Sundstrand Corporation

Hamilton Sundstrand Corporation

Hassan Mansir

Roger M Shervington

Vijay K Maddali

John F Defenbaugh

David G Halsey

Jayant G Vaidya

Madan L Bansal

Thomas S Latos

Robert Grennan

Mohammad Shahamat

William J Greenlee

Dam Nguyen

John Hefter

Carl Wagner

Kurt Duesterhoeft

Dennis M Kramer

An apparatus for limiting a peak voltage of a generator provides an auxiliary winding within the stationary exciter filed magnetic structure. The auxiliary winding is coupled to a controllable current source that provides a current to the auxiliary winding based upon an operating speed of the generator. The current flow is effective for moving the quiescent flux bias point of the exciter field magnetic structure for limiting the peak voltage for any operating speed of the generator.

Apparatus and method for limiting generator peak voltage

Losses in efficiency of operation of a dynamoelectric machine as a result of eddy current losses and poor coolant efficiency and/or disruption of the magnetic circuit in a rotor by coolant passages is avoided in a dynamoelectric machine including a stator (18) in which a rotor (16) is journaled. The rotor includes a stack (16) of thin laminations (17) made of a ferromagnetic material to define a rotor body. The rotor body includes a plurality of equally angularly spaced poles (58) separated by recesses (64). Coolant passages (76) located in the rotor at or just radially inward of the base (72) of each pole (58) and substantially radially outward of the rotational axis (56) of the rotor (14) to maximize cooling efficiency of the poles (58) without disrupting the magnetic circuit in the rotor. Slots (80) are placed in the tips (70) of the poles (58) of selected laminations (17) and extend generally radially inward to reduce eddy current losses.

Rotor for a dynamoelectric machine

Axial compactness is achieved in a generator set including an internal combustion (10) having a main shaft (16) journalled for rotation about an axis (56) and having an end (18, 54) with a flywheel (20) mounted on the end. A first rotatable magnet assembly (21) having axially facing poles is disposed on the flywheel (20) and a stator (24, 72) including generator windings (102, 104) is provided adjacent the magnets (21). A second rotatable magnet assembly (21, 22) is opposite the first magnet assembly (21) and adjacent the stator (24, 72) and has axially facing poles directed toward the poles on the first magnetic assembly (21) and is coupled to the first magnetic assembly for rotation therewith.

Axially compact generator set and refrigeration system employing the same

A multiple output synchronous generator in accordance with the instant invention comprises a stator having a first stator winding having a number of poles p and a second stator winding having a number of poles 2*p*n where p and n are any whole numbers, the first and second stator windings being wound utilizing a 60.degree. phase belt winding configuration such that the first stator winding is magnetically decoupled from the second stator winding preventing interaction therebetween. The generator additionally comprises a rotor rotatably disposed within the stator defining an airgap therebetween. The rotor has a first field winding of a first polarity and a second field winding having a second number of windings wound thereon for generating a flux across the airgap such that the flux induces a voltage in the first and second stator windings. These first and second field windings are configured such that the flux generated in the airgap comprises a fundamental component and an even harmonic component of substantially equal magnitude. The winding configuration of the stator and rotor insure that only the fundamental flux component and odd harmonics induce a voltage in the first stator winding, and only the even harmonic component and even harmonics induce a voltage in the second stator winding. The magnetic decoupling of the first and second stator windings ensures that harmonic distortion induced in the second output by external equipment powered thereby is not reflected in the first output, thereby maintaining a 'clean-bus' for use by utilization equipment sensitive to such distortion.

Multiple output decoupled synchronous generator and electrical system

A quasi regulated electric generator, comprising a stator having teeth on an inner periphery defining slots therebetween, stator windings disposed in the slots forming output phases, a rotor rotatably mounted within the stator, the rotor having permanent magnets mounted thereon forming rotor poles which induce a voltage in the stator windings when the rotor is driven by an external prime mover, and a series saturation circuit coupled to an external source of dc current for saturating the stator, decreasing the induced voltage thereby. Magnetic slot closers are placed in the slots in which are disposed the series saturation circuit to aid tooth saturation.

Quasi regulated permanent magnet generator

A voltage regulator for a DC power generation system which is comprised of a prime mover driven generator producing an AC voltage output which is rectified to a DC voltage output for use by the system senses the AC voltage output and the DC voltage output, and selects the lower of these two for comparison with a voltage reference to produce a voltage error output signal for use in controlling the DC voltage output. The voltage regulator further comprises tuned compensation of the error output signal prior to use in controlling the DC voltage output. The tuned compensation comprises a proportional-integral lead-lag network. The voltage regulator additionally senses the AC current generated by the generator, and adjusts at least one zero location of the compensation network in response thereto to improve stability margins during light loading conditions, and to improve transient performance requirements under heavier loading conditions.

Voltage regulator and method for DC power generating system

A system of protection for an AC/DC hybrid electric power generation and distribution system having an AC portion comprising at least one source of AC power producing AC current coupled by first power feeders to a DC portion comprising at least one AC to DC converter producing DC current, the DC current being coupled by second power feeders to utilization equipment, comprises AC current sensors producing current sense signals proportional in magnitude to the AC current and DC current sensors producing current sense signals proportional in magnitude to the DC current. The AC current sensors define an entrance to a zone of protection, and the DC current sensors define an exit from the zone of protection. The AC and DC current sense signals are relationally compared to detect the presence of a differential current fault within the zone of protection. The protection system further discriminates the location of the fault between the AC portion and the DC portion of the hybrid power system by monitoring the ripple content in the sensed AC current. The relationship function utilized varies with the type of AC to DC conversion equipment to compensate for the power loss and transformer step up or down ratio (if used) to ensure tracking of the current level between AC current and DC output current. In addition to differential current fault protection, the instant invention detects shorted and open rectifiers, phases, and sensors.

Differential current fault protection for an AC/DC hybrid system and

A switched reluctance machine comprises a stator having an even plurality of salient stator poles, each of which having a stator winding disposed thereon and electrically coupled one to another to form diametrically opposed pole pairs which may be coupled to an external source of electrical energy, a rotor having an even plurality of salient rotor poles, and at least one compensation coil disposed on each of the rotor poles. The compensation coils are electrically coupled one to another to form diametrically opposed compensation pairs in which flows a flux generating current when one of the stator windings of a pole pair is either open of shorted. The flux generated equalizes the unbalance forces resulting from the faulted stator winding, thereby increasing the fault tolerant capability of the switched reluctance machine.

Switched reluctance machine having unbalance forces compensation coils

The problem of effectively and quickly detecting fault conditions in an electromotive machine (10) is solved using a current transformer assembly (28) having a neutral lead (44). The neutral lead (44) comprises a single piece copper strap (80) having laterally extending strips or posts (81-83) provided for connection to the neutral end conductors (31-33) of armature windings (22 and 24). The strap (80) is punched and bent into shape to include the three neutral posts (81-83). Each neutral post (81-83) carries a current transformer (46-48).

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Rockford, IL, United States of America

Hassan Mansir