operating conditions, including adjusting the magnitude or direction of thrust generated at rotor blades 216, or providing a thrust reversal feature that may be useful under certain operating conditions (e.g., when landing an aircraft), or desirably adjusting acoustic noise generated at least in part by rotor blades 216, vanes 220, or aerodynamic interactions from rotor blades 216 relative to vanes 220. More specifically, for Figure 2In the embodiment of the present invention, rotor assembly 212 is depicted as having a pitch change mechanism 258 for rotating rotor blades 216 about their respective pitch axes 260 , and bucket assembly 218 is depicted as having a pitch change mechanism 262 for rotating buckets 220 about their respective pitch axes 264 .

[0069] Provided as an example only Figure 2 210A. Thus, it should be understood that the engine 210A may have other suitable configurations. For example, in other example embodiments, the engine 210A may have other suitable numbers of shafts or spools, turbines, compressors, etc.; fixed pitch blades or vanes 216, 220, or both; direct drive configurations (i.e., gearbox 256 may not be included); etc. For example, in other exemplary embodiments, the engine 210A may be a three-spool engine with a medium speed compressor and / or turbine. In such configurations, it should be understood that the terms "high" and "low" used herein with respect to speeds and / or pressures of turbines, compressors, or spools are convenient terms for distinguishing components, but do not require any particular relative speeds and / or pressures, and do not exclude additional compressors, turbines, and / or spools or shafts.

[0070] Additionally or alternatively, in other exemplary embodiments, any other suitable gas turbine engine may be provided. For example, in other exemplary embodiments, the gas turbine engine may be a turboshaft engine, a turboprop engine, a turbojet engine, etc. Further, for example, while the engine is depicted as a single non-ducted rotor engine, in other embodiments, the engine may include a multi-stage open rotor configuration, and aspects of the present disclosure described below may be incorporated therein.

[0071] In addition, in other exemplary embodiments, the engine 210A can be configured as a ducted turbofan engine. For example, in another exemplary embodiment of the present disclosure, the engine 210A can include a nacelle that at least partially circumferentially surrounds the rotor assembly 212 and the turbine 230, defining a bypass passage therebetween. In this configuration, the blades 220 of the blade assembly 218 can extend between and connect the nacelle and the shroud 248.

[0072] Still reference Figure 2 As noted, the first propeller 200A includes an electric motor 300A operably coupled to a rotating component thereof. In this regard, the first propeller 200A is an aviation hybrid electric propulsion machine. In particular, as Figure 2As shown, the motor 300A is mechanically coupled to the low-speed spool 255 of the gas turbine engine 210A, and more specifically, to the low-speed shaft 246 of the low-speed spool 255. As shown, the motor 300A is embedded in the core of the gas turbine engine 210A. Specifically, the motor 300A is positioned in the radial direction R on the inner side of the turbomachinery flow path 254. In addition, for this embodiment, the motor 300A is positioned approximately at the rear end of the gas turbine engine 210A, and at least partially overlaps with or is behind the low-pressure turbine 242 in the axial direction A. However, in other exemplary embodiments, the motor 300A may be positioned at other suitable locations within the gas turbine engine 210A. For example, in some embodiments, the motor 300A may be coupled to the low-speed spool 255 at other suitable locations. For example, in some embodiments, the motor 300A may be positioned in front of the low-pressure compressor 244 in the axial direction A, and positioned in the inner side of the turbomachinery flow path 254 in the radial direction R. In addition, as Figure 2 As shown, electric machine 300A, which is mechanically coupled to low-speed shaft 246 , is electrically coupled to power bus 184 and is electrically connected to its associated power converter power supply 188A.

[0073] In addition to or in lieu of the gas turbine engine 210A having the electric machine 300A coupled to the low-speed spool 255, in some embodiments, the gas turbine engine 210A may include an electric machine 302A mechanically coupled to the high-speed spool 253 of the gas turbine engine 210A, and more specifically, to the high-speed shaft 238 of the high-speed spool 253. Figure 2 As shown, the electric machine 302A is embedded in the core of the gas turbine engine 210A and is mechanically coupled to the high-speed shaft 238. The electric machine 302A is positioned inboard of the turbomachinery flow path 254 in the radial direction R and in front of the combustion section 140 in the axial direction A. However, in other exemplary embodiments, the electric machine 302A may be positioned at other suitable locations within the gas turbine engine 210A. Although not shown, the electric machine 302A mechanically coupled to the high-speed shaft 238 may be electrically coupled to the power bus 184 and may be electrically connected to its own power converter power supply.

[0074] Like the motor 300A mechanically coupled to the low-speed spool 255, the motor 302A mechanically coupled to the high-speed spool 253 can be an electric motor operable to drive or propel the high-speed shaft 238, for example, during engine burst. In other embodiments, the motor 302A can be a generator operable to convert mechanical energy into electrical energy. In this way, the electricity generated by the motor 302A can be directed to various engine and / or aircraft systems. In some embodiments, the motor 302A can be a dual-function motor / generator.

[0075] Reference now Figure 3 , Figure 4 and Figure 5 , Figure 3 A schematic diagram of an electric power system 400 including an electric machine 450 according to an example embodiment of the present disclosure is provided. Figure 4 A schematic diagram of the multi-phase windings of an electric machine 450 is provided. Figure 5 A power converter system 410 ( Figure 3 ) is a schematic diagram of a first power converter unit 418. Generally, the power system 400 includes a power converter system 410, a motor 450, and a plurality of cables 404, 405, 406, 407 electrically connecting the power converter system 410 and the motor 450. For example, the cables 404, 405, 406, 407 can be shielded cables.

[0076] exist Figure 3-5 In the embodiment of FIG. 4 , the power converter system 410 is an AC / DC power converter system. Figure 3-5 In the embodiment depicted in FIG. 4 , power converter system 410 has a first power converter unit 418, a second power converter unit 428, a third power converter unit 438, and a fourth power converter unit 448. Power converter units 418, 428, 438, 448 may be separate or independent units, or alternatively, may be units of a single power converter. Figure 3 In FIG. 4 , the first power converter 418 and the second power converter 428 form a single power converter by connecting the DC outputs in series or in parallel. Figure 3 In the embodiment, the third power converter 438 and the fourth power converter 448 form a single power converter by connecting the DC outputs in series or in parallel. The first and second power converter units 418, 428 are associated with the first channel 401, and the third and fourth power converter units 438, 448 are associated with the second channel 402. Figure 3 , first channel 401 is a dual DC output channel, and likewise, second channel 402 is a dual DC output channel. In some alternative embodiments, first power converter unit 418 may be associated with the first channel, second power converter unit 428 may be associated with the second channel, third power converter unit 438 may be associated with the third channel, and fourth power converter unit 448 may be associated with the fourth channel. In such embodiments, the first, second, third, and fourth channels may be single DC output channels.

[0077] The first power converter unit 418 includes a first switching element 411, the second power converter unit 428 includes a second switching element 412, the third power converter unit 438 includes a third switching element 413, and the fourth power converter unit 448 includes a fourth switching element 414. The first switching element 411 corresponds to all the switching elements of the first power converter unit 418, the second switching element 412 corresponds to all the switching elements of the second power converter unit 428, the third switching element 413 corresponds to all the switching elements of the third power converter unit 438, and the fourth switching element 414 corresponds to all the switching elements of the fourth power converter unit 448. The first, second, third and fourth switching elements 411, 412, 413, 414 may be any suitable type of switching elements, such as insulated gate bipolar transistors, power MOSFETs, etc.

[0078] The first, second, third and fourth switching elements 411, 412, 413, 414 may each include a switching element for each power phase of the power system 400. As an example, refer to Figure 5 , the first switching element 411 includes a plurality of switching devices or elements associated with each phase. In particular, for this embodiment, the first switching element 411 includes a first switching element S1, a second switching element S2, a third switching element S3, a fourth switching element S4, a fifth switching element S5, and a sixth switching element S6 associated with the A phase. The first switching element 411 also includes a first switching element S1, a second switching element S2, a third switching element S3, a fourth switching element S4, a fifth switching element S5, and a sixth switching element S6 associated with the B phase. In addition, the first switching element 411 includes a first switching element S1, a second switching element S2, a third switching element S3, a fourth switching element S4, a fifth switching element S5, and a sixth switching element S6 associated with the C phase. Figure 3 The second, third and fourth switching elements 412, 413, 414 of the second power converter unit 428, the third power converter unit 438 and the fourth power converter unit 448 schematically shown in FIG. 4 can be connected with Figure 5 The first switching element 411 of the illustrated first power converter unit 418 is arranged in a similar manner.

[0079] By switching on or off the switching device or element of the first switching element 411, the AC phase terminal can be connected to one of the plurality of DC bus rails. Figure 5In the illustrated embodiment, there are three DC bus rails that make up the three-level converter unit, including a positive DC bus rail 490, an intermediate DC bus rail 492, and a negative DC bus rail 494. In alternative embodiments, the switching elements of the phase legs of the first power converter unit 418 can be connected to more than three DC bus rails. In still other embodiments, a two-level converter unit can also be implemented in which the switching elements of the phase legs can be connected to only two DC bus rails, such as a positive DC bus rail and a negative DC bus rail. As will be understood, the switching devices or elements that turn on or off the second, third and fourth switching elements 412, 413, 414 can connect the AC phase terminal of a given power converter unit 428, 438, 448 to one of its multiple DC bus rails in a manner similar to that described above with respect to the switching action of the first switching element 411.

[0080] Additionally, the power system 400 may be grounded by connecting one of the DC bus rails 490, 492, 494 to a ground reference, which is typically a conductive frame of the power system 400. The ground reference may be disconnected or connected to one of the DC bus rails 490, 492, 494 through one or more high impedance devices, such as one or more resistors and / or capacitors. Parasitic capacitance may exist between the DC rails and the frames inside and outside the converter, which may provide a path for common mode emissions.

[0081] The first, second, third and fourth switching elements 411, 412, 413, 414 may be controlled by one or more controllable devices. For example, the switching elements 411, 412, 413, 414 may be controlled by one or more associated gate drivers. Figure 3 , one or more first gate drivers 421 are associated with the first switching element 411, one or more second gate drivers 422 are associated with the second switching element 412, one or more third gate drivers 423 are associated with the third switching element 413, and one or more fourth gate drivers 424 are associated with the fourth switching element 414. The one or more gate drivers 421, 422, 423, 424 may be controlled to drive or modulate their respective switching elements 411, 412, 413, 414, for example to control the power provided to or drawn from the motor 450.

[0082] The first, second, third and fourth gate drivers 421, 422, 423, 424 may each include one or more gate drivers. Figure 5As shown, for phase A, the first gate driver 421 includes a first driver D1 for driving the first switching element S1, a second driver D2 for driving the second switching element S2, a third driver D3 for driving the third switching element S3, a fourth driver D4 for driving the fourth switching element S4, a fifth driver D5 for driving the fifth switching element S5, and a sixth driver D6 for driving the sixth switching element S6. Similarly, for phase B, the first gate driver 421 includes a first driver D1 for driving the first switching element S1, a second driver D2 for driving the second switching element S2, a third driver D3 for driving the third switching element S3, a fourth driver D4 for driving the fourth switching element S4, a fifth driver D5 for driving the fifth switching element S5, and a sixth driver D6 for driving the sixth switching element S6. Similarly, for phase C, the first gate driver 421 includes a first driver D1 for driving the first switching element S1, a second driver D2 for driving the second switching element S2, a third driver D3 for driving the third switching element S3, a fourth driver D4 for driving the fourth switching element S4, a fifth driver D5 for driving the fifth switching element S5, and a sixth driver D6 for driving the sixth switching element S6. It should be understood that in other exemplary embodiments, more or less than Figure 5 The number of drivers depicted in is possible. For example, in some embodiments, one driver can drive multiple switching elements.

[0083] The power converter system 410 may also include one or more processors and one or more memory devices. The one or more processors and one or more memory devices may be embodied in one or more controllers or computing devices. For example, for this embodiment, the one or more processors and one or more memory devices are embodied in the controller 440. The controller 440 may be communicatively coupled to various devices (e.g., gate drivers 421, 422, 423, 424, one or more sensors, and other computing devices). The controller 440 may be communicatively coupled to these devices via suitable wired and / or wireless connections. Typically, the controller 440 may be coupled to a plurality of controllers or computing devices. Fig.25 The method shown is constructed and described in the accompanying text.

[0084] In alternative embodiments, one or more processors and one or more memory devices may be embodied in multiple controllers. For example, in some embodiments, each power converter unit 418, 428, 438, 448 may have an associated controller for controlling the switching action of their respective switching elements 411, 412, 413, 414. In yet other embodiments, the first and second power converter units 418, 428 associated with the first channel 401 may have a dedicated controller for controlling the switching action of the first and second switching elements 411, 412. Similarly, the third and fourth power converter units 438, 448 associated with the second channel 402 may have a dedicated controller for controlling the switching action of the third and fourth switching elements 413, 414.

[0085] In addition, the power converter system 410 may include one or more devices for reducing common mode. For this embodiment, the power converter system 410 includes a first DC side common mode reduction device 430 and a first AC side common mode reduction device 432 associated with the first channel 401. The power converter system 410 also includes a second DC side common mode reduction device 434 and a second AC side common mode reduction device 436 associated with the second channel 402. In general, the common mode reduction devices 430, 432, 434, 436 can suppress electromagnetic noise transmitted along their respective channels 401, 402.

[0086] The motor 450 defines an axial direction A ( Figure 3 The motor 450 includes a rotor 452 and a stator 460. The rotor 452 may be mechanically coupled to a rotating component, such as a rotating component of a gas turbine engine. The rotor 452 may be rotatable about the rotation axis AX. The rotor 452 is depicted as being outside the stator 460 in the radial direction R, and therefore, the motor 450 is configured as an outer rotor configuration. However, the inventive aspects of the present disclosure are also applicable to motors having an inner rotor configuration.

[0087] The rotor 452 includes a plurality of magnets 454. The stator 460 includes a plurality of multi-phase windings or coils wound therein (e.g., within slots defined between teeth of the stator 460). For the illustrated embodiment, the stator 460 includes a first multi-phase winding 461, a second multi-phase winding 462, a third multi-phase winding 463, and a fourth multi-phase winding 464.

[0088] Each multi-phase winding 461, 462, 463, 464 may include windings or coils for various power phases. Figure 4As best shown, the first multi-phase winding 461 includes windings for a first phase A, a second phase B, and a third phase C. For the first phase A of the first multi-phase winding 461, a positive-side winding A1 of the first multi-phase winding 461 passes through one of the slots of the stator 460, turns, and a return side-A2 of the first multi-phase winding 461 returns through one of the slots of the stator 460. For the second phase B of the first multi-phase winding 461, a positive-side winding B2 of the first multi-phase winding 461 passes through one of the slots of the stator 460, turns, and a return side-B1 of the first multi-phase winding 461 returns through one of the slots of the stator 460. For the third phase C of the first multi-phase winding 461, a positive-side winding C1 of the first multi-phase winding 461 passes through one of the slots of the stator 460, turns, and a return side-C2 of the first multi-phase winding 461 returns through one of the slots of the stator 460.

[0089] The second multi-phase winding 462 also includes windings for a first phase A, a second phase B, and a third phase C. For the first phase A of the second multi-phase winding 462, a deflection side winding-A2 of the second multi-phase winding 462 passes through one of the slots of the stator 460, turns, and a return side A1 of the second multi-phase winding 462 returns through one of the slots of the stator 460. For the second phase B of the second multi-phase winding 462, a deflection side winding-B1 of the second multi-phase winding 462 passes through one of the slots of the stator 460, turns, and a return side B2 of the second multi-phase winding 462 returns through one of the slots of the stator 460. For the third phase C of the second multi-phase winding 462, a deflection side winding-C2 of the second multi-phase winding 462 passes through one of the slots of the stator 460, turns, and a return side C1 of the second multi-phase winding 462 returns through one of the slots of the stator 460.

[0090] The third multi-phase winding 463 also includes windings for a first phase A, a second phase B, and a third phase C. For the first phase A of the third multi-phase winding 463, a deflection side winding-A1 of the third multi-phase winding 463 passes through one of the slots of the stator 460, turns, and a return side A2 of the third multi-phase winding 463 returns through one of the slots of the stator 460. For the second phase B of the third multi-phase winding 463, a deflection side winding-B2 of the third multi-phase winding 463 passes through one of the slots of the stator 460, turns, and a return side B1 of the third multi-phase winding 463 returns through one of the slots of the stator 460. For the third phase C of the third multi-phase winding 463, a deflection side winding-C1 of the third multi-phase winding 463 passes through one of the slots of the stator 460, turns, and a return side C2 of the third multi-phase winding 463 returns through one of the slots of the stator 460.

[0091] The fourth multi-phase winding 464 also includes windings for a first phase A, a second phase B, and a third phase C. For the first phase A of the fourth multi-phase winding 464, a deflection side winding A2 of the fourth multi-phase winding 464 passes through one of the slots of the stator 460, turns, and a return side-A1 of the fourth multi-phase winding 464 returns through one of the slots of the stator 460. For the second phase B of the fourth multi-phase winding 464, a deflection side winding B1 of the fourth multi-phase winding 464 passes through one of the slots of the stator 460, turns, and a return side-B2 of the fourth multi-phase winding 464 returns through one of the slots of the stator 460. For the third phase C of the fourth multi-phase winding 464, a deflection side winding C2 of the fourth multi-phase winding 464 passes through one of the slots of the stator 460, turns, and a return side-C1 of the fourth multi-phase winding 464 returns through one of the slots of the stator 460.

[0092] like Figure 3 and Figure 5 As shown, the first multi-phase winding 461 is electrically connected to the first switching element 411 of the power converter system 410, the second multi-phase winding 462 is electrically connected to the second switching element 412, the third multi-phase winding 463 is electrically connected to the third switching element 413, and the fourth multi-phase winding 464 is electrically connected to the fourth switching element 414. For example, Figure 5 The first switching element 411 is depicted as being electrically coupled to the A, B, and C phase windings of the first multi-phase winding 461. It should be understood that Figure 3 The second, third and fourth switching elements 412, 413, 414 schematically shown in FIG. 4 can be connected with Figure 5 The depicted first switching element 411 is electrically coupled to their respective multi-phase windings 462 , 463 , 464 in a similar manner to the first multi-phase winding 461 .

[0093] It is noteworthy that the first multi-phase winding 461 and the second multi-phase winding 462 are electrically in phase with each other. That is, the angle of the AC voltage of the second multi-phase winding 462 is electrically one hundred and eighty degrees (180°) out of phase with the angle of the AC voltage of the first multi-phase winding 461. For example, for this embodiment, the first multi-phase winding 461 has an AC voltage angle of zero degrees (0°), while the second multi-phase winding 462 has an AC voltage angle of one hundred and eighty degrees (180°). Therefore, the first multi-phase winding 461 and the second multi-phase winding 462 are electrically in phase with each other.

[0094] In addition, for this embodiment, the third multi-phase winding 463 and the fourth multi-phase winding 464 are electrically in phase with each other. In other words, the angle of the AC voltage of the fourth multi-phase winding 464 is electrically one hundred and eighty degrees (180°) out of phase with the angle of the AC voltage of the third multi-phase winding 463. For example, for this embodiment, the third multi-phase winding 463 has an AC voltage angle of zero degrees (0°), while the fourth multi-phase winding 464 has an AC voltage angle of one hundred and eighty degrees (180°). Therefore, the third multi-phase winding 463 and the fourth multi-phase winding 464 are electrically in phase with each other.

[0095] As will be explained in more detail herein, the first and second multi-phase windings 461, 462 associated with the first channel 401 are arranged and constructed to operate at opposite angles of the AC voltage relative to each other, so that the common-mode voltage can be offset or reduced via the PWM control scheme disclosed herein. In particular, this arrangement of the first and second multi-phase windings 461, 462 ensures that their common-mode voltage waveforms or waveform shapes are the same or nearly the same. Similarly, the third and fourth multi-phase windings 463, 464 associated with the second channel 402 are arranged and constructed to operate at opposite angles of the AC voltage relative to each other, so that the common-mode voltage can be offset or reduced via the PWM control scheme disclosed herein. In particular, this arrangement of the third and fourth multi-phase windings 463, 464 ensures that their common-mode voltage waveforms or waveform shapes are the same or nearly the same.

[0096] like Figure 4 As best shown in FIG. 4 , the multiphase windings 461, 462, 463, 464 can be strategically arranged as a dual anti-phase winding pair arrangement. Among other benefits, this arrangement can help balance radial forces during operation of the motor 450. As shown, the first multiphase winding 461 is arranged relative to the second multiphase winding 462 in a radial direction R, and the third multiphase winding 463 is arranged relative to the fourth multiphase winding 464 in a radial direction R. In this regard, the first multiphase winding 461 and the second multiphase winding 462 balance the radial forces between them, and the third multiphase winding 463 and the fourth multiphase winding 464 balance the radial forces between them. This allows the multiphase windings 461, 462 associated with the first channel 401 to be balanced, and the multiphase windings 463, 464 associated with the second channel 402 to be balanced. Furthermore, this balanced arrangement of the multi-phase windings 461 , 462 , 463 , 464 allows one of the channels to continue operating at its full power even if the channel is not in use or fails.

[0097] In addition, the stator 460 of the motor 450 defines a plurality of sectors or sections. In particular, for this embodiment, the stator 460 defines four sectors, including a first sector 471, a second sector 472, a third sector 473, and a fourth sector 474. The sectors 471, 472, 473, 474 are equal or substantially equal in size. As shown, the first, second, third, and fourth multi-phase windings 461, 462, 463, 464 are wound in a corresponding one of the sectors of the stator 460. More specifically, the first multi-phase winding 461 is wound in the first sector 471, the second multi-phase winding 462 is wound in the second sector 472, the third multi-phase winding 463 is wound in the third sector 473, and the fourth multi-phase winding 464 is wound in the fourth sector 474.

[0098] Apart from Figure 3 , Figure 4 and Figure 5 In addition, now refer to Figure 6 , an example control scheme will now be provided in which common-mode emissions associated with power system 400 may be canceled or reduced. Figure 6 A topology of a control system 420 of an electric power system 400 according to an example embodiment of the present disclosure is provided. As shown, a controller 440, or more specifically, one or more processors thereof, receives one or more system requirements 480. The system requirements 480 may be received from a system-level controller or computing device (e.g., controller 182 ( Figure 1 System demand 480 may indicate what power system 400 requires, such as a desired power output or thrust output of a propeller to which motor 450 is mechanically coupled.

[0099] The command generator 446, which may be a set of computer executable instructions or logic, may be executed by one or more processors of the controller 440 to generate one or more commands based at least in part on the system demand 480. The one or more processors of the controller 440 may execute the command generator 446 to generate voltage, current, torque, and / or other demands based at least in part on the system demand 480. In particular, as Figure 6As shown, one or more processors of the controller 440 can execute the command generator 446 to generate a voltage command for each multi-phase winding 461, 462, 463, 464. For example, voltage commands Va1, Vb1, Vc1 can be generated for the first, second and third phases A, B, C of the first multi-phase winding 461. Similarly, voltage commands Va2, Vb2, Vc2 can be generated for the first, second and third phases A, B, C of the second multi-phase winding 462. Similarly, voltage commands Va3, Vb3, Vc3 can be generated for the first, second and third phases A, B, C of the third multi-phase winding 463. In addition, voltage commands Va4, Vb4, Vc4 can be generated for the first, second and third phases A, B, C of the fourth multi-phase winding 464.

[0100] like Figure 6 As further shown in FIG. 4 , the voltage commands generated for each of the multi-phase windings 461, 462, 463, 464 can be received by one or more processors of the controller 440 and can be input into the pulse width modulator 448. The pulse width modulator 448, which can be a set of computer executable instructions or logic, can be executed by one or more processors of the controller 440 to generate one or more control signals. The one or more processors of the controller 440 can control the switching elements 411, 412, 413, 414 of the power converter system 410 to generate a PWM signal based at least in part on the one or more control signals.

[0101] In particular, as shown, the pulse width modulator 448 may include a first modulator 441 for generating a first control signal CS1 associated with the first multi-phase winding 461, a second modulator 442 for generating a second control signal CS2 associated with the second multi-phase winding 462, a third modulator 443 for generating a third control signal CS3 associated with the third multi-phase winding 463, and a fourth modulator 444 for generating a fourth control signal CS4 associated with the fourth multi-phase winding 464. Figure 6 As shown, the generated control signals CS1 and CS2 can be directed to their respective gate drivers 421, 422. Based on the received control signal CS1, the gate driver 421 can drive the first switching element 411 to generate a first PWM signal, thereby presenting a first common mode signal Vcm1. Based on the received control signal CS2, the gate driver 422 can drive the second switching element 412 to generate a second PWM signal, thereby presenting a second common mode signal Vcm2. Based on the received control signal CS3, the gate driver 423 can drive the third switching element 413 to generate a third PWM signal, thereby presenting a third common mode signal Vcm3. Based on the received control signal CS4, the gate driver 424 can drive the fourth switching element 414 to generate a fourth PWM signal, thereby presenting a fourth common mode signal Vcm4.

[0102] The control signals may be generated based at least in part on their associated voltage commands. As an example, Fig. 7A The graph of depicts the voltage commands Va1, Vb1, Vc1 associated with the first, second and third phases A, B, C of the first multi-phase winding 461. Fig. 7A In the graph of , the amplitudes of the voltage commands Va1, Vb1, and Vc1 are shown as time functions. When executing the first modulator 441 of the pulse width modulator 448, one or more processors of the controller 440 can generate a first control signal CS1. For example, the first control signal CS1 associated with the A phase of the power system 400 can be generated at least in part based on the voltage command Va1. The first switching element 411 can be controlled based on the first control signal CS1 associated with the A phase to generate a first PWM signal associated with the A phase of the power system 400, Figure 7B The curve diagram shows PWM-Val.

[0103] Likewise, when executing the first modulator 441 of the pulse width modulator 448, the one or more processors of the controller 440 may generate a first control signal CS1 associated with the B phase of the power system 400 based at least in part on the voltage command Vb1. Figures 7A to 7D Described in (see Figure 6 ), but the first PWM signal PWM-vb1 associated with the B phase of the power system 400 can be generated at least in part based on the first control signal CS1 associated with the B phase. Similarly, when executing the first modulator 441 of the pulse width modulator 448, one or more processors of the controller 440 can generate the first control signal CS1 associated with the C phase of the power system 400 based at least in part on the voltage command VC1. Although not in Figures 7A to 7D Described in (see Figure 6 ), but the first PWM signal PWM-vc1 associated with the C phase of the power system 400 may be generated at least in part based on the first control signal CS1 associated with the C phase. Therefore, the first PWM signals PWM-Va1, PWM-Vb1, PWM-Vc1 may be generated at least in part based on their respective voltage commands Va1, Vb1, Vc1. Fig. 8A The graph depicts the voltage commands Va1, Vb1, Vc1 (eg, Fig. 7A ). Fig. 8A In the graph of , the amplitudes of the voltage commands Va1 , Vb1 , Vc1 are shown as a function of time.

[0104] Any suitable technique may be used to generate the first control signal / PWM signal. As an example technique, the voltage command signal may be compared to a carrier signal. For example, Figure 8B As shown in the graph of , the voltage command Va1 can be compared with the carrier signal CS-V1. For this embodiment, the carrier signal CS-V1 has a triangular pattern, however, in other embodiments, the carrier signal CS-V1 can have other suitable patterns or waveforms. When comparing the voltage command signal Va1 with the carrier signal CS-V1, in the case where the voltage command Va1 is higher than the carrier signal CS-V1, the first switching element 411 is controlled so that the generated first PWM signal PWM-Va1 has the maximum amplitude in this case. On the contrary, in the case where the voltage command Va1 is lower than the first carrier signal CS-V1, the first switching element 411 is controlled so that the generated first PWM signal PWM-Va1 has the minimum amplitude in this case. In this way, the first PWM signal Va1 can be generated at least partially based on its associated voltage command Va1. The first PWM signal PWM-Vb1 associated with the voltage command Vb1 and the first PWM signal PWM-Vc1 associated with the voltage command Vc1 can be generated in the same manner using the carrier signal CS-V1. As a result, the first PWM signal can be generated using a comparison technique based on their respective voltage commands.

[0105] The generation of the first PWM signals PWM-Val, PWM-Vb1, and PWM-Vc1 presents a first common-mode voltage signal Vcm1. The first common-mode voltage signal Vcm1 presented is Figure 7C The pattern or waveform of the first common-mode voltage signal Vcm1 takes into account the first PWM signal PWM-Va1 generated based on the voltage command Va1, the first PWM signal PWM-Vb1 generated based on the voltage command Vb1, and the first PWM signal PWM-Vc1 generated based on the voltage command Vc1. In particular, for a given time instance, the amplitude of the first common-mode voltage signal Vcm1 can be the average amplitude of the three generated first PWM signals PWM-Val, PWM-Vb1, PWM-Vc1 associated with the first multi-phase winding 461. In other words, the first common-mode voltage signal Vcm1 can be determined according to the following equation:

[0106]

[0107] Among them, V cm1 is the amplitude of the first common mode voltage signal, PWM-Va1 is a pulse width modulation signal generated based on the voltage command Va1, PWM-Vb1 is a pulse width modulation signal generated based on the voltage command Vb1, and PWM-Vc1 is a pulse width modulation signal generated based on the voltage command Vc1.

[0108] The generation of the second PWM signals PWM-Va2, PWM-Vb2, PWM-Vc2 presents a second common mode voltage signal Vcm2. The second common mode voltage signal Vcm2 associated with the second multi-phase winding 462 is presented at Fig.7D The second common mode voltage signal Vcm2 may be presented in a similar manner to the first common mode voltage signal Vcm1 except as provided below.

[0109] Fig.9A The graph of depicts the voltage commands Va2, Vb2, Vc2 associated with the first, second and third phases A, B, C of the second multi-phase winding 462. Fig.9A In the graph of , the amplitudes of the voltage commands Va2, Vb2, Vc2 are shown as a function of time. It is worth noting that since the second multi-phase winding 462 is arranged and wound to operate in an electrically opposite phase relative to the first multi-phase winding 461, the voltage commands Va2, Vb2, Vc2 are shown to have opposite waveforms relative to the voltage commands Va1, Vb1, Vc1 (see Figure 8B ).

[0110] When executing the second modulator 442 of the pulse width modulator 448, one or more processors of the controller 440 may generate a second control signal CS2. For example, the second control signal CS2 associated with the A phase of the power system 400 may be generated based at least in part on the voltage command Va2. The second switching element 412 may be controlled based on the second control signal CS2 associated with the A phase to generate a second PWM signal PWM-Va2 associated with the A phase of the power system 400. The second control signal CS2 associated with the B phase of the power system 400 may be generated based at least in part on the voltage command Vb2. The second switching element 412 may be controlled based on the second control signal CS2 associated with the B phase to generate a second PWM signal PWM-Vb2 associated with the B phase of the power system 400. In addition, the second control signal CS2 associated with the C phase of the power system 400 may be generated based at least in part on the voltage command Vc2. The second switching element 412 may be controlled based on the second control signal CS2 associated with the C phase to generate a second PWM signal PWM-Vc2 associated with the C phase of the power system 400.

[0111] Any suitable technique may be used to generate the second control signal / PWM signal. As described above, in some example embodiments, the voltage command signal may be compared to the carrier signal. For example, Fig. 9BAs shown in the graph of , the voltage command signal Va2 can be compared with the second carrier signal CS-V2. For this embodiment, the second carrier signal CS-V2 has a triangular pattern, however, in other embodiments, the second carrier signal CS-V2 can have other suitable patterns or waveforms. It is worth noting that one or more processors of the controller 440 have compared the second carrier signal CS-V2 with the first carrier signal CS-V1 (see Figure 8B In this regard, the second carrier signal CS-V2 is the inverse of the first carrier signal CS-V1.

[0112] refer to Fig. 9B , when comparing the voltage command Va2 with the second carrier signal CS-V2, in the case where the voltage command Va2 is higher than the second carrier signal CS-V2, the second switch element 412 is controlled so that the generated second PWM signal PWM-Va2 has the maximum amplitude in this case. On the contrary, in the case where the voltage command Va2 is lower than the second carrier signal CS-V2, the second switch element 412 is controlled so that the generated second PWM signal PWM-Va2 has the minimum amplitude in this case. In this way, the second PWM signal PWM-Va2 can be generated at least partially based on its associated voltage command Va2. The second PWM signals PWM-Vb2, PWM-Vc2 can be generated in the same way using the second carrier signal CS-V2 and their respective voltage commands Vb2, Vc2.

[0113] The presented pattern or waveform of the second common-mode voltage signal Vcm2 takes into account the second PWM signal PWM-Va2 generated based on the voltage command Va2, the second PWM signal PWM-Vb2 generated based on the voltage command Vb2, and the second PWM signal PWM-Vc2 generated based on the voltage command Vc2. In particular, for a given time instance, the amplitude of the second common-mode voltage signal Vcm2 may be the average amplitude of the three generated second PWM signals PWM-Va2, PWM-Vb2, PWM-Vc2 associated with the second multi-phase winding 462. In other words, the second common-mode voltage signal Vcm2 may be determined according to the following equation:

[0114]

[0115] Among them, V cm2 is the amplitude of the second common mode voltage signal, PWM-Va2 is a pulse width modulation signal generated based on the voltage command Va2, PWM-Vb2 is a pulse width modulation signal generated based on the voltage command Vb2, and PWM-Vc2 is a pulse width modulation signal generated based on the voltage command Vc2.

[0116] By Figure 7C The first common mode signal Vcm1 presented in the graph is depicted with Fig.7D It can be understood that, since the first multi-phase winding 461 and the second multi-phase winding 462 are arranged and constructed to operate in opposite phases relative to each other electrically, the second common mode signal Vcm2 has the same or nearly the same waveform as the first common mode signal Vcm1. In addition, shifting the second carrier signal CS-V2 relative to the first carrier signal CS-V1 by one hundred eighty degrees (180°) effectively shifts the polarity of the second common mode signal Vcm2 relative to the first common mode signal Vcm1.

[0117] Therefore, when the first switching element 411 is modulated by its associated gate driver 421 at least in part based on the first control signal CS1, the first PWM signals PWM-Val, PWM-Vb1, PWM-Vc1 are generated, thereby presenting the first common mode signal Vcm1. Similarly, when the second switching element 412 is modulated by its associated gate driver 422 at least in part based on the second control signal CS2, the second PWM signals PWM-Va2, PWM-Vb2, PWM-Vc2 are generated, thereby presenting the second common mode signal Vcm2. Since the second common mode signal Vcm2 has the same or almost the same waveform as the first common mode signal Vcm1 but with opposite polarity, the common mode emission associated with the first channel 401 can be offset or reduced. Therefore, many benefits can be achieved. For example, the need for an EMI filter (in combination with the common mode reduction device discussed below) can be eliminated. Additionally, canceling or reducing common mode emissions can reduce shaft voltages and bearing currents, thereby potentially: reducing bearing stresses, eliminating the need for shaft grounding brushes, eliminating the need for bearing insulation sleeves or ceramic bearings, and / or reducing leakage currents through shaft loads (e.g., gears or sensors). Other benefits and advantages may also be realized. Notably, canceling common mode emissions may be achieved in embodiments where the first power converter unit 418 and the second power converter unit 428 are connected in series, in parallel, or are separate units.

[0118] Fig.10 Depicted is a simplified diagram depicting various signals as a function of time. Specifically, Fig.10 The generated first PWM signals PWM-Va1, PWM-Vb1, PWM-Vc1 and the presented first common mode signal Vcm1 are shown, as well as the generated second PWM signals PWM-Va2, PWM-Vb2, PWM-Vc2 and the presented second common mode signal Vcm2. As shown, the first common mode signal Vcm1 "mirrors" the second common mode signal Vcm2. Therefore, the sum of the first common mode signal Vcm1 and the second common mode signal Vcm2 is essentially a flat constant line, which represents ideal common mode cancellation.

[0119] As will be appreciated, common mode emissions associated with the second channel 402 may be reduced or eliminated in the same or similar manner as described above with respect to the first channel 401. In general, the third common mode voltage signal Vcm3 may be presented in the same or similar manner as described above with respect to the first common mode signal Vcm1. In particular, when executing the third modulator 443 of the pulse width modulator 448, one or more processors of the controller 440 may generate a third control signal CS3. For example, the third control signal CS3 associated with the A phase of the power system 400 may be generated at least in part based on the voltage command Va3, the third control signal CS3 associated with the B phase of the power system 400 may be generated at least in part based on the voltage command Vb3, and the third control signal CS3 associated with the C phase of the power system 400 may be generated at least in part based on the voltage command Vc3. The third switching element 413 may be controlled based on the third control signal CS3 to generate the third PWM signals PWM-Va3, PWM-Vb3, PWM-Vc3, thereby presenting the third common mode voltage signal Vcm3.

[0120] In addition, generally, the fourth common-mode voltage signal Vcm4 can be presented in the same or similar manner as described above with respect to the second common-mode signal Vcm2. In particular, when executing the fourth modulator 444 of the pulse width modulator 448, one or more processors of the controller 440 can generate a fourth control signal CS4. For example, the fourth control signal CS4 associated with the A phase of the power system 400 can be generated at least in part based on the voltage command Va4, the fourth control signal CS4 associated with the B phase of the power system 400 can be generated at least in part based on the voltage command Vb4, and the fourth control signal CS4 associated with the C phase of the power system 400 can be generated at least in part based on the voltage command Vc4. The fourth switching element 414 can be controlled based on the fourth control signal CS4 to generate the fourth PWM signal PWM-Va4, PWM-Vb4, PWM-Vc4, thereby presenting the fourth common-mode voltage signal Vcm4.

[0121] It is noteworthy that, since the third multi-phase winding 463 and the fourth multi-phase winding 464 are arranged and constructed to operate electrically in opposite phases relative to each other, when the third and fourth common-mode voltage signals Vcm3 and Vcm4 are presented, the fourth common-mode voltage Vcm4 has the same or almost the same waveform as the third common-mode voltage Vcm3. In addition, the carrier signal associated with the fourth multi-phase winding 464 is offset by one hundred and eighty degrees (180°) relative to the carrier signal associated with the third multi-phase winding 463, so that the polarity of the fourth common-mode voltage signal Vcm4 is offset relative to the third common-mode voltage signal Vcm3. Therefore, the third common-mode signal Vcm3 and the fourth common-mode signal Vcm4 have the same or almost the same waveform with opposite polarity. Since the fourth common-mode signal Vcm4 has the same or almost the same waveform as the third common-mode signal Vcm3 but with opposite polarity, the common-mode emission associated with the second channel 402 can be offset or reduced. In this way, the above-mentioned benefits can be achieved.

[0122] It should be understood that the topology of the control system 420 is a non-limiting example. For example, in some embodiments, the control system 420 may include multiple controllers rather than a single controller. In such embodiments, each controller may include its own command generator or a set of computer executable instructions or logic and a PW modulator. For example, in some example embodiments, a first controller associated with the first channel 401 may include a command generator that, when executed by one or more processors of the first controller, causes the one or more processors of the first controller to generate one or more commands associated with the first and second multi-phase windings 461, 462 based at least in part on the system requirements 480. The first controller may also include a first modulator 441 and a second modulator 442 for generating a first control signal CS1 associated with the first multi-phase winding 461 and for generating a second control signal CS2 associated with the second multi-phase winding 462, respectively. In addition, a second controller associated with the second channel 402 may include a command generator that, when executed by one or more processors of the second controller, causes the one or more processors of the second controller to generate one or more commands associated with the third and fourth multi-phase windings 463, 464 based at least in part on the system requirements 480. The second controller may further include a third modulator 443 and a fourth modulator 444 for generating a third control signal CS3 associated with the third multiphase winding 463 and for generating a fourth control signal CS4 associated with the fourth multiphase winding 464, respectively. Other topologies are also possible. For example, the control system 420 may include at least one controller dedicated to controlling each power converter unit.

[0123] The inventive aspects of the present disclosure may also be applied to other multi-channel power systems. In particular, in some embodiments, common mode emissions may be canceled or reduced between two power channels rather than within a single power channel, as described above with respect to Figure 3 The multi-channel embodiments disclosed.

[0124] As an example, Fig.11 A schematic diagram of a power system 500 according to an example embodiment of the present disclosure is provided. As will be explained below, Fig.11 The power system 500 is arranged and constructed to operate so that common mode emissions can be canceled or reduced between its two power channels. As shown, generally, Fig.11 The power system 500 includes a power converter system 510, a motor 550, and one or more cables 504, 506 electrically coupling the power converter system 510 and the motor 550. For example, the cables 504, 506 may be shielded cables.

[0125] for Fig.11 In the illustrated embodiment, the power converter system 510 is an AC / DC power converter system. Fig.11 As shown, the power converter system 510 has a first power converter unit 518 and a second power converter unit 528. The power converter units 518, 528 may be separate or independent units, or alternatively, may be units of a single power converter. Fig.11 , the first power converter unit 518 and the second power converter unit 528 are independent units. In an alternative embodiment, the first power converter unit 518 and the second power converter unit 528 can form a single power converter by connecting the first power converter unit 518 and the second power converter unit 528 in series or in parallel. The first power converter unit 518 includes a first switching element 511, and the second power converter unit 528 includes a second switching element 512. The first power converter unit 518 is associated with the first channel 501, and the second power converter unit 528 is associated with the second channel 502. The first and second switching elements 511, 512 can be any suitable type of switching elements, such as insulated gate bipolar transistors, power MOSFETs, etc.

[0126] The first and second switching elements 511, 512 may each include a switching element for each phase power of the power system 500. For example, the first switching element 511 may include a switching element associated with the A phase of the power system 500, a switching element associated with the B phase, and a switching element associated with the C phase. Similarly, the second switching element 512 may include a switching element associated with the A phase of the power system 500, a switching element associated with the B phase, and a switching element associated with the C phase.

[0127] The first and second switching elements 511, 512 may be controlled by one or more controllable devices. For example, the first and second switching elements 511, 512 may be controlled by one or more associated gate drivers. Fig.11 , one or more first gate drivers 521 are associated with the first switching element 511, and one or more second gate drivers 522 are associated with the second switching element 512. The one or more gate drivers 521, 522 may be controlled to drive or modulate their respective switching elements 511, 512, for example to control the power provided to or drawn from the motor 550. The first and second gate drivers 521, 522 may each include one or more gate drivers.

[0128] The power converter system 510 may also include one or more processors and one or more memory devices. The one or more processors and one or more memory devices may be embodied in one or more controllers or computing devices. For example, for this embodiment, the one or more processors and one or more memory devices are embodied in the controller 540. The controller 540 may be communicatively coupled to various devices (e.g., gate drivers 521, 522, one or more sensors (e.g., current and / or voltage sensors), and other computing devices). The controller 540 may be communicatively coupled to these devices via suitable wired and / or wireless connections. In general, the controller 540 may be coupled to a plurality of controllers or computing devices. Fig.25 The invention is constructed and operates in the manner shown in and described in the accompanying text.

[0129] In addition, the power converter system 510 can include one or more common mode reduction devices. For this embodiment, the power converter system 510 includes a DC side common mode reduction device 530 and an AC side common mode reduction device 532. In general, the common mode reduction devices 530, 532 can suppress electromagnetic noise transmitted along the first and second channels 501, 502, as discussed further below.

[0130] The motor 550 defines an axial direction A ( Fig.11 The motor 550 also defines a rotation axis AX extending in the axial direction A. In addition, as shown, the motor 550 has a rotor 552 and a stator 560. The rotor 552 can be mechanically coupled to a rotating component (e.g., a rotating component of a gas turbine engine). The rotor 552 can rotate around the rotation axis AX. The rotor 552 is depicted as being outside the stator 560 in the radial direction R, and therefore, the motor 550 is configured as an outer rotor configuration. However, as previously described, the inventive aspects of the present disclosure are also applicable to motors having an inner rotor configuration.

[0131] The rotor 552 includes a plurality of magnets 554. The stator 560 includes a plurality of multi-phase windings or coils wound therein (e.g., within slots defined between teeth of the stator 560). For the depicted embodiment, the stator 560 includes a first multi-phase winding 561 and a second multi-phase winding 562. The first multi-phase winding 561 is associated with the first channel 501, while the second multi-phase winding 562 is associated with the second channel 502. Each multi-phase winding 561, 562 may include windings or coils for various power phases. For example, the first multi-phase winding 561 may include windings for a first phase A, a second phase B, and a third phase C. Similarly, the second multi-phase winding 562 may include windings for a first phase A, a second phase B, and a third phase C. In addition, as Fig.11 Schematically depicted, the first multi-phase winding 561 is electrically coupled to the first switching element 511 of the power converter system 510 , and the second multi-phase winding 562 is electrically coupled to the second switching element 512 .

[0132] It is noteworthy that the first multi-phase winding 561 associated with the first channel 501 and the second multi-phase winding 562 associated with the second channel 502 are electrically in opposite phase relative to each other. That is, the angle of the AC voltage of the second multi-phase winding 562 is electrically out of phase with respect to the angle of the AC voltage of the first multi-phase winding 561 by one hundred and eighty degrees (180°). For example, for this embodiment, the first multi-phase winding 561 has an AC voltage angle of zero degrees (0°), while the second multi-phase winding 562 has an AC voltage angle of one hundred and eighty degrees (180°). Therefore, the first multi-phase winding 561 and the second multi-phase winding 562 are electrically in opposite phase relative to each other. As will be explained below, the first multi-phase winding 561 associated with the first channel 501 and the second multi-phase winding 562 associated with the second channel 502 are arranged and constructed to operate at opposite angles of AC voltage relative to each other. This arrangement, together with the PWM control scheme disclosed herein, helps to cancel common mode emissions.

[0133] In addition, if Fig.11 As best shown in FIG. 5 , the first and second multi-phase windings 561, 562 can be strategically arranged as an interlaced anti-phase winding pair arrangement. Among other benefits, this arrangement can help balance radial forces during operation of the motor 550. As shown, the first multi-phase winding 561 is arranged in a first group 565 and a second group 566. The first group 565 and the second group 566 of the first multi-phase winding 561 are positioned relative to each other in a radial direction R. In this regard, when the first channel 501 is operated, the first group 565 and the second group 566 of the first multi-phase winding 561 balance the radial forces between them. Even when the second channel 502 is not used or fails, this balanced arrangement of the first multi-phase winding 561 allows the first channel 501 to continue to operate at its full power. The first group 565 and the second group 566 can be electrically connected in series or in parallel with each other.

[0134] The second multi-phase winding 562 is also arranged in the first group 567 and the second group 568. The first group 567 and the second group 568 of the second multi-phase winding 562 are positioned relative to each other in the radial direction R. The first group 567 and the second group 568 can be electrically connected in series or in parallel with each other. As shown in the figure, the first group 565 of the first multi-phase winding 561 is positioned between the first group 567 and the second group 568 of the second multi-phase winding 562 in the circumferential direction C, and the second group 566 of the first multi-phase winding 561 is positioned between the first group 567 and the second group 568 of the second multi-phase winding 562 in the circumferential direction C. In this way, when the second channel 502 is operated, the first group 567 and the second group 568 of the second multi-phase winding 562 balance the radial force between them. Even if the first channel 501 is not used or fails, this balanced arrangement of the second multi-phase winding 562 allows the second channel 502 to continue to operate at its full power.

[0135] In addition, the stator 560 of the motor 550 defines a plurality of sectors or sections. In particular, for this embodiment, the stator 560 defines four sectors, including a first sector 571, a second sector 572, a third sector 573, and a fourth sector 574. The sectors 571, 572, 573, 574 are equal or substantially equal in size. As shown, the first group 565 and the second group 566 of the first multi-phase winding 561 and the first group 567 and the second group 568 of the second multi-phase winding 562 are each wound in a corresponding one of the sectors 571, 572, 573, 574 of the stator 560. More specifically, the first group 565 of the first multi-phase winding 561 is wound in the first sector 571, the second group 566 of the first multi-phase winding 561 is wound in the second sector 572, the first group 567 of the second multi-phase winding 562 is wound in the third sector 573, and the second group 568 of the second multi-phase winding 562 is wound in the fourth sector 574.

[0136] Apart from Fig.11 In addition, we also refer to Fig.12 , an example control scheme by which common-mode emissions associated with the power system 500 may be canceled or reduced will now be provided. Fig.12 A topology of a control system 520 of a power system 500 is provided. It should be understood that the topology of the control system 520 is intended to be a non-limiting example. For example, in other embodiments, the control system 520 may include multiple controllers, for example, one for controlling the first switching element 511 and one for controlling the second switching element 512.

[0137] like Fig.12As shown, controller 540, or more specifically, one or more processors thereof, receives one or more system requirements 580. System requirements 580 may be received from a system-level controller or computing device (e.g., controller 182 ( Figure 1 System requirements 580 may indicate what is required by power system 500, such as a desired power output or thrust output of a propeller to which motor 550 is mechanically coupled.

[0138] The command generator 546, which may be a set of computer executable instructions or logic, may be executed by one or more processors of the controller 540 to generate one or more commands based at least in part on the system demand 580. For example, the one or more processors of the controller 540 may execute the command generator 546 to generate voltage, current, torque, and / or other demands based at least in part on the system demand 580. In particular, as Fig.12 As shown, one or more processors of the controller 540 may execute a command generator 546 to generate a voltage command for each multi-phase winding 561, 562. For example, voltage commands Va1, Vb1, Vc1 may be generated for the first, second, and third phases A, B, C of the first multi-phase winding 561. Similarly, voltage commands Va2, Vb2, Vc2 may be generated for the first, second, and third phases A, B, C of the second multi-phase winding 562.

[0139] The voltage commands generated for each of the multi-phase windings 561, 562 may be received by one or more processors of the controller 540 and may be input into a pulse width modulator 548. The pulse width modulator 548, which may be a set of computer executable instructions or logic, may be executed by one or more processors of the controller 540 to generate control signals. The one or more processors of the controller 440 may control the switching elements 511, 512 of the power converter system 510 to generate PWM signals based at least in part on the one or more control signals.

[0140] In particular, as shown, the pulse width modulator 548 may include a first modulator 541 for generating a first control signal CS1 associated with the first multi-phase winding 561 and a second modulator 542 for generating a second control signal CS2 associated with the second multi-phase winding 562. Fig.12 As shown, the generated control signals CS1 and CS2 can be directed to their respective gate drivers 521, 522. Based on the received control signal CS1, the gate driver 521 can drive the first switching element 511 to generate a first PWM signal, thereby presenting a first common mode signal Vcm1. Based on the received control signal CS2, the gate driver 522 can drive the second switching element 512 to generate a second PWM signal, thereby presenting a second common mode signal Vcm2.

[0141] The first control signal CS1 may be generated at least in part based on the voltage commands associated with them. In particular, when executing the first modulator 541 of the pulse width modulator 548, one or more processors of the controller 540 may generate the first control signal CS1. For example, the first control signal CS1 associated with the A phase of the power system 500 may be generated at least in part based on the voltage command Va1, the first control signal CS1 associated with the B phase of the power system 500 may be generated at least in part based on the voltage command Vb1, and the first control signal CS1 associated with the C phase of the power system 500 may be generated at least in part based on the voltage command Vc1. The first switching element 511 may be controlled based on the first control signal CS1 associated with the A phase to generate the first PWM signal PWM-Val associated with the A phase of the power system 500. Similarly, the first switching element 511 may be controlled based on the first control signal CS1 associated with the B phase to generate the first PWM signal PWM-Vb1 associated with the B phase of the power system 500. Likewise, the first switching element 511 can be controlled based on the first control signal CS1 associated with the C phase to generate the first PWM signal PWM-Vc1 associated with the C phase of the power system 500. The first PWM signals PWM-Va1, PWM-Vb1, PWM-Vc1 can be generated using any suitable technique, such as the carrier signal comparison technique disclosed above.

[0142] Based on the received control signal CS1, the gate driver 521 can drive the first switching element 511 to generate the first PWM signals PWM-Val, PWM-Vb1, PWM-Vc1 so as to present the first common mode signal Vcm1. The pattern or waveform of the first common mode voltage signal Vcm1 takes into account the first PWM signal PWM-Va1 generated based on the voltage command Va1, the first PWM signal PWM-Vb1 generated based on the voltage command Vb1, and the PWM signal PWM-Vc1 generated based on the voltage command Vc1. Specifically, for a given example, the amplitude of the first common mode voltage signal Vcm1 can be the average amplitude of the three generated PWM signals PWM-Val, PWM-Vb1, PWM-Vc1 associated with the first multi-phase winding 561.

[0143] The second control signal CS2 may be generated at least in part based on the voltage commands associated with them. In particular, when executing the second modulator 542 of the pulse width modulator 548, the one or more processors of the controller 540 may generate the second control signal CS2. For example, the second control signal CS2 associated with the A phase of the power system 500 may be generated at least in part based on the voltage command Va2, the second control signal CS2 associated with the B phase of the power system 500 may be generated at least in part based on the voltage command Vb2, and the second control signal CS2 associated with the C phase of the power system 500 may be generated at least in part based on the voltage command Vc2.

[0144] The second switching element 512 may be controlled based on the second control signal CS2 associated with the A phase to generate a second PWM signal PWM-Va2 associated with the A phase of the power system 500. Similarly, the second switching element 512 may be controlled based on the second control signal CS2 associated with the B phase to generate a second PWM signal PWM-Vb2 associated with the B phase of the power system 500. Likewise, the second switching element 512 may be controlled based on the second control signal CS2 associated with the C phase to generate a second PWM signal PWM-Vc2 associated with the C phase of the power system 500.

[0145] Based on the received control signal CS2, the gate driver 422 can drive the second switching element 412 to generate the second PWM signals PWM-Va2, PWM-Vb2, PWM-Vc2 so as to present the second common mode signal Vcm2. The pattern or waveform of the second common mode voltage signal Vcm2 takes into account the second PWM signal PWM-Va2 generated based on the voltage command Va2, the second PWM signal PWM-Vb2 generated based on the voltage command Vb2, and the second PWM signal PWM-Vc2 generated based on the voltage command Vc2. Specifically, for a given example, the amplitude of the second common mode voltage signal Vcm2 can be the average amplitude of the three generated PWM signals PWM-Va2, PWM-Vb2, PWM-Vc2 associated with the second multi-phase winding 562.

[0146] The second PWM signals PWM-Va2, PWM-Vb2, PWM-Vc2 can be generated using any suitable technique (e.g., the carrier signal comparison technique disclosed above). It is worth noting that one or more processors of the controller 540 can offset the polarity of the second carrier signal with which the voltage commands Va2, Vb2, Vc2 are compared (e.g., offset one hundred eighty degrees (180°) relative to the first carrier signal with which the voltage commands Va1, Vb1, Vc1 are compared) so that the presented second common-mode signal Vcm2 is ultimately opposite in polarity relative to the presented first common-mode signal Vcm1.

[0147] It is noteworthy that, since the first multi-phase winding 561 and the second multi-phase winding 562 are arranged and constructed to operate electrically in phase opposition relative to each other, the second common mode signal Vcm2 presented has the same or nearly the same waveform as the first common mode signal Vcm1 presented. In addition, shifting the second carrier signal associated with the second multi-phase winding 562 by one hundred eighty degrees (180°) relative to the first carrier signal associated with the first multi-phase winding 561 effectively shifts the polarity of the second common mode voltage signal Vcm2 relative to the first common mode voltage signal Vcm1.

[0148] Thus, when the first switch element 511 is modulated by its associated gate driver 521 at least in part based on the first control signal CS1, the first PWM signals PWM-Val, PWM-Vb1, PWM-Vc1 are generated so as to present the first common mode signal Vcm1. Similarly, when the second switch element 512 is modulated by its associated gate driver 522 at least in part based on the second control signal CS2, the second PWM signals PWM-Va2, PWM-Vb2, PWM-Vc2 are generated so as to present the second common mode signal Vcm2. Since the second common mode signal Vcm2 has the same or almost the same waveform as the first common mode signal Vcm1 but with opposite polarity, the common mode emission between the first channel 501 and the second channel 502 can be offset or reduced due to the first common mode voltage signal Vcm1 and the second common mode voltage signal Vcm2 having the same or almost the same waveform with opposite polarity. Thus, many benefits can be achieved. For example, the need for an EMI filter can be eliminated (in conjunction with other aspects of the present disclosure discussed below). Additionally, canceling or reducing common mode emissions can reduce shaft voltages and bearing currents, potentially: reducing bearing stresses, eliminating the need for shaft grounding brushes, eliminating the need for bearing insulation sleeves or ceramic bearings, and / or reducing leakage currents through shaft loads (e.g., gears or sensors). Other benefits and advantages may also be realized.

[0149] In some embodiments, the first channel 501 and the second channel 502 are paired with the same electrical load. Doing so can keep the operating conditions and load levels the same or nearly the same. Advantageously, this can enhance the ability of the system 500 to cancel or reduce common-mode emissions. In yet another embodiment, the first channel 501 and the second channel 502 are paired with separate but identical or nearly identical (i.e., within five percent (5%) of each other) electrical loads. Doing so can keep the operating conditions and load levels the same or nearly the same. As noted, this can enhance the ability of the system 500 to cancel or reduce common-mode emissions.

[0150] The inventive aspects of the present disclosure may also be applied to single channel power systems. In this regard, common mode emissions may be canceled or reduced within a single power channel in a similar manner as disclosed above.

[0151] As an example, Fig.13 A schematic diagram of a power system 600 according to an example embodiment of the present disclosure is provided. As shown in the figure, Fig.13 The power system 600 is a single channel power system. Fig.13 The power system 600 is arranged and constructed to operate so that common mode emissions can be canceled or reduced within the channel 601. In general, Fig.13 The power system 600 includes a power converter system 610, a motor 650, and one or more cables 604, 606 electrically coupling the power converter system 610 and the motor 650. For example, the cables 604, 606 may be shielded cables.

[0152] As shown, the power converter system 610 includes a first switching element 611 and a second switching element 612. The power converter system 610 also includes one or more first gate drivers 621 for driving the first switching element 611 and one or more second gate drivers 622 for driving the second switching element 621. In addition, the power converter system 610 includes a DC side common mode reduction device 630 and an AC side common mode reduction device 632 for suppressing electromagnetic noise transmitted along the channel 601. The power converter system 610 also includes a controller 640. The controller 640 can be communicatively connected with various components (such as gate drivers 621, 622). Generally, the controller 640 can be in a Fig.25 The invention is constructed and operates in the manner shown in and described in the accompanying text.

[0153] The motor 650 has a rotor ( Fig.13 ) and a stator 660. The rotor can be mechanically coupled to a rotating component (e.g., a rotating component of a gas turbine engine). The rotor can rotate about an axis of rotation and can include a plurality of magnets. The stator 660 includes a plurality of multi-phase windings or coils wound therein (e.g., in slots defined between teeth of the stator 660). For the illustrated embodiment, the stator 660 includes a first multi-phase winding 661 and a second multi-phase winding 662. The first multi-phase winding 661 and the second multi-phase winding 662 are both associated with the channel 601. Each multi-phase winding 661, 662 may include windings or coils for various power phases. In addition, as Fig.13 As schematically depicted in , the first multi-phase winding 661 is electrically coupled to the first switching element 611 of the power converter system 610 , and the second multi-phase winding 662 is electrically coupled to the second switching element 612 .

[0154] It is noteworthy that the first multi-phase winding 661 and the second multi-phase winding 662 are electrically in opposite phase relative to each other. That is, the angle of the AC voltage of the second multi-phase winding 662 is electrically one hundred and eighty degrees (180°) out of phase with the angle of the AC voltage of the first multi-phase winding 661. For example, for this embodiment, the first multi-phase winding 661 has an AC voltage angle of zero degrees (0°), while the second multi-phase winding 662 has an AC voltage angle of one hundred and eighty degrees (180°).

[0155] In addition, for this embodiment, the first and second multi-phase windings 661, 662 can be strategically arranged as an interleaved anti-phase winding pair arrangement. Among other benefits, this arrangement can help balance radial forces during operation of the motor 650. As shown, the first multi-phase winding 661 is arranged in a first group 665 and a second group 666. The first group 665 and the second group 666 of the first multi-phase winding 661 are positioned relative to each other along the radial direction R. The first group 665 and the second group 666 can be electrically connected in series or in parallel with each other.

[0156] The second multi-phase winding 662 is also arranged in the first group 667 and the second group 668. The first group 667 and the second group 668 of the second multi-phase winding 662 are positioned relative to each other along the radial direction R. The first group 667 and the second group 668 can be electrically connected in series or in parallel with each other. As shown in the figure, the first group 665 of the first multi-phase winding 661 is positioned between the first group 667 and the second group 668 of the second multi-phase winding 662 in the circumferential direction, and the second group 666 of the first multi-phase winding 661 is positioned between the first group 667 and the second group 668 of the second multi-phase winding 662 in the circumferential direction.

[0157] In addition, the stator 660 of the motor 650 defines a plurality of sectors or sections. In particular, for this embodiment, the stator 660 defines four sectors, including a first sector 671, a second sector 672, a third sector 673, and a fourth sector 674. The sectors 671, 672, 673, 674 are equal or substantially equal in size. As shown, the first and second groups 665, 666 of the first multi-phase winding 661 and the first and second groups 667, 668 of the second multi-phase winding 662 are each wound in a corresponding one of the sectors 671, 672, 673, 674 of the stator 660. More specifically, the first group 665 of the first multi-phase winding 661 is wound in the first sector 671, the second group 666 of the first multi-phase winding 661 is wound in the second sector 672, the first group 667 of the second multi-phase winding 662 is wound in the third sector 673, and the second group 668 of the second multi-phase winding 662 is wound in the fourth sector 674.

[0158] Can be compared with the above Figure 3The common mode emission may be cancelled and / or reduced in the channel 601 in a similar manner as disclosed in the first channel 401 or the second channel 402 of the multi-channel power system 400. Therefore, for the sake of brevity, the control scheme by which the common mode emission associated with the power system 600 may be cancelled or reduced will not be repeated.

[0159] However, in summary, one or more processors of the controller 640 may receive a voltage command associated with the first multi-phase winding 661 and a voltage command associated with the second multi-phase winding 662. The one or more processors of the controller 640 may then generate a first control signal based at least in part on the voltage command associated with the first multi-phase winding 661, and generate a second control signal based at least in part on the voltage command associated with the second multi-phase winding 662. The one or more processors of the controller 640 may control the first switching device 611 based on the first control signal to generate a first PWM signal presenting a first common-mode signal. Similarly, the one or more processors of the controller 640 may control the second switching device 612 based on the second control signal to generate a second PWM signal presenting a second common-mode signal.

[0160] It is noteworthy that the second common-mode signal presented can have the same or similar waveform with opposite polarity relative to the first common-mode signal presented. Because the first and second multi-phase windings 661, 662 are electrically in opposite phase relative to each other, the common-mode signals have the same waveform, and the polarity of the common-mode signals is opposite to each other due to one or more processors changing the polarity of the generated second PWM signal (for example, by shifting the second carrier signal by one hundred eighty degrees (180°)). Many benefits and advantages associated with this cancellation technique are possible.

[0161] The inventive aspects of the present disclosure may also be applied to other single-channel power systems. As an example, Fig.14 A schematic diagram of a power system 700 according to an example embodiment of the present disclosure is provided. As shown in the figure, Fig.14 The power system 700 is a single-channel power system. Typically, Fig.14 The power system 700 includes a power converter system 710, a motor 750, and one or more cables 704, 706 electrically connecting the power converter system 710 and the motor 750. For example, the cables 704, 706 can be shielded cables. Fig.14 In the illustrated embodiment, the power converter system 710 is configured to Fig.13 The power converter system 610 of the illustrated power system 600 is constructed in the same manner, and therefore, the power converter system 710 will not be described in detail.

[0162] The motor 750 includes a first multi-phase winding 761 and a second multi-phase winding 762. The first multi-phase winding 761 and the second multi-phase winding 762 are arranged and constructed to operate electrically in opposite phases relative to each other. For this embodiment, the first and second multi-phase windings 761, 762 are strategically arranged as a separated anti-phase winding pair arrangement. Among other benefits, this arrangement can help balance radial forces during the operation of the motor 750. As shown, the first multi-phase winding 761 and the second multi-phase winding 762 are positioned relative to each other along the radial direction R defined by the motor 750. In particular, for this embodiment, the stator 760 of the motor 750 defines a first half sector 771 and a second half sector 772. As shown, the first multi-phase winding 761 is wound in the first half sector 771 (e.g., in the slot defined by the teeth of the stator 760), and the second multi-phase winding 762 is wound in the second half sector 772 (e.g., in the slot defined by the teeth of the stator 760).

[0163] Can be compared with the above Figure 3 The common mode emission may be cancelled and / or reduced in the channel 701 in a similar manner as disclosed in the first channel 401 or the second channel 402 of the multi-channel power system 400. Therefore, for the sake of brevity, the control scheme that may cancel or reduce the common mode emission associated with the power system 700 is not repeated here.

[0164] Fig.15 A schematic diagram of another single-channel power system 800 is provided according to an example embodiment of the present disclosure. In general, Fig.15 The power system 800 includes a power converter system 810, a motor 850, and one or more cables 804, 806 electrically connecting the power converter system 810 and the motor 850. For example, the cables 804, 806 can be shielded cables. Fig.15 In the embodiment shown, the power converter system 810 is connected to Fig.13 The power converter system 610 of the illustrated power system 600 is constructed in the same manner, and therefore, the power converter system 810 will not be described in detail.

[0165] The first multi-phase winding 861 and the second multi-phase winding 862 are wound within the stator 860 of the motor 850. The first multi-phase winding 861 and the second multi-phase winding 862 are arranged and constructed to operate electrically in phase opposition relative to each other. For this embodiment, the first and second multi-phase windings 861, 862 are strategically wound or arranged in a juxtaposed anti-phase arrangement. In some example embodiments, in order to form a juxtaposed anti-phase arrangement, the first and second multi-phase windings 861, 862 can terminate at opposite ends. In some embodiments, the coil in the slot can be divided into two coils, one for each of the first and second multi-phase windings 861, 862. In yet other embodiments, the coil in the same pole group can be divided into two separate first and second multi-phase windings 861, 862. Among other benefits, this arrangement can help balance radial forces during operation of the motor 850.

[0166] Can be compared with the above Figure 3 The common mode emission can be cancelled and / or reduced in the channel 801 in a similar manner as disclosed in the first channel 401 or the second channel 402 of the multi-channel power system 400. Therefore, for the sake of brevity, the control scheme that can cancel or reduce the common mode emission associated with the power system 800 will not be repeated here.

[0167] Although aspects of the invention have been described and illustrated herein in the context of an electric power system having a radial flux rotating electric machine, aspects of the invention are also applicable to electric power systems having an axial flux rotating electric machine.

[0168] Reference now Fig.16 , a power system 400 ′ according to an exemplary aspect of the present disclosure is provided. Fig.16 The exemplary power system 400 ′ may be similar to that described above with reference to, for example, Figures 3 to 5 The power system 400 is constructed in substantially the same manner. Therefore, the same or similar numbers may refer to the same or similar parts.

[0169] For example, as schematically depicted, Fig.16 The exemplary power system 400' of FIG. 4 includes an electric machine 450' having a first multi-phase winding 461' and a second multi-phase winding 462'. In particular, the first multi-phase winding 461' is a first three-phase winding having phase A, phase B, and phase C. Similarly, the second multi-phase winding 462' is a second three-phase winding having phase A, phase B, and phase C. As will be described with reference to the above Figures 3 to 5 As understood in the discussion of , the first multi-phase winding 461 ′ and the second multi-phase winding 462 ′ are electrically in opposite phase with respect to each other.

[0170] The exemplary power system 400' also includes a power converter system 410', which includes a power converter unit (not separately labeled). The power converter unit of the power converter system 410' includes a first switching element 411' electrically connected to the first multi-phase winding 461' and a second switching element 412' electrically connected to the second multi-phase winding 462'. It is worth noting that the power converter system 410' also includes a housing, and the first switching element 411' and the second switching element 412' are located (and more specifically, co-located) within the housing (see, e.g. Figure 3 ; unmarked).

[0171] Briefly, as will be further understood from the above discussion, although not depicted, the power system 400' may also include one or more processors configured to operate the first switching element 411' and the second switching element 412' according to a pulse width modulation schedule. Specifically, the one or more processors may be configured to: A) generate one or more first pulse width modulation (PWM) signals to control the first switching element 411' so as to present a first common mode signal, the first PWM signal being generated at least in part based on one or more voltage commands associated with the first multi-phase winding 461'; and B) generate one or more second PWM signals to control the second switching element 412' so as to present a second common mode signal, the second pulse width modulation signal being generated at least in part based on one or more voltage commands associated with the second multi-phase winding 462'. The second common mode signal may have an opposite polarity relative to the first common mode signal to significantly reduce the common mode signal / common mode emission generated in the electrical output of the power system 400'. For example, the second common mode signal may have the same waveform as the first common mode signal, but with an opposite polarity.

[0172] Still reference Fig.16 It will be appreciated that the exemplary power system 400' includes a plurality of common-mode reduction devices to further reduce common-mode signals in the electrical output of the power system 400' and to further reduce common-mode signals in the electrical inputs of, for example, the first switching element 411' and the second switching element 412'. More specifically, the power system 400' includes a first DC-side common-mode reduction device 430' and a first AC-side common-mode reduction device 432'.

[0173] for Fig.16In the embodiment of the present invention, the first DC side common mode reduction device 430' includes a plurality of capacitors which are coupled to the first switching element 411' on the DC side 411'-1 of the first switching element 411' and further connected to the second switching element 412' on the DC side 412'-1 of the second switching element 412'. The plurality of capacitors coupled to the first switching element 411' on the DC side 411'-1 of the first switching element 411' and coupled to the second switching element 412' on the DC side 412'-1 of the second switching element 412' include a plurality of Y capacitors 482'.

[0174] More specifically, as will be appreciated, the first switching element 411' includes a first segment 411'A electrically connected to the first electrical line 404A and to the first multi-phase winding 461', a second segment 411'B electrically connected to the second electrical line 404B and to the first multi-phase winding 461', and a third segment 411'C electrically connected to the third electrical line 404C and to the first multi-phase winding 461'. As schematically depicted, each of the first, second and third segments 411'A, 411'B, 411'C are electrically connected to a common DC positive line 486'A and a common DC negative line 486'B.

[0175] Furthermore, the power converter unit includes a plurality of first filter capacitors, or more precisely, a plurality of X-capacitors 484, electrically connected to the common DC positive line 486'A and the common DC negative line 486'B. The plurality of first filter capacitors may help smooth the output voltage from the first switching element 411'.

[0176] Still reference Fig.16 , multiple Y capacitors 482' are similarly electrically connected to the common DC positive line 486'A and the common DC negative line 486'B. Multiple Y capacitors 482' are electrically connected to the common DC positive line 486'A and the common DC negative line 486'B at locations opposite to the corresponding X capacitors 484 from the corresponding segments 411'A, 411'B, 411'C.

[0177] In the above manner and as Fig.16 The inclusion of a plurality of Y capacitors 482' depicted in FIG. 4 may allow the Y capacitors 482' to shunt common mode current from the first switching element 411', thereby reducing common mode emissions.

[0178] Still reference Fig.16The plurality of Y capacitors 482' of the first DC side common mode reduction device 430' also include a plurality of Y capacitors 482' electrically connected to the first segment 412'A, the second segment 412'B and the third segment 412'C of the second switching element 412' and arranged in a manner similar to that described above with reference to the first segment 411'A, the second segment 411'B and the third segment 411'C of the first switching element 411'.

[0179] Although not separately labeled, it is understood that the plurality of Y capacitors 482' each include an electrical connection to one or more ground connections. The one or more ground connections may be a common ground connection within the structure including the first switching element 411' and the second switching element 412'.

[0180] Alternatively, the one or more ground connections may be a single ground connection.

[0181] observe Fig.16 The AC side 411'-1 of the first switching element 411' and the AC side 412'-2 of the second switching element 412' in the motor 450', it should be understood that the power system 400' also includes a cable 404' extending from the first multi-phase winding 461' of the motor 450' to the first switching element 411' and a cable 405' extending from the second multi-phase winding 462' of the motor 450' to the second switching element 412'. The power converter system 410' includes a first plurality of dv / dt filters 490' along the cable 404' and a second plurality of dv / dt filters 491' along the cable 405'. The first plurality of dv / dt filters 490' and the second plurality of dv / dt filters 491' can limit the voltage change rate within the cables 404', 405' during operation.

[0182] As described above, the power converter system 410' also includes a first AC side common mode reduction device 432'. The first AC side common mode reduction device 432' includes a device for reducing the common mode current on the AC side 411'-2 of the first switching element 411' and the AC side 412'-2 of the second switching element 412'. More specifically, for Fig.16 In an exemplary embodiment, the means for reducing common mode current on the AC side 411'-2 of the first switching element 411' and the AC side 412'-2 of the second switching element comprises a first plurality of filter capacitors 492' on the AC side 411'-2 of the first switching element 411', a second plurality of filter capacitors 493' on the AC side 412'-2 of the second switching element 412', or both. In particular, for Fig.16In an embodiment of the present invention, the means for reducing common mode current on the AC side 411 ′- 2 of the first switching element 411 ′ and the AC side 412 ′- 2 of the second switching element 412 ′ comprises a first plurality of filter capacitors 492 ′ and a second plurality of filter capacitors 493 ′.

[0183] exist Fig.16 In the depicted embodiment, the first plurality of filter capacitors 492' are connected to one or more ground connections 494', and the second plurality of filter capacitors 493' are also connected to one or more ground connections 494'. Notably, in the depicted embodiment, the means for reducing common mode currents, and more specifically, the first plurality of filter capacitors 492' and the second plurality of filter capacitors 493', are located between the first plurality of dv / dt filters 490' and the motor 450', and between the second plurality of dv / dt filters 491' and the motor 450', respectively.

[0184] By including a first plurality of filter capacitors 492' connected to one or more ground connections 494' and a second plurality of filter capacitors 493' connected to one or more ground connections 494', a ground path may be provided for common mode currents within the cables 404', 405'.

[0185] It is noteworthy that by operating the power system 400' according to a pulse width modulation schedule, including the first DC side common mode reduction device 430' and the first AC side common mode reduction device 432', a path is provided for common mode current on the DC side and the AC side of the first switching element 411' and the second switching element 412'. This configuration can reduce the overall common mode current emission in the power output of the power converter system 410'.

[0186] However, it should be understood that Fig.16 The exemplary aspects depicted in are provided as examples only. In other exemplary aspects, the power system 400' can have any other suitable configuration. For example, now refer to Fig.17 and Fig.18 , two power systems 400 are provided according to two additional exemplary aspects of the present disclosure. Fig.17 and Fig.18 The exemplary power system 400 may be similar to that described above with reference to Fig.16 The exemplary power system 400' is constructed in substantially the same manner. For example, Fig.17 and Fig.18The exemplary power systems 400 each include a device for reducing common mode current on the AC side 411'-2 of the first switching element 411' and the AC side 412'-2 of the second switching element 412'. The device includes a first plurality of filter capacitors 492' on the AC side 411'-2 of the first switching element 411', a second plurality of filter capacitors 493' on the AC side 412'-2 of the second switching element 412', or both.

[0187] However, it is worth noting that in Fig.17 and Fig.18 In an exemplary embodiment of the present invention, the first plurality of filter capacitors 492' are not connected to the one or more ground connections 494', and similarly, the second plurality of filter capacitors 493' (if included, see Fig.18 ) is also not connected to one or more ground connections 494'.

[0188] For example, special reference Fig.17 In the embodiment of the present invention, the first plurality of filter capacitors 492' are connected to the second plurality of filter capacitors 493' via connection lines 495'.

[0189] Instead, specific reference is now made to Fig.18 , the device for reducing common mode current on the AC side 411'-2 of the first switching element 411' and the AC side 412'-2 of the second switching element 412' includes only a first plurality of filter capacitors 492' on the AC side 411'-2 of the first switching element 411'. However, in the exemplary aspect depicted, the first plurality of filter capacitors 492' are also electrically connected to the AC side 412'-2 of the second switching element 412'. More specifically, the device also includes a plurality of connecting lines 495', each of which electrically connects a filter capacitor of the first plurality of filter capacitors 492' to a cable of the cable 405' extending between the second multi-phase winding 462' and the second switching element 412'.

[0190] It is worth noting that since the first and second multi-phase windings 461', 462' are electrically opposite to each other, as described above with reference to Fig.17 and Fig.18 The electrical connection cables 404 ′, 405 ′ may allow electrically opposite common mode current emissions to connect to and cancel each other.

[0191] In addition, in still other exemplary embodiments of the present disclosure, the power system 400' can be constructed according to still other suitable configurations. Fig.19 , Fig. 20 and Fig.21 , three additional power systems 400 ′ are provided according to three additional exemplary aspects of the present disclosure. Fig.19 , Fig. 20 and Fig.21 The exemplary power system 400' may be configured in a similar manner as one or more of the exemplary power systems 400' described above.

[0192] For example, Fig.19 , Fig. 20 and Fig.21 Each of the exemplary embodiments of the present invention includes an electric machine 450' having a first multi-phase winding 461' and a second multi-phase winding 462', and a power converter system 410' having a first switching element 411' connected to the first multi-phase winding 461' via a cable 404' and a second switching element 412' connected to the second multi-phase winding 462' via a cable 405'. The power converter system 410' also includes a first plurality of dv / dt filters 490' on an AC side 411'-2 of the first switching element 411' and a second plurality of dv / dt filters 491' on an AC side 412'-2 of the second switching element 412'.

[0193] The power converter systems 410 ′ each further include means for reducing common mode currents on the AC side 411 ′- 2 of the first switching element 411 ′ and the AC side 412 ′- 2 of the second switching element 412 ′.

[0194] Specific reference Fig.19 In an exemplary embodiment, a device for reducing common-mode current on the AC side 411'-2 of the first switching element 411' and the AC side 412'-2 of the second switching element 412' includes an electrical connection 496' between the first plurality of dv / dt filters 490' and the second plurality of dv / dt filters 491'. The electrical connection 496' can connect the neutral points of the first plurality of dv / dt filters 490' and the second plurality of dv / dt filters 491' (i.e., connect the neutral points of the dv / dt filters 490' on opposite converter sections) to cancel the common-mode current to or from the first switching element 411' and the second switching element 412'.

[0195] Special References Fig. 20 In an embodiment, the means for reducing common mode current on the AC side 411'-2 of the first switching element 411' and the AC side 412'-2 of the second switching element 412' comprises a first electrical connection 496'A between a first plurality of dv / dt filters 490' and one or more ground connections 494', and a second electrical connection 496'B between a second plurality of dv / dt filters 491' and one or more ground connections 494'. In addition, with specific reference to Fig.21In an embodiment, the first electrical connection 496'A further includes a first capacitor 497'A, and the second electrical connection further includes a second capacitor 497'B.

[0196] Fig. 20 and / or Fig.21 An exemplary aspect of can create a loop such that capacitors 497'A and 497'B (eg, Fig.21 ) acts as a low impedance return path for common-mode current.

[0197] In addition, in still other exemplary embodiments of the present disclosure, the power system 400' can be constructed according to still other suitable configurations. Fig. 22 , a power system 400 ′ according to yet another exemplary aspect of the present disclosure is provided. Fig. 22 The exemplary power system 400' may be configured in a manner similar to one or more of the exemplary power systems 400' described above.

[0198] For example, Fig. 22 The exemplary power system 400' includes a motor 450' having a first multi-phase winding 461' and a second multi-phase winding 462', and a power converter system 410' having a first switching element 411' connected to the first multi-phase winding 461' via a cable 404 and a second switching element 412' connected to the second multi-phase winding 462' via a cable 405'. The power converter system 410' also includes a first plurality of dv / dt filters 490' on an AC side 411'-2 of the first switching element 411' and a second plurality of dv / dt filters 491' on an AC side 412'-2 of the second switching element 412'.

[0199] The power converter system 410 ′ further comprises means for reducing common mode current on the AC side 411 ′- 2 of the first switching element 411 ′ and the AC side 412 ′- 2 of the second switching element 412 ′.

[0200] In particular, for Fig. 22 In an exemplary embodiment, the device for reducing common mode current on the AC side 411'-2 of the first switching element 411' and the AC side 412'-2 of the second switching element 412' includes a first plurality of LC filters 498' on the AC side 411'-2 of the first switching element 411' and a second plurality of LC filters 499' on the AC side 412'-2 of the second switching element 412'.

[0201] The first plurality of LC filters 498' is located between the first plurality of dv / dt filters 490' and the first switching element 411', and the second plurality of LC filters 499' is located between the second plurality of dv / dt filters 491' and the second switching element 412'. More specifically, the first plurality of LC filters 498' includes an LC filter 498' for each line 404' extending to the first multiphase winding 461' (and each segment of the first switching element 411'), and the second plurality of LC filters 499' includes an LC filter 499' for each line 405' extending to the second multiphase winding 462' (and each segment of the second switching element 412').

[0202] exist Fig. 22 , only the first LC filter 498' in the first plurality of LC filters 498' and the first LC filter 499' in the second plurality of LC filters 499' are depicted for clarity, but it should be understood that the first plurality of LC filters 498' includes the second LC filter 498' and the third LC filter 498' arranged together with the second segment 411'B and the third segment 411'C in a manner similar to the arrangement of the first LC filter 498' with the first segment 411'A, and the second plurality of LC filters 499' includes the second LC filter 499' and the third LC filter 499' arranged together with the second segment 412'B and the third segment 412'C in a manner similar to the arrangement of the first LC filter 499' with the first segment 412'A.

[0203] refer to Figures 16 to 22 In general, it should be appreciated that several embodiments of the apparatus for reducing common mode current on the AC side 411'-2 of the first switching element 411' and the AC side 412'-2 of the second switching element include two or more connections to the one or more ground connections 494'. It should be appreciated that the one or more ground connections 494' may be a common ground connection within the structure containing the first switching element 411' and the second switching element 412'.

[0204] In this manner, it should be appreciated that the one or more ground connections 494' may be a high Z ground connection, a low Z ground connection, or any other suitable ground connection.

[0205] Alternatively, the one or more ground connections may be a single ground connection.

[0206] Furthermore, it should be understood that Figures 16 to 22 An exemplary embodiment of the present invention is described as follows: Figures 3 to 5 However, it should be understood that in other exemplary aspects, Figures 16 to 22 The embodiments may be additionally or alternatively combined with the above referenced Figures 11 to 15 The invention may be used with an electric machine (and / or power converter system) configured in a similar manner as described above or in any other suitable configuration.

[0207] Now briefly refer to Fig.23 and Fig.24 , Fig.23 A schematic diagram of a power system 400 ″ is provided that may include and may operate in accordance with one or more exemplary aspects of the present disclosure. Fig.23 The exemplary power system 400 ″ includes three test locations L1 , L2 , and L3 to determine common mode signals / common mode emissions within the exemplary power system 400 ″. Fig.24 A table is provided showing exemplary reductions in common mode emissions in various exemplary embodiments of the present disclosure relative to a basic configuration.

[0208] Fig.24 Example 1 in represents a basic configuration in which the power system 400" does not include a DC side common mode reduction device (e.g., 430, 430') or an AC side common mode reduction device (e.g., 432, 432'). In addition, the power system 400" in Example 1 is not operated according to the pulse width modulation scheme disclosed herein. The results of Example 1 form a baseline.

[0209] Fig.24 Example 2 in represents an electric power system 400″, wherein the electric power system 400″ does not include a DC side common mode reduction device (e.g., 430, 430′) or an AC side common mode reduction device (e.g., 432, 432′). However, the electric power system 400″ of Example 2 operates according to the pulse width modulation scheme disclosed herein. As shown, operating according to Example 2 can provide the desired common mode emission reduction at positions L1 and L3.

[0210] Example 3 shows a power system 400", wherein the power system 400" includes the above reference Fig.16 The DC side common mode reduction device 430' (Y capacitor 482') and the above reference Figures 16 to 18 One or more of the configured AC side common mode reduction devices (ie, devices for reducing common mode currents) in the discussed exemplary embodiments. As will be appreciated, the exemplary system of Example 3 can provide the desired common mode emission reduction at each of the three locations L1, L2, and L3.

[0211] Example 4 shows an electric power system 400", wherein the electric power system 400" includes the above reference Fig.16 The DC side common mode reduction device 430' (Y capacitor 482') and the above reference Figures 19 to 21One or more of the configured AC side common mode reduction devices (ie, devices for reducing common mode currents) in the discussed exemplary embodiments. As will be appreciated, the exemplary system of Example 4 can provide the desired common mode emission reduction at each of the three locations L1, L2, and L3.

[0212] Example 5 shows a power system 400", wherein the power system 400" includes the above reference Fig.16 The DC side common mode reduction device 430' (Y capacitor 482') and the above reference Fig. 22 One or more of the exemplary embodiments discussed configures an AC side common mode reduction device (ie, a device for reducing common mode current). As will be appreciated, the exemplary system of Example 5 can provide the desired common mode emission reduction at each of the three locations L1, L2, and L3.

[0213] Fig.25 An example computing system 950 is provided according to an example embodiment of the present disclosure. For example, the computing devices or elements described herein (e.g., controller 440, controller 540, controller 640, controller 740, and controller 840) may include various components and perform various functions of the computing system 950 described below.

[0214] like Fig.25 As shown, the computing system 950 may include one or more computing devices 960. The computing device 960 may include one or more processors 960A and one or more memory devices 960B. The one or more processors 960A may include any suitable processing device, such as a microprocessor, a microcontroller, an integrated circuit, a logic device, and / or other suitable processing device. The one or more memory devices 960B may include one or more computer executable or computer readable media, including but not limited to non-transitory computer readable media, RAM, ROM, hard disk drives, flash drives, and / or other memory devices.

[0215] One or more memory devices 960B may store information accessible by one or more processors 960A, including computer-readable instructions 960C executable by one or more processors 960A. Instructions 960C may be any instruction set that causes one or more processors 960A to operate when executed by one or more processors 960A. In some embodiments, instructions 960C may be executed by one or more processors 960A to cause one or more processors 960A to operate, such as any operation and function for which the computing system 950 and / or computing device 960 are constructed, such as controlling the operation of the power system. Instructions 960C may be software written in any suitable programming language or may be implemented in hardware. Additionally and / or alternatively, instructions 960C may be executed in logically and / or virtually separated threads on processor 960A. Memory device 960B may further store data 960D accessible by processor 960A. For example, data 960D may include models, lookup tables, databases, etc.

[0216] The computing device 960 may also include a network interface 960E for communicating with other components of the system 950 (e.g., via a communication network), for example. The network interface 960E may include any suitable components for interfacing with one or more networks, including, for example, transmitters, receivers, ports, controllers, antennas, and / or other suitable components. One or more devices may be configured to receive one or more commands from the computing device 960, or to provide one or more commands to the computing device 960.

[0217] The technology discussed herein refers to computer-based systems, actions taken by computer-based systems, information sent to computer-based systems, and information from computer-based systems. Those of ordinary skill in the art will recognize that the inherent flexibility of computer-based systems allows for a variety of possible configurations, combinations, and divisions of tasks and functions between and among components. For example, the processing discussed herein can be implemented using a single computing device or multiple computing devices working in combination. Databases, memories, instructions, and applications can be implemented on a single system or distributed on multiple systems. Distributed components can operate sequentially or in parallel.

[0218] Further aspects are provided by the subject matter of the following clauses:

[0219] An electric power system comprises: an electric motor comprising a first multi-phase winding and a second multi-phase winding, wherein the first multi-phase winding and the second multi-phase winding are electrically in opposite phase with respect to each other; and an electric power converter system comprising: a first switching element, which is electrically connected to the first multi-phase winding and has a DC side and an AC side; a second switching element, which is electrically connected to the second multi-phase winding and has a DC side and an AC side; a plurality of capacitors, which are connected to the first switching element at the DC side of the first switching element and to the second switching element at the DC side of the second switching element; and a device for reducing common mode current on the AC side of the first switching element and the AC side of the second switching element.

[0220] An electric power system according to any preceding clause, wherein the device for reducing common-mode current on the AC side of the first switching element and the AC side of the second switching element comprises: a first plurality of filter capacitors on the AC side of the first switching element, a second plurality of filter capacitors on the AC side of the second switching element, or both.

[0221] An electric power system according to any preceding clause, wherein the device for reducing the common-mode current on the AC side of the first switching element and the AC side of the second switching element comprises: a first plurality of filter capacitors, the first plurality of filter capacitors being on the AC side of the first switching element; and a second plurality of filter capacitors, the second plurality of filter capacitors being on the AC side of the second switching element.

[0222] An electric power system as in any preceding clause, wherein the first plurality of filter capacitors are connected to one or more ground connections, and wherein the second plurality of filter capacitors are also connected to the one or more ground connections.

[0223] A power system as described in any preceding clause, wherein the first plurality of filter capacitors are connected to the second plurality of filter capacitors.

[0224] An electric power system according to any preceding clause, wherein the power converter system further includes a first plurality of dv / dt filters on the AC side of the first switching element and a second plurality of dv / dt filters on the AC side of the second switching element, and wherein the device for reducing the common mode current on the AC side of the first switching element and the AC side of the second switching element is located between the first plurality of dv / dt filters and the second plurality of dv / dt filters and the motor.

[0225] An electric power system according to any preceding clause, wherein the device for reducing the common mode current of the AC side of the first switching element and the AC side of the second switching element comprises: a first plurality of filter capacitors on the AC side of the first switching element, wherein the first plurality of filter capacitors are also electrically connected to the AC side of the second switching element.

[0226] An electric power system according to any preceding clause, wherein the power converter system further includes a first plurality of dv / dt filters on the AC side of the first switching element and a second plurality of dv / dt filters on the AC side of the second switching element, and wherein the device for reducing the common-mode current on the AC side of the first switching element and the AC side of the second switching element includes: an electrical connection between the first plurality of dv / dt filters and the second plurality of dv / dt filters.

[0227] An electric power system according to any preceding clause, wherein the power converter system further includes a first plurality of dv / dt filters on the AC side of the first switching element and a second plurality of dv / dt filters on the AC side of the second switching element, and wherein the device for reducing the common-mode current on the AC side of the first switching element and the AC side of the second switching element includes: a first electrical connection, the first electrical connection being between the first plurality of dv / dt filters and one or more ground connections; and a second electrical connection, the second electrical connection being between the second plurality of dv / dt filters and the one or more ground connections.

[0228] An electrical power system as described in any preceding clause, wherein the first electrical connection comprises a first capacitor, and wherein the second electrical connection comprises a second capacitor.

[0229] A power system as described in any preceding clause, wherein the power converter system comprises a housing, and wherein the first switching element and the second switching element are located within the housing.

[0230] An electric power system according to any preceding clause, wherein the device for reducing the common mode current on the AC side of the first switching element and the AC side of the second switching element comprises: a first plurality of LC filters, wherein the first plurality of LC filters are on the AC side of the first switching element; and a second plurality of LC filters, wherein the second plurality of LC filters are on the AC side of the second switching element.

[0231] A power system as described in any preceding clause, wherein the power converter system further includes a first plurality of dv / dt filters on the AC side of the first switching element and a second plurality of dv / dt filters on the AC side of the second switching element, wherein the first plurality of LC filters are located between the first plurality of dv / dt filters and the first switching element, and wherein the second plurality of LC filters are located between the second plurality of dv / dt filters and the second switching element.

[0232] A power system as claimed in any preceding clause, wherein the plurality of capacitors coupled to the first switching element at the DC side of the first switching element and coupled to the second switching element at the DC side of the second switching element comprises a plurality of Y capacitors.

[0233] The power system according to any of the preceding clauses further includes one or more processors, which are constructed to: generate one or more first pulse width modulation (PWM) signals to control the first switching element so as to present a first common mode signal, the first PWM signal being generated at least in part based on one or more voltage commands associated with the first multi-phase winding; and generate one or more second PWM signals to control the second switching element so as to present a second common mode signal, the second PWM signal being generated at least in part based on one or more voltage commands associated with the second multi-phase winding, the second common mode signal having an opposite polarity relative to the first common mode signal.

[0234] A power system as described in any preceding clause, wherein the second common mode signal has the same waveform as the first common mode signal.

[0235] A power system as described in any preceding clause, wherein, in generating the one or more second PWM signals, the one or more processors are configured to: offset the polarity of each of the one or more second PWM signals.

[0236] An electrical power system as described in any preceding clause, wherein the first polyphase winding and the second polyphase winding are associated with the same channel of the electrical power system.

[0237] An electric power system as described in any preceding clause, wherein the first multi-phase winding is associated with a first channel of the electric power system and the second multi-phase winding is associated with a second channel of the electric power system.

[0238] An electric power system according to any preceding clause, wherein the electric machine defines a radial direction, and wherein the first multi-phase windings are arranged in a first group and a second group positioned relative to each other along the radial direction, and wherein the second multi-phase windings are arranged in a first group and a second group positioned relative to each other along the radial direction.

[0239] An electric power system as described in any preceding clause, wherein the electric machine has a stator defining sectors, and wherein the first and second groups of the first polyphase windings and the first and second groups of the second polyphase windings are each wound within a respective one of the sectors of the stator.

[0240] An electric power system according to any preceding clause, wherein the power converter system has a third switching element and a fourth switching element, and wherein the motor further comprises: a third multi-phase winding electrically connected to the third switching element; and a fourth multi-phase winding electrically connected to the fourth switching element, the fourth multi-phase winding being electrically opposite in phase to the third multi-phase winding.

[0241] An electric power system according to any preceding clause, wherein the electric machine defines a radial direction, and wherein the first multi-phase winding is arranged opposite the second multi-phase winding along the radial direction, and the third multi-phase winding is arranged opposite the fourth multi-phase winding along the radial direction.

[0242] An electric power system as described in any preceding clause, wherein the electric machine has a stator defining sectors, and wherein the first multi-phase winding, the second multi-phase winding, the third multi-phase winding and the fourth multi-phase winding are wound within a respective one of the sectors of the stator.

[0243] An electric power system as described in any preceding clause, wherein the electric machine has a stator defining a first half-sector and a second half-sector, and wherein the first multi-phase winding is wound within the first half-sector and the second multi-phase winding is wound within the second half-sector.

[0244] An electric power system as claimed in any preceding clause, wherein the first and second polyphase windings are wound in a juxtaposed anti-phase arrangement.

[0245] An electrical power system as described in any preceding clause, wherein the electrical machine has a rotor and a stator, and wherein the rotor is mechanically coupled to a rotating component of a gas turbine engine.

[0246] This written description uses examples to disclose the present disclosure, including the best mode, and also to enable any person skilled in the art to practice the present disclosure, including making and using any device or system and performing any combined method. The patentable scope of the present disclosure is defined by the claims and may include other examples that occur to those skilled in the art. These other examples are intended to fall within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not differ substantially from the literal language of the claims.

Claims

1. A power system, characterized in that: include: an electric machine comprising a first multi-phase winding and a second multi-phase winding, the first multi-phase winding and the second multi-phase winding being electrically in opposite phase relative to each other; as well as A power converter system, the power converter system comprising: a first switching element electrically connected to the first multi-phase winding and having a DC side and an AC side; a second switching element electrically connected to the second multi-phase winding and having a DC side and an AC side; a plurality of capacitors coupled to the first switching element at the DC side of the first switching element and coupled to the second switching element at the DC side of the second switching element; and Means for reducing common mode current on the AC side of the first switching element and the AC side of the second switching element.

2. The power system according to claim 1, characterized in that: in, The means for reducing common mode currents of the AC side of the first switching element and the AC side of the second switching element comprises: A first plurality of filter capacitors on the AC side of the first switching element, a second plurality of filter capacitors on the AC side of the second switching element, or both.

3. The power system according to claim 1, characterized in that: in, The means for reducing common mode currents of the AC side of the first switching element and the AC side of the second switching element comprises: a first plurality of filter capacitors on the AC side of the first switching element; and A second plurality of filter capacitors is provided on the AC side of the second switching element.

4. The power system according to claim 3, characterized in that: in, The first plurality of filter capacitors are connected to one or more ground connections, and wherein the second plurality of filter capacitors are also connected to the one or more ground connections.

5. The power system according to claim 3, characterized in that: in, The first plurality of filter capacitors are connected to the second plurality of filter capacitors.

6. The power system according to claim 3, characterized in that: in, The power converter system further includes a first plurality of dv / dt filters on the AC side of the first switching element and a second plurality of dv / dt filters on the AC side of the second switching element, and wherein the device for reducing the common-mode current on the AC side of the first switching element and the AC side of the second switching element is located between the first plurality of dv / dt filters and the second plurality of dv / dt filters and the motor.

7. The power system according to claim 1, characterized in that: in, The means for reducing common mode currents of the AC side of the first switching element and the AC side of the second switching element comprises: A first plurality of filter capacitors on the AC side of the first switching element, wherein the first plurality of filter capacitors are also electrically connected to the AC side of the second switching element.

8. The power system according to claim 1, characterized in that: in, The power converter system further comprises a first plurality of dv / dt filters on the AC side of the first switching element and a second plurality of dv / dt filters on the AC side of the second switching element, and wherein the means for reducing common mode current on the AC side of the first switching element and the AC side of the second switching element comprises: Electrical connections between the first plurality of dv / dt filters and the second plurality of dv / dt filters.

9. The power system according to claim 1, characterized in that: in, The power converter system further comprises a first plurality of dv / dt filters on the AC side of the first switching element and a second plurality of dv / dt filters on the AC side of the second switching element, and wherein the means for reducing common mode current on the AC side of the first switching element and the AC side of the second switching element comprises: a first electrical connection between the first plurality of dv / dt filters and one or more ground connections; and A second electrical connection is provided between the second plurality of dv / dt filters and the one or more ground connections.

10. The power system according to claim 9, characterized in that: in, The first electrical connection comprises a first capacitor, and wherein the second electrical connection comprises a second capacitor.

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