Abstract: An electrical machine is disclosed, capable of functioning as either a motor or generator, which has a salient pole rotor (23) and a stator having multiple phase windings (21) each comprising a concentrated, full pitch winding with one stator slot per pole per phase. The pole faces (27) of the salient poles of the rotor may be tapered to produce an air gap which increases from the front to the back of the pole face to counter the effect of armature reaction MMF. The taper of the pole faces is selected such that the resultant total flux density in the air gap from field and armature currents is quasi-rectangular. The quasi-rectangular flux densities rotating in the air gap produce quasi-rectangular phase voltages and currents when the machine is operated as a generator, and, when operated as a motor, the machine is adapted to accept quasi-rectangular supply currents or voltages of the type readily produced by variable frequency converter power supplies.

Abstract: A servomotor control system includes a sensor for sensing the velocity of a servomotor (101), a sensor for sensing an actual current flowing into the servomotor (101), a power drive circuit for driving the servomotor (101), and control units (MP1, MP2). The control unit MP1 performs a velocity loop computation to derive a current command for the servomotor based on an offset velocity between a velocity command for the servomotor and the sensed actual velocity. The control unit MP2 performs a current loop computation to obtain a command for the power drive circuit. In the current loop computation of the control unit MP2 a velocity compensation signal is obtained by amplifying the sensed actual velocity by a predetermined magnification, so that the command for the power drive circuit is compensated by the velocity compensation signal. The velocity loop computation is executed at a period longer than that at which the current loop computation is executed.

Abstract: Highly reliable and consistent starting is achieved by first initializing the rotor position, namely establishing the rotor in a known starting position. This is accomplished by gating on two pairs of SCRs in sequence and supplying current pulses through the gated SCRs to the stator of the motor to rotate the rotor to a first position and then to a second position, the rotor coming to a complete stop in each of those positions. The rotor aligns itself with the magnetic field created by the stator in each position and any ambiguity in the rotor position is eliminated. Thereafter, the inverter is operated asynchronously in a second mode with predetermined pairs of the inverter SCRs being sequentially gated into conduction at an increasing frequency to current pulse energize the motor to effect step-by-step rotation of the rotor at a faster and faster rate, the motor current being reduced to zero at the termination of each energizing pulse to force commutate the conducting pair of SCRs.

Abstract: To provide for fast response of a servo drive with a synchronous machine in which the same torque is available over the entire rotational range of the machine regardless of angular position of the rotor, phase currents to phase windings, preferably three-phase, are controlled in dependence on required torque, and steered to the respective phase windings by a rotor position transducer in such a manner that the sum of all the phase currents remains constant, and is connected to the respective phase windings, in pulses, during an electrical angular range when induced armature counter electromotive force voltages in the respective phase windings, which have an essentially trapezoidal shape, are in their flat or unvarying range within the voltage distribution during revolution of the rotor. Thus, currents are supplied to the phase windings only when the counter EMF voltages are essentially constant.

Abstract: A method is disclosed for braking a two-phase synchronous electric motor of the magnetized rotor type, driving a mechanical device. By this method the current supplied to the electric motor is controlled as a function of the actual position and the actual angular speed of the rotor within the braking period on the basis of information derived from the motor itself without additional detector devices. Perfectly proportioned braking is achieved taking into account individual motor and load characteristics and their possible variation, for example with temperature.

Abstract: A control circuit of a synchronous motor with two induction windings, including an electrical power supply assembly (5), two oscillators (2,3) whose outputs are connected respectively to the windings of the motor (1), an intermediary circuit (4), connected on one side to the power supply and on the other to the oscillators, and a central unit for control of the thyristors.The electrical power supply assembly (5) delivers a current of a given unique polarity, and has its output terminals connected by means of a freewheel branch including at least one freewheel diode (6) whose cathode is connected to the positive terminal.

Abstract: A relatively simple inverter-motor system, comprising a minimum number of circuit components, is provided by employing a voltage-controlled thyristor inverter which in turn drives a synchronous motor having a leading power factor. With the motor current leading the motor voltage, the thyristor switching devices will be motor-commutated, thereby precluding the need for any auxiliary commutating elements or circuits to effect forced commutation. Since, with a leading power factor, the current through a conducting thyristor falls to zero before the thyristor has to be switched off, ample turn-off time is provided. Furthermore, as compared to a conventional forced commutated voltage source inverter, the customary reactive diodes, usually shunting the switching devices in an inverter to permit the flow of reactive motor current, are not necessary.

Abstract: A brushless motor comprising seven or more armature windings mounted on a stator, a field magnet mounted on a rotating shaft to rotate therewith with respect to the armature windings, a plurality of semiconductor commutating devices, each being connected to one of the armature windings, and Hall sensors for detecting the polarity of magnetic fields immediately opposite the windings. Each commutating device controls the direction of the electric current to be fed to its respective armature winding, according to the magnetic polarity detected by the Hall sensors. The armature windings are connected together at one end thereof and are connected to respective commutating devices at the other ends thereof.

Abstract: An apparatus and method for increasing the maximum speed of rotation of a synchronous machine having constant excitation field strength is disclosed. The synchronous machine is preceded by a converter, which has an adjusted current reference value as an input. The adjusted current reference value comprises an active-current reference value and a reactive-current reference value. For actual speeds n.sub.ist, the absolute value .vertline.n.sub.ist .vertline. of which is above a predetermined value n.sub.o, the amplitude of the active-current reference value is limited to a value which is inversely proportional to the factor .vertline.n.sub.ist .vertline./n.sub.o. The value n.sub.o is a predetermined speed at which the sum of the magnet wheel voltage of the synchronous machine and the voltage drop in the stator winding is maximally equal to the largest possible output voltage of the converter. To obtain the adjusted current reference value, a reactive-current reference value shifted 90.degree.

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: Control system for driving a synchronous motor at a speed greater than a rated speed with a rotational speed detector for the rotor mounted on the motor, rotational position detector for detecting the rotational position of the field pole of the motor, an error signal generator which produces the difference between a desired speed signal and an actual rotational speed signal, and a calculating device for calculating armature current component values Id, Iq and power-factor .phi..

Abstract: A pulse generating system for providing firing pulses to selectively trigger solid state control devices connected to a three-phase A.C. line system, and more specifically to trigger said devices in selected relation with respect to the phase and frequency of the A.C. line.

Abstract: A static frequency changer for feeding a synchronous machine and composed of a mains side static converter, a machine side static converter and a direct current intermediate circuit connected between the converters, is further provided with an additional static converter connected at the machine side in parallel opposition to the machine side static converter, and a direct voltage capacitor connected in parallel to the additional converter.

Abstract: Regulation of inverter-machine drive system torque and frequency in accordance with operator commands is achieved by the use of an improved, microcomputer-based, control apparatus. At machine frequencies less than a preselected machine frequency, inverter pulse width modulation signal pulses and half cycle polarity signal pulses are supplied by the control apparatus to the inverter to regulate the duration and conduction sequence, respectively, of inverter switching devices in accordance with pulse width modulation signal data computed by equilateral triangulation and stored half cycle polarity signal data. At frequencies above the preselected machine frequency, when computation of inverter pulse width modulation signal data becomes impractical, inverter pulse width modulation signal pulses are synthesized from stored data. This achieves simplification of control hardware and provides improved machine drive system performance.

Abstract: An inverter (34) which provides power to an A. C. machine (28) is controlled by a circuit (36) employing PWM control strategy whereby A. C. power is supplied to the machine at a preselectable frequency and preselectable voltage. This is accomplished by the technique of waveform notching in which the shapes of the notches are varied to determine the average energy content of the overall waveform. Through this arrangement, the operational efficiency of the A. C. machine is optimized. The control circuit includes a microcomputer and memory element which receive various parametric inputs and calculate optimized machine control data signals therefrom. The control data is asynchronously loaded into the inverter through an intermediate buffer (38). A base drive and overlap protection circuit is included to insure that both transistors of a complimentary pair are not conducting at the same time.

Abstract: A self-controlled polyphase synchronous motor drive system having means for producing rotor digital timing signals representative of the position of the rotor relative to the stator, means for producing pulse width modulation control signals wherein the pulse width thereof is responsive to a motor power factor command signal, a plurality of phase control means equal in number to the number of phases of the polyphase stator and responsive to the variable pulse width modulation control signals and including means for producing a modulated analog reference signal from one of two selected stator voltages and means for summing the amplitude modulated analog reference signal with an unmodulated analog reference signal produced from the other of the two selected stator voltages and for comparing the sum thereof with a threshold voltage signal to produce as an output therefrom two motor voltage derived digital timing signals for each phase of the polyphase stator in response to the speed of the motor such that an abs

Abstract: The disclosed inverter system comprises three three-phase inverters connected in parallel across a positive and a negative terminal of a DC source including a negative terminal, and two three-phase transformers each including star-connected primary windings connected at one end to three AC outputs of the mating inverter and at the other ends connected to the neutral source terminal. Three secondary windings of each transformer are serially connected to those of the other transformer across three star-connected phase windings of a synchronous motor and three AC output of that inverter not connected to the transformer. The motor includes a neutral terminal connected to the neutral source terminal.

Abstract: An alternating current machine drive system, comprised of an alternating current machine and an inverter configured of a plurality of pairs of transistors with the transistors of each pair coupled in series-aiding fashion and each of the pairs of serially coupled transistors connected across a direct current source, is controlled in accordance with inverter current. The transistors of each inverter transistor pair are alternately rendered conductive to supply alternating current at the inverter output in accordance with a current error signal, proportional to the difference in magnitude between actual inverter phase current and a sinusoidal reference signal, with the conduction state of the transistors of each pair reversing each time the current error signal exceeds an upper and lower hysteresis limit, which limits vary in accordance with actual inverter phase current.

Abstract: A programmable electronic speed control for controlling the speed of a motor responsive to an ac signal source. A triac switch is interposed between the ac signal source and the motor. A programmable digital counter is connected between the ac signal source and the triac switch. The programmable counter counts zero voltage crossings of the ac signal generated by the ac signal source and repetitively causes the triac switch to alternately pass and block selectable numbers of cycles of the ac signal to the motor. The speed of the motor is determined by the relationship between the selectable numbers of cycles of the ac signal which are alternately passed and blocked by the triac switch. The speed control is particularly suited for use in controlling the pump motor and/or the program timer motor in a beverage dispensing machine.

Abstract: In a commutatorless motor device including a synchronous motor driven through a frequency converter including gate-controlled electric valves, and a device for detecting the phase voltages of the synchronous motor, a device for dividing the detected phase voltages by a signal corresponding to the speed of the synchronous motor. The outputs of the dividing device are fed to a logic signal converter which converts them into signals corresponding to the position of the rotating magnetic field of the synchronous motor. The outputs of the logic signal converter are passed through a logic circuit and a gate-pulse generating circuit for generating gate pulses for controlling the electric valves of the frequency converter.

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 phase lock loop commutation position control and method for a drive system for a DC field motor having a rotor and a plurality of stator windings is disclosed. Electric power is supplied to the stator windings in accordance with gating signals. The gating signals are generated in accordance with timing signals, which are provided in response to a clocking signal. A position signal is furnished as a function of the position of the rotor with respect to a preselected stator position. An error signal is generated proportionally to the phase difference between a preselected timing signal and the position signal. The clocking signal is produced as a function of the error signal. The invention also can include a shift signal produced as a function of the rotation of the rotor. The shift signal is added to the error signal effectively to cause the preselected timing signal to be advanced with respect to the position signal.

Abstract: A control device for a thyristor motor is disclosed by which the advance angle is switched at a predetermined slow rate of change in order to avoid an abrupt change in the motor torque. The thyristor motor comprises a thyristor frequency converter for a frequency conversion and a synchronous motor driven by the frequency converter, and in the thyristor motor the advance angle is switched at low and high speeds of the motor.

Abstract: A synchronous motor having a polyphase armature winding and a field winding is driven by a frequency converter. A position signal associated with the rotational position of the synchronous motor is adapted to be shifted in phase by the maximum of 180.degree. to the advance and lag side by a position control signal, so that a firing pulse for the frequency converter is generated by a combination of a phase-shifted position signal and a reverse signal. Thus the operation modes are switched stably between motoring and regenerative and between forward and reverse operations by changing the magnitude of the phase control signal and reversing the polarity thereof.

Abstract: A control system for a commutatorless motor comprises a frequency converter which includes two graetz-connected thyristor converters and D.C. lines interconnecting the converters, between an A.C. motor and an A.C. power supply. Motoring operation and regenerating operation are selectively effected between the motor and the power supply. In switching the operation mode, one of the converters which has been operated in a recitifier operation mode is first switched to an inverter operation mode, and after it has been confirmed that a control voltage to determine a firing angle of the one converter has been shifted to an inverter region, the other convertor is switched to the rectifier operation mode.

Abstract: A polyphase inverter system for supplying alternating current power to a load through the use of conduction controlled devices such as controlled rectifiers which are selectively rendered conductive in a sequence and at a rate which determines the frequency of the electrical power delivered to the load, includes an inverter control employing a source of pulses and an open-ended, bidirectional shift register. The contents of the register are shifted in response to the application thereto of the pulses, in combination with a direction signal. The instantaneous contents of the register serve to initiate gating signals for rendering conductive the controlled rectifiers. Logic means associated with and responsive to a specified configuration of the register contents develop, in combination with the directional signal, a predetermined bit pattern to be inserted into the register.

Abstract: An improved current supply apparatus for at least one load object capable of delivering reactive power. A DC current source is connected to at least two parallel circuit branches that each include a thyristor connected in series to a winding of an interphase transformer inductor. The ends of the load object are connected to an associated tap point intermediate the thyristor and inductor winding of each branch. The thyristors are successively ignited to conduct current during a portion of a current supply cycle to provide an output current of changing polarity to the load object.

Abstract: To achieve synchronization of an inverter-synchronous machine drive system, feedback of a phase angle signal, derived in part from stator current drawn by, and voltage supplied to, the synchronous machine, is provided to control the frequency of inverter thyristor conduction. At light or zero synchronous machine load conditions, machine stator current may be of insufficient magnitude to permit derivation of the phase angle feedback signal; therefore, substitute simulated stator current signals, proportional to a preselected combination of inverter thyristor gating pulses, are utilized to derive the phase angle feedback signal, thereby allowing inverter-synchronous machine drive synchronism to be maintained.

Abstract: Control systems for starting and synchronously driving gyroscope rotors establish magnetic polarization of the rotor ring prior to start-up and then accelerating the magnetic field vector as the rotor accelerates to its normal operating speed.

Abstract: An inverter system for supplying variable frequency alternating current power to a load such as an a.c. motor includes an inverter bridge of controlled rectifiers which are selectively rendered conductive by the application thereto of gating pulses. The gating signals result from a control circuit which includes a voltage controlled oscillator responsive to a command signal having a d.c. magnitude and polarity which in turn outputs a signal having a substantially saw-tooth wave shape. Comparator circuits responsive to the saw-tooth wave shape signal provide timing pulses and direction signals which are applied to a shift register to effect movement of the register contents the extant status of which initiates the production of the gating signals for rendering the semiconductors conductive.

Abstract: In a control system of an AC motor fed from a frequency converter including a thyristor rectifier and a thyristor inverter, the speed of the motor is controlled by a current control system comprising a speed control circuit responsive to a reference speed signal and an actual speed signal, and a current control circuit which produces a pulse signal supplied to the rectifier. The inverter is controlled by another pulse signal corresponding to the angular position of the rotor of the motor. An additional current instruction circuit is provided which in response to the two pulse signals described above controls the current control circuit.

Abstract: An improved current supply apparatus for the power windings of a synchronous machine wherein a first center tap of a first power winding is connected to one side of a current source and a second center tap of a second power winding is connected to the other side of the current source. The respective ends of the power windings are connected by thyristors that are ignited at times determined by the angular position of a rotor of the synchronous machine. Each thyristor is ignited to conduct current during one-fourth of a power supply cycle to generate an output current of changing polarity that is applied to the power windings to drive the synchronous machine.

Abstract: A synchronous motor having multi-phase armature windings and a field winding is drived by a frequency converter. Actual torque is determined from a sinusoidal position signal representative of rotational position of the synchronous motor and the armature current. The actual torque value is compared with a command torque signal, whereby the armature current is controlled in dependence on difference or deviation resulting from the comparison thereby to cancel the torque ripple. Torque ripple can thus be suppressed to a satisfactory degree even at a low rotation speed of the synchronous motor.

Abstract: A controlled current inverter system forms the basis of an a.c. motor drive system for furnishing the motor load with a variable frequency, variable magnitude a.c. current from an inverter which is supplied from a variable d.c. current source by way of a d.c. link including an inductor. Torque is the control parameter employed in the system and the motor speed and torque are controlled through the control of motor flux and motor current, by maintaining a controlled ratio between the direct and quadrature motor currents, through separate control paths to the d.c. source and the inverter. A third control path functioning on the difference between the desired and actual motor flux serves as a modifier to the main control paths to improve overall operation and control. Means associated with the basic control paths provide for dynamic braking of the motor.

Abstract: A control system for a multi-phase synchronous machine having a shaft driven at variable speed or for developing a variable torque angle includes shaft angular position detectors that derive first and second output pulses respectively representing a shaft angular displacement corresponding with each pole of the machine and a predetermined shaft angular displacement within each pole. In response to a plurality of the second output pulses, a frequency locked loop derives a variable frequency pulse output. Individual pulses are selectively inserted and deleted from the variable frequency output to derive a variable phase pulse output representing machine torque angle. A triangle up/down counter responds to the variable phase output to derive a pulse output signal having a frequency that is a submultiple of the variable frequency output and a phase determined by the phase of the variable phase output.

Abstract: A power switching apparatus for use in the control of a D.C. load such as a D.C. motor comprises a power transistor with its emitter-collector path connected in series with the D.C. motor and a battery. A base current of the power transistor is supplied from the battery through a controllable impedance element. A control unit is provided to vary the impedance of the controllable impedance element in response to the current flowing through the emitter-collector path in such a manner that the base current changes as substantially the inverse-function of a characteristic curve indicating a D.C. amplification factor versus collector current of the power switch transistor.

Abstract: An apparatus for numerical control of a thyristor inverter comprises a decoder connected to a clock counter and a bidirectional counter, a control unit and a switching unit having seven AND gates, a NOT gate, a sign flip-flop, and a delay circuit. The clock counter is coupled to the first inputs of the first and second AND gates, the output of the first AND gate is coupled to the gate electrodes of the main and recharging thyristors of the thyristor inverter, and the outputs of the second and third gates are AND coupled to the gate electrode of the dropping thyristor. The first output of the decoder is coupled to the first inputs of the third and fourth AND gates, the output of an additional AND gate being coupled to the gate electrode of an additional thyristor and, via the delay circuit, to the gate electrode of the recharging thyristor. The control unit is coupled to the first inputs of the fifth, sixth and seventh AND gates.

Abstract: The invention comes within the field thyristor bridge control.A device for controlling a Graetz rectifier bridge for driving a synchronous machine which operates at variable speed, it being connected to this machine by its AC terminals and its voltage at the terminals being substantially proportional to its frequency, characterized in that the firing pulses of each thyristor of the Graetz rectifier bridge come from the comparison of a control signal U.sub.c chosen as a function of the required firing angle .alpha. of the thyristor to be fired, with a sinusoidal phase reference curve whose amplitude is made independent from the operation frequency of the Graetz rectifier bridge.The invention applies in particular to the driving of synchronous rotating machines which operate at variable speed.

Abstract: An A.C. current control system for an A.C. power supply device for feeding a load comprises a closed control loop for controlling the power supply device on the basis of results of comparison between an output signal from a reference current waveform generator for generating a reference current waveform and an output signal from a load current waveform detector for detecting the waveform of load current. A load voltage detector is provided, the output signal from which is positively fed back to the closed control loop for compensating deviation in the current control due to electromotive force or like factors of the load.

Abstract: An AC rotary machine apparatus comprises an AC rotary machine having AC windings forming five or seven phases and an AC feeder having solid state switches feeding AC power to the AC windings in five or seven phases.

Abstract: A motor drive apparatus has G groups (G.gtoreq.2) of m-phases inverter units and G groups (G.gtoreq.2) of m-phases AC windings for feeding through the m-phases inverter units to the m-phases AC windings and G groups (G.gtoreq.2) of DC power sources which are connected to G groups of the inverter units so as to form alternative series closed loops on the DC circuit.

Abstract: A decogging feedback control for current source inverter motor drives uses a change of instantaneous torque feedback signal with no dc component that is a function of only the instantaneous pulsating component of measured torque. The change of torque signal modulates the voltage applied to the dc link and therefore the dc link current to materially reduce the detrimental cogging torque pulsations and stabilize the motor, and can be switched out at a low frequency above which it is not needed so that the motor can respond properly to rapid variations in torque.

Abstract: A drive circuit for a brushless motor of the type having a rotor magnet and energizable stator windings. The drive circuit includes position sensors for sensing the rotary position of the rotor magnet and for generating varying position signals corresponding to the sensed rotary position. A plurality of amplifier stages is coupled to the position sensors, the amplifier stages being responsive to the position signals to produce drive currents which are supplied to the stator windings.

Abstract: A system for driving an inductor type synchronous motor for minute control includes an inductor type synchronous motor having first means for driving m numbers of phases and a group of first magnetic teeth, second means equipped with a group of second magnetic teeth; and power feed equipment for feeding power to the driving windings of the individual phases; wherein the minute control characterized by the electrical resolution number R per electrical angle 2m (2m being one fundamental cycle) of the power feed equipment is larger than 3 m points (R.sub.2 3 m) or is stepless; and the power feed equipment feeds electric-waves of current or voltage to the driving windings, the electric-waves being trigonometric functional patterns formed by a control means of the power feed equipment.

Abstract: A power circuit arrangement for a power conditioning system adapted to supply variable frequency, variable magnitude voltage to an electromagnetic device such as an electric motor having a center-tapped winding includes first and second inverting thyristors connected to the respective winding ends and connected in series with a transistor chopper across a unidirectional source so that the inverting thyristors may be gated on alternately at a relatively low modulation frequency while the chopper is time ratio controlled at a higher carrier frequency to selectively vary the voltage applied to the winding; a capacitor in shunt to the chopper which is overcharged due to winding leakage reactance when the chopper is turned off to reverse bias and "soft" commutate the thyristors when they are not conducting load current; a free-wheeling thyristor connected between the winding center tap and the chopper and poled to form a low-impedance free-wheeling path for winding current in series with the inverting thyristors w