Abstract: There are performed converting electric currents Iu, Iv, and Iw flowing through the synchronous motor into a d-axis actual current Idfb and a q-axis actual current Iqfb on rotational coordinate axes which rotate synchronously with a rotor magnetic flux vector, on the basis of an actual position &thgr; of the rotor of the synchronous motor; estimating a d-axis simulated current Idob and a q-axis simulated current Iqob on the basis of the d-axis actual current Idfb, the q-axis actual current Iqfb, a d-axis actual voltage command Vdref, and a q-axis actual voltage command Vqref; generating a d-axis actual voltage command Vdref and a q-axis actual voltage command Vqref on the basis of a d-axis current command Idref, a q-axis current command Iqref, a d-axis simulated current Idob, and a q-axis simulated current Iqob; and converting the d-axis actual voltage command Vdref and the q-axis actual voltage command Vqref into actual voltage commands Vuref, Vvref, and Vwref on the basis of the actual position &thgr; of a

Abstract: A rotor angle detecting apparatus for a DC brushless motor is capable of detecting the angle of the rotor of the DC brushless motor with accuracy without the need for a position detecting sensor. A motor controller has a high-frequency voltage imposer, an angle detector, a U-phase current sensor, and a W-phase current sensor for detecting the rotor angle of the DC brushless motor. The angle detector detects the rotor angle &thgr; using a current value IU_s detected by the U-phase current sensor, a current value IW_s detected by the W-phase current sensor, and high-frequency components depending on high-frequency voltages vu, vv, vw, when the high-frequency voltages vu, vv, vw are imposed on command values VU_c, VV_c, VW_c for three-phase voltages by the high-frequency voltage imposer.

Abstract: A method for controlling starting of a synchronous motor having an excellent starting ability and capable of coming into a commutation mode in a short time is provided. An AC current having a predetermined frequency is supplied to a field coil 81 of a synchronous motor 8 by an inverter 91, thereby starting the synchronous motor 8. By detecting a terminal voltage of the field coil 81 of the synchronous motor 8 at the starting time, and decreasing a voltage waveform component based on the AC current supplied by the inverter 91 from the detected voltage, the waveform is corrected so that the voltage waveform component based on the counter electromotive force can be confirmed (110). And after integrating the corrected waveform (111) and converting the same into a square wave (112), a phase difference between the same (104) and an output of a 120° energization waveform generating circuit 102 is detected to be fed back.

Abstract: Electronic device for controlling a synchronous motor with permanent-magnet rotor, comprising an alternating voltage current source at mains frequency connected in series with said synchronous motor (1), at least one static switch (2) connected in series with said synchronous motor (1), and an electronic circuit (3) that acts on said static switch (2). Said electronic circuit (3) determines the timing for the firing of the static switch (2) taking as reference the zero-crossing of the mains voltage (Vr) and applying a firing time (Td) starting from said reference, said firing time (Td) being obtained as a function of the position of the rotor (1A) of the motor (1) in the previous half-cycles.

Abstract: Circuits and methods for use with an integrated circuit chip having internal back EMF estimation to control a permanent magnet synchronous motor includes an AC current feedback circuit, a scaling circuit, and a current regulator. Additionally, a speed regulator may be employed. In one embodiment, during operation at very low speed, the speed regulator is in an open loop control mode due to a back EMF detection limitation of the IC chip, and only the current regulator is active. A feedback current signal, together with a user-defined command current signal, serves the input of the current regulator, which controls the AC motor current and drives the motor speed from standstill. Once the motor speed reaches a certain level, the measured back EMF from the IC chip is sufficient to estimate the motor speed, which is compared with a user-defined command speed, and an error of the these two signals provides the input of a speed regulator.

Abstract: A motor driver generates a signal synchronized with the rotation of a three-phase by comparing each of induction voltages generated in the motor's coils with a specified standard voltage. A triangular wave signal is generated such that its frequency increases with the speed of rotation of the motor increases. A standard value is set according to a change in the amplitude of the triangular wave signal and a noise mask signal is generated by comparing this standard value with the triangular wave signal. Noise is removed from the synchronized signals by using the noise mask signal, and currents are supplied to the coils of the motor by using the synchronized signals from which noise has been removed. With such a motor driver, noise can be effectively eliminated because both the noise mask time and the position detecting time can be varied gently.

Abstract: Axial error calculation unit is provided for estimating an axial error &Dgr;&thgr; between a d-q axis and a dc-qc axis by using Ld, Lq, Ke, Id*, Iq*, Idc and Iqc in a range of all rotational speeds except zero of a rotational speed command of a synchronous motor, Ld denoting an inductance on a magnetic pole axis d of the synchronous motor, Lq an inductance on a q axis orthogonal to the magnetic pole axis d, Ke a generated power constant of the motor, Id* a current command of the d axis, Iq* a current command on a q axis, Idc a detected current value on an assumed dc axis on control, and Iqc a detected current value on an assumed qc axis orthogonal to the assumed dc axis. Irrespective of presence of saliency, position sensorless control can be achieved in a wide range a low to high speed zone.

Abstract: An apparatus and method of powering a light source are provided. The apparatus includes a motor, a voltage stabilizing circuit, and a light source. The motor includes a field assembly and an armature assembly. The field assembly includes an intermediate tap on a field winding that forms a variable field winding power source. The stabilizing circuit connects to the intermediate tap and includes a voltage regulator having an output that is connected to a light source to be stabilized.

Abstract: The present invention relates to a motor drive system which comprises a fan controller circuit operable to generate a PWM control signal for control of a motor speed. The fan controller circuit comprises a current detection circuit and a motor speed determination circuit. The system further comprises a fan driver circuit operable to drive a motor at a duty cycle based on the PWM control signal from the fan controller circuit. The fan driver circuit comprises a current sink circuit operable to draw current from the PWM control signal when the PWM control signal is high and when the motor reaches a predetermined position. In the addition, the current detection circuit is operable to detect the current draw on the PWM control signal and provide an indication signal to the fan speed determination circuit associated with such detection. Further, the motor speed determination circuit is operable to determine the speed of the motor based upon a timing associated with successive current draw detections.

Abstract: A method and system for diagnostics and ascertaining status of an electric machine coupled to a polyphase bus. The method and system include: detecting a rotational position with a position encoder coupled to the electric machine; controlling an inverter having an input coupled to a direct current bus and an output coupled to the polyphase bus, where the inverter is responsive to commands from a controller coupled to the inverter and to the position encoder. The method and system further include measuring a current from the direct current bus; capturing a torque current; calculating a current error; establishing a bound limit for the torque current; comparing the current error to the bound limit. The method and system also include: determining whether a fault exists by evaluating if the bound limit has been exceeded; incrementing a fault counter if a fault exists; decrementing a fault counter if no fault exists; and indicating a failure if the fault counter exceeds a predetermined limit.

Abstract: In a ripple voltage detection system of a rectified waveform, a motor rotation detection structure is provided to increase ripple voltage by modifying number of windings, to bring cogging torque and number of parts to be equivalent, and to achieve automatic operation function. In the motor rotation detection structure used for automatic operation function of switching device such as vehicle power windows or the like, rotor of this motor includes an armature core with a plurality of slots arranged between teeth, a plurality of coils wound around each of the slots, a commutator with a plurality of segments connected to each of the coils and the like. Winding number of each of the coils is modified per each of the slots, and potential difference between the segments adjoining to each other and having different winding number is increased. So, the ripple voltage generated at a rotation of the armature core is increased in comparison with the segments having the same winding number.

Abstract: A power corresponding to an A/C voltage command id1* is applied in the d-axis direction of rotational coordinates of a stopped synchronous motor via a current control unit, a three-phase converting unit, and a power converter. Further, by using “an amplitude value of a current iq′ in the q-axis direction of the rotational coordinates generated in response to the A/C voltage command id1*” which is fed back and detected via a current detector and a dq converting unit, a field pole position estimation value &thgr;{circumflex over ( )} is converged. The field pole position is estimated by using the converged field pole position estimation value &thgr;{circumflex over ( )} as a true value of the field pole position &thgr; of the synchronous motor.

Abstract: A method is for decoding three logic signals produced by three Hall effect sensors installed in an electronically-switched three-phase brushless motor according to a sequence of six driving phases to be switched synchronously with a rotor position. The method includes determining a real phasing of the three Hall effect sensors at 60, 120, 300 or 240 electrical degrees. The determining is accomplished by decoding a whole set of eight possible combinations of the three logic signals produced by the three Hall effect sensors. The real phasing of the three Hall effect sensors is discriminated based upon two dissimilar combinations from among six valid combinations, the six valid combinations from among the eight possible combinations. The method further includes determining the rotor position based upon the real phasing of the three Hall effect sensors and generating logic driving signals synchronous with the rotor position.

Abstract: A surface-mounted permanent magnet synchronous machine drive and a method of controlling the machine drive. Flux weakening and current regulating loops cooperate to provide automatic transition to the flux weakening mode (operation above base speed), regardless of DC bus voltage, load or other operating conditions. The modulation index (d) is used as a condition for automatic start of flux weakening operation is very useful because this point can be easily changed by software when necessary, regardless of the value of DC bus voltage. This feature provides significant performance improvement. No look-up tables are used in the flux weakening loop. The on-set point for flux weakening is automatically adjusted, and may be changed through software. An appropriate d-axis current component is injected over the entire speed range, providing the maximum available torque (which corresponds to the q-axis current component).

Abstract: A method for the excitation of the radial force and torque winding systems of electrical drives with integrated magnetic bearings. The drives comprise an electrical machine with torque and radial force windings which are introduced in the stator or rotor, a position and angle sensor system and analog or digital electronic circuitry for the control, regulation, monitoring and feeding of the machine. A model is used for setting the rotor position (36,37) and the rotational angle of the rotor (&phgr;) which describes the relationship between the forces acting radially and tangentially at the rotor or at the stator respectively and the loop currents, and indeed in such a manner that it takes into account the deviations from the sinusoidal form of the force components, which depend on the rotational angle of the rotor (&phgr;).

Abstract: When torque control is performed for suppressing speed change within one rotation using a synchronous motor (6) controlled by an inverter (5) for a load having cyclic torque changing, an arrangement is employed which includes inverter control means (8) (10) for controlling the inverter (5) so as to superpose a changing amount upon an amplitude and phase of a current waveform or voltage waveform, so that torque control is realized for reducing low speed vibration of a cyclic intermittent load with maximum efficiency condition and with practical arrangement.

Abstract: A drive control apparatus for an electric synchronous machine is composed of armature current control means and transient operation detection means. When the synchronous machine is intended to increase power in a transient operation, the current control means supplies the armature winding with compensation current to cancel counter-electromotive force formed when field current is supplied to the field winding through a mutual inductance of the field winding and the armature winding.

Abstract: A winding fault detection system provides classification and identification of winding faults or winding malfunctions. The fault detection system provides signals to individual electronic switches for segmented primary windings each having an electrical phase and grouped into sub-phases which are individually switch into or out of an excitation supply or isolated through the electronic switching in response to signals from the winding fault detection system. Each primary winding forms an electrical member which includes a stator having a poly-phase winding, and there is a secondary electrical member magnetically coupled with the stator. Each primary has magnetic field sensors which detect phase angle and magnitudes of radial components of air gap flux by magnetic measurement probes between each secondary electrical member and each primary electrical member and derives an electrical signal for a component of air gap flux contributing to electromagnetic torque at each position of each stator's periphery.

Abstract: A motor control system or electronic motor starter is optimized to replace electromechanical motor starters. Heat dissipation requirements are reduced by utilizing a by-pass contactor when the motor is in a run mode. The electronic motor starter derives power from an AC motor control signal conventionally utilized to power the coritactor coil associated with a conventional electromechanical starter.

Abstract: A synchronous motor control system which can freely regulate n-phase electric currents in a synchronous motor to control the characteristics of the synchronous motor. The synchronous motor control system can enhance the output torque per unit weight of a synchronous motor (40) simultaneously with reducing torque ripples. The waveform of three phase alternating currents is freely corrected over a range of +30 degrees from a specified electrical angle, at which a target phase current drawing a sine-wave curve reaches its peak value. It is assumed that this range of .+-.30 degrees corresponds to a range of 0 degree to 60 degrees. By way of example, the waveform is controlled to the peak value of the phase current in a range of 0 degree to 28 degrees. The correction of the phase current is carried out for the target phase which produces the primary magnetic flux of a revolving magnetic field.

Abstract: A motor controller comprising drive unit for supplying power to the stator windings of a motor based on a current command, a stator current detection unit for detecting the stator current flowing in the stator windings, a saturation degree production unit for producing the saturation degree data indicating the extent to which the stator current deviates from the current command based on the current command and the stator current, a reference value production unit for producing a reference value of the saturation degree, a gain production unit for producing a gain indicating the rate at which the current command is changed, and a current command production unit for producing the current command data based on the saturation degree, the reference value and the gain, wherein the gain production unit produces the gain data based on at least one of the rotational speed of the motor and the current command.

Abstract: A motor controller comprises a stator current production unit for producing stator current commands that are command values for the stator current flowing through the stator windings, a drive unit for supplying electric power to the stator windings based on the stator current commands, a stator current detection unit ZU, ZV, and ZW, for detecting the stator currents flowing through the stator windings, and a saturation degree production unit for producing a saturation degree indicating by how much the stator current is not following the stator current command. The stator current production unit produces the stator current commands based on the saturation degree. The saturation degree production unit produces the saturation degree based on the current commands, the stator current signals, and the pole-position signals.

Abstract: To provide a control system for a permanent magnet synchronous motor which can ensure stability of the current control system, even if the revolution frequency of the motor becomes higher and the terminal voltage of the motor exceeds the inverter maximum output voltage. In this method, when the revolution frequency of the motor exceeds a specified value, the size of the voltage vector is made a specified voltage vector, and a modulation factor based on its value is obtained. At the same time, a magnetic flux direction current correction value is found based on the size of a voltage vector from a polarity coordinates conversion unit and the above specified voltage vector size. Then, the magnetic flux direction current instruction is corrected by that value.

Abstract: Apparatus controlling switching of a polyphase switched reluctance motor (M). There is a set (10-16) of windings for each motor phase, each set of windings including at least two separate windings (10A, 10B-16A, 16B). One winding (10B) from one set (10) of windings is connected together with one (12A) winding from another set (12) of windings to form a combined set (10C) of windings. Each winding from the one set of windings is connected only to the one winding from the other sets of windings thereby to produce a number of combined sets of windings corresponding to the number of motor phases. A motor controller (18) selectively energizes and de-energizes the combined sets of windings in a predetermined sequence through an inverter (20). One switch (22a) operated by the inverter is interposed between the controller and one side of each of the combined sets of windings; and, a second switch (22b) is interposed between the inverter and the other side of each of the combined sets of windings.

Abstract: A synchronous machine effectively absorbs higher harmonics in an AC system to which the synchronous machine is linked. The synchronous machine includes a damper winding, disposed on each magnetic pole and constituting by itself an independent closed circuit; capacitors, each of which is connected in parallel with each of several damper winding divisions obtained by dividing the damper winding at predetermined winding turns; a DC reactor for blocking flowing-in of higher harmonics to a DC power supply for DC excitation; a series resonant circuit further including the damper winding and the capacitors; and a series resonant circuit including the field winding and capacitors. Resonant frequencies of both series resonant circuits are set at 6 nf (n: an integer, f: a fundamental frequency) so as to greatly reduce impedance of the damper winding and the field circuit seen from an armature of the synchronous machine, by which to extinguish or reduce higher harmonics (6n.+-.1)f of the AC system.

Abstract: The present invention provides a sensorless circuit for detecting rotational speed of a rotor in an induction motor. The circuit includes a switch between the AC source driving the motor and a motor phase winding. When the switch is closed, there is developed across the phase winding a voltage waveform from the AC source. When the switch is subsequently opened, there is developed across the winding a residual voltage waveform induced by the rotor. The speed of the motor is determined by measuring a time interval between selected points on the voltage waveform.

Abstract: A controller for a permanent magnet synchronous motor which includes a D-axis current command section and a Q-axis current command section. The D-axis current command section increases the command value of the D-axis current so as to set a judged value to be zero by leading the current phase when the judged value is positive. In addition, the D-axis current command section decreases the command value of the D-axis current when the judged value is negative. Moreover, the D-axis current command section holds the command value of the D-axis current at a predetermined minimum value when the decreasing command value of the D-axis current becomes smaller than the predetermined minimum value. The Q-axis current command section is responsible for supplying a command value of the Q-axis current.

Abstract: The present invention provides a digital circuit for controlling application of DC excitation to the rotor field winding of a synchronous electric motor. The circuit detects the analog slip frequency of the motor and converts the analog signal to a digital signal. A digital timer produces a timing signal after a predetermined time interval. After the frequency of the slip signal has slowed sufficiently, as indicated by the timing signal, a control signal is supplied to a thyristor to gate the thyristor and provide DC excitation to the rotor field winding.

Abstract: A control for operating an electromagnetic machine in a starting mode of operation detects a magnitude of a parameter of power applied to an armature winding of the electromagnetic machine relative to a stationary frame of reference and converts the detected parameter magnitude into field and torque producing components relative to a rotating frame of reference. A power source coupled to the armature winding is controlled during operation in the starting mode such that a rotor of the machine is accelerated.

Abstract: Device for starting a synchronous motor with a permanent-magnet rotor, particularly with two stator poles and two rotor poles, including a static power switch, a triac, arranged in series between the stator winding of the motor and the alternating-voltage source at mains frequency. The triac is controlled by an electronic circuit which processes three factors, namely the current flowing through the coil of the synchronous motor, the position and polarity of the permanent magnet of the rotor, and the polarity of the alternating-voltage source.

Abstract: A switched stepping motor for use in a computer-controlled processing system, the motor being capable AC or DC operation in a continuous or stepwise manner for completing a variety of operations such as lathe cutting, drilling, planning, milling, abrading, and boring.

Abstract: In a brushless synchronous motor in which a short-circuited protective winding (9) is associated with the field winding (2) of the rotor the starting conditions are improved in that the protective winding (9) consists of two winding sections (10, 11), which have different numbers of turns and are either wound in mutually opposite senses or are wound in the same sense but connected in opposition.

Abstract: A synchronous machine drive apparatus is provided with a first exciting winding or windings having a first axis and second exciting windings having a second axis. A DC current responsive to the current of the armature windings is applied to the second DC exciting winding. A fundamental exciting current component I.sub.FO and an additional exciting component .DELTA.I.sub.F responsive to the current of the armature windings are applied to the first DC exciting winding or windings, whereby with respect to the current distribution around the gap of the synchronous machine, the armature reaction is correctly compensated.

Abstract: An excitation system for a synchronous machine comprising an exciter having its output connected through a current relay in parallel with a starting-protecting unit. The starting-protecting unit includes parallel branches, each comprising a series-connected resistor and thyristor switch having a voltage-sensitive threshold element connected between its anode and gate. A turn-on unit for the parallel branches of the starting-protecting unit includes a voltage-sensitive overvoltage detector connected in parallel with the exciter output, in which the voltage setting is lower than that of the threshold element of the parallel branches of the starting-protecting unit. A memory unit; and a pulse-forming unit. The output of the overvoltage detector is connected through the memory unit to the input of the pulse-forming unit. The output of the pulse-forming unit is connected via the contacts of the current relay to the gates of the thyristor switches in the parallel branches of the starting-protecting unit.

Abstract: An apparatus for compensation of commutation dips in the curves representing synchronizing voltages developed by an excitation system of a synchronous machine comprises a thyristor converter and a matching transformer, and includes measuring transformers. Two of the measuring transformers have their primaries coupled to secondaries and primaries of the matching transformer in antiphase relation to each other, while primaries of a third measuring transformer are coupled to the arms of the thyristor converter in antiphase relation to the primaries of the second measuring transformer. The opposite ends of the primaries of each of the measuring transformers are joined together to constitute common points. The secondaries of the measuring transformers are coupled in cophasal relation to one another. One end of each of the secondaries is coupled to a respective adjusting resistor which has its movable contact connected via scaling resistors to a respective operational amplifier.

Abstract: A control system regulates operation of an electrical motor having multiple stator and rotor coils by regulating the phase displacement (1) between the rotor and stator energizing signals, (2) between the signals passed to the individual rotor coils, and (3) between the signals passed to the individual stator coils. A recorder coupled to the lines over which the phase-regulating signals are supplied to the rotor and stator coils can record these signals for later application to the motor to repeat the initial movement. Additionally displacement of the motor shaft produces signals which can be recorded for later duplication of the original shaft displacement. The phase-regulating signals for the rotor and stator coils can be supplied from a variable frequency oscillator, or a data processor, or any other suitable source.

Abstract: A rotatable transformer field excitation system for an armature converter-fed variable speed self-controlled brushless polyphase synchronous motor wherein the armature converter is energized from an alternating current voltage source having one or more phases, and wherein the motor includes a rotor having a wound field winding and a rectifier circuit mounted on the rotor and rotatable therewith to energize the field winding with direct current from the rectifier circuit, and wherein the rotatable transformer includes a primary winding having a number of phases equal to the phases of the alternating current voltage source and having a plurality of coils located in slots on the inner periphery of and defining at least two poles of a rotatable transformer stator, the slots being spaced a predetermined distance from the center of the rotor axis, and a separate rotatable secondary winding, the number of phases of which equals the phases of the rotatable transformer, the secondary winding being formed by a pluralit

Abstract: An AC motor has polyphase stator windings connected to an AC bus and has polyphase rotor windings connected directly or through impedances to capacitors. The capacitances of the capacitors are selected so as to be such that the AC motor exhibits a small input impedance for a specific frequency to be eliminated, thereby preventing the power factor from being since the fundamental frequency is not affected in any way under a light load. As a result, harmonics can be eliminated without causing any excessive AC source voltage.

Abstract: In a synchronous generator-motor, having both its main armature windings and exciter winding located on the stator and both the main field winding and the exciter armature windings including a rectifier for providing DC current to the main field located on the rotor and also including a voltage regulator responsive to the main armature voltage for regulating the current applied to the exciter field; the effects of transient currents in the main field windings resulting from load removal during the generator mode of operation and the voltages induced during motor start-up are substantially reduced by utilizing a resistive circuit operatively controlled by a transistor switching network that is in turn responsive to the exciter voltage and the induced voltage in the main field windings.

Abstract: A superconductive field winding is provided for the rotor of a dynamoelectric machine. The winding consists of a number of multi-turn coils of a superconductive conductor which are wound about the periphery of the rotor thereby defining at least one pole pair. Selected coils of each pole pair are series-connected in groups of two coils or more and all of the series connected coil groups are connected in parallel one to another. Resistance elements connected in series with the parallel connected coils cause the current density of coil conductors disposed in regions of high field intensity to be reduced in relation to the current density of conductors lying in regions of low field intensity, thereby allowing the use of higher source current. A net increase in the useful external magnetic field is therefore obtained for a given amount of superconductive material.