Abstract: A method and apparatus for improving the performance of polyphase AC machines. The polyphase AC machines are excited both with a fundamental frequency and with an odd harmonic of the fundamental frequency. The odd harmonic flux wave is phase controlled so as to interact with otherwise waste harmonic flux waves generated by the rotor. The interaction of the harmonic flux waves enhances the pull-out torque, power factor, and efficiency of the polyphase AC machine.

Abstract: The drive system connects a servomotor via a clutch to a shaft after the motor has started up from a standstill to a speed in synchronism with the supply frequency to the servomotor. The clutch may also be actuated to disengage the servomotor from the shaft when the servomotor is slowed to a predetermined speed during stopping of the servomotor. A transmission is employed between the servomotor and the shaft to compensate for any shocks to the motor when engaging the clutch.

Abstract: A gate-controlled electric drive comprises a synchronous motor (2) having m windings (2) and provided with a shaft position transducer whose output is connected to an address input of a permanent memory. The outputs for setting a pulse width code of said permanent memory are connected to inputs of pulse-width modulators, while outputs for setting a polarity code of said permanent memory are connected to inputs of a reverser. The outputs of the pulse-width modulators are connected to control inputs of corresponding control units, whereas inputs for setting polarity of the control units are connected to outputs of the reverser. The outputs of each control unit are connected to inputs of a respective switching unit based on bidirectional switches connected in a bridge circuit, a switching unit being connected to the respective winding of the synchronous motor.

Abstract: A generator/motor system comprises a generator/motor having a primary winding and a secondary winding installed on the motor rotor coupled to a prime mover/load, a main circuit interposed between a power system and the primary winding of the generator/motor, an excitation circuit including a frequency converter inserted between a part of the main circuit and the secondary winding of the generator/motor, a frequency difference detector for determining the difference between the frequency of the power system and a frequency dependent on the rotational speed of the load, and a phase-shift control device for controlling the firing phase of the frequency converter in the excitation circuit by use of a signal from the frequency difference detector as a reference signal.

Abstract: A compact, high efficiency non-interruptive motor generator power system for generating and supplying to a load A.C. of a substantially constant frequency and of a substantially constant voltage, the motor thereof being a synchronous A.C. motor energizable from a source of irregular and interruptible A.C. line power, the generator being capable of converting its rotational energy into the A.C. output for many seconds after interruption of the A.C. line power. The power system comprises a high efficiency, synchronous permanent magnet A.C. motor and an A.C. generator coupled to and driven by the motor. Both the motor and generator have a high rotational enertia common rotor wherein an outer cylindrical shell contains motor and generator rotor elements of high permeability soft magnetic material with a surface layer of magnetizable permanent magnetic material, and in each stator is an excitation coil, energizable with A.C.

Abstract: An electric machine which is adapted to function as a motor or generator without any major electrical or mechanical modifications and conforms to conventional electric machine manufacturing practices. This machine has associated therewith, microprocessor controls. There is provided two balanced phase synchronous electrical machines whose moving windings are attached to a common carrier and whose stationary windings are attached to a common body. One of the two balanced phase electric machines is electrically and mechanically designed to be a balanced phase synchronous power motor or power generator at the utility frequency while the other balanced phase electric machine is electrically and mechanically designed for a higher frequency. The high frequency electric machine is driven by a modulated high frequency signal whose modulation frequency is equal to the utility frequency.

Abstract: A synchronous A.C. electrical motor comprising (A) a stator having a body of slotted, soft ferromagnetic, low eddy current loss material, the slots having A.C. power windings to produce a rotating magnetic field, an excitation coil energizable with single phase A.C. located in two adjacent slots with a pole piece between them, and feedback windings located in slots such that when A.C. potential therefrom is conveyed to the excitation coil the excitation A.C.

Abstract: A power conditioner having a source and load converter each using a phase-locked loop to control their respective converter firings achieves synchronization with a supply mains by determining the phase error between supply mains and motor voltages by obtaining the instantaneous difference between the output signals of the source and load phase locked loops. This phase error is passed through a simple gain and summed with a speed regulator setpoint, which now becomes an inverter frequency regulator with the nominal setpoint being the supply mains frequency. The voltage amplitude error between the supply mains and the motor is obtained by comparing the absolute value of the source voltage with the properly scaled absolute value of the integrated motor voltage and this error signal is input to the flux regulator in a synchronous or induction motor controller in place of the normal input when not synchronizing.

Abstract: An electric rotating machine which is adapted to function as a motor or a generator without any major electrical or mechanical modifications. This machine has associated therewith, microprocessor controls. There is provided two balanced phase synchronous electrical rotating machines whose rotors are attached to a common axial. One of the two balanced phase electric rotating machines is electrically and mechanically designed to be a balanced phase synchronous power motor or power generator at the utility frequency while the other balanced phase electric rotating machine is electrically and mechanically designed for a higher frequency. Depending on the modulation type of signal, applied to the stator of the second machine, each of the electrical phase windings of the two rotors are either electrically wired together or electronically connected by a demodulator circuit.

Abstract: This invention relates to synchronous motor starters and provides a starter including a flywheel connected to the rotor shaft of a synchronous motor by yieldable connection means. When the synchronous motor reaches operating speed as an induction motor the yieldable connection means is in a stressed state and acts to subsequently accelerate the flywheel relative to the rotor shaft of the motor and further to decelerate the flywheel relative to the rotor shaft so that the motor reaches synchronism.

Abstract: An apparatus and method for accelerating textile winder synchronous motor drives from standstill to rated running speed wherein a synchronous motor is first accelerated asynchronously to a first intermediate speed, then decelerated to and synchronized at a second intermediate speed, then accelerated synchronously to rated speed, while thereby limiting current drawn by the motor to levels not exceeding rated current. The method is automatically followed using apparatus which varies motor input frequency responsive to a predetermined sequence of control signals supplied from a signal source via a transient response profiler which converts sudden changes in signal strength to smooth, gradual changes. As more specifically described herein, only two controllers are needed, and a switching network including time-delay devices selectively supplies one signal or the other via an integrator to a variable frequency converter.