Sundstrand Corporation

Clarence F Dolan

Mahesh J Shah

Bernard A Raad

Derek N Walton

Walter J Iseman

Jeffrey D Baldwin

Anthony Blakeley

Derrick N Walton

Leakage of a coolant into the air gap (16) of a dynamoelectric machine so as to cause undesirable windage losses may be avoided through the use of a composite rotor sleeve (44) including a continuous film (46) of polyimide material on its radially inner surface and surrounding the machine rotor (22).

Composite rotor sleeve

A brushless electrical power generating system (10) in accordance with the invention includes a main generator (16) having a rotor (30) on which is wound a field winding (32) and a stator (112) on which is wound a winding (36) for producing an alternating current electrical output having at least one phase; an exciter (14) having a rotor (24) mounted coaxial to the rotor of the main generator and a stator (110) on which is wound a stator winding (18) and an electrical field shield (40) disposed between the stators of the exciter and the main generator for shielding the winding of the stator of the main generator from an electric field produced by the winding of the stator of the exciter whereby capacitive coupling of any electrical noise present within the current flowing in the stator winding of the exciter to the alternating current electrical power output is reduced.

Electrical power generating system having reduced conducted emissions in

A brushless generator in accordance with the present invention includes a main generator having a stator (12) on which is wound at least one phase winding (52-56), each phase winding producing a phase output (.PHI.A-.PHI.C); a number of current transformers (20-24) equal in number to a number of phases present in the main generator, each current transformer being magnetically coupled to a conductor (48) of a different phase winding; and a plurality of annular disks (40), equal in number of the number of phases, each annular disk having an annulus (46) containing the conductor of the phase winding of a different phase, slot (42) extending from an inner radius (44) defining the annulus to an outer radius (50) defining an outer cirucmference of the disk, each annular disk being held by a support (10) for the current transformer, having a permeability greater than 1020-type steel and attenuating harmonics of a fundamental frequency of AC produced by the main generator.

Brushless electrical power generator with reduced harmonics

A brushless electrical power generating system (100) in accordance with the invention includes an exciter (14) for producing alternating current from an exciter rotor; a rectifier (20) mounted for rotation with the exciter rotor for producing a rectified control current from the AC current; a common mode inductor (112), coupled to the control current, for cancelling common mode noise components within the rectified control current; and a main generator (22), having a rotating field winding (24) mounted on a main generator rotor excited by the control current and producing an alternating current power output from a stator.

Brushless power generating system having reduced conducted emissions in

A starting system and method for starting a prime mover connected to a generator by an actuable torque link utilizes a hybrid permanent magnet/induction machine having a rotor coupled to a rotor of the main generator and a stator having windings therein. The method includes the step of applying AC power to the hybrid machine stator windings so that the hybrid machine initially acts as an induction motor to accelerate the hybrid machine rotor, following which the hybrid machine acts as a synchronous motor to rotate the main generator rotor at a particular speed DC power is then applied to a main generator field winding and AC power is supplied to a set of main generator armature windings so that the main generator operates as a synchronous motor to develop motive power the torque link is activated once the main generator is operating as a synchronous motor to bring the prime mover up to self-sustaining speed. Inasmuch as the hybrid machine may comprise part of a brushless synchronous generator, the present system and method does not require additional components and reduces transients in the AC power applied to the hybrid machine and generator.

Starting system and method using a hybrid permanent magnet/induction

A starting system for starting a prime mover connected to a generator by a torque link includes an induction motor having a torque rating substantially equal to the minimum torque required to rotate the rotor of the generator from rest to a particular speed within a predetermined time period while the torque link is deactuated, a source of electrical power, contactors for connecting the source of electrical power to the induction motor when the torque link is deactuated to accelerate the generator rotor to the particular speed, a second set of contactors for connecting the source of electrical power to the generator windings once the generator rotor has reached a particular speed to cause the generator to operate as a synchronous motor and a torque link actuator for actuating the torque link once the generators operating as a synchronous motor to bring the prime mover up to starting speed. The usual large magnitude transient developed in the source of electrical power is thus broken down into three transients of lesser magnitude.

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Rockford, IL, United States of America

Clarence F Dolan