Abstract: A winding of an electric machine is provided, where the winding includes at least one series of serially connected AC bars. Each AC bar includes a series of serially connected turns formed by litz wire having a plurality of strands, and at least one cooling tube. Individual strands of the plurality of strands are respectively positioned substantially adjacent to the at least one cooling tube at at least one transfer point for providing heat transfer from the respective individual strands to the at least one cooling tube.

Abstract: Keybar voltages in electric machines are reduced by electromagnetically optimizing the positioning of the keybars with respect to stator winding phase belts, the selection of the number of keybars, the selection of the number of stator slots, and/or the direction of rotation of a rotor with respect to the stator.

Abstract: A fault current limiter (FCL) comprises: an air core flat clock spiral inductor comprising wound electrically conductive material and insulated turns; and two terminations configured for attaching the spiral inductor in series with a power carrying conductor.

Abstract: A differential probe is scanned along a stator core tooth portion to detect lamination faults. The probe utilizes two magnetic flux injection yokes arranged side-by-side in relatively close proximity, each yoke having two arm portions and two core-tooth flux-injection surfaces, each yoke being wound with an excitation coil winding and at least one yoke-arm of each yoke having a magnetic flux sensor. Current is supplied to the excitation coil windings on each yoke to inject magnetic flux into the stator core laminations while the probe is moved in a scanning process along the core teeth across the laminations. The magnetic flux differential detected at adjacent regions in the core by flux sensors on each of the two yokes is used to incrementally evaluate the core for laminations faults. The output produced by the differential probe may be converted to a digital signal and provided to a computer system for storage and future analysis.

Abstract: A probe includes at least one core and at least one sense coil associated with the core. The ends of the core are arranged in a contact-free, spaced relationship between opposed surfaces of adjacent lamination teeth of a stator. Air gaps are maintained between the ends of the probe core and the opposed surfaces. The total of the two air gaps is constant. The probe is supported on a carriage arrangement and moved along the teeth. Variations in leakage flux produced with the stator energized with an energization winding to produce a flux which is a few percent of is normal energization level, are monitored.

Abstract: A method for evaluating core stack pressure includes: positioning a magnetic yoke near the core, the magnetic yoke being wound by an excitation winding; supplying current to the excitation winding to inject magnetic flux into the core; measuring a signal resulting from the injected magnetic flux; and using the measured signal to evaluate the core stack pressure. A system for implementing the method includes the magnetic yoke; a current supply for supplying the current; a sensor for measuring the signal; and a computer for using the measured signal to evaluate core stack pressure.

Abstract: A hybrid synchronous machine includes a cylindrical element having slots; excitation windings situated in at least some of the slots; and permanent magnets situated in at least some of the slots. For a hybrid salient pole machine 16 a cylindrical element has salient poles with excitation windings situated around the salient poles and permanent magnets supported by the salient poles.

Abstract: A differential probe is scanned along a stator core tooth portion to detect lamination faults. The probe utilizes two magnetic flux injection yokes arranged side-by-side in relatively close proximity, each yoke having two arm portions and two core-tooth flux-injection surfaces, each yoke being wound with an excitation coil winding and at least one yoke-arm of each yoke having a magnetic flux sensor. Current is supplied to the excitation coil windings on each yoke to inject magnetic flux into the stator core laminations while the probe is moved in a scanning process along the core teeth across the laminations. The magnetic flux differential detected at adjacent regions in the core by flux sensors on each of the two yokes is used to incrementally evaluate the core for laminations faults. The output produced by the differential probe may be converted to a digital signal and provided to a computer system for storage and future analysis.

Abstract: A probe includes at least one core and at least one sense coil associated with the core. The ends of the core are arranged in a contact-free, spaced relationship between opposed surfaces of adjacent lamination teeth of a stator. Air gaps are maintained between the ends of the probe core and the opposed surfaces. The total of the two air gaps is constant. The probe is supported on a carriage arrangement and moved along the teeth. Variations in leakage flux produced with the stator energized with an energization winding to produce a flux which is a few percent of is normal energization level, are monitored.

Abstract: A power generator that operates at a reduced temperature level includes a flux shunt that reduces the amount of fringing magnetic flux axially impinging upon a stator, flange, and multiple keybars during operation of the generator. By reducing the amount of axially impinging flux, the flux shunt reduces an operating temperature of the stator and flange and reduces a voltage differential between keybar voltages induced by the flux in the multiple keybars.

Abstract: A method for evaluating core stack pressure includes: positioning a magnetic yoke near the core, the magnetic yoke being wound by an excitation winding; supplying current to the excitation winding to inject magnetic flux into the core; measuring a signal resulting from the injected magnetic flux; and using the measured signal to evaluate the core stack pressure. A system for implementing the method includes the magnetic yoke; a current supply for supplying the current; a sensor for measuring the signal; and a computer for using the measured signal to evaluate core stack pressure.

Abstract: A power generator that operates at a reduced temperature level includes a flux shunt that reduces the amount of fringing magnetic flux axially impinging upon a stator, flange, and multiple keybars during operation of the generator. By reducing the amount of axially impinging flux, the flux shunt reduces an operating temperature of the stator and flange and reduces a voltage differential between keybar voltages induced by the flux in the multiple keybars.

Abstract: A power generator that operates at a reduced temperature level includes a flux shunt that reduces the amount of fringing magnetic flux axially impinging upon a stator, flange, and multiple keybars during operation of the generator. By reducing the amount of axially impinging flux, the flux shunt reduces an operating temperature of the stator and flange and reduces a voltage differential between keybar voltages induced by the flux in the multiple keybars.

Abstract: A hybrid synchronous machine includes a cylindrical element having slots; excitation windings situated in at least some of the slots; and permanent magnets situated in at least some of the slots. For a hybrid salient pole machine 16 a cylindrical element has salient poles with excitation windings situated around the salient poles and permanent magnets supported by the salient poles.

Abstract: A fault current limiter (FCL) comprises: an air core flat clock spiral inductor comprising wound electrically conductive material and insulated turns; and two terminations configured for attaching the spiral inductor in series with a power carrying conductor.

Abstract: A stator core-end of an electric generator utilizes amorphous metal laminate packages to reduce eddy currents and heating in the stator core thereby increasing generator capacity. The packages are formed as complete units before installation into the stator core. The amorphous metal laminate packages comprise alternating layers of amorphous metal laminates and non-amorphous metal laminates.

Abstract: A hybrid synchronous machine includes a cylindrical element having slots; excitation windings situated in at least some of the slots; and permanent magnets situated in at least some of the slots, the permanent magnets comprising radially magnetized permanent magnets.

Abstract: An assembly for transferring current comprises at least one electrically conductive slip ring; at least one electrically conductive brush for supplying current to the at least one slip ring; and an electric or pressure actuator driven vibration source for changing the position of the brush with respect to the slip ring. If desired, brush current can shared by using inductance variations or by selective coupling of rotor windings to the slip rings.

Abstract: A method for detecting core faults comprises: (a) positioning a magnetic yoke near at least one tooth of the core, the magnetic yoke being wound by a winding and comprising two core-facing surfaces and at least one flux sensor situated on at least one of the two core-facing surfaces; (b) supplying current to the winding to inject magnetic flux into the at least one tooth of the core; (c) using the at least one flux sensor to measure a signal resulting from the injected magnetic flux; and (d) using the measured signal to detect variations in flux on the at least one core-facing surface representative of core faults.

Abstract: A method for detecting core faults includes: positioning a magnetic yoke near at least one tooth of the core, the magnetic yoke being wound by a winding and comprising two core-facing surfaces and at least one flux sensor situated on at least one of the two core-facing surfaces; supplying current to the winding to inject magnetic flux into the at least one tooth; using the at least one flux sensor to measure a signal resulting from the injected magnetic flux; and using the measured signal to detect variations in flux on the at least one core-facing surface representative of core faults. A system includes: at least one magnetic yoke for being positioned near at least one tooth of the core and being wound by a winding and comprising two core-facing surfaces; and at least one flux sensor situated on at least one of the two core-facing surfaces.