Abstract: An electrical machine comprising a rotor is presented. The electrical machine includes the rotor disposed on a rotatable shaft and defining a plurality of radial protrusions extending from the shaft up to a periphery of the rotor. The radial protrusions having cavities define a fluid path. A stationary shaft is disposed concentrically within the rotatable shaft wherein an annular space is formed between the stationary and rotatable shaft. A plurality of magnetic segments is disposed on the radial protrusions and the fluid path from within the stationary shaft into the annular space and extending through the cavities within the radial protrusions.

Abstract: An electric machine and stator assembly are provided that include a continuous stator portion having stator teeth, and a tooth tip portion including tooth tips corresponding to the stator teeth of the continuous stator portion, respectively. The tooth tip portion is mounted onto the continuous stator portion.

Abstract: A system and method for exciting an electrical machine with instantaneous non-sinusoidal current waveforms is disclosed. The system includes an inverter that controls current flow and terminal voltages in an electrical machine and a controller programmed to input an initial sinusoidal current demand to the inverter, thereby causing the inverter to output an initial sinusoidal input current. The controller is further programmed to receive feedback on an air gap magnetic field in the electrical machine generated by the initial sinusoidal current demand, determine an instantaneous fundamental component and instantaneous harmonic components of the air gap magnetic field, apply a correction to the instantaneous fundamental component of the air gap magnetic field to generate an ideal fundamental component, generate a non-sinusoidal current demand based on the ideal fundamental component, and input the non-sinusoidal current demand to the inverter, thereby causing the inverter to output a non-sinusoidal current.

Abstract: An electrical motor bearing condition monitoring system includes an assembly that includes a shaft, a first bearing race coupled to the shaft, a plurality of bearing balls, and a second bearing race coupled to the first bearing race via the plurality of bearing balls. A portion of the assembly has a magnetic field encoded thereon. The monitoring system includes a magnetic field sensor positioned proximately to the magnetized assembly and configured to measure the magnetic field, and a processing unit configured to detect changes in the magnetic field via the magnetic field sensor that occur due to passage of electrical current through the bearing balls.

Abstract: An electrical machine comprising a rotor is presented. The electrical machine includes the rotor disposed on a rotatable shaft and defining a plurality of radial protrusions extending from the shaft up to a periphery of the rotor. The radial protrusions having cavities define a fluid path. A stationary shaft is disposed concentrically within the rotatable shaft wherein an annular space is formed between the stationary and rotatable shaft. A plurality of magnetic segments is disposed on the radial protrusions and the fluid path from within the stationary shaft into the annular space and extending through the cavities within the radial protrusions.

Abstract: An internal permanent magnet (IPM) machine is provided. The IPM machine includes a stator assembly and a stator core. The stator core also includes multiple stator teeth. The stator assembly is further configured with stator windings to generate a stator magnetic field when excited with alternating currents and extends along a longitudinal axis with an inner surface defining a cavity. The IPM machine also includes a rotor assembly and a rotor core. The rotor core is disposed inside the includes a shaft. The shaft further includes multiple protrusions alternately arranged relative to multiple bottom structures provided on the shaft. The rotor assembly also includes multiple stacks of laminations disposed on the protrusions and dovetailed circumferentially around the shaft. The rotor assembly further includes multiple pair of permanent magnets for generating a magnetic field, which magnetic field interacts with the stator magnetic field to produce a torque.

Abstract: An internal permanent magnet (IPM) machine is provided. The IPM machine includes a stator assembly and a stator core. The stator core also includes multiple stator teeth. The stator assembly is further configured with stator windings to generate a magnetic field when excited with alternating currents and extends along a longitudinal axis with an inner surface defining a cavity. The IPM machine also includes a rotor assembly and a rotor core. The rotor core is disposed inside the cavity and configured to rotate about the longitudinal axis. The rotor assembly further includes a shaft. The shaft further includes multiple protrusions alternately arranged relative to multiple bottom structures provided on the shaft. The rotor assembly also includes multiple stacks of laminations disposed on the protrusions and dovetailed circumferentially around the shaft.

Abstract: An interior permanent magnet machine is disclosed. The machine comprises an air gap, and a rotor comprising a plurality of multilayered magnets each placed substantially along circumferential chords of the air gap, wherein each of the magnets comprises a plurality of segments and at least one segment adjacent said air gap comprises a high resistivity magnetic material. A method to make an interior permanent magnet machine is also disclosed.

Abstract: An interior permanent magnet electric machine is disclosed. The interior permanent magnet electric machine comprises a rotor comprising a plurality of radially placed magnets each having a proximal end and a distal end, wherein each magnet comprises a plurality of magnetic segments and at least one magnetic segment towards the distal end comprises a high resistivity magnetic material.

Abstract: A method to make a high resistivity permanent magnetic material comprising a non-conductive phase and a permanent magnetic phase microstructure, is disclosed. The method comprises the steps of, (a) disposing at least one layer comprising a non-conductive powder and at least one layer comprising a permanent magnetic powder adjacent to each other to obtain a multilayer, (b) compressing the multilayer, and (c) sintering the multilayer. A method to make a high resistivity soft magnetic material comprising a microstructure comprising a bulk metallic glass phase and a soft magnetic crystalline metal phase, is also disclosed.

Abstract: An electrical machine is disclosed. The electrical machine comprises a first discontinuous volume comprising a high resistivity soft magnetic material.

Abstract: A cooling system for an electrical machine is provided. The cooling system includes at least one baffle enclosing multiple endwindings, wherein the at least one baffle is configured to guide a cooling fluid flow to multiple regions of interest in the machine.

Abstract: A fault tolerant synchronous permanent magnet machine is disclosed that reduces rotor losses by limiting eddy-current losses in the retaining sleeve. The machine limits eddy-current loss by any one or combination of axially segmenting the retaining sleeve, providing a highly electrically conductive non-magnetic shield to the retaining sleeve, and by configuring stator teeth width, stator teeth tip width, and slot distribution of the stator.

Abstract: An electromagnetic machine for extracting power from a turbine engine includes an outer rotor and an inner rotor rotatably supported adjacent to a stator. The stator is disposed between the inner and outer rotors. The stator has an inner set of windings disposed on an inner surface adjacent to the inner rotor, and an outer set of windings on an outer surface of the stator adjacent to the outer rotor. A plurality of permanent magnets are disposed on an inner surface of the outer rotor element and on an outer surface of the inner rotor element. Air gaps are defined between the outer surface of the stator and the outer permanent magnets, and between the inner surface of the stator portion and the inner permanent magnets. The inner stator windings form a set of multiple-phase windings, and the outer stator windings form a set of multiple-phase windings.

Abstract: A PM machine is provided. The PM machine includes a stator including a stator core, wherein the stator core defines multiple step-shaped stator slots. The stator includes multiple fractional-slot concentrated windings wound within the step-shaped stator slots. The stator also includes at least one slot wedge configured to close an opening of a respective one of the step-shaped stator slots, wherein the slot wedge is further configured to adjust the leakage inductance in the PM machine. The PM machine also includes a rotor having a rotor core and disposed outside and concentric with the stator, wherein the rotor core includes a laminated back iron structure disposed around multiple axially-segmented magnets.

Abstract: A PM machine is provided. The PM machine includes a stator including a stator core, wherein the stator core defines multiple step-shaped stator slots. The stator includes multiple fractional-slot concentrated windings wound within the step-shaped stator slots. The stator also includes at least one cooling tube disposed around the windings. The stator further includes a first insulation layer disposed around the cooling tube. The stator also includes a second insulation layer disposed around the first insulation layer. The stator further includes at least one slot wedge configured to close an opening of a respective one of the step-shaped stator slots, wherein the slot wedge is further configured to adjust a leakage inductance in the PM machine. The PM machine also includes a rotor having a rotor core and disposed outside and concentric with the stator, wherein the rotor core includes a laminated back iron structure disposed around multiple magnets.

Abstract: A synchronous reluctance machine is provided. The synchronous reluctance machine includes a stator having a stator core, the stator core including a number of fractional-slot concentrated windings wound around multiple stator teeth. The synchronous reluctance machine also includes a rotor having a rotor core and disposed with an air gap inside and concentric with the stator, wherein the rotor core includes a number of laminated sheets, wherein each of the laminated sheets is axially skewed with respect to neighboring ones of the laminated sheets, and wherein each of the laminated sheets includes multiple ferromagnetic regions and multiple non-ferromagnetic regions formed of a single material.

Abstract: A system for generating supplemental electrical power from the low-pressure (LP) turbine spool of a turbofan engine includes a high-speed, high magnetic pole count, generator, a gearbox, a controller and a power converter. The LP turbine spool is mechanically coupled to the generator portion by the gearbox for driving the generator portion. The controller portion has a speed-sensing element for sensing the LP turbine speed. The controller portion disables the power converter when the generator exceeds a predetermined speed, and enables the power converter when the generator portion is less or equal to the predetermined speed. The effective load on the generator is reduced to approximately zero when the LP turbine spool exceeds the predetermined speed, permitting the generator to be electrically bound up to the predetermined speed and mechanically bound in excess of the predetermined speed.

Abstract: A rotor for an electric machine includes a rotor core constructed of magnetically-permeable material. The rotor core may include a first cavity having a first curved end portion and a second cavity having a first curved end portion disposed adjacent the first curved end portion of the first cavity. The rotor may also include a permanent-magnet cluster. The permanent-magnet cluster may include a permanent-magnet layer that substantially magnetically isolates a portion of the rotor core disposed inside the permanent-magnet cluster from portions of the rotor core disposed outside the permanent-magnet cluster. The permanent-magnet layer may include one or more permanent-magnet pieces disposed in the first cavity and one or more permanent-magnet pieces disposed in the second cavity.

Abstract: A synchronous reluctance machine is provided. The synchronous reluctance machine includes a stator having a stator core, the stator core including a number of fractional-slot concentrated windings wound around multiple stator teeth. The synchronous reluctance machine also includes a rotor having a rotor core and disposed with an air gap inside and concentric with the stator, wherein the rotor core includes a number of laminated sheets, wherein each of the laminated sheets is axially skewed with respect to neighboring ones of the laminated sheets, and wherein each of the laminated sheets includes multiple ferromagnetic regions and multiple non-ferromagnetic regions formed of a single material.