Abstract: A method and an apparatus for driving and controlling a synchronous motor using permanent magnets as its field system are herein disclosed. When a rotational speed of the synchronous motor using the permanent magnets as the field system is more than a base rotational speed, a current condition computing section computes a field weakening reference current in accordance with a battery voltage, a reference torque and a rotational speed. An inverter performs the field weakening control of the the synchronous motor using the permanent magnets as the field system in accordance with the field weakening reference current sent from the current condition computing section to prevent the deterioration of efficiency and the deficiency of output due to the excessive or insufficient field weakening current. The current condition computing section determines optimum reference current by the use of a converged battery voltage, when the battery voltage is converged to a constant value after initial control.

Abstract: A position command method and apparatus for shortening the acceleration and deceleration times of a servo controlled apparatus by effectively utilizing the torque of the controlled apparatus. A value of speed per unit time is developed on the basis of speed and position data, and a constant speed or an acceleration or deceleration function processing may be selectably performed. In the position commanding method and its unit of the present invention, the deceleration stop distance of output speed is computed at all times or is held as a list data as described above and moreover is compared with a residual distance XR. Consequently, the deceleration stop distance does not have to coincide with the residual portion from the acceleration command, and the acceleration/deceleration curve alone can be realized in an independent form. Also, the speed change can be made smoother by correcting the cross point of independently formed acceleration and/or deceleration curves defining a corner section.

Abstract: A system controls a one-pole synchronous motor, with a magnetized rotor and a stator provided with two pairs of coils. The motor includes a floating common node to which are connected first coil terminals, the second terminal of each first coil of a coil pair is connected to a first supply terminal through a first respective switch, and the second terminal of each second coil of a coil pair is connected to a second supply terminal through a second respective switch. The control system includes a circuit operable for controlling switches in a stepping or self-switching mode, and at least one detection circuit using the voltage occurring at the floating common node so as to detect at least one operation condition of the motor.

Abstract: In an AC servomotor control system consisting of an inverter for controlling a rotational speed and an output torque of an AC servomotor, a converter for controlling a DC voltage at a connecting point between an inverter and a converter, and a controller, the DC voltage is controlled at a constant voltage when the rotational speed is under a rated speed .omega..sub.b, and controlled as an increasing voltage in proportion to the rotational speed when it is over the rated speed .omega..sub.b so that the output torque of the servomotor is maintained at a constant torque.

Abstract: A synchronous electric machine has a voltage and speed regulator, comprising a stator provided with a secondary winding and a rotor provided with a primary winding, intended for connection to a feeder grid (operating as a motor) or a user grid (operating as an alternator). The stator winding (ES) is coupled with a second stator winding (e) feeding a static rectifier circuit (R) whose output is connected to a superconducting energy storage winding (BS). The rectifier circuit is controlled by a computer (C) programmed to inject active and reactive power into the stator in such a manner as to attenuate transient conditions.

Abstract: The motor control system for an electric motor having no mechanical means integral therewith for commutating current provides the ability to control position, velocity and torque of such a motor to the degree achievable with DC motors having mechanical commutators. Such a result is achieved by maintaining a desired spatial relationship between the resultant magnetic field created by the stationary member and the movable member of the electric motor. The control system includes detecting apparatus for detecting parameters of the motor that dictate, in part, the desired spatial relationship within the motor and command apparatus for creating a motor command signal which, when generated in the motor, causes the desired spatial relationship to be established. The present invention also permits maintenance of an optimal spatial relation--a spatial relationship that causes the motor to produce desired torque with a minimum excitation.

Abstract: Stabilized operation of a damperless synchronous motor, which is driven by a voltage source inverter energized by a d-c bus voltage, is obtained under transient conditions, such as during sudden variations of load torque, in order to maintain the torque angle in the motor relatively stable at all times and within the stability limit. This is achieved by employing transient changes in either the d-c bus voltage, the d-c bus current or the motor voltage, which changes reflect transient variations of the torque angle, to rapidly adjust the inverter frequency as necessary to hold the torque angle reasonably constant. For example, if there is an abrupt load increase on the motor, the bus voltage tends to drop and the motor tends to slow down, the torque angle thereby tending to increase.

Abstract: The electric machine comprises a multiphase armature winding 6, a superconducting field winding 4, and a multiphase compensating winding 3 constructed in the form of sections 10. Each phase of the winding 3 is connected in series to one of the phases of the armature winding 6 through a sliding contact. The sections 10 comprise conductors of all the phases, and each phase of the winding 3 is so connected to a separate rectifier 14, 15, 16 that a unidirectional current flows therethrough.

Abstract: An adjustable speed machine-commutated inverter-synchronous motor drive includes control of the inverter at a selected rate without positioning. The line converter is controlled so as to maintain a relation I=f(T) and the relation E/l=g(T) is established by applying to the field regulator loop a reference which is a function of T, where T is the torque, I the current drawn by the motor drive and E the excitation voltage. Accordingly, the torque is not sensed. The functions are chosen so that the commutation margin angle is safe under natural commutation by the EMF of the motor and also chosen to improve drive operation.

Abstract: Apparatus for controlling a salient-pole machine includes a stator current control element to make the stator current i.sup.S follow preset desired values i.sub..phi..sup.S*. A field current control element develops from preset desired flux values .psi.*, from the flux signal output of a flux computer (direction .phi..sub.L) and from an inductance parameter (the shunt inductance X.sub.q of the machine) a fictitious field current value signal i.sub.O.sup.E*, which represents the field current value which would be used to control a hypothetical nonsalient-pole machine. This signal i.sub.O.sup.E* is modified by a correction factor derived from the product of the longitudinal component of the flux .psi..sub.d (from the flux computer) and the different between the reciprocals ((1/X.sub.q)-(1/X.sub.d)) of the shunt and series inductances of the machine, to give a field current control signal that accounts for the asymmetry of the salient-pole machine.

Abstract: A voltage V.sub.ac of a synchronous motor is converted into positive and negative voltages of a predetermined magnitude relative to the ground during the positive and negative half-wave periods, respectively. The voltage is delivered during the positive and negative periods of a current I.sub.b and is used as a signal representing a power factor. The difference between a target value of the power factor and the signal representing the power factor thus delivered is used for compensating for the difference between a target current of a field system and a feed-back signal thereby to control a field current.

Abstract: In a rotating machine converter controlled drive, the EMF vector components formed from the stator current and stator voltage are integrated by means of a-c voltage integrators, the output quantities of which establish the components of the machine flux vector. In the converter control the parallel and normal components of the stator current relative to this flux vector are introduced. The a-c voltage integrators include zero controllers in a feedback circuit, into which the difference between the machine flux components and corresponding model flux components are introduced. The model flux components are calculated in a computing model circuit from the stator current, magnetization current and rotor position.

Abstract: An AC motor having AC windings with an internal electromotive force is driven by an electric valve feeding apparatus having electric valves commutated by the internal electromotive force of the AC windings. The commutation of the electric valve is carried out under the condition of U>.pi./m where m designates the number of commutation times per AC cycle of the electric valve feeding apparatus and U designates a commutation overlapping angle of the electric angle to feed the current to the AC windings whereby the motor is driven by the electric valve feeding apparatus.

Abstract: A load-commutated inverter synchronous machine drive system control apparatus comprises at least one microcomputer for determining optimum or desired values for inverter turn-off time, inverter link current and machine air gap flux from machine drive system voltage and currents. Inverter frequency is regulated in accordance with the difference in magnitude between optimum and actual inverter turn-off time to minimize the inverter turn-off angle irrespective of machine frequency, thereby reducing synchronous machine reactive power. Inverter link current and synchronous machine field current are regulated responsive to the difference in magnitude between optimum and actual inverter link current and the difference in magnitude between optimum and actual machine air gap flux, respectively, thereby assuring machine operation at maximum efficiency.