Abstract: An interference of control signals is caused by a deviation in the start timings of counting between counters of timer counter units of a first MCU and a second MCU. And thus, when a count value of the counter of the MCU of a parent reaches a predetermined value D, the MCU of the parent transmits a trigger signal to the MCU of a child. The MCU of the child obtains the time difference between the start timings of the counts of the counters of the parent and the child from the difference between the D and a count value E of the child at that time. A count period of the child until a maximum value of the count value is reached is adjusted by the time difference.

Abstract: The invention discloses an intrinsically safe field device for process automation technology, comprising: at least one sensor element for detecting at least one measurand; a secondary coil for transmitting and receiving data—in particular, values derived from the measurand—from a primary coil, and for receiving power from the primary coil, wherein the secondary coil comprises first and second connections; a second coupling body that is designed to be complementary to a first coupling body, wherein the second coupling body comprises the secondary coil; and a circuit assembly that is arranged downstream of the secondary coil. Within the circuit assembly, Zener diodes are connected upstream of rectifier diodes.

Abstract: The invention relates to a method for operating an electric machine (4), in particular of a motor vehicle (1), having a stator (10) with at least one stator coil. The stator coil is energized in order to set a required torque of the electric machine (4), and a temperature of the stator (10) of the electric machine (4) is detected by means of a temperature sensor (12). The current flowing through the stator coil is monitored in order to plausibility-check the detected temperature. In order to plausibility-check the temperature, the current in the stator coil is increased while maintaining the same torque, and the temperature is monitored for a temperature increase.

Abstract: A rotor portion of a synchronous machine includes a rotor. The rotor carries a field winding and a re-chargeable power storage device. The re-chargeable power storage device is electrically connected to the field winding to provide electrical power to the field winding while in generate or motor mode, and to provide electrical power to the re-chargeable power storage device while in a charge mode.

Abstract: A method detects faults during a steady state of an operation of an induction motor. The method measures, in a time domain, a signal of a current powering the induction motor with a fundamental frequency and determines, in a frequency domain, a set of frequencies with non-zero amplitudes, such that a reconstructed signal formed by the set of frequencies with non-zero amplitudes approximates the signal measured in the time domain. The determining includes a compressive sensing via searching within a subband including the fundamental frequency of the signal subject to condition of a sparsity of the signal in the frequency domain. The method detects a fault in the induction motor if the set of frequencies includes a fault frequency different from the fundamental frequency.

Abstract: A method for suppressing a speed fluctuation of a permanent magnet synchronous motor is provided in the present disclosure, including: obtaining a target speed ?_ref, a feedback speed, a fluctuation speed ??, a q-axis inductance Lq and a permanent magnet flux linkage ?f of the permanent magnet synchronous motor; performing a PI adjusting on ?? to obtain a q-axis reference current Iq_ref, and obtaining a q-axis target voltage U*q according to Iq_ref, ?_ref, ?? and ?f; performing a PI control on a q-axis actual voltage according to U*q to obtain a q-axis compensation current Iq_add; obtaining a d-axis target voltage U*d according to Iq_ref, Iq_add, ?_ref, ?? and Lq; performing a PI control on a d-axis actual voltage according to U*d to obtain a d-axis compensation current Id_add; superposing Iq_add and Iq_ref to perform a feedforward compensation on a q-axis current and superposing Id_add and the d-axis reference current to perform a feedforward compensation on a d-axis current.

Abstract: A method for controlling electromagnetic torque of a three-phase synchronous machine with permanent magnets, including measuring current delivered to the three phases of the machine, transposing the three measured currents into a direct current component and a quadratic current component using Park's transformation, and receiving an instruction for the quadratic current component. When the direct current component is negative, a defluxing control mode is activated in which the machine is controlled from a direct voltage component and a quadratic voltage component of the machine, the direct voltage component and the quadratic voltage component being determined in Park's plane.

Abstract: Cells in a phase leg of a multilevel converter are controlled through regulating, using tap-changer control, the modulation index of the converter to above 0.80, providing a group of carrier waves for the phase leg, where these carrier waves are identical but displaced in time from each other with a time delay, providing a voltage reference for the phase leg being separate from voltage references provided for other phase legs, stop switching of the cells when waveform values of a power transmission converter waveform are detected to be in a selected interval around a peak value of the power transmission converter waveform and control switching of the cells based on comparisons of the respective carrier waves with the voltage reference when the waveform values of the power transmission converter waveform are detected to be outside the selected interval.

Abstract: A field winding type synchronous motor comprises a stator, a rotor with field windings, a brushless exciter, and a rectification circuit rectifying an output of the brushless exciter. A first circuit in parallel with the field windings includes a discharge resistor and a first switching device with a backward diode. The discharge resistor and the first switching device are connected in series. A second switching device is provided in one of the DC lines connecting the first circuit and the rectification circuit. The first switching device is controlled by a potential obtained by resistor dividing of an induced voltage in the field windings and a connection from the potential via a diode to anode adjacent to the rectification circuit on the one of the DC lines with the second switching device thereon. The second switching device is closed in a synchronous speed.

Abstract: A motor control device according to the present invention includes: a boost converter circuit 30 that boosts a direct-current voltage; an inverter 40 that generates a drive pulse for a motor 50 from the direct-current voltage of the boost converter circuit 30; and a control section 60 that presets a set value Id_hold obtained by multiplying a set value Id_max by an intermediate current threshold coefficient ?, controls a pulse width of the drive pulse of the inverter 40 based on a speed deviation, controls a d-axis current in the motor 50 based on the speed deviation so that the pulse width of the drive pulse of the inverter 40 does not exceed a threshold value, and controls the direct-current voltage of the boost converter circuit 30 based on the speed deviation so that the d-axis current in the motor 50 does not exceed the set value Id_hold.

Abstract: This system provides a wide range of smooth and precisely controlled low and high speeds for pan-tilt-zoom surveillance cameras, in which a brushless motor is controlled by a Microcontroller in a low speed mode by sinusoidal synchronous commutation, in a high speed mode by block commutation, and in a transition phase from the low speed mode to the high speed mode by modulating integrated pulse-width modulation (PWM) square waves with sine waves. PID and lookup table registers are used by a microcontroller for a smooth transition from high speed mode to low speed mode, and from low speed mode to high speed mode, phase locking a sine position during transitions, in order to give a surveillance camera an ability to quickly move from one target to another at up to 100 degrees per second yet track objects that are moving very slowly.

Abstract: A synchronous electrical motor includes a rotor with a DC field winding. An exciter is configured to energize the DC field winding by generating a DC current in a first direction across the DC field winding when activated. A control system is configured to control a current flow across the DC field winding, the control system including a field discharge resistor and a by-passing circuitry. The by-passing circuitry is configured to implement a first by-passing to electrically by-pass the field discharge resistor during a current flow in the first direction across the DC field winding, and to implement a second by-passing to electrically by-pass the field discharge resistor during a current flow in a second direction across the DC field winding. The control system is able to direct all the DC current generated by the exciter to flow across the DC field winding.

Abstract: A field winding type synchronous motor comprises a stator, a rotor with field windings, a brushless exciter, and a rectification circuit rectifying an output of the brushless exciter. A first circuit in parallel with the field windings includes a discharge resistor and a first switching device with a backward diode. The discharge resistor and the first switching device are connected in series. A second switching device is provided in one of the DC lines connecting the first circuit and the rectification circuit. The first switching device is controlled by a potential obtained by resistor dividing of an induced voltage in the field windings and a connection from the potential via a diode to anode adjacent to the rectification circuit on the one of the DC lines with the second switching device thereon. The second switching device is closed in a synchronous speed.

Abstract: A variable-flux motor drive system including a permanent-magnet motor including a permanent magnet, an inverter to drive the permanent-magnet motor, and a magnetize device to pass a magnetizing current for controlling flux of the permanent magnet. The permanent magnet is a variable magnet whose flux density is variable depending on a magnetizing current from the inverter. The magnetize device passes a magnetizing current that is over a magnetization saturation zone of magnetic material of the variable magnet. This system improves a flux repeatability of the variable magnet and a torque accuracy.

Abstract: A variable magnetic flux motor drive system includes: a variable magnetic flux motor having a variable magnet which is a low-coercive permanent magnet; an inverter that drives the variable magnetic flux motor 1; an inverter as a magnetization unit which supplies a magnetization current for controlling a magnetic flux of the variable magnet; and a boosting unit boosting an input DC voltage to a predetermined target value to output it to the inverter. The variable magnetic flux motor drive system makes it possible to achieve size reduction and high efficiency, while securing a voltage required for supplying a magnetization current when controlling the magnetic flux of the variable magnet.

Abstract: A synchronous electrical motor includes a rotor with a DC field winding. An exciter is configured to energize the DC field winding by generating a DC current in a first direction across the DC field winding when activated. A control system is configured to control a current flow across the DC field winding, the control system including a field discharge resistor and a by-passing circuitry. The by-passing circuitry is configured to implement a first by-passing to electrically by-pass the field discharge resistor during a current flow in the first direction across the DC field winding, and to implement a second by-passing to electrically by-pass the field discharge resistor during a current flow in a second direction across the DC field winding. The control system is able to direct all the DC current generated by the exciter to flow across the DC field winding.

Abstract: A sensorless commutation circuit and sensorless driving apparatus for a brushless motor includes a voltage divided unit, a control signal output unit, a switch unit and a comparison unit. The voltage divided unit outputs a voltage divided signal according to a phase voltage signal of the brushless motor. The control signal output unit outputs a filter control signal, wherein the filter control signal has a same switching cycle as a pulse width modulation control signal that drives the brushless motor. The switch unit is coupled to the control signal output unit and the voltage divided unit, and outputs a comparison signal according to the filter control signal and the voltage divided signal. The comparison unit is coupled to the switch unit, and outputs a correct commutation signal according to the comparison signal.

Abstract: A variable-flux motor drive system including a permanent-magnet motor including a permanent magnet, an inverter to drive the permanent-magnet motor, and a magnetize device to pass a magnetizing current for controlling flux of the permanent magnet. The permanent magnet is a variable magnet whose flux density is variable depending on a magnetizing current from the inverter. The magnetize device passes a magnetizing current that is over a magnetization saturation zone of magnetic material of the variable magnet. This system improves a flux repeatability of the variable magnet and a torque accuracy.

Abstract: In a drive control circuit of a linear vibration motor, the drive signal generating unit generates a drive signal whose phase is opposite to that of the drive signal generated during the motor running, after the running of the linear vibration motor has terminated; this drive signal of opposite phase includes a high impedance period during which the driver unit is controlled to a high impedance state. An induced voltage detector detects an induced voltage occurring in the coil. A comparator has a function as a hysteresis comparator in which the output level does not vary in a predetermined dead band, and the comparator outputs a high-level signal or a low-level signal during the high impedance period. When an in-phase signal is consecutively outputted from the comparator during the consecutive high-impedance periods, the drive signal generating unit determines that the linear vibration motor has come to a stop.

Abstract: The present invention relates to a winding synchronous machine having a moving object including an inverter circuit, wherein a winding synchronous machine, including a winding synchronous motor or generator having a moving object including an inverter circuit, is provided, the winding synchronous machine being characterized by comprising: a moving-object inverter circuit connected to the moving object of the winding synchronous machine; and a moving-object circuit control device connected to the moving-object inverter circuit so as to control the moving-object inverter circuit.

Abstract: A variable-flux motor drive system including a permanent-magnet motor including a permanent magnet, an inverter to drive the permanent-magnet motor, and a magnetize device to pass a magnetizing current for controlling flux of the permanent magnet. The permanent magnet is a variable magnet whose flux density is variable depending on a magnetizing current from the inverter. The magnetize device passes a magnetizing current that is over a magnetization saturation zone of magnetic material of the variable magnet. This system improves a flux repeatability of the variable magnet and a torque accuracy.

Abstract: A stator has multi-phase stator coils that are wound around a stator core by concentrated winding. A rotor has rotor coils that are wound at multiple portions of a rotor core in the circumferential direction and diodes that serve as rectifier unit that is connected to the rotor coils and that varies the magnetic characteristics of the respective rotor coils alternately in the circumferential direction. A rotary electric machine driving system includes a decreasing/increasing pulse superimposing unit that superimposes decreasing pulse current for a pulse-shaped decrease on a q-axis current command for passing currents through the stator coils and that superimposes increasing pulse current for a pulse-shaped increase on a d-axis current command.

Abstract: A method for braking the thermal engine of an automobile using a multiple-phase rotary electric machine (1) connected to the thermal engine and including a stator and a rotor (4) having at least one excitation winding (41). A shortcut of at least one phase of the multiple-phase rotary machine is included during the stop phase of the thermal engine. The multiple-phase rotary electric machine is capable of braking the thermal engine of an automobile during the stop phase thereof due to the fact that a shortcut is induced, during the stop phase of the thermal engine, of at least one of the phases thereof.

Abstract: A variable-flux motor drive system including a permanent-magnet motor including a permanent magnet, an inverter to drive the permanent-magnet motor, and a magnetize device to pass a magnetizing current for controlling flux of the permanent magnet. The permanent magnet is a variable magnet whose flux density is variable depending on a magnetizing current from the inverter. The magnetize device passes a magnetizing current that is over a magnetization saturation zone of magnetic material of the variable magnet. This system improves a flux repeatability of the variable magnet and a torque accuracy.

Abstract: In a separately excited electrical synchronous machine, and a method for operating a synchronous machine, coil windings, in particular in the form of excitation coils, are disposed on the rotor, the electrical supply of the coil windings being achieved with the aid of an inductive rotation transmitter, whose secondary winding is connected to the rotor and whose primary winding, which is inductively coupled to the secondary winding, is stationary, especially connected to the stator of the synchronous machine.

Abstract: A brushless, synchronous machine is provided. A brushless, synchronous motor includes a rotor, a stator extending around at least a portion of the rotor and separated from the rotor by an air gap, a first stator winding, a second stator winding, a third stator winding, a drive circuit, a first rotor winding, a second rotor winding, and a diode bridge. The first stator winding, the second stator winding, and the third stator winding are mounted to the stator to generate square waves. The drive circuit is configured to provide a current to the first stator winding, the second stator winding, and the third stator winding, wherein the current includes an alternating current (AC) component and a direct current (DC) component. The first rotor winding is mounted to the rotor to form a plurality of third harmonic coils. The second rotor winding is mounted to the rotor.

Abstract: A rotating electrical machine including a first member (10) capable of generating a magnetic field which rotates relative to the first member, and a second member (6) which is provided with a winding through which a current can flow, such that the rotating magnetic field drives the second member in rotation. An electrical value which is at least related to the current is measured (18) and the generation of the rotating magnetic field is started (12) at a time which is determined as a function of the electrical value which is measured. A method of controlling the machine is also disclosed.

Abstract: A rotating electrical machine system includes a stator that has stator windings of a plurality of phases, and that generates a stator magnetomotive force in accordance with stator current of different phases, which is supplied to the stator windings of the plurality of phases; a rotor on which rotor windings are wound such that rotor current is generated in accordance with the stator magnetomotive force generated by the stator and a magnetic pole is formed by the rotor current; and a control unit that controls an output torque from the rotor, by controlling the stator current. In a case where a predetermined torque is output from the rotor, the control unit applies a pulse to the stator current so as to increase the stator current and reduce the rotor current, when a temperature of the rotor is high as compared with when the temperature of the rotor is low.

Abstract: A motor controller controlling a permanent magnet motor including a rotor provided with a plurality of low coercivity permanent magnets having a coercivity low enough to allow modification in amount of magnetization, the motor controller including a position detector including one or more position sensors to detect a rotational position of the rotor; an inverter circuit connected between a direct current voltage supply source and windings of the permanent magnet motor and configured by a plurality of semiconductor switching elements of multiple phases connected thereto; and a magnetization controller that magnetizes the plurality of low coercivity permanent magnets constituting the rotor by energizing the windings of the permanent magnet motor through the inverter circuit such that all of the low coercivity permanent magnets are magnetized to a uniform level of magnetization by energizing the windings twice at same timings specified based on a sensor signal outputted by the position sensor.

Abstract: A method and an apparatus are described for determining a field current through a field winding in an electrical machine with a stator and a rotor. The electrical machine includes a field-circuit transformer to produce, by induction of an electrical current on the rotor side, field current with which a field winding is energized in order to generate an excitation magnetic field. The method includes driving the primary side of the field-circuit transformer to produce a field current in the rotor, which is derived from the current induced on the secondary side in the field-circuit transformer; measuring one or more phase currents in one or more primary-side phases of the field-circuit transformer; determining a maximum value depending on the one or more measured phase currents; determining the field current through the field winding depending on the determined maximum value.

Abstract: The present invention provides a superconductive rotating electric machine drive control system that has higher efficiency and is smaller size and lighter in weight than conventional systems, and also provides a superconductive rotating electric machine drive control method to be implemented in the superconductive rotating electric machine drive control system. By the superconductive rotating electric machine drive control system and the superconductive rotating electric machine drive control method in accordance with the present invention, a control operation is performed so that the field current If2 applied to the superconductive field winding of the synchronous rotating electric machine satisfies an equation for the field current If2 in accordance with the variation of the electric power exchanged between the synchronous rotating electric machine and the power unit.

Abstract: A multi-phase AC motor driving device in which occurrence of failure is not erroneously determined is provided. In a multi-phase AC motor driving device including an inverter circuit; current detecting resistances Ru, Rv, and Rw, respectively arranged on lower arm of the respective phase of the inverter circuit, for detecting phase current of the motor; and a control portion and a PWM circuit for controlling ON/OFF operation of switching devices of the inverter circuit, the determination on the occurrence of failure based on the current values detected by the current detecting resistances is not made if relays connected between the inverter circuit and the motor are turned ON and all the switching devices of the lower arms of the respective phases are turned OFF.

Abstract: A starting method and system for a motor where the motor may be started as an induction motor by applying a magnetizing current to build flux through the stator, with the field current set at the maximum permissible exciter stator current (i.e., the current that will cause rated no-load current in the main field at the transition speed). The motor stator currents will be maintained at a value that allows the motor to generate sufficient breakaway torque to overcome any stiction. At a specific transition speed or after a period of time, the drive will initiate a transition from induction motor control to synchronous motor control by removing the initial magnetizing current, and a field current is then applied to the motor through the DC exciter. Once this transition is completed, the drive may ramp up to the desired speed demand.

Abstract: A control circuit of a motor includes at least two sensor chips and at least two winding sets. The sensor chips are electrically connected to each other, and each of the winding sets has a first winding and a second winding. The first end of the first windings and the first end of the second windings are electrically connected to each other, and the second end of the first windings and the second end of the second windings are electrically connected to the sensor chips correspondingly. In addition, a motor having the control circuit is also disclosed.

Abstract: An inverter is capable of converting a direct current from a direct current power supply into an alternating current and supplying it to an armature winding. A rectifier circuit is capable of rectifying the current, that has been converted to an alternating current by the inverter, into a direct current and supplying it to the field winding. The amount of the alternating current supplied to the armature winding and the amount of the direct current supplied to the field winding are in a proportional relationship, and implementation of switching control of the inverter controls both the amount of the alternating current supplied to the armature winding and the amount of the direct current supplied to the field winding while this proportional relationship therebetween is maintained.

Abstract: A motor controller including a vector controller that controls a permanent magnet motor including a rotor being provided with a permanent magnet having a coercivity low enough to allow modification in amount of magnetization and that executes a vector control by detecting current flowing at the permanent magnet motor; a speed/position detector that detects a rotational speed and a rotational position of the permanent magnet motor; a magnetization controller that increases or decreases the magnetization of the permanent magnet depending on the rotational position of the permanent magnet motor through adjustment in status of the magnetization of the permanent magnet by way of armature counteraction; and a demagnetization detector that detects a decrease in the magnetization of the permanent magnet magnetized by the magnetization controller during operation of the permanent magnet motor.

Abstract: A rotor position detection circuit detects a position of a rotor in a motor from a detection signal of an induced voltage generated in a stator coil. The circuit includes: a first low pass filter having a first reference potential for filtering the detection signal; a comparator for comparing an output signal from the first low pass filter with a predetermined reference voltage and for outputting a rotation position signal; and a second low pass filter having a second reference potential for filtering a virtual neutral point potential of the motor. The first reference potential is the filtered virtual neutral point potential, and the second reference potential is a ground.

Abstract: The present invention provides a superconductive rotating electric machine drive control system that has higher efficiency and is smaller size and lighter in weight than conventional systems, and also provides a superconductive rotating electric machine drive control method to be implemented in the superconductive rotating electric machine drive control system.

Abstract: The invention relates to a synchronous motor (12,32) having a number of stator coils and an armature (16, 36) having at least one permanent magnet (17, 37) which produces a magnetic field in a main flux direction, having at least one coil winding (20, 40) which is fitted to the armature (16, 36) such that a component of an alternating magnetic field, which is applied with the aid of the stator coils (15, 35), can be used to induce in it a secondary current which can be tapped off by means of a load (25, 45) which can be arranged adjacent to the armature.

Abstract: In a method of estimating a magnetic pole position in a synchronous motor, an alternating current voltage having ?- and ?-axes components in an ?? coordinates system representing a two-phase alternating current coordinates system is applied to the motor, and ?- and ?-axes components of an alternating current are detected from the motor. A wave height of the alternating current changing with time is approximated to a wave height not depending on time, so that a differentiated value of the wave height with respect to time is substantially set at zero. An induced voltage of the motor is calculated from the components of the alternating current voltage and the components of the alternating current. The magnetic pole position is estimated from the induced voltage.

Abstract: A speed-variable field winding type of synchronous rotary electric machine is provided, where a rotor with plural-phase windings faces a rotor with a field winding. A field current is limited to flow through the field winding in one direction thereof. A fundamental component of armature current, which corresponds a synchronizing current for producing a rotating magnetic field rotating in sync with the rotation of the rotor, is supplied to the armature windings. The synchronizing current is adjusted in frequency to change a rotor rotation speed. A pulsed rotor exciting current is supplied to the armature windings. The exciting current causes the field winding to induce the field current only during a specified current-supply duration shorter than a one cycle of the synchronizing current. The number of current-supply times for the exciting current, per electrical angle 2? and per phase, has a positive correlation with the cycle of the synchronizing current.

Abstract: An object of the present invention is to provide a controller of a field winding type synchronous motor that can stably output torque even if the d-axis current pulsates by reducing torque pulsation without causing fluctuations in the magnetic flux acting on the torque, and also provide an electric drive system, an electric four wheel driving vehicle, and a hybrid automobile. A motor control unit 100 performs control so that a desired torque be generated from a field winding type motor 20 having a field winding 22f on the rotor. Based on a current Id flowing in the d-axis direction out of the currents flowing in a stator winding 22a of the field winding type motor 20, the motor control unit 100 calculates an induced voltage Vf2 being induced in the field winding 22f and compensates a field voltage Vf of the field winding based on the induced voltage Vf2, thus suppressing pulsation of the field current flowing in the field winding of the field winding type motor 20.

Abstract: A power regulator with a bypass and splice capacity includes at least one phase member and a driver. Each one of the at least one phase member includes two cooling fins, two SCR thyristors, a conductive resilient tab and a conductive rigid tab. The cooling fins are conductive and adjacent to each other. The SCR thyristors are mounted on the cooling fins and are inversely connected in parallel to each cooling fin. The conductive resilient tab is mounted on one of the cooling fins and has a moveable contact. The conductive rigid tab is mounted on the other cooling fin and has a stationary contact aligned with the movable contact. When the driver is energized, the driver drives the conductive resilient tab and the moveable contact is contacts the stationary contact and power is bypassed and spliced through the cooling fins.

Abstract: A driving apparatus of a synchronous motor fixes all the switching devices of an inverter at OFF in accordance with a value of an all-OFF control pulse signal outputted by a pulse generator. A motor current keeps flowing through free wheel diodes for a predetermined period even after all the switching devices shift to the OFF state. Therefore, pulse generator changes an induced voltage detection signal to an H (high) level after the passage of the time in which a motor current drops down to zero. A terminal voltage of the motor is taken in to acquire an induced voltage and a rotor position is estimated.

Abstract: A control system for a synchronous machine including a converter for converting DC voltage to AC voltage or AC voltage to DC voltage. The synchronous machine is driven by the converter. The control system further includes a magnetic pole position presuming device for performing a presuming operation to presume a magnetic pole position of the synchronous machine based on high-frequency components of a voltage applied to the synchronous machine and a current flowing into the synchronous machine, and a control device for controlling the converter based on the magnetic pole position presumed by the magnetic pole position presuming device. The control device controls the converter so as to contain significant high-frequency components in the voltage or the current used in the presuming operation when a mean voltage or a mean current output from the converter is spatially in a region close to a straight line containing starting and ending points of non-zero voltage vector output from the converter.

Abstract: A desired q-axis current is determined based on a desired torque, and a desired d-axis current is determined based on the rotating speed of a synchronous motor when the terminal voltage of the synchronous motor coincides with a predetermined maximum permissible voltage to weaken a magnetic field created by the synchronous motor equivalently and to prevent the drop of the output torque of the synchronous motor. The desired d-axis current is determined based on the desired torque and the rotating speed. Therefore, the desired d-axis current can be reduced when a high torque is not necessary and undesired increase of the desired d-axis current can be prevented. Thus the synchronous motor operates efficiently, heat generation of the synchronous motor is prevented and power factor is improved.

Abstract: A rotation control method of a synchronous motor, the motor comprising: a stator having AC windings thereround; and a rotor, being mounted within said stator, rotatably, wherein on an each surface, opposing to the rotor, of poles building up the stator, are formed plural numbers of teeth portions, and on a surface of the rotor, being made of permanent magnet, opposing to the poles of the stator, are also formed plural numbers of teeth portions, with a width being nearly equal to that of the teeth portion in a circumference direction thereof, and further AC voltages having a predetermined voltage-frequency characteristic is supplied to AC windings wound around the poles of the stator, and the AC voltages supplied from the inverter is so determined in the voltage-frequency characteristic thereof, at least within a part of frequency band equal or less than a predetermined rated frequency, a pull-out torque of the synchronous motor is equal to or greater that a rated pull-out torque at the predetermined rated fre

Abstract: A dynamoelectric machine combining the functions of an exciter, a turning motor, and a starting motor for a turbine. The machine operates in a first mode where the slip between a first stator winding and a first armature winding is positive and thus the magnetic fields interact and operate as a motor to turn the turbine. In a second mode the slip is negative as the turbine turns the shaft and the first stator winding and the first armature operate as an exciter for supplying excitation to the rotating field winding of a main generator.

Abstract: A motor control apparatus includes a phase current detecting section for detecting phase currents to a motor, a current phase/current peak value calculating section for calculating a current phase based on the phase currents, a voltage phase setting section for adding a predetermined phase difference to the current phase and setting the resultant sum as a voltage phase, a phase voltage setting section for setting phase voltages to the motor based on the voltage phase and the command voltage. Basically, the motor is operated by maintaining the voltage at constant and always monitoring the current/voltage phases so as to maintain a constant phase difference, without the motor axis position being predicted.

Abstract: An exciter assembly supplies current to a superconducting load. The exciter assembly includes a transformer for generating the current and an optical emitter and an optical receiver. The transformer includes a stationary winding portion having a stationary winding and a rotatable winding portion having a rotatable winding that outputs the current for the superconducting load. The optical emitter and the optical receiver define an optical path over which information is exchanged between the stationary winding portion and the rotatable winding portion.