Abstract: A system includes a stator core, which includes a plurality of teeth and a plurality of bridges. The plurality of teeth are disposed about an axis of the stator core, wherein each tooth of the plurality of teeth extends in a radial direction from a proximal end to a distal end. Each bridge of the plurality of bridges is disposed between two adjacent teeth and connects the proximal ends of the two teeth. The plurality of teeth and the plurality of bridges define a plurality slots, each having a proximal end and a distal end, wherein the proximal end of each slot is closed and the distal end of each slot is open.

Abstract: A magnet management method of controlling a ferrite-type permanent magnet electrical machine includes receiving and/or estimating the temperature permanent magnets; determining if that temperature is below a predetermined temperature; and if so, then: selectively heating the magnets in order to prevent demagnetization and/or derating the machine. A similar method provides for controlling magnetization level by analyzing flux or magnetization level. Controllers that employ various methods are disclosed. The present invention has been described in terms of specific embodiment(s), and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims.

Abstract: A permanent magnet machine, a rotor assembly for the machine, and a pump assembly. The permanent magnet machine includes a stator assembly including a stator core configured to generate a magnetic field and extending along a longitudinal axis with an inner surface defining a cavity and a rotor assembly including a rotor core and a rotor shaft. The rotor core is disposed inside the cavity and configured to rotate about the longitudinal axis. The rotor assembly further including a plurality of permanent magnets for generating a magnetic field which interacts with the stator magnetic field to produce torque. The permanent magnets configured as one of internal or surface mounted. The rotor assembly also including a plurality of retaining clips configured to retain the plurality of permanent magnets relative to the rotor core. The pump assembly including an electric submersible pump and a permanent magnet motor for driving the pump.

Abstract: A permanent magnet (PM) machine includes a rotor and a stator assembly. The rotor includes a plurality of permanent magnets disposed about an axis of rotation. The stator assembly includes a stator body, a plurality of coil sides and a plurality of sintered iron magnetic wedges. The stator body includes a plurality of stator teeth defining a plurality of stator slots, each stator slot having an inside position and an outside position, such that each of the plurality of stator slots includes a first plurality of inside positions, and a first plurality of outside positions. The first plurality of coil sides are disposed in each of the first plurality of inside positions and the first plurality of outside positions. The first plurality of coil sides correspond to a first power phase. The first plurality of coil sides are electrically coupled to one another by a first plurality of end-coils.

Abstract: A synchronous reluctance machine includes a rotor having a first plate, a second plate, a first set of rotor poles, and a first set of axial stiffeners. Each rotor pole of the first set of rotor poles includes a first plurality of laminations axially stacked between the first plate and the second plate, and each lamination of the first plurality of laminations includes first channels configured to carry magnetic flux and a first plurality of passages spaced between the first channels. Each axial stiffener of the first set of axial stiffeners is disposed within a respective passage of the first plurality of passages. A first end of each axial stiffener of the first set of axial stiffeners interfaces with the first plate, and a second end of each axial stiffener of the first set of axial stiffeners interfaces with the second plate.

Abstract: A method for estimating a speed of an induction motor includes applying a voltage to the induction motor and measuring a current of the induction motor. A current fast fourier transform (FFT) of the current is then determined and a slip of the induction motor is calculated based on the current FFT. A speed of the induction motor is then estimated based on the slip of the induction motor.

Abstract: A magnetic component including at least one region is disclosed. The at least one region includes nitrogen and a concentration of the nitrogen in the at least one region is graded across a dimension of the at least one region. Further, a saturation magnetization in the at least one region is graded across the dimension of the at least one region. Further, a method of varying the magnetization values in at least one region of the magnetic component is disclosed.

Abstract: A magnetic component including first and second regions, and a method of varying the magnetization values in different regions of the magnetic component are disclosed. The first and the second regions are characterized by a nitrogen content that is different from each other. At least one of the first region and the second region is partially-magnetic and has a nitrogen content in a range from about 0.1 weight % to about 0.4 weight % of that region. A concentration of carbon, if present, of both the first and second regions is less than about 0.05 weight % of the respective regions.

Abstract: A permanent magnet machine includes a stator configured to generate a stator magnetic field when excited with alternating currents and extends along a longitudinal axis with an inner surface defining a cavity, a rotor disposed inside said cavity and configured to rotate about the longitudinal axis, and a plurality of permanent magnets for generating a magnetic field, which interacts with the stator magnetic field to produce a torque. At least one of the plurality of permanent magnets has a light rare earth material including neodymium and praseodymium, and less than about 5 weight percent of a heavy rare earth material, wherein the weight percentage of neodymium is larger than the weight percentage of praseodymium but smaller than three times of the weight percentage of praseodymium.

Abstract: A rotor component that comprises a rotor circuit configured for use with either an interior permanent magnet (IPM) machine or a synchronous reluctance machine (SRM) that includes a pole circuit made of a conductive, non-magnetic material and has a midpoint that substantially aligns with a d-axis of the IPM or SRM. An electric machine with a similar rotor component therein or having a loop or ring of a conductive, non-magnetic material that is substantially concentric about a d-axis of the electric machine.

Abstract: An internal permanent magnet machine includes a rotor assembly having a shaft comprising a plurality of protrusions extending radially outward from a main shaft body and being formed circumferentially about the main shaft body and along an axial length of the main shaft body. A plurality of stacks of laminations are arranged circumferentially about the shaft to receive the plurality of protrusions therein, with each stack of laminations including a plurality of lamination groups arranged axially along a length of the shaft and with permanent magnets being disposed between the stacks of laminations. Each of the laminations includes a shaft protrusion cut formed therein to receive a respective shaft protrusion and, for each of the stacks of laminations, the shaft protrusion cuts formed in the laminations of a respective lamination group are angularly offset from the shaft protrusion cuts formed in the laminations in an adjacent lamination group.

Abstract: A magnet management method of controlling a ferrite-type permanent magnet electrical machine includes receiving and/or estimating the temperature permanent magnets; determining if that temperature is below a predetermined temperature; and if so, then: selectively heating the magnets in order to prevent demagnetization and/or derating the machine. A similar method provides for controlling magnetization level by analyzing flux or magnetization level. Controllers that employ various methods are disclosed. The present invention has been described in terms of specific embodiment(s), and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims.

Abstract: A method for estimating a speed of an induction motor includes applying a voltage to the induction motor and measuring a current of the induction motor. A current fast fourier transform (FFT) of the current is then determined and a slip of the induction motor is calculated based on the current FFT. A speed of the induction motor is then estimated based on the slip of the induction motor.

Abstract: A rotor assembly that includes at least one integral non-magnetic rotor retaining structure comprising a plurality of individual rotor retaining discs, the discs having predefined slots; and a plurality of magnetic segments retained within the slots of the discs of the respective integral non-magnetic rotor retaining structure.

Abstract: A permanent magnet machine, a rotor assembly for the machine, and a pump assembly. The permanent magnet machine includes a stator assembly including a stator core configured to generate a magnetic field and extending along a longitudinal axis with an inner surface defining a cavity and a rotor assembly including a rotor core and a rotor shaft. The rotor core is disposed inside the cavity and configured to rotate about the longitudinal axis. The rotor assembly further including a plurality of permanent magnets for generating a magnetic field which interacts with the stator magnetic field to produce torque. The permanent magnets configured as one of internal or surface mounted. The rotor assembly also including a plurality of retaining clips configured to retain the plurality of permanent magnets relative to the rotor core. The pump assembly including an electric submersible pump and a permanent magnet motor for driving the pump.

Abstract: A system and method for heating ferrite permanent magnets in an electrical machine is disclosed. The permanent magnet machine includes a stator assembly and a rotor assembly, with a plurality of ferrite permanent magnets disposed within the stator assembly or the rotor assembly to generate a magnetic field that interacts with a stator magnetic field to produce a torque. A controller of the electrical machine is programmed to cause a primary field current to be applied to the stator windings to generate the stator magnetic field, so as to cause the rotor assembly to rotate relative to the stator assembly. The controller is further programmed to cause a secondary current to be applied to the stator windings to selectively generate a secondary magnetic field, the secondary magnetic field inducing eddy currents in at least one of the stator assembly and the rotor assembly to heat the ferrite permanent magnets.

Abstract: An electric machine, such as an Internal Permanent magnet or Synchronous Reluctance machine, having X phases, that includes a stator assembly, having M slots, with a stator core and stator teeth, that 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 that defines a cavity; and a rotor assembly, having N poles, disposed within the cavity which is configured to rotate about the longitudinal axis, wherein the rotor assembly includes a shaft, a rotor core located circumferentially around the shaft. The machine is configured such that a value k=M/(X*N) wherein k is a non-integer greater than about 1.3. The electric machine may alternatively, or additionally, include a non-uniformed gap between the exterior surface of the rotor spokes and the interior stator surface of the stator.

Abstract: An electric machine that includes a rotor core made of magnetic steel; a stator configured with stationary windings therein; openings disposed within or on the rotor core; and a rotor circuit that is configured to introduce saliency based on an orientation of part of the rotor circuit in relationship to a pole location of the electric machine, where the rotor circuit is made of a conductive, non-magnetic material. A rotor component and various embodiments of electric machines are also disclosed. The present invention has been described in terms of specific embodiment(s), and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims.

Abstract: A rotor core is provided for an electric machine. The rotor core includes a body extending a length along, and being configured to rotate about, a central longitudinal axis. The body includes spokes arranged radially about the central longitudinal axis and conductor openings arranged radially about the central longitudinal axis. The radial arrangement of the spokes and conductor openings about the central longitudinal axis includes an alternating pattern of spokes and conductor openings. The spokes include slots extending therethrough along the central longitudinal axis. The slots are positioned radially about the central longitudinal axis between adjacent conductor openings. The rotor core also includes conductors extending within the conductor openings of the body.

Abstract: An internal permanent magnet machine includes a rotor assembly having a shaft comprising a plurality of protrusions extending radially outward from a main shaft body and being formed circumferentially about the main shaft body and along an axial length of the main shaft body. A plurality of stacks of laminations are arranged circumferentially about the shaft to receive the plurality of protrusions therein, with each stack of laminations including a plurality of lamination groups arranged axially along a length of the shaft and with permanent magnets being disposed between the stacks of laminations. Each of the laminations includes a shaft protrusion cut formed therein to receive a respective shaft protrusion and, for each of the stacks of laminations, the shaft protrusion cuts formed in the laminations of a respective lamination group are angularly offset from the shaft protrusion cuts formed in the laminations in an adjacent lamination group.