Abstract: An alternator system having an alternating current (ac) voltage source includes a switched-mode rectifier (SMR) coupled to the ac voltage source and having an output port coupled to an output of the alternator system, and a controller coupled to said switched-mode rectifier so as to provide a controlled pulse sequence synchronized with an angular rotor position of the (ac) voltage source to activate and deactivate the switched-mode rectifier. The controller further includes a PWM generator having a first input to receive a total duty ratio signal synchronized with an angular rotor position of the (ac) voltage source. The switched mode rectifiers are controlled to increase power output levels at lower speeds near idle. The controller combines improved idle speed power output levels with load matching improvements from PWM control for more efficient operation when compared to circuits using conventional control or PWM load matching control alone.

Abstract: The present invention provides a means to reduce holding current and driving current of EMVD's effectively and practically and to provide soft landing of a valve. The invention incorporates a nonlinear mechanical transformer as part of an EMVD system. The nonlinear mechanical transformer is designed for the spring and the inertia in the EMVD to have desirable nonlinear characteristics. With the presently disclosed invention, the holding current and driving current are reduced and soft valve landing is achieved. The nonlinear characteristics of a nonlinear mechanical transformer can be implemented in various ways. The concept of the invention can be applied not only to EMVD's but also to general reciprocating and bi-stable servomechanical systems, where smooth acceleration, soft landing, and small power consumption are desired.

Abstract: An alternator system having an alternating current (ac) voltage source includes a switched-mode rectifier (SMR) coupled to the ac voltage source and having an output port coupled to an output of the alternator system, and a controller coupled to said switched-mode rectifier so as to provide a controlled pulse sequence synchronized with an angular rotor position of the (ac) voltage source to activate and deactivate the switched-mode rectifier. The controller further includes a PWM generator having a first input to receive a total duty ratio signal synchronized with an angular rotor position of the (ac) voltage source. The switched mode rectifiers are controlled to increase power output levels at lower speeds near idle. The controller combines improved idle speed power output levels with load matching improvements from PWM control for more efficient operation when compared to circuits using conventional control or PWM load matching control alone.

Abstract: The present invention provides a means to reduce holding current and driving current of EMVD's effectively and practically and to provide soft landing of a valve. The invention incorporates a nonlinear mechanical transformer as part of an EMVD system. The nonlinear mechanical transformer is designed for the spring and the inertia in the EMVD to have desirable nonlinear characteristics. With the presently disclosed invention, the holding current and driving current are reduced and soft valve landing is achieved. The nonlinear characteristics of a nonlinear mechanical transformer can be implemented in various ways. The concept of the invention can be applied not only to EMVD's but also to general reciprocating and bi-stable servomechanical systems, where smooth acceleration, soft landing, and small power consumption are desired.

Abstract: An alternator system having an alternating current (ac) voltage source includes a switched-mode rectifier (SMR) coupled to the ac voltage source and having an output port coupled to an output of the alternator system, and a controller coupled to said switched-mode rectifier so as to provide a controlled pulse sequence synchronized with an angular rotor position of the (ac) voltage source to activate and deactivate the switched-mode rectifier. The controller further includes a PWM generator having a first input to receive a total duty ratio signal synchronized with an angular rotor position of the (ac) voltage source. The switched mode rectifiers are controlled to increase power output levels at lower speeds near idle. The controller combines improved idle speed power output levels with load matching improvements from PWM control for more efficient operation when compared to circuits using conventional control or PWM load matching control alone.

Abstract: A magnet carrier assembly for holding and carrying a high-energy-product permanent magnet is arranged for releasable attachment to a rotor of an axial disc or drum type rotor in an electric machine. The permanent magnet placed in a container which then receives a cover. The magnet carrier assembly includes a mounting flange at one end and a locating and mounting tab at an opposite end for attaching the assembly to the rotor. In certain applications, the rotor has recesses which have a size and shape complementary to the size and shape of the magnet carrier assembly. The recesses are circumaxially located around the radial periphery of the rotor at the poles of the rotor. In other embodiments, the magnet carrier assembly includes a key which is received in a mating groove in a rotor surface and is used to transfer to the rotor the electromagnetic shear force developed by the high-energy-product permanent magnet.

Abstract: A magnet carrier assembly for holding and carrying a high-energy-product permanent magnet is arranged for releasable attachment to a rotor of an axial disc or drum type rotor in an electric machine. The permanent magnet placed in a container which then receives a cover. The magnet carrier assembly includes a mounting flange at one end and a locating and mounting tab at an opposite end for attaching the assembly to the rotor. In certain applications, the rotor has recesses which have a size and shape complementary to the size and shape of the magnet carrier assembly. The recesses are circumaxially located around the radial periphery of the rotor at the poles of the rotor. In other embodiments, the magnet carrier assembly includes a key which is received in a mating groove in a rotor surface and is used to transfer to the rotor the electromagnetic shear force developed by the high-energy-product permanent magnet.

Abstract: When a closed circuit is formed by joining superconducting wires with superconducting joints, the current in that circuit adjusts itself as required to maintain whatever total flux linkage the circuit had at the instant superconductivity was achieved. In particular, a closed circuit which first becomes superconducting under conditions of zero net flux linkage maintains zero net flux linkage as long as the circuit remains superconducting. By appropriately configuring a set of short-circuited superconducting coils, a field inside a volume described by the coils is kept substantially more uniform than it would be if the same volume were magnetized by the same source in the absence of the short-circuited coils. This property is used to insure that the volume within the coils exhibits improved magnetic field homogeneity.

Abstract: In the design of large electromagnets having high magnetic field uniformity requirements it is common practice to employ a set of correction coils and coil circuits, each coil being excited so as to correct for a specially defined, symmetrically shaped error field. The error field is typically defined as certain terms in a spherical harmonic expansion for the field. The present invention proposes instead to provide a set of correction coil circuits in which the creation of a desired spherical harmonic is achieved by exciting a set of correction coils with a specified set of currents, and in which the same coils can further be used to create a spherical harmonic of substantially different symmetry by exciting the same coils with a different set of currents. In the present invention, a linear combination of spherical harmonic components may be effected, so as to increase the flexibility of operation and the correction capability of the magnet and correction coil structure.

Abstract: A small portion of a lead for a superconducting coil is made to function as a controllable resistor with a low resistance value and fast thermal response so as to be capable of rapidly being switched between the superconducting and resistive states. The device is thus capable of fine adjustment of the current flowing in a superconducting loop. The switch includes lengths of parallel conductor so that the resulting section of superconductive material is cryostable. The superconducting oil lead is disposed on a substrate so as to permit ready access for helium or other cryogenic coolant to most lead surfaces. The small mass and close contact with the coolant produce rapid turn-on and turn-off response characteristics. Furthermore, the low overall resistance causes the coil current to decay slowly, thus preventing precise control of the superconducting current.

Abstract: Disclosed is a winding for a high voltage electrical generator comprising a plurality of bundles of conducting member arranged whereby highest voltage is impressed on the innermost bundle and lowest voltage is impressed on the outmost bundles. The bundles of the winding are wrapped within sheets of electrical insulation with the cumulative insulation thickness being in approximate proportion to the voltage gradient across the bundles of the winding.

Abstract: A star (wye) connected air gap polyphase armature having limited voltage differences between physically adjacent coil windings at the phase boundary for the different phase circuits. The unconnected lead of the coil or coils at the first edge of the phase belt region forms the neutral terminal for connection of the phase winding in a star or wye circuit comprised of other similarly formed phase windings, and the unconnected lead of the last coil or coils remaining at the middle of the phase belt region forms the line terminal for the multiple coil phase winding to thereby minimize voltage differences between turns of physically-adjacent phase windings at the phase boundaries.

Abstract: In a dynamoelectric machine having armature conductors located in the air-gap separating rotor and stator, the conductors are secured to the stator structure. Conductor fastening means are provided which maintain the armature conductors and their support members in compression in all modes of operation of the machine.

Abstract: Armature conductors are mounted to the ferromagnetic stator core of an AC machine by a plurality of flexible supports. Each support comprises a plurality of teeth interleaved with spacers having a discontinuity which creates a spring section on each tooth. The structure of the support provides a flexible mounting which will accommodate differential thermal expansion between the armature conductors and the stator core during operation while providing rigid attachment between the conductors and the stator core in the radial and azimuthal directions.