Sundstrand Corporation

Intellectual Property Law Department Sundstrand Corporation

Mahesh J Shah

John B Huss

Jayant G Vaidya

Clarence F Dolan

Derek N Walton

George H Seffernick

Alexander Cook

John J Dhyanchand

Alexander Krinickas, Jr

Sampat S Shekhawat

Barry J Parker

Derrick N Walton

Leo A Lynch

Barry L Maltby

An electric power generating system comprises a low reactance, large airgap permanent magnet generator driven by a hydraulic motor to generate a poly-phase AC output voltage. Because the permanent magnet generator is a low reluctance, large airgap machine, the output voltage regulation is low over the desired loading range of the system. The output voltage is controlled within acceptable limits by trimming the output speed of the hydraulic motor through the use of a servovalve. The control for the servovalve senses a parameter of output power and generates a speed control signal to compensate for deviations in the generator output. The system includes protection circuitry which monitors at least one parameter of the output power. This protection circuitry generates an output protection signal in response to a deviation in the monitored parameter which exceeds predetermined limits. In response to this signal, an on/off solenoid, which is coupled between the hydraulic motor and the external source of hydraulic power, terminates the flow of hydraulic power to the hydraulic motor. This results in a termination of the power generation by the permanent magnet generator. In one embodiment of the instant invention, the permanent magnet generator includes a second stator winding which is used to generate a second output voltage. A rectification circuit is coupled to this second output to transform the voltage produced thereon to a dc voltage to power dc loads.

Hydraulically driven low reactance, large air gap permanent magnet

An improvement in a generator having a rotor, a stator, a magnetic field structure disposed on one of the rotor and the stator and an armature winding disposed on the other end of the rotor and the stator wherein the armature winding is disposed in a useful flux path comprises an additional armature winding disposed in a leakage flux path wherein auxiliary power is developed by the additional armature winding for one or more electrical loads.

Permanent magnet generator with auxiliary winding

A method of and system for controlling an induction motor detects input frequency to the motor and connects windings of the motor in one of a plurality of configurations in dependence upon the detected frequency.

Method of and system for controlling a variable speed induction motor

Electromotive apparatus comprising at least one winding (30) including a plurality of generally triangular coil turns (34). A plurality of generally triangular stator segments (55, 56, 57) are mounted within the coil turns (34). The winding is formed by a hollow conductor, and it is shaped for connection to a source of cooling fluid. A molded support (32) is fastened to the windings 30 and to the segments (55, 56, 57) for supporting the apparatus at its outer diameter.

Stator windings for axial gap generators

A starting/generating system operable in a starting mode and in a generating mode utilizes a dual permanent magnet generator (DPMG) having a motive power shaft and an armature winding together with a power converter having an input and an output. Relays are operable in the starting mode to connect the output of the power converter to the DPMG armature winding and are operable in the generating mode to connect the input of the power converter to the DPMG armature winding. The power converter is controlled in the starting mode such that the DPMG is operated as a motor to produce motive power at the motive power shaft and is controlled in the generating mode such that electrical power developed in the DPMG armature winding is converted into output power.

Power conversion system with dual permanent magnet generator having

A permanent magnet generator having a plurality of permanent magnet generator units which produce a controlled output potential by mutual magnetic flux linkage between the permanent magnet generator units to produce the controlled output potential in accordance with the invention includes a plurality of permanent magnet rotors (20 and 22) mounted on a drive shaft (26) with at least one of the rotors being rotatable with respect to the drive shaft to vary an angular position of the at least one of the rotors relative to the shaft to produce a mutual variable magnitude magnetic axial field extending parallel to the drive shaft; at least one stator (26, 28, 72) disposed at a position axially offset from the plurality of rotors which is magnetically coupled to the variable magnitude permanent magnet axially field; and a mechanism (46, 48) responsive to a stator fault for angularly positioning the rotors relative to each other so that the permanent magnetic field coupled to the at least one stator is zero.

Axial gap dual permanent magnet generator

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 variable reluctance motor (10, 100, 200) for providing holding torque in accordance with the invention includes a magnetically permeable rotor (12); a stator (18) axially aligned with the rotor having at least one phase winding (22) for producing a magnetic field causing the rotor to rotate; and a first cylindrical magnet (26) mounted coaxial with and outboard from a first side of the rotor which creates a permanent magnetic field coupling the rotor to the magnet to provide holding torque.

Variable reluctance motor providing holding torque

A stator drain supports stator windings and rotor bearings and permits fluid coolant for the rotor bearings to be drained outward past the stator windings from the bearings. The drain is formed of a non-metallic material and has an inner surface for supporting a bearing liner of the rotor bearings, a plurality of spaced openings for receiving stator windings and drain slots extending through the annular member at locations corresponding to spaces between the stator windings for draining the fluid coolant. The stator drain is useful in a dual permanent magnet generator, for example.

Stator drain and electrical apparatus employing the same

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 three phase inverter (40) is disclosed for use with loads (100) which are unbalanced. A transformer (80) having primary windings (82), (84) and (86) which are respectively connected to phase outputs (52, 54 and 56) has a secondary having individual windings (88, 90 and 92) connected in a delta configuration which minimizes the flow of unbalanced current in the unbalanced load. A second embodiment utilizes a transformer in an interconnected configuration. A neutral connecting the conductive switches to the load is unnecessary with the invention.

Growing community of inventors

Rockford, IL, United States of America

Mahesh J Shah