Gm Global Technolgoy Operations, Inc.

Trw Limited

Rajeev Vyas

Chandra S Namuduri

Thomas W Nehl

Peter James Savagian

Varsha K Sadekar

Alexandru Rajala

Mark J Rychlinski

Suresh Gopalakrishnan

Lei Hao

Alireza Fatemi

Michael G Reynolds

William T Ivan

Stephen Gregory Poulos

Markus Demmerle

Fausto Eleazar Vazquez Flores

Ashish V Gadre

William A Powers, Jr

An electric machine including a stator, a rotor within the stator, and a shaft to which the rotor is mounted. The shaft extends through the stator. A first bearing and a second bearing support the shaft within the stator to allow the shaft and the rotor to rotate within the stator. The rotor is between the first bearing and the second bearing. A first magnetic core is at the shaft between the rotor and the first bearing. The first magnetic core is configured to suppress a bearing current flowing across the shaft, the first bearing, and the second bearing.

System for reducing bearing currents in an electric machine

A method for identifying and mapping a maximum instantaneous stall torque capability of a fuel cell cathode valve includes: maintaining a temperature of an electric motor at a predetermined temperature, wherein the predetermined temperature is equal to or less than a freezing point of water (0&#xb0; C.), and the electric motor includes motor brushes, commutator poles, a stator, a rotor rotatable with respect to the stator, and a shaft coupled to the rotor; locking the shaft of the electric motor such that the shaft is incapable of rotating, thereby fixing the shaft at a locked position; mounting the shaft of the electric motor to a dynamometer; supplying electrical energy to the electric motor; monitoring an instantaneous stall torque of the electric motor; and monitoring a rotor electrical resistance.

Identification and mapping of fuel cell cathode valve ice breaking stall torque capability

A vehicle including a cooling fan that is rotatably coupled to an electric motor that is electrically powered by a DC power source via an inverter is described. A method for controlling the cooling fan includes monitoring, via a first controller, a vehicle speed, and selecting a preferred operating state for the electric motor based upon the vehicle speed. The preferred operating state includes one of a first command associated with controlling the cooling fan to force air through the cooling system, a second command associated with a fan brake request, and a third command associated with an energy recovery mode. A discrete message from the first controller is communicated to an inverter controller, wherein the discrete message is based upon the preferred operating state for the electric motor. The inverter controller controls the inverter to control the electric motor in response to the discrete message.

Method and apparatus for controlling an electric motor of a cooling fan

An electrical system includes a direct current (DC) voltage bus, a power supply providing a supply voltage to the DC voltage bus, an electric machine connected to the power supply, a reverse current protection (RCP) circuit positioned between the power supply and the electric machine, the RCP circuit including an energy dissipating element, and a controller. As part of an associated method, the controller detects a reverse current condition in which a current flows from the electric machine toward the power supply when an induced voltage of the electric machine exceeds a voltage level of the voltage bus. The controller transmits a control signal to the RCP circuit to direct the electrical current through the energy dissipating element for a duration of the reverse current condition or for a predetermined duration equal to or greater than that of the reverse current condition.

Electrical system with reverse current protection circuit

A rotor of a permanent magnet synchronous machine includes a rotor core structure. A first set of apertures are formed in a first radial layer of the rotor core structure having a first set of permanent magnets disposed therein forming respective poles. A second set of apertures formed in a second radial layer of the rotor core structure of each pole. A third set of apertures is formed in a third radial layer of the rotor core structure. A second set of permanent magnets is inserted within the third set of apertures. A plurality of bridges each extends across a respective side of each of the third set of apertures in the third radial layer. The plurality of bridges provides structural support of the rotor core structure when operating. The plurality of bridges are integrally formed as single-piece laminations.

Spoke-type PM machine with bridge

A conductor is provided for an electric machine having an axis, a radial direction extending outward from the axis, and a tangential direction perpendicular to the radial direction. The conductor includes a solid core, having radial faces substantially perpendicular to the radial direction of the electric machine and tangential faces substantially perpendicular to the tangential direction of the electric machine. At least one tangential depression is formed on at least one of the tangential faces. The tangential depression creates a tangential void within a rectangular envelope defined by the solid core. Therefore, the surface area of the solid core is greater than the surface area of the rectangular envelope.

Bar conductor shapes for electric machines

A rotor for an interior permanent synchronous machine. A rotor core structure includes an outer cylindrical wall juxtaposed to an air gap. A plurality of arcuately-shaped cavities is formed within the rotor core structure. The plurality of arcuately-shaped cavities is substantially concentrically layered with respect to an outer cylindrical wall of the rotor core structure. Each arcuately-shaped cavity extending between first and second end sections is juxtaposed to the outer cylindrical surface wall of the rotor structure and includes an intervening center section. A plurality of permanent magnets is inserted within the plurality of arcuately-shaped cavities. Each first end section retains a respective first permanent magnet having a first magnet field strength. Each second end section retains a respective second permanent magnet having the first magnetic field strength. Each center section retains a respective third permanent magnet having a second magnet field strength less than the first magnetic field strength.

Bi-permanent magnets in synchronous machines

A rotor for a permanent synchronous machine includes a rotor having a plurality of arcuately-shaped cavities formed within a rotor core structure. The plurality of arcuately-shaped cavities substantially concentrically layered with respect to an outer cylindrical wall of the rotor core structure. A plurality of permanent magnets is inserted within the plurality of arcuately-shaped cavities. Each cavity layer retains a permanent magnet of a first magnetic field strength disposed in end sections and a permanent magnet of a second magnetic field strength in a center section of each cavity layer. Each respective cavity includes an air barrier formed between the magnets having different magnetic field strengths. The air barrier generates a reluctance within an air barrier gap for directing a flow of flux generated by each third permanent magnet in a preceding layer in a direction toward each third permanent magnet in a succeeding layer.

Magnetic barrier for minimizing demagnetization in bi-permanent magnet synchronous machines

A conducting wire for a stator of an electric machine includes a cross section having a first side, a second side, a third side and a fourth side. The third side and the fourth side are parallel with each other, with the first side and the second side extending between the third side and the fourth side. The first side and the second side each define a concave depression.

Conducting wire for electric machine

An interior permanent magnet (IPM) machine having a rotor and a stator is provided. The rotor includes a radially inner barrier devoid of magnets, and a radially outer barrier having at least one permanent magnet, each barrier having two pockets with one pocket disposed at an angle relative to the other. At least one of the pockets of the inner barrier has a shape of an irregular quadrilateral. At least one of the pockets of the outer barrier has a substantially trapezoidal shape with a first side generally parallel to a second side, wherein the first side has a portion slanted relative to the third side. In such an IPM machine, demagnetization of the outer barrier magnet is limited when operating temperatures and electrical current exceed operating conditions prescribed by design specifications.

Interior permanent magnet machine

A rotor (,) for an electric machine (,) includes a first elongated rotor segment (,) having a plurality of axially extending rotor poles (,) arranged in a circular array about a central axis (,) that extends longitudinally through the first rotor segment(,). A second axially extending rotor segment (,) engages and is fixed relative to the first rotor segment (,). The second rotor segment (,) has a plurality of axially extending rotor poles (,) arranged in a circular array about the central axis (,). The poles (,) of the second rotor segment (,) are rotated in a first direction about the central axis relative to the poles (,) of the first rotor segment (,). Preferably the rotor (,) also includes a third axially extending rotor segment (,) that engages and is fixed relative to at least one of the first and second rotor segments (,). The third rotor segment (,) also has a plurality of axially extending rotor poles (,) arranged in a circular array about the central axis (,). The poles (,) of the third rotor segment (,) are rotated about the central axis (,) relative to the poles (,) of each of the first and second rotor segments (,).

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Rochester Hills, MI, United States of America

Rajeev Vyas