Abstract: An exciter comprises a stator armature defining a plurality of circumferentially spaced apart winding slots separated by respective stator teeth. first exciter winding with multiple phases, a second exciter winding with multiple phases. The individual windings of the first and second exciter windings are seated in the winding slots. For each phase of each of the first and second exciter windings there are two leads configured to connect to a generator control unit (GCU).

Abstract: A method of estimating a d-q axis inductance of a permanent magnet synchronous motor includes the following steps. First, building an equivalent motor control block through enabling two of the three phases, and disabling the remaining one of the three phases, and locking a rotor. Afterward, incorporating a back EMF observer into a DC motor control block, and making the DC motor control block correspond to the back EMF observer by commanding an angular speed of the DC motor control block to be zero. Afterward, introducing the equivalent motor control block into the DC motor control block, and using the back EMF observer to estimate the back EMF, and repeating above steps taking turns to disable one phase so as to obtain three sets of motor inductances respectively. Finally, estimating the d-q axis inductance by introducing the three sets of equivalent motor inductances into an inductance relational equation.

Abstract: A power tool includes a motor, a power supply device, a driver circuit, a parameter acquisition module, and a controller. The motor includes a stator and a rotor. The motor is configured to generate a reluctance torque. The driver circuit is electrically connected to the motor to drive the motor. The parameter acquisition module is configured to acquire a current of the motor, a rotational speed of the motor, and a position of the rotor. The controller is configured to: according to at least one of the current of the motor, the rotational speed of the motor, or the position of the rotor, dynamically adjust a current applied to the stator so that an included angle between a stator flux linkage of the motor and a rotor flux linkage of the motor ranges from 90° to 135°.

Abstract: This application discusses techniques for providing sensorless rotor position information of a multiple phase motor without using predetermined motor parameters or models, other than the number of phases of the motor. In certain examples, motor rotor position information can be provided using samples of current from zero-voltage vectors of the motor windings.

Abstract: An arrangement with a synchronous generator for the conversion of mechanical power into electrical power, with a predetermined number of pole pairs, an asynchronous machine, with a pronounced rotor winding, which is mechanically coupled to a rotor of the synchronous generator and has a number of pole pairs at least 1 greater than the synchronous generator.

Abstract: A synchronous machine for connection to an electrical system may include a stator configured as a portion of the synchronous machine; a rotor configured as a portion of the synchronous machine being rotatable with respect to the stator; and a control circuit to control the rotor to allow the rotor to continuously slip with respect to the stator.

Abstract: A computer-implemented method includes, responsive to absence of a motor controller receiving communication packets for a predetermined time during a drive cycle, operating by the controller (i) an inverter to output voltage at a setpoint defined by an inverter terminal voltage at expiration of the predetermined time, and (ii) a motor coupled with the inverter to apply torque according to a change in the voltage.

Abstract: A system and method for controlling a speed of a permanent magnet AC motor (38) based on a delay angle of a triac-controlled AC voltage signal (66) from a triac (34). A simulated load (54) connected to the triac (34) enables a load current and creates the signal (66). A first detector (48) detects a zero-crossing point of the AC voltage signal, and a second detector (50) detects a subsequent turn-on instance of the triac (34). A speed command generator (52) measures an interval between the zero-crossing point and the subsequent turn-on instance, and converts the delay angle to a speed command for controlling the speed of the motor (38). The simulated load (54) may include resistors (70) having a resistance which causes the load current to be below a holding current rating of the triac (34), thereby causing the triac (34) to turn off after the interval has been measured.

Abstract: At least one example embodiment discloses a drive system including a motor including a rotor, the motor configured to receive a measured current, a controller configured to generate a voltage for the motor at a stationary reference frame, the voltage having a frequency and the measured current being based on the voltage, a filter configured to obtain position information of the rotor based on the measured current and a nonlinear observer configured to estimate a rotor position of the motor during the stationary reference frame based on the position information. The controller is configured to control the motor based at least in part on the estimated rotor position.

Abstract: A motor speed controller controls a motor speed to generate a phase reference pulse; generates a FG pulse per rotary angle of the motor; detects a difference between the number of phase reference pulses and the number of FG pulses for output as an integer number phase difference; detects and measures a time difference between an edge of the phase-reference pulse and an edge of the FG pulse in units of the reference clock for output as a decimal fraction phase difference; adds the integer number phase difference to the decimal fraction phase difference at a predetermined ratio for output as a phase difference; and controls driving of the motor in accordance with the phase difference.

Abstract: A motor control apparatus according to the embodiment includes a rotational position estimating unit, a change amount estimating unit, and an inductance estimating unit. The rotational position estimating unit estimates a rotational position of a rotor from a motor parameter including a q-axis inductance of a motor on a basis of an output current to the motor and a voltage reference. The change amount estimating unit estimates a change amount of an output torque with respect to a current phase change of the motor corresponding to a high frequency signal whose frequency is higher than a drive frequency of the motor. The inductance estimating unit estimates an inductance value that obtains a maximum torque on a basis of the change amount as the q-axis inductance.

Abstract: A method of driving an alternating-current (AC) motor while periodically obtaining a rotator angle of the AC motor. The method includes: (a) driving the AC motor by a dS-axis voltage, which is a voltage for an exciting current in a stationary reference frame, and a qS-axis voltage, which is a voltage for generating a rotational force in the stationary reference frame, while sequentially applying different dS-axis voltages and different qS-axis voltages to the AC motor in a control injection period; and (b) obtaining a rotator angle by a dS-axis voltage value, a qS-axis voltage value, a dS-axis current value, and a qS-axis current value in the control injection period.

Abstract: A slide-out or retractable room for a mobile living quarters, such as a recreational vehicle, is provided with actuating assemblies mounted on opposite side walls of the slide-out room and the adjacent wall of the main living area. The actuating assemblies include a pair of parallel gear racks mounted on the side wall, which are engaged by pinions rotated by torque shafts mounted on the main living quarters. Each torque shaft is rotated by a separate motor. A roller engages a bearing surface on the lower portion of the gear racks. Accordingly, the slide-out room is extended and retracted by rotating the torque shafts to cause the gear racks and the attached slide-out room to extend and retract. The weight of the slide-out room is supported by the rollers, thereby supporting the slide-out room off of the floor of the main living quarters as it extends and retracts.

Abstract: In a method and a device for pulse width modulated (PWM-) activation of an electrical drive motor (2) of an adjustment arrangement based on a reference of the mechanical system of the adjustment arrangement that corresponds to a relationship between the force (F) on the drive motor (2) and the adjustment path (s) or the adjustment time (t) of the adjustment arrangement stored in a memory (9), an anticipated future force value (F(t+t0)) is determined based on the reference of the mechanical system in order to adjust the PWM activation in advance by utilizing this future force value such that motor synchronization fluctuations can be prevented upon anticipated mechanical fluctuations in the adjustment arrangement.

Abstract: The present invention provides a simple, robust, and universal position observer for use with sensorless synchronous machines. The observer may be implemented using an equivalent EMF model of a synchronous machine or, alternately, using a sliding mode controller based on the equivalent EMF model of the synchronous machine. The observer may be used on any type of synchronous machine, including salient or non-salient pole machines such as a permanent magnet, interior permanent magnet, wound rotor, or reluctance synchronous machine. The observer provides low sensitivity to parameter variations and disturbances or transient conditions in the machine. In addition, no knowledge of speed is required as an input to the observer and an estimated position may be calculated using a subset of the machine parameters.

Abstract: A hybrid drive device includes a first motor; an operative mechanism that drivingly connects the first motor to an engine of a vehicle; a second motor that is drivingly connected to a drive wheel; an engine rotation speed sensor that detects a rotation speed of the engine; a magnetic pole position sensor that detects a magnetic pole position of the second motor; a current sensor that detects a current flowing to the first motor; a sensorless motor control device that estimates a magnetic pole position of the first motor based on the current detected by the current sensor, and drivingly controls the first motor; and a second motor control device that drivingly controls the second motor based on the magnetic pole position detected by the magnetic pole position sensor.

Abstract: A method and apparatus to provide estimates of electrical parameters for line-connected induction motors during either steady-state or dynamic motor operations. The electrical parameters are calculated from the motor nameplate data and voltage and current measurements. No speed sensors or electronic injection circuits are needed. The method can be divided into 4 major steps. First, complex space vectors are synthesized from voltage and current measurements. Second, the instantaneous rotor speed is detected by calculating the rotational speed of a single rotor slot harmonic component with respect to the rotational speed of the fundamental frequency component. Third, the positive sequence fundamental frequency components are extracted from complex space vectors. Finally, least-squares estimates of the electrical parameters are determined from a dynamic induction motor equivalent circuit model.

Abstract: A press machine controller (10) for controlling a press machine (30) having a servo motor (41) to drive a slide (38) via a reduction mechanism (37) changed in reduction ratio in accordance with the position of the slide (38) is disclosed. The device includes a command generator (20) for generating at least one of a position command, a speed command and a torque command for the servo motor (41); a vibration command generator (13) for generating a vibration command based on a parameter preset for the press machine controller (10); a slide position detector (12) for detecting the position of the slide (38); and a vibration command adding portion (21, 22, 23) for adding the vibration command to any one of the position command, the speed command and the torque command for the servo motor (41) in the case where the slide position is in a predetermined range. The press machine, even if stopped with the slide at the bottom dead center, can be restarted with a small torque.

Abstract: A method for starting a motor (14) with a bidirectional rotation direction, to rotate a fluid circulation centrifugal pump (10) having a predetermined optimum hydraulic efficiency depending on the starting rotation direction thereof. The method provides an initial motor (14) starting in either rotation direction, with subsequent pump (10) rotation in the same direction and, subsequently, a periodical interruption and restoration of the motor (14) power feeding as many times (N, N?) as to ensure the motor (14) starting, at least one or more times within a predetermined time interval (Ttot, Ts), in the rotation direction which corresponds to the predetermined pump (10) optimum hydraulic speed.

Abstract: A method of constant airflow control includes various controls to accomplish a substantially constant airflow rate over a significant change of the static pressure in a ventilation duct. One control is a constant I·RPM control, which is primarily used in a low static pressure range. Another control is a constant RPM control, which is primarily used in a high static pressure range. These controls requires neither a static pressure sensor nor an airflow rate sensor to accomplish substantially constant airflow rate while static pressure changes.

Abstract: A machine comprising a rotor, a stator (12), a control bridge (10) with controlled switches, and a control device (20, 30) supplying control signals (C) to the control bridge (10), wherein the control device comprises means (30) for applying to at least one switch of the control bridge a control signal with a phase-lead relative to a signal representing the position of the rotor relative to the stator. According to the invention, the applying means comprise means (30) for adjusting the phase lead (d) from a plurality of values for a given rotational speed of the rotor.

Abstract: In various embodiments, an electric motor drive system (400, FIG. 4) and a motor vehicle (1000, FIG. 10) include an inverter (404, FIG. 4) adapted to generate (604, FIG. 6), based on inverter control inputs, a number, N, of phase current waveforms (118, FIG. 1), and a phase current sampling apparatus (408, FIG. 4) having a same number, N, of current sensors (502, 503, 504, FIG. 5). Each of the current sensors is adapted to receive one of the phase current waveforms, and the current sensors are adapted simultaneously to sample the phase current waveforms and to generate digital values representing amplitudes of the phase current waveforms. The system and motor vehicle also include a controller (410, FIG. 4) adapted to receive the digital values, to perform an evaluation of the digital values, and to generate the inverter control inputs (462, FIG. 4) based on the evaluation.

Abstract: This application describes a motor designed to operate as a reluctance machine at low speeds and as an induction machine at high speeds. The drive waveform is composed of one or more harmonics to be used to match the reluctance pattern of the stator-rotor, causing the rotor to rotate due to the reluctance effect, and one or more other harmonics to induce current in the rotor, causing the rotor to rotate due to the induction effect and the subsequent interaction of the stator and rotor magnetic fields. The two effects are generally not applied simultaneously.

Abstract: A synchronous electric machine operates as a starter-generator for an aircraft. When operating in a starting mode, a main stator of the machine is supplied with electrical power at a constant frequency. An exciter stator is supplied with variable frequency power. As rotational speed increases, the exciter variable frequency changes correspondingly to maintain synchronous operation of the machine and maximum torque. In a generator mode, variable frequency is applied to the exciter stator with the exciter frequency varying as a function of rotational speed of an engine driving the machine. This provides for a constant frequency output from the machine.

Abstract: The system (ECS) comprises a rectifier circuit (RC) to supply a direct current voltage (VB) as output; a driver circuit (DC) which is connected to a rectifier circuit (RC) and includes a plurality of controlled switches (SW1-SW4) which can permit passage of a current in the stator winding (W) selectively in one direction and in the opposite direction; a sensor (PS) which can supply a signal (H) which is indicative of the angular position of the rotor (R); and a control circuit (CC) which is designed to receive a signal (RS) which is indicative of the speed of rotation required (?ref) for the motor (M), and is connected to the position sensor (PS).

Abstract: A driver with a reverse-rotation preventer for an inflatable rotating exhibit is mounted inside an inflatable rotating exhibit having a transparent inflatable body and a rotating body and has a rotating assembly and a reverse-rotation preventer. The rotating assembly connects to and rotates the rotating body and has a synchronous motor that rotates in a direction and has a shaft. The shaft is driven by the synchronous motor and rotates the rotating body. However, the synchronous motor will reverse its rotation when the rotating body encounters even temporary resistance while rotating. The reverse-rotation preventer applies a resistance when the rotating body rotates in the wrong direction to make the synchronous motor reverse rotation. Consequently, the reverse-rotation preventer ensures that the rotating inflatable exhibit rotates in the desired direction.

Abstract: The present invention relates to electrically magnetized synchronous machine comprising an electrically magnetized rotor, and electrically supplied sator windings, whereby it further comprises non-linear means, optionally controllable, such as rectifying means in a series with three sator phase windings, whereby a rotor field winding is arranged to be fed from said non-linear means.

Abstract: For a multiphase alternating current (AC) wound field synchronous machine (WFSM) that has a stator with a selected number of poles, the WFSM having an associated exciter and multiphase AC permanent magnet machine (PMM) directly coupled to the WFSM, a method of sensing the position of a rotor in the WFSM comprises the steps of: configuring a stator for the PMM to have a number of poles that is a sub-multiple of the selected number of WFSM stator poles; configuring a rotor for the PMM to have high saliency; applying multiphase AC power of a selected frequency to the PMM stator; detecting at least one set of stator harmonic currents of the multiphase AC power resulting from the rotor saliency; converting the detected PMM harmonic stator currents from their multiphase coordinates to ?? coordinates; rotating the converted PMM stator currents into a reference frame for at least one selected harmonic to generate ?? coordinate harmonic current vectors; and estimating the position of the WFSM rotor based on the values

Abstract: A driver for an inflatable rotating exhibit is mounted inside an inflatable rotating exhibit having a transparent inflatable body and a rotating body and has a rotating assembly and a reverse-rotation preventer. The rotating assembly connects to and rotates the rotating body, has a synchronous motor. The synchronous motor rotates in a direction and has a shaft. The shaft is driven by the synchronous motor and rotates the rotating body. However, the synchronous motor will reverse its rotation when the rotating body encounters even temporary resistance while rotating. The reverse-rotation preventer applies a resistance when the rotating body rotates in the wrong direction to make the synchronous motor reverse rotation again to the desired direction. So the reverse-rotation preventer ensures that the rotating inflatable exhibit rotates in the desired direction.

Abstract: A self-magnetizing motor incorporates a control circuit that starts the motor, controls a magnetizing unit, and then operates the motor. The control circuit can include relay, such as a bi-directional conductive power semiconductor device, and one or more PTC (Positive Temperature Coefficient) switches. This control circuit eliminates the need for a separate controller and the implementation costs can be reduced.

Abstract: A driver for an inflatable rotating exhibit is mounted inside an inflatable rotating exhibit having a transparent inflatable body and a rotating body and has a rotating assembly and a reverse-rotation preventer. The rotating assembly connects to and rotates the rotating body, has a synchronous motor. The synchronous motor rotates in a direction and has a shaft. The shaft is driven by the synchronous motor and rotates the rotating body. However, the synchronous motor will reverse its rotation when the rotating body encounters even temporary resistance while rotating. The reverse-rotation preventer applies a resistance when the rotating body rotates in the wrong direction to make the synchronous motor reverse rotation again to the desired direction. So the reverse-rotation preventer ensures that the rotating inflatable exhibit rotates in the desired direction.

Abstract: A field winding synchronous generator-motor includes: a power conversion section that is connected to an electric rotating machine and operating as a generator-motor, and that controls the electric rotating machine; a compensation amount storage section that stores a compensation capable of improving characteristics of the electric rotating machine from a reference position of a rotor; a positional compensation operation section that makes a compensation operation of positional information from a rotor position and a value of the compensation amount storage section; a conducting phase storage section that stores a conducting phase to each armature winding from the reference position; and a rectangular wave application voltage command section that commands a rectangular wave application voltage to each armature winding with respect to the power conversion section from a value of the positional compensation operation section and a value of the conducting phase storage section.

Abstract: A method for sensorless estimation of rotor speed and position of a permanent magnet synchronous machine, when the permanent magnet synchronous machine is fed with a frequency converter, the method comprising the steps of forming a stator voltage reference for the permanent magnet synchronous machine, injecting a high frequency signal (uc) into the stator voltage reference, measuring a DC-link current (idc) of the frequency converter when the permanent magnet synchronous machine (4) is fed with a voltage (Us,ref) corresponding to a sum of the stator voltage reference and the injected signal, calculating a stator current estimate (îs), calculating a current error (?s) as a difference between the stator current estimate and the measured DC-link current, and estimating a rotor speed ({circumflex over (?)}m) and position ({circumflex over (?)}m) of the permanent synchronous machine based on the current error.

Abstract: An object is to provide a driving device capable of detecting a current of a motor without any trouble even in a low rotation speed/low load state to continue a sensor-less vector control, in a case where the motor is driven by the sensor-less vector control, and the driving device comprises: a main inverter circuit for applying a pseudo alternating voltage to a permanent magnet type motor M to drive the motor; a current sensor 6 which detects the current flowing through the motor; and a control circuit which controls the main inverter circuit. Based on an output of the current sensor, the control circuit separates the current flowing through the motor into a torque current component and a field current component to control commutation of the main inverter circuit by the sensor-less vector control.

Abstract: Methods and systems are provided for controlling synchronous machines. The method comprises generating a d-axis current command and a q-axis current command, producing a modified current command from the q-axis current command, converting the d-axis current command to a first voltage command, converting the modified current command to a second voltage command, and supplying the first and second voltage commands to the synchronous machine. The modified current command limits a terminal voltage generated by the permanent magnet machine.

Abstract: A method for correcting speed feedback in a drive motor by calculating the averages of speed reference and speed measurement for both downward and upward constant-speed travel and then identifying the gain and zero factors and correcting the measured speed measurement to the correct value.

Abstract: A motor control system for a wound field synchronous dynamoelectric machine used as an electrical starter and a generator for aeronautical engines that uses its integral auxiliary permanent magnet generator as an angular position sensor in its starting mode.

Abstract: A method drives a synchronous electric motor, particularly to start a fan/exhaust fan. The method includes measuring the supply voltage value of the electric motor windings being proportional to the mass flow rate. The method also includes measuring a real load angle, by a signal coming from a Hall sensor associated with the motor rotor; performing a comparison with an optimal load angle corresponding to a reference mass flow rate of fluid being exhausted; and changing the voltage value and the operating frequency applied to the electric motor up to reach a value of the real load angle corresponding to said optimal load angle value.

Abstract: A method of starting a permanent magnet machine. A machine stator voltage in a stationary reference frame is sensed. An initial speed of a rotor of the machine is estimated based on the sensed voltage, and state variables of control algorithms are initialized based on the estimated initial speed. This method can provide smooth startup and/or restart at any speed.

Abstract: In order to control the position of a mobile body without using a position detector, a magnetic pole position of a rotor of a synchronous motor is estimated based on electrical quantities in relation to electric power supplied to the synchronous motor and then the mobile body position is estimated based on the estimated magnetic pole position.

Abstract: A drive control apparatus, which controls an AC motor subjected to rotational drive by applying a rectangular wave voltage thereto, comprising: an actual torque detection section for detecting an actual torque value T outputted from the AC motor; an estimated torque calculation section for calculating an estimated torque value Tm based on a motor model with the AC motor in a simulated state; and a voltage phase calculation section wherein the voltage phase calculation section calculates a first voltage phase ?fb based on the actual torque value T and a command torque value T*, and a second voltage phase ?ff based on the estimated torque value Tm and the command torque value T* respectively, and outputs a value obtained by making the voltage phase subjected to weighting addition, as a voltage phase ?v.

Abstract: In the control of a synchronous motor having a permanent magnet, an alternating current power supply voltage that is input to a power amplifier or a direct current link voltage of which input voltage is rectified is measured. A reactive current (a d-axis current) or a current control phase advance is changed, according to this power supply voltage. With this arrangement, reactive current control or current phase control can be carried out directly according to a change in the input power supply voltage. A motor control device includes a voltage measuring unit that measures a voltage supplied to a driving amplifier, and a current control unit that controls a current passed to a synchronous motor based on the measured voltage. The voltage measuring unit measures a voltage supplied to the amplifier. The current control unit controls a current that is passed to the synchronous motor, according to the measured voltage.

Abstract: An apparatus for use with a signal generator and a motor controller includes a velocity compensator, an adjustor, and a velocity regulator. The signal generator provides a reference velocity signal, and the motor controller receives an output signal and uses the output signal to control a torque input signal applied to the motor. The velocity compensator is operable to receive the reference velocity signal, determine a derivative of the reference velocity signal, and generate a velocity compensation signal based on the derivative. The adjustor is operable to adjust the reference velocity signal as a function of the velocity compensation signal. The velocity regulator is operable to compare the adjusted reference velocity signal to a feedback velocity signal and generate the output signal received by the motor controller for adjusting the torque input signal based on the comparison.

Abstract: In an automatic transmission position control by a motor, it is determined whether the present instant belongs to a starting period, that is, the present instant is immediately after resetting of a control unit or application of power to it. If it is the starting period, an actual shift position that is detected from an output of an output shaft sensor for detecting a rotation position of a motor is set as an instructed shift position. With this measure, even if the control unit is reset for a certain reason while the vehicle is running, the instructed shift position is not changed in association with the resetting. This prevents trouble that the shift position is switched contrary to the intention of the driver, whereby the reliability of a position switching control can be increased.

Abstract: A position sensing apparatus (300) derives rotor position of a synchronous machine (200) from signals output from the machine (200). In one embodiment, the position sensing apparatus (300) comprises: a bandpass filter (322) that filters phase voltage signals output from main stator windings (216) of the synchronous machine (200) during AC excitation, thereby extracting a rotor position-indicating component from the phase voltage signals; a converter (324) that converts the filtered phase voltages into balanced two-phase quadrature signals, the balanced two-phase quadrature signals indicating positioning of the rotor (212); and an excitation controller (204) for controlling AC excitation frequency as a function of rotor speed.

Abstract: The object of the invention is to inhibit the axial displacement caused by the insufficiency of a control response angular frequency of a frequency arithmetic unit of a synchronous motor and realize high-precision torque control also in acceleration/deceleration. To achieve the object, the axial displacement of the synchronous motor caused by the insufficiency of the control response angular frequency of the frequency arithmetic unit is estimated in consideration of the control response angular frequency and input ??c3 (=??c1+??c2) including an estimated value ??c2 in addition to an axial displacement operated value ??c1 to the frequency arithmetic unit is acquired. Hereby, even if the frequency arithmetic unit has an insufficient control response angular frequency, the quantity of axial displacement which will be caused by the insufficiency is estimated as a second axial displacement signal ??c2, is added and input.

Abstract: A 3-phase AC current flowing to a 3-phase synchronous motor is converted through coordinate conversion to a d-axis current id and a q-axis current iq in a dq-axis coordinate system which rotates in synchronization with the motor rotation and a phase ? of a rectangular wave voltage is calculated based upon the current deviation between a q-axis current command value iq* and the q-axis current iq. A 3-phase rectangular wave voltage is generated from a DC source based upon the calculated phase ? and is applied to the 3-phase synchronous motor.

Abstract: A method for implementing active deadtime control of an inverter associated with an electric motor is disclosed. In an exemplary embodiment, the method includes receiving a command voltage signal indicative of a desired load to be driven by the motor. Based upon the value of the command voltage signal, a determined value of deadtime is applied to switching circuitry in the inverter, wherein the value of deadtime relates to an amount of time in which the switching of a device in the switching circuitry is delayed so as to prevent a short circuit condition within the inverter.

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: Electric motor for driving members that rotate at speeds of greater than 40,000 revolutions per minute, includes a stator housing induction coils, a rotor supporting multiple permanent magnets and located coaxially inside the stator, and multiple Hall sensors integral with the stator and capable of detecting the position of one or more points on the rotor as it rotates in order appropriately to time the injection of the induction currents into the coils as a function of the position of the permanent magnets. The motor includes elements for deactivating all but one of the Hall sensors when the rotor speed of oration exceeds 40,000 revolutions/mm, elements for measuring the rotor speed of rotation as it describes each n-th revolution; and elements for bringing about in the next or (n+1) th revolution of the rotor the injection of the currents into the coils.