Patent application number | Description | Published |
20080224651 | METHOD AND SYSTEM FOR CONTROLLING PERMANENT MAGNET AC MACHINES - Methods and systems are provided for controlling permanent magnet machines under varying loads. The method comprises generating a d-axis voltage command and a q-axis voltage command, producing a modified d-axis current command based on the q-axis voltage command and a d-axis current command, converting the modified d-axis current command to a modified d-axis voltage command, and transmitting the modified d-axis voltage command and the q-axis voltage command to the PM machine. The d-axis voltage command is based on a d-axis current command. | 09-18-2008 |
20080256782 | METHODS FOR FORMING A MAGNET IN A ROTOR - Methods are provided for forming/inserting a magnet in a rotor. One method includes coating a plurality of magnetizable particles with a non-metallic material, inserting the coated particles in a rotor, and magnetizing the coated particles. Another method includes inserting a plurality of magnetizable particles into a rotor, submersing the rotor in motor varnish to coat the particles with motor varnish, and magnetizing the particles. Yet another method includes inserting a plurality of magnetizable particles in a rotor, inserting a non-metallic material into the rotor, mixing the particles and non-metallic material to form a mixture, curing the mixture to coat each particle with non-metallic material, and magnetizing the particles. Still another method includes mixing a plurality of magnetizable particles with a non-metallic material, curing the non-metallic material to coat each particle with non-metallic material, inserting the coated particles in a rotor, and magnetizing the coated particles. | 10-23-2008 |
20080282531 | CONCENTRATED WINDING MACHINE WITH MAGNETIC SLOT WEDGES - Methods and apparatus are provided for improving operational characteristics of a concentrated winding machine. According to an example embodiment, a method comprises fabricating a magnetic slot wedge that is adapted to be joined to a first stator tooth and a second stator tooth, the first and second stator tooth part of a fixed-tooth stator that does not allow relative movement between the first stator tooth and the second stator tooth. | 11-20-2008 |
20080303368 | MULTI-LAYER MAGNET ARRANGEMENT IN A PERMANENT MAGNET MACHINE FOR A MOTORIZED VEHICLE - A permanent magnet machine includes a stator having a hollow core, a rotor rotatably disposed inside the hollow core, and a plurality of multilayered permanent magnets embedded in the rotor. Each multilayered permanent magnet has opposite first and second ends, and includes a first magnet disposed at the first end, and a second magnet disposed at the second end and coupled to the first magnet. The second magnet has higher magnet strength than the first magnet, and also has lower high-temperature stability than the first magnet. | 12-11-2008 |
20080303370 | PERMANENT MAGNET MOTORS WITH REDUCED TORQUE RIPPLE AND METHODS FOR DESIGNING THE SAME - Permanent magnet motors with improved torque ripple and methods for designing the same have been provided. The permanent magnet motor can include a stator having a hollow core and defining a plurality of slots; a winding disposed in each of the slots; a rotor rotatably disposed inside the hollow core of the stator; and a plurality of permanent magnets supported by the rotor. Each of the slots has a slot opening, and at least one of the slot openings can be off-center with respect to the respective slot. | 12-11-2008 |
20090001996 | SYSTEMS AND METHODS TO EVALUATE PERMANENT MAGNET MOTORS - Methods and systems for evaluating a permanent magnet motor are provided. The method includes the steps of spinning a rotor of the permanent magnet motor; determining a total harmonic distortion of the permanent magnet motor; and comparing the determined total harmonic distortion of the permanent magnet motor with a baseline total harmonic distortion. | 01-01-2009 |
20090127942 | CONCENTRATED WINDING MACHINE WITH MAGNETIC SLOT WEDGES - Methods and apparatus are provided for improving operational characteristics of a concentrated winding machine. According to an example embodiment, an apparatus comprises stator teeth having distal ends, the stator teeth arranged in an annular fashion about an axis to define stator slots between adjacent teeth and slot openings between the distal ends of the adjacent teeth, the stator teeth structured to prevent relative movement between adjacent teeth. The apparatus further comprises magnetic wedges structured to be inserted between the distal ends of the adjacent teeth to close the slot openings. | 05-21-2009 |
20090140592 | METHODS AND APPARATUS FOR A PERMANENT MAGNET MACHINE WITH AN ADDED AIR BARRIER - An internal permanent magnet machine (“IPM machine”) of the type used, for example, with traction motors and hybrid electric vehicles, includes a rotor with an additional air barrier provided above the first magnet barrier in the same rotor slot. Each magnet only fills a portion of each cavity, thereby defining the air barriers. The added air barrier above the permanent magnet of the first layer acts as a barrier to the first layer magnet and lowers the magnet flux. | 06-04-2009 |
20090140593 | METHODS AND APPARATUS FOR A PERMANENT MAGNET MACHINE WITH ADDED ROTOR SLOTS - An internal permanent magnet machine (“IPM machine”) of the type used, for example, with traction motors and hybrid electric vehicles, includes a rotor with additional, small rotor slots configured to provide and averaging effect with respect to rotor barriers provided therein. | 06-04-2009 |
20090140596 | METHODS AND APPARATUS FOR A BAR-WOUND STATOR WITH PARALLEL CONNECTIONS - A bar-wound stator design with parallel connections is characterized by a shorter end turn length as compared to conventional stranded winding. The stator includes an inner winding set and an outer winding set provided within a plurality of slots, wherein the inner winding set is parallel to the outer winding set, and each winding set comprises multiple phases; and wherein the inner winding set and the outer winding set are staggered one slot within the plurality of slots. | 06-04-2009 |
20090251096 | METHOD AND APPARATUS FOR TORQUE RIPPLE REDUCTION - Methods and apparatus are provided for reducing torque ripple in a permanent magnet motor system comprising a permanent magnet motor coupled to an inverter. The method comprises the steps of receiving a torque command, generating a torque ripple reduction signal in response to the torque command, modifying operational control signals in response to the torque ripple reduction signal to generate reduced ripple operational control signals, and providing the reduced ripple operational control signals to the inverter for control of the permanent magnet motor. | 10-08-2009 |
20090295316 | GEARLESS WHEEL MOTOR DRIVE SYSTEM - Methods and apparatus are provided for an electric vehicle embodying an axial flux traction motor directly coupled to a wheel thereof. The traction motor comprises a stator having coils for producing a magnetic field, an annular rotor magnetically coupled to the stator and mechanically to an output shaft. Permanent magnets of alternating polarity are mounted on the annular rotor. Magnetic shunts bridge a portion of the stator slots above the coils. The magnets are arranged in groups with group-to-group spacing exceeding magnet-to-magnet spacing. Adjacent edges of the magnets diverge. The method comprises, looking up d- and q-axis currents to provide the requested torque and motor speed for the available DC voltage, combining at least one of the d- and q-axis currents with a field weakening correction term, converting the result from synchronous to stationary frame and operating an inverter therewith to provide current to the coils of the motor. | 12-03-2009 |
20100199489 | METHODS FOR FORMING A MAGNET IN A ROTOR - Methods are provided for forming/inserting a magnet in a rotor. One method includes coating a plurality of magnetizable particles with a non-metallic material, inserting the coated particles in a rotor, and magnetizing the coated particles. Another method includes inserting a plurality of magnetizable particles into a rotor, submersing the rotor in motor varnish or another viscous, non-metallic material to coat the particles, and magnetizing the particles. Yet another method includes inserting a plurality of magnetizable particles in a rotor, inserting a non-metallic material into the rotor, mixing the particles and non-metallic material to form a mixture, curing the mixture to coat each particle with non-metallic material, and magnetizing the particles. Still another method includes mixing a plurality of magnetizable particles with a non-metallic material, curing the non-metallic material to coat each particle with non-metallic material, inserting the coated particles in a rotor, and magnetizing the coated particles. | 08-12-2010 |
20100207471 | POWERTRAIN WITH DUAL ROTOR MOTOR/GENERATOR - A powertrain is provided that includes an engine as well as a transmission having an input member and an output member. The powertrain also includes a motor/generator that has an energizable stator, a first rotor and a second rotor (i.e., a dual rotor motor). Both of the rotors are rotatable via energization of the stator. A first torque-transmitting mechanism, referred to as the engine clutch, is selectively engagable to connect the engine for common rotation with one of the first and the second rotors. A second torque-transmitting mechanism, referred to as the motor clutch, is selectively engagable to connect the first rotor for common rotation with the second rotor. The transmission input member is continuously connected for common rotation with the other of the first and second rotors. | 08-19-2010 |
20100213781 | METHODS AND APPARATUS FOR A PERMANENT MAGNET MACHINE WITH ASYMMETRICAL ROTOR MAGNETS - In general, the various embodiments are directed to a permanent magnet machine (“PM machine”), and more specifically an internal permanent magnet machine (“IPM machine”) that includes rotor magnets configured asymmetrically with respect to the rotor periphery, thereby producing an averaging effect similar to that achieved through traditional skewing of the rotor magnets. In alternate embodiments, the span, placement and/or shape of the magnets may vary from one pole to the next. | 08-26-2010 |
20100277027 | SKEW PATTERN FOR A PERMANENT MAGNET ROTOR - A rotor for an electric machine includes a plurality of magnet stacks having at least five permanent magnets formed into a skew pattern within each of the magnet stacks. The skew pattern has a skew angle and at least two skew steps, and is an angle of rotation about the axis between individual magnets adjacent to the skew steps. The skew pattern may be an axially-symmetric V-shape. The plurality of magnet stacks may have five, six, or eight permanent magnets therein. The number of skew steps may be equal to two or three. The skew angle may be calculated as 360 degrees, divided by the number of skew steps plus one, multiplied by the least common multiple of the number of rotor poles and the number of the plurality of stator slots. | 11-04-2010 |
20100295491 | METHODS AND SYSTEMS FOR DIAGNOSING STATOR WINDINGS IN AN ELECTRIC MOTOR - Systems and methods are provided for identifying a fault condition in stator windings in an electric motor. A method comprises applying a first signal at a first electrical angle to the stator windings and measuring a second signal from the stator windings in response to the first signal. The method further comprises determining a measured response for the electric motor at the first electrical angle based on the second signal and obtaining a nominal response for the electric motor at the first electrical angle. A fault condition is identified when a magnitude of the difference between the measured response and the nominal response is greater than a threshold value. | 11-25-2010 |
20100320864 | METHODS AND APPARATUS FOR A BAR-WOUND STATOR WITH ROTATED CONDUCTORS - A bar-wound stator includes a plurality of bar-type conductors disposed within the plurality of slots, wherein, within each slot, at least one of the bar-type conductors has an orientation that differs from the remaining bar-type conductors within that slot by a predetermined angle. For example, conductors with rectangular cross-sections can be inserted such that the conductors closest to the inner surface of the stator are rotated ninety degrees with respect to the remaining conductors. | 12-23-2010 |
20110037339 | CONCENTRATED WINDING MACHINES WITH REDUCED TORQUE RIPPLE AND METHODS FOR DESIGNING THE SAME - Systems and methods are provided for a motor having a concentrated winding construction with reduced torque ripple. A motor comprises a stator including a plurality of tooth segments disposed circumferentially to establish a hollow core and a rotor rotatably disposed inside the hollow core. The plurality of tooth segments define a plurality of slot openings associated with a plurality of slots. Each slot of the plurality of slots has a slot opening and at least one slot opening of the plurality of slot openings is asymmetric with respect to the plurality of slot openings. | 02-17-2011 |
20110050026 | INSULATION ASSEMBLY FOR A STATOR CORE - An assembly for providing electrical insulation in a stator core of a vehicular electric machine is provided. The stator core has a channel and the assembly comprises a first conductive element disposed through the channel, and a second conductive element disposed through the channel and substantially adjacent to the first conductive element. The assembly also comprises a first electrically insulating film having a first end residing between the first and second conductive elements. | 03-03-2011 |
20110089883 | MOTOR PHASE WINDING FAULT DETECTION METHOD AND APPARATUS - A method of detecting a phase winding fault in a multi-phase electric machine is executable via a motor controller, and includes measuring feedback signals of the machine, including each phase current, and generating reference phase voltages for each phase. The method includes calculating a predetermined voltage value using the feedback signals and reference phase voltages, and comparing the voltage value to a corresponding threshold to determine the fault. A control action is executed when the voltage value exceeds the corresponding threshold. The voltage value is one or more of: a ratio of a normalized zero sequence voltage to a modulation index, an RMS voltage for each phase, and total harmonic distortion of each phase current. An apparatus detects the fault, and includes a motor controller and an algorithm as set forth above. The apparatus may include a voltage inverter for generating a multi-phase alternating current output for powering the machine. | 04-21-2011 |
20110175482 | OPTIMIZED STATOR TOOTH TIP FOR A MOTOR WITH AXIALLY INSERTED STATOR WINDINGS - An electric motor includes a rotor and a stator assembly concentrically located about the rotor. The stator assembly includes a stator stack and a plurality of spaced apart stator teeth extending radially from the stator stack. The plurality of stator teeth defines a plurality of stator slots. Each stator tooth defines a stator tooth tip. The stator tooth tips are shaped to reduce the magnetic flux generated by the stator assembly during operation of the electric motor | 07-21-2011 |
20110187304 | MOTOR PHASE WINDING FAULT DETECTION METHOD AND APPARATUS - A method of detecting a phase winding fault in a multi-phase electric machine is executable via a motor controller, and includes measuring feedback signals of the machine, including each phase current, and generating reference phase voltages for each phase. The method includes calculating a predetermined voltage value using the feedback signals and reference phase voltages, and comparing the voltage value to a corresponding threshold to determine the fault. A control action is executed when the voltage value exceeds the corresponding threshold. The voltage value is one or more of: a ratio of a normalized negative sequence voltage to a modulation index, an RMS voltage for each phase, and total harmonic distortion of each phase current. An apparatus detects the fault, and includes a motor controller and an algorithm as set forth above. The apparatus may include a voltage inverter for generating a multi-phase alternating current output for powering the machine. | 08-04-2011 |
20120218069 | HIGH FREQUENCY ROTARY TRANSFORMER FOR SYNCHRONOUS ELECTRICAL MACHINES - A high frequency rotary transformer for an electrical machine includes a primary transformer component having a primary transformer winding, and a secondary transformer component having a secondary transformer winding. The primary transformer winding is configured to be coupled to a DC power source via a DC to AC converter. The secondary transformer winding is configured to be coupled to a winding of the rotor. Each of the primary and secondary transformer components are mechanically coupled to either the stator or the rotor. The secondary transformer component is configured to rotate with respect to the primary transformer component to produce a magnetic flux via the primary transformer winding and the secondary transformer winding. | 08-30-2012 |
20120286613 | ASYMMETRIC STATOR TEETH IN AN ELECTRIC MOTOR - A permanent magnet motor includes a permanent magnet rotor, a stator surrounding the rotor having a plurality of teeth radially inwardly oriented toward a longitudinal axis of the stator wherein each tooth has a tooth length and a tooth tip surface geometry. An asymmetric air gap is defined by variations in the tooth lengths and tooth tip surface geometries. | 11-15-2012 |
20120293105 | ROTOR SLOT ASYMMETRY IN AN ELECTRIC MOTOR - An electric motor includes a stator configured to receive electrical energy and generate an electromagnetic field in accordance with the electrical energy received. A rotor is in electromagnetic communication with the stator and is configured to rotate in accordance with the electromagnetic field generated by the stator. The rotor includes a plurality of poles including a first set of poles and a second set of poles. The first set of poles defines a first slot and the second set of poles defines a second slot that has a different configuration than the first slot to reduce a torque ripple effect. The electric motor may be used in a system having a power source configured to output direct current energy and an inverter configured to convert direct current energy to alternating current energy. | 11-22-2012 |
20130020896 | ROTOR FOR A PERMANENT MAGNET ELECTRIC MACHINE - A rotor for a permanent magnet electric machine includes an axis of rotation, an outer surface, and a cross-section orthogonal to the axis of rotation with a non-circular contour of the outer surface defined by a plurality of radii angularly distributed around the axis of rotation. | 01-24-2013 |
20130069470 | INTERIOR PERMANENT MAGNET MACHINE WITH RADIALLY ASYMMETRIC MAGNET CONFIGURATION - An interior permanent magnet machine is provided with a rotor that includes a plurality of slots and at least one barrier defined by the plurality of slots. A plurality of first and second magnets are disposed within the barrier. The rotor is configured such that at least one of the first magnets is located at a different radial distance from the center of the rotor relative to at least one of the second magnets. The rotor may be configured to produce an averaging effect similar to that achieved through traditional skewing of rotor magnets. The rotor includes a plurality of poles defined by respective pole axes in the rotor and may be configured to reflect radial asymmetry between poles (pole-to-pole) and/or radial asymmetry within a pole. | 03-21-2013 |
20130147299 | INTERIOR PERMANENT MAGNET MACHINE WITH POLE-TO-POLE ASYMMETRY OF ROTOR SLOT PLACEMENT - An interior permanent magnet machine includes a rotor having a plurality of slots. First and second slots are disposed in a first pole and the third and fourth slots are disposed in a second pole. A first barrier is defined by the first, second, third and fourth slots. The slots are configured to be symmetric relative to their respective pole axes. A first angle is defined between the first and second slots. A second angle is defined between the third and fourth slots. The first angle is configured to be sufficiently different from the second angle so that torque ripple is minimized. Thus the rotor is configured such that the angular configuration of slots in a first pole is different from the angular configuration of slots in a second pole of the rotor. | 06-13-2013 |
20130147302 | ROTOR BARRIER SHAPING FOR DEMAGNETIZATION MITIGATION IN AN INTERNAL PERMANENT MAGNET MACHINE - A rotor core for an Internal Permanent Magnet (IPM) machine includes a cavity having a magnet disposed therein. The cavity defines an air slot adjacent a radially outermost edge of the magnet disposed therein. A leakage flux path extends across the air slot and connects opposing sides of the cavity. The leakage flux path is oriented in an approximate tangential relationship relative to an axis of rotation of the rotor core, and is angled relative to the radially outermost edge of the magnet disposed within the cavity to direct flux away from the magnet. The cavity further includes an air pocket disposed along a radial inner surface of the magnet relative to the axis of rotation, adjacent the air slot of the cavity. | 06-13-2013 |
20130147303 | MULTI-LAYER ARC-SHAPED PERMANENT MAGNET MACHINE WITH REDUCED ROTATIONAL STRESS - An interior permanent magnet machine includes a rotor configured to magnetically interact with a stator. First and second dividers are integrally formed within the rotor and configured to create a first layer of three respective first segments. Each of the respective first segments may be substantially arc-shaped. A plurality of first magnets may be positioned in the first layer. The first magnets may be substantially arc-shaped and defined around an arc center. A third and a fourth divider may be integrally formed within the rotor and configured to create a second layer of three respective second segments. The placement of dividers or structural webs provides for increased rotational speed and reduced rotational stress compared to an undivided arc-shaped magnet configuration. | 06-13-2013 |
20130147309 | ROTOR GEOMETRY FOR REDUCTION OF TORQUE RIPPLE IN A WOUND FIELD MACHINE - An electric machine is provided with a rotor configured to be rotatable within a stator. A first and second tooth are disposed circumferentially along an outer perimeter of the rotor and at least partially define a first slot. The first and the second tooth define a respective first and second outer edge extending between a respective tooth base and a respective tooth tip. An arc radius from the origin to the outer perimeter of the rotor varies along the first outer edge of the first tooth, thereby creating a first non-uniform gap between the rotor and the stator. The arc radius from the origin to the outer perimeter of the rotor varies along the second outer edge of the second tooth, thereby creating a second non-uniform gap between the rotor and the stator. The rotor geometry is configured to reduce torque ripple without skewing either the rotor or the stator. | 06-13-2013 |
20130270952 | AXIALLY ASYMMETRIC PERMANENT MAGNET MACHINE - A permanent magnet machine is provided with a rotor positioned at least partially within a stator. The rotor includes first and second ring segments oriented axially around a central axis. The rotor defines first and second configurations in the first and second ring segments, respectively. The first configuration is sufficiently different from the second configuration such that torque ripple may be minimized. A first layer of slots, defining a slot outer edge, may be formed in the rotor. In one embodiment, a stator-to-slot gap varies between the first and second ring segments. In another embodiment, a stator-rotor gap varies between the first and second ring segments. In another embodiment, a bridge thickness varies between the first and second ring segments. Thus the rotor exhibits axial asymmetry. | 10-17-2013 |
20130270957 | POLE-TO-POLE ASYMMETRY IN INTERIOR PERMANENT MAGNET MACHINES WITH ARC-SHAPED SLOTS - An interior permanent magnet machine includes a rotor formed with a plurality of slots that are substantially arc-shaped and referred to herein as arc segments. A first layer of arc segments are disposed in a first pole. The first layer defines a first configuration relative to a first arc center. A second layer of arc segments are disposed in a second pole. The second layer defines a second configuration relative to a second arc center. The rotor is configured such that the first configuration is different from the second configuration, thereby exhibiting pole-to-pole asymmetry. The first configuration is sufficiently different from the second configuration such that torque ripple may be minimized. In one embodiment, the first layer includes first, second and third arc segments. The rotor may be configured such that the second arc segment is radially offset relative to the first and third arc segments. | 10-17-2013 |
20130328454 | ROTOR HUB ASSEMBLY WITH NON-MAGNETIC RESOLVER SHIELDING RING - A hub assembly for an electric machine includes a rotor hub and a machine rotor. Rotation of the machine rotor generates an electromagnetic (EM) field. The hub assembly includes a resolver rotor that encodes an angular position of the machine rotor as a set of resolver signals. An EM field barrier ring between the resolver rotor and the rotor hub adds a magnetic barrier between the machine rotor and the resolver rotor to reduce noise in the resolver signals. The resolver rotor may be bonded to the EM field barrier ring. The EM field barrier ring may have an L-shaped cross section, and may be press-fitted into a pocket of the rotor hub. A vehicle includes a transmission having an input member and an electric machine having a rotor shaft connected to the input member of the transmission. The electric machine includes the hub assembly noted above. | 12-12-2013 |
20140042860 | INTERIOR PERMANENT MAGNET MACHINE HAVING OFF AXIS CENTERED ARC GEOMETRY - A rotor core defines a plurality of cavities, and includes one magnet disposed within each cavity. Each magnet includes a cross section that defines an arcuate shape having an arc center. The magnets are arranged about a pole axis to define a first group of magnets disposed on a first side of the pole axis, and a second group of magnets disposed on a second side of the pole axis. The arc centers of each of the magnets of the first group of magnets and the second group of magnets are spaced from each other and are spaced from the pole axis. The plurality of magnets is arranged in a plurality of layers. The arc centers of each of the magnets in each of the layers are spaced from each other. | 02-13-2014 |
20140167547 | ELECTRIC MACHINE WITH FRACTIONAL SLOT WINDINGS - An electric machine includes a stator core defining a number of stator slots (Z). A rotor assembly is positioned at least partially within the stator core. The rotor assembly includes at least one permanent magnet and defines a number of poles (M). A plurality of stator windings are positioned in the number of stator slots and define a number of phases (M). The machine defines a non-integer slots per pole per phase value (X), which is expressed as a mixed fraction in the form of A.(B/C), where A, B and C are integers. Optimal configurations for the electric machine are specified that maximize torque while minimizing torque ripple, noise and manufacturing complexity. In one embodiment, the slots per pole per phase value (X) is 2½. In another embodiment, the slots per pole per phase value (X) is 3½. | 06-19-2014 |
20140217848 | INTERIOR PERMANENT MAGNET MACHINE - An interior permanent magnet machine includes a stator including a plurality of electrical conductors. The interior permanent magnet machine further includes a rotor concentrically disposed in relation to the stator. The rotor is configured to rotate relative to the stator about a rotational axis and includes a plurality of polar pieces arranged annularly about the rotational axis. At least one of the polar pieces includes a magnetic layer configured to magnetically interact with the electrical conductors. The magnetic layer has a substantially conic section shape. | 08-07-2014 |
20140252903 | INTERIOR PERMANENT MAGNET MACHINE HAVING A MIXED RARE EARTH MAGNET AND FERRITE MAGNET ROTOR - A rotor core for an internal permanent magnet machine includes at least one ferrite pole and at least one rare earth pole, arranged radially about an axis in alternating relationship. The ferrite poles define a plurality of first pole cavities, and the rare earth poles define a plurality of second pole cavities. One of a plurality of ferrite magnets is disposed within each of the first pole cavities of the ferrite poles, and one of a plurality of rare earth magnets is disposed within each of the second pole cavities of the rare earth poles. | 09-11-2014 |
20140319953 | BAR WOUND STATOR WINDING LAYOUT WITH LONG-PITCHED AND SHORT-PITCHED COILS - A stator assembly includes a plurality of stator slots defining a plurality of slot layers. The assembly includes a plurality of hairpins each having respective first and second legs positioned in respective ones of the slot layers. Each of the hairpins is one of a short-pitched coil, a long-pitched coil and a full-pitched coil. The short-pitched, long-pitched and full-pitched coils are configured to extend over a first, second and third number of the stator slots, respectively. The hairpins may be divided into first, second, third, fourth, fifth and sixth hairpin layers. One of the hairpin layers includes at least one short-pitched coil, and another of the hairpin layers includes at least one long-pitched coil. The first, third and fifth hairpin layers each may include at least two short-pitched coils while the second, fourth and sixth hairpin layers each may include at least two long-pitched coils. | 10-30-2014 |
20140319959 | INSULATION SYSTEM FOR AN ELECTRIC MACHINE - A bar wound stator includes a stator core defining a plurality of slots. Bar-type conductors are disposed within each slot. Each slot includes a slot liner and an insulator cap. Each slot liner includes an end portion disposed against an inner wall surface, and side portions disposed against a first wall surface and a second wall surface respectively. Each insulator cap includes a base portion disposed against an outer wall surface, and side portions disposed against the first wall surface and the second wall surface respectively. The side portions of the insulator cap in each slot overlap the side portions of the slot liner in each slot along the first wall surface and the second wall surface respectively. Each slot includes a recessed feature in each of the first wall surface and the second wall surface to accommodate the overlapping side portions of the insulator cap and the slot liner. | 10-30-2014 |
20150022126 | METHOD AND APPARATUS FOR MONITORING A PERMANENT MAGNET ELECTRIC MACHINE - A controller-implemented method for monitoring a permanent magnet electric machine includes determining a threshold direct-axis (d-axis) current corresponding to inception of irreversible demagnetization of the permanent magnet based upon material properties of a permanent magnet mounted in a rotor of the PM electric machine and a temperature of the permanent magnet. A d-axis current associated with controlling the PM electric machine is determined, and a state of health of the PM electric machine is determined based upon the threshold d-axis current and the monitored d-axis current. | 01-22-2015 |
20150028713 | STATOR ASSEMBLY WITH WINDING SETS HAVING HAIRPINS FROM MULTIPLE HAIRPIN LAYERS - A stator assembly includes a plurality of stator slots defining multiple slot layers. The assembly includes a plurality of hairpins each having a respective first leg positioned in one of the multiple slot layers and a respective second leg positioned in another of the multiple slot layers. Each hairpin is configured to allow a current to flow from the respective first leg to the respective second leg. The plurality of hairpins is divided into multiple hairpin layers. The hairpins form multiple winding sets, such as first, second, third and fourth winding sets. Each of the winding sets at least partially includes the hairpins from at least two of the multiple hairpin layers. The multiple slot layers may include six slot layers. The multiple hairpin layers may include six hairpin layers. Thus, at least one of the hairpin layers may be “shared” by two winding sets. | 01-29-2015 |
20150084452 | INTERIOR PERMANENT MAGNET MACHINE WITH POLE-TO-POLE ASYMMETRY OF ROTOR SLOT PLACEMENT - An interior permanent magnet machine includes a rotor having a plurality of slots. First and second slots are disposed in a first pole and the third and fourth slots are disposed in a second pole. A first angle is defined between respective centerlines of the first and second slots. A second angle is defined between respective centerlines of the third and fourth slots. The first angle is configured to be sufficiently different from the second angle so that torque ripple is reduced. Thus the rotor is configured such that the angular configuration of slots in a first pole is different from the angular configuration of slots in a second pole of the rotor. | 03-26-2015 |