Abstract: A compressor is powered by a motor which is, in turn, powered by a variable speed drive (VSD). The switching frequency and voltage/frequency relationship of the VSD may be adjusted dynamically to maximize efficiency.

Abstract: A method and associated apparatus for operating an electrical machine includes providing a brushless excitation system including at least one rectifier having at least one diode. The method also includes providing at least one voltage amplitude limiter assembly including at least one resistor and at least one transient voltage suppressor (TVS) electrically coupled with the at least one resistor to form at least one voltage suppression unit. The method further includes transmitting an electrical signal having a current and a voltage to each voltage suppression unit, the voltage having an amplitude. The method also includes electrically coupling the at least one voltage amplitude limiter assembly to the at least one diode. The method further includes transmitting the electrical signal through the rectifier and the voltage suppression unit such that voltage amplitude excursions of the electrical signal are facilitated to be reduced.

Abstract: The invention indicates a correct one of multiple rotor positions. For example, the invention can determine, in a PM machine, which of two possible positions a rotor is in when the position is known only within ±? radians. If the actual rotor position is known to be one of ? and ?+?, for example as indicated by a resolver, the proposed invention can be used to determine whether the actual position is ? or ?+?.

Abstract: There is provided a controller for a motor capable of changing the phase difference between two rotors that can prevent demagnetization of permanent magnets or the rotors. The motor has two rotors each having a permanent magnet and phase difference changing driving means for changing the phase difference between the rotors. The controller has a demagnetization determining means for determining whether or not demagnetization of the permanent magnets of the rotors occurs during operation of the motor, and rotor phase difference controlling means for controlling the phase difference changing driving means to change the phase difference between the rotors from a current phase difference to a phase difference that results in a higher strength of a composite field of the permanent magnets if the result of determination by the demagnetization determining means is positive.

Abstract: A motor controller capable of suppressing a large speed change generated at the time of changeover from a synchronous operation mode to a position feedback operation mode and implementing even acceleration characteristics regardless of the load torque by estimating a torque of a permanent magnet motor in the synchronous operation mode for driving the permanent magnet motor and setting an initial value of a current command value in a position sensor-less operation mode on the basis of information of the torque estimated value.

Abstract: A method and system for controlling a current regulator motor control for parking a motor rotor in a predetermined position, wherein a first current command and a first angle command are supplied to a current regulator for a first parking time, to move the rotor to an intermediate position; and a second current command and a second angle command are supplied to the current regulator for a second parking time, to move the rotor to a predetermined position. The current regulator may have a normal voltage output range, and a circuit may be provided for limiting a voltage output of the current regulator to a reduced voltage output range for at least a portion of the parking time. Advantageously the motor is a permanent-magnet synchronous motor with sinusoidal back-EMF.

Abstract: A controller of a permanent magnet type rotary motor of the present invention includes: a current difference calculator decomposing a primary voltage difference which is a difference between a primary voltage of the permanent magnet type rotary motor and a maximum voltage corresponding to a source voltage, into a field-axis voltage difference component and a torque-axis voltage difference component in the rotatory magnetic flux coordinate by the use of a phase angle of the primary voltage, and calculating a field-axis current difference component and a torque-axis current difference component in the rotatory magnetic flux coordinate by the use of the voltage difference component, a field-axis inductance, and a torque-axis inductance; and a target current corrector correcting a field-axis target current and a torque-axis target current in the rotatory magnetic flux coordinate so that current difference components are zero.

Abstract: A method and a system in connection with a speed and position sensorless permanent magnet synchronous machine equipped with an output filter and driven by an inverter, which method comprises the steps of forming a speed-adaptive full-order observer based on the dynamic model of the combination of the permanent magnet synchronous machine (PMSM) and the output filter, measuring the inverter output current (iA), estimating inverter output current (îA), determining the estimate for the electrical angular speed ({circumflex over (?)}m) using the estimated and measured inverter output currents (îA, iA) in an adaptation law, injecting a voltage signal (uc) into the inverter voltage reference (uA,ref 0) to obtain a modified voltage reference (uA,ref), detecting an error signal (?) from the measured inverter output current (iA), and calculating the speed correction term (??) used in the adaptation of the observer from the error signal (?).

Abstract: In a motor control device according to the invention, upon velocity control of a motor, a superimposed signal generating unit 9 outputs a superimposed signal idh of a repetitive waveform, such as a triangular wave or a sine wave. A d-axis current command generating unit 10 adds the superimposed signal idh generated by the superimposed signal generating unit 9d to a d-axis current command idc*0 and outputs a d-axis current command idc*. An axial misalignment detecting unit 11 (11a, 11b, 11c, and 11d) receives the d-axis current command idc* and a q-axis current command iqc* and outputs an axial misalignment angle estimation value ??^. An axial misalignment correction unit 12 receives the axial misalignment angle estimation value ??^ and an actual detected position ?m and outputs a position after correction ?m?. Therefore, detection and correction can be performed in real time through calculation at a given timing during a normal operation.

Abstract: A motor drive control circuit includes a rotation control amplifier that compares the lower of a voltage limiting reference voltage of a reference voltage source and a rotation speed control voltage, which controls the rotation speed of the motor, on a terminal with a peak voltage from an impedance element that detects a drive current of a motor. The motor drive control circuit further includes a rotation limiting comparator that compares a voltage that is substantially equal to the voltage limiting reference voltage with the peak voltage, a synthesis circuit that amplifies rotation position detection signals from the motor according to the output voltage of the rotation control amplifier, a PWM output comparator that compares the outputs of the synthesis circuit with a triangular wave voltage and outputs PWM signals, and a motor-driver control circuit that removes an output period of the rotation limiting comparator from the ON period of each PWM signal and controls a motor driver that drives the motor.

Abstract: Methods and apparatus are provided for providing a torque boost in an electric motor system at low speeds. The electric motor system comprises an alternating current (AC) synchronous electric motor, an inverter and a controller. The inverter is coupled to the AC synchronous electric motor and provides electric control therefore. The controller is coupled to the inverter and provides operational control signals thereto for operation of the electric motor. The controller includes a torque command gain block which modifies a torque command to generate a boosted torque signal in response to a detected speed of the electric motor, the torque command modified to define the boosted torque signal defined in accordance with a torque dependent scaling factor calculated in response to the torque command.

Abstract: An apparatus and method for controlling high speed operation of a motor for controlling high speed operation of a motor by estimating the position and the speed of the rotor of a synchronous motor without a PI regulator to eliminate the users' inconvenience and to secure the reliability of the control of a rotor's position and speed of a synchronous motor, which includes: a reference frame transformer that receives triangular coordinate voltages and currents and converts them to static coordinate voltages and currents, a flux observer that receives the converted static coordinate voltages and currents and observes and outputs the flux of the stator, a position estimator that receives the converted static coordinate currents and the observed flux of the stator and estimates and outputs the position of the rotor, and a speed estimator that receives the estimated position of the rotor and estimates and outputs the speed of the rotor.

Abstract: In one aspect a method for operating a synchronous motor is provided. The method includes the following: Determining an electrical angle of rotation on the basis of a speed, with the synchronous motor being controlled according to the electrical angle of rotation, Determining a position of a rotor of the synchronous motor on the basis of the electrical angle or rotation and Determining the speed on the basis of the position of the rotor. In an other aspect a drive system and a machine are provided. The machine has a plurality of synchronous motors with stator windings used to generate electrical poles. The drive system operates the synchronous motors synchronously.

Abstract: A circuit arrangement (1) for generating motor characteristic curves, in particular for stabilizing the pull-out torque of a two-phase synchronous motor (2) by using a series-connected element (14). The series-connected element (14) is connected between a first line conductor (12.1) formed as a neutral conductor and the common phase (11) of the synchronous motor (2), and a second line conductor (12.2) implemented as a conductor is connected with a phase of the synchronous motor (2).

Abstract: The present invention provides an electro-mechanical energy exchange system with a variable speed synchronous reluctance motor-generator having an all-metal rotor. A bi-directional AC-to-DC electric power converter interconnects the motor-generator with a DC bus. First and second hybrid controllers provide current regulation for the motor-generator and voltage regulation for the DC bus. Use of both feedback and feedforward control elements provides a controller particularly suited for operating high speed devices.

Abstract: A controller for a motor performs field weakening control by changing a phase difference between two rotors, which are concentrically disposed, and by accurately recognizing the phase difference.

Abstract: A control and power device for a rotating electrical machine comprising a management circuit and a power circuit including a number of power transistors and driver circuits associated with the power transistors. The invention is characterized in that it comprises connection means between the management circuit and the driver circuits for switching on the driver circuits and transmitting at least one transit potential between the management circuit and the driver circuits. The invention is applicable to alternator-starter.

Abstract: The synchronous motor driving apparatus including position sensors provided in the synchronous motor, a current polarity detection circuit for detecting the polarities of the currents in the respective phase windings of the synchronous motor, an inverter driving the synchronous motor, a motor speed calculation unit calculating the rotational speed of the synchronous motor depending on the output signals from the position sensors, a speed control unit outputting a first voltage adjusting component (q-axis current command value Iq*) to cause the rotational speed of the synchronous motor to approach a speed command value and a phase control unit outputting a second voltage adjusting component (d-axis current command value Id*) to cause the phase differences between the phases of the position sensor signals and of the currents in the respective phase windings of the synchronous motor to become a predetermined value.

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 driving circuit has a driving circuit module, a rotation rate detecting module and a rotation status detecting module. The driving circuit module is used to drive an AC fan motor and has at least a driving IC having two controlling outputs and a rotation status detecting output. The rotation rate detecting module has a transistor and an photo coupler. The transistor is connected to one of the two controlling outputs of the driving IC. The photo coupler is connected to the transistor and outputs a rotation rate signal to compute the rotation rate of the AC fan motor. The rotation status detecting module has an photo coupler connected to the rotation status detecting output of the driving IC and outputting a rotation status signal to determine whether the AC fan motor operates normally.

Abstract: In one aspect a method for operating a synchronous motor is provided. The method includes the following: Determining an electrical angle of rotation on the basis of a speed, with the synchronous motor being controlled according to the electrical angle of rotation, Determining a position of a rotor of the synchronous motor on the basis of the electrical angle or rotation and Determining the speed on the basis of the position of the rotor. In an other aspect a drive system and a machine are provided. The machine has a plurality of synchronous motors with stator windings used to generate electrical poles. The drive system operates the synchronous motors synchronously.

Abstract: An electronic start control device for unidirectionally rotating a permanent-magnet rotor (14) of a synchronous motor (10), comprises: a static switch (22) for series connection to a winding of a stator (12) of the synchronous motor (10); and a position sensor (24) for detecting a position of the rotor (14) of the synchronous motor (10) and for providing a corresponding output (Pcon). The device is characterised by including an AC to AC converter (26) having an input (Va) from an alternating current-voltage source (Vac) at a fixed frequency connected in series with the stator (12) of the synchronous motor (10), and a single output (Vc) derived from the voltage input (Va); and an XNOR unit (28) having a first input (G1) in communication with the output (Vc) of the AC to AC converter (26), a second input (G2) in communication with an output (P) of the position sensor (24), and an output (GO) in communication with the static switch (22).

Abstract: A field-winding type of synchronous machine comprises a stator with an armature winding wound phase by phase, a rotor having a rotor core with a field winding wound, and a circuit enabling an armature current to pass the armature winding, the armature current corresponding to a synchronous current producing a rotation field rotating at an electrical-angle rotation speed agreeing to a rotation speed of the rotor. The synchronous machine further comprises a current suppressor and a current supplier. The current suppressor is connected to the field winging and suppresses, into a unidirectional current, an induced alternating current induced through the field winding in response to the armature current passing the armature winding. The current supplier supplies, phase by phase, to the armature winding a rotor exciting current whose waveform is different from the synchronous current only during a predetermined period of time shorter than one cycle of the synchronous current.

Abstract: A drive assembly for a vehicle door is provided. The drive assembly includes a motor having a driving member. The drive assembly further includes a housing having a shaft rotatably received therein. The drive assembly further includes an input member being rotatably received upon the shaft. The input member is operatively associated with the driving member. The drive assembly further includes a rotor fixedly secured to the shaft. The drive assembly further includes first and second Hall effect sensor modules mounted to the housing in a facing spaced relationship with respect to the plurality of teeth of the rotor that generate first and second signals, respectively. The first and second signals have a quadrature relationship with respect to one another and indicate a rotational direction of the rotor when the plurality of teeth are rotating past the first and second Hall effect sensor modules.

Abstract: A magnetic pole position in a synchronous motor having salient poles is estimated from an instructed voltage applied to the motor, a current generated from the instructed voltage and parameters. To estimate the position substantially matching with a true magnetic pole position, a phase matching voltage having a phase matching with the estimated magnetic pole position previously obtained is applied to the motor. The phase matching voltage has a harmonic frequency higher than that of the instructed voltage. A phase matching current generated from the phase matching voltage is detected from the motor. A value of at least one of the parameters is corrected such that a difference in phase between the phase matching voltage and the phase matching current substantially becomes zero. An estimated magnetic pole position is calculated from the instructed voltage, the generated current and the parameter having the corrected value.

Abstract: A brushless DC motor drive apparatus for driving a rotor includes a drive circuit rotating the rotor, a current shutdown and auto-restart circuit coupled to the drive circuit, and a DC voltage comparison circuit coupled to the current shutdown and auto-restart circuit. The current shutdown and auto-restart circuit detects blockage of the rotor via the DC voltage comparison circuit and shuts off the power to the drive circuit accordingly.

Abstract: A motor driving apparatus makes a carrier signal of an inverter be synchronized with a carrier signal of a DC/DC converter, and determines a phase difference between both the carrier signals based on a ratio of an input voltage inputted to the DC/DC converter and an input voltage inputted to the inverter, and a percentage of modulation and a power factor which are operation parameters of the inverter. When the frequency of the carrier signal of the DC/DC converter is set to be twice as high as that of the carrier signal of the inverter, an optimal phase difference is determined based on the ratio of the input voltage of the DC/DC converter and the input voltage of the inverter.

Abstract: A plurality of parameters of a Permanent Magnet Synchronous Motor (PMSM) is determined by a motor controller for differentiating between a plurality of PMSMs. This is achieved by first applying regulated DC motor currents at a commanded fixed rotor angle and measuring a quadrature voltage; parking the PMSM at standstill, Then, after selecting an initial set of controller parameters; applying the quadrature voltage equal to zero and measuring a time constant. Then, accelerating the PMSM with a constant torque up to a preset target speed and measuring a total acceleration time taccelerate until the preset target speed ?target is reached. After regulating a stator current at 0 value, measuring the quadrature voltage and a freewheeling motor speed ?freewheel immediately after applying the 0 stator current; and calculating an electrical constant KE of the PMSM; a load inertia J; and a set of parameters for the controller.

Abstract: Speed regulator for a brushless DC motor, wherein the DC motor comprises a stator, a rotor and an electromagnet wherein the electromagnet is in the vicinity of the stator, the rotor produces a permanent magnetic field and the electromagnet is activated to generate an alternating magnetic field; furthermore comprising a power supply and a regulating element, the regulating element being connected to the power supply to regulate the power feed to the electromagnet, so that, during use, a torque generated by the DC motor is regulated, characterized in that the speed regulator is able to generate a voltage V(?) as a function of rotor speed of revolution, rotor position (?), rotor load and motor activation, wherein the speed regulator sets the change in the voltage V(?) of the motor as a function of the rotor position ? in such a way that the instantaneous torque T(?), at least in the vicinity of the reversal in polarity of the driving magnetic field, complies with the conditions that the derivative (?)/?? is esse

Abstract: A direct current motor controlling method includes a mean for transforming a duty signal to computed value by a microprocessor unit. The microprocessor unit computes the computed value and then produces a target value by executing a dichotomy method, a rotation method and a transformed function, capable of reducing executing time and executing load of the microprocessor unit and saving memory space. The microprocessor unit sends a frequency signal to a driving circuit unit according to the target value. The driving circuit unit receives the frequency signal and then provides a driving voltage to a power switch. The power switch provides a voltage to a direct current motor or not according to the driving voltage for controlling output performance of the direct current motor.

Abstract: A single-phase permanent magnet motor control apparatus, in particular, a low price, flat output torque, low vibration, low noise single-phase permanent magnet motor control apparatus, and a fan and pump using such a single-phase permanent magnet motor control apparatus are provided. In a single-phase permanent magnet motor control apparatus for driving a single-phase permanent magnet motor by using a DC power supply, a converter for converting DC to AC, and a control circuit for controlling the converter, a motor current measuring unit, a terminal voltage measuring unit, a correction unit for correcting an impedance drop in motor constants, and a calculation unit for finding an induced voltage to be obtained by control are included, and a polarity of a terminal voltage is determined on the basis of a value of the found induced voltage.

Abstract: The invention relates to a method of adjusting motor parameters in a variable speed drive intended for controlling a synchronous electric motor with permanent magnets M. The method comprises a step of determining the deviations ?ID and ?IQ between references and measurements of the flux current and motor torque current, a step of calculating a correction value ?RS of the stator resistance, a correction value ?L of the inductance and a correction value ?KE of the flux constant of the motor, on the basis of the integral terms of the deviations ?ID and ?IQ, a step of adjusting the values of the parameters of the motor model on the basis of ?RS, ?L and ?KE, a step of formulating the control voltages UD and UQ to be applied to the motor M by using the said adjusted values of the motor parameters.

Abstract: Let the rotating axis whose direction coincides with the direction of the current vector that achieves maximum torque control be called the qm-axis, and the rotating axis perpendicular to the qm-axis be called the dm-axis. A motor control device switches its operation between low-speed sensorless control and high-speed sensorless control according to the rotation speed of the rotor. In low-speed sensorless control, the magnetic salient pole of the motor is exploited, and the d-q axes are estimated by, for example, injection of a high-frequency rotating voltage. In high-speed sensorless control, the dm-qm axes are estimated based on, for example, the induction voltage produced by the rotation of the rotor. During high-speed sensorless control, the ?(dm)-axis current is kept at zero irrespective of the ?(qm)-axis current.

Abstract: Provided is a motor having a combination of a plurality of coil pairs and a permanent magnet, wherein these coil pairs are supplied with an excitation signal from a drive circuit so as to be excited at alternate opposite poles, and the permanent magnet is constituted such that the plurality of polar elements is disposed to become alternating opposite poles; the drive circuit is constituted to supply an excitation signal having a prescribed frequency to the coil pairs, and relatively move the coil pairs and permanent magnet with the magnetic attraction repulsion between the coils and permanent magnet; and the drive circuit is constituted to supply to the coil pairs a waveform signal corresponding to the pattern of the back electromotive voltage to be generated in accordance with the relative movement between the coil pairs and permanent magnet.

Abstract: Presence/absence of a failure in a feedback control system of a motor is monitored. When a failure is detected in the feedback control system, the motor is driven by switching to an open-loop control. During the open-loop control, the motor is rotated by sequentially switching the motor current supply phase without feeding back encoder count information. The position count is incremented or decremented every time the current supply phase is switched. When the position count has reached a target count, it is determined that the rotor has reached a target position, whereupon the open-loop control is finished.

Abstract: The rotor position of a synchronous motor is determined, in that for a plurality of current vectors distributed over one electrical rotation of the synchronous motor, the amount of the current vector which is necessary to attain a defined deflection of the rotor is determined. The position of the rotor may be calculated from the position of the minima of the amounts thus determined, taking into account the direction of rotation of the rotor. The engagement of a brake may ensure that grooving forces and machine vibrations play no role for the method to determine the rotor position.

Abstract: An electric actuator including at least a first P-phase automatically-switched brushless synchronous motor, P being an integer ranging between 1 and 6, and N pairs of poles at the rotor, N being an integer not less than 1. The actuator also includes a position sensor outputting signal to control an electronic circuit controlling the motor. The rotor of the motor drives a gear ratio reducing mechanism. The position sensor is coupled to the reduction unit output shaft to measure the absolute angular position of the reduction unit output shaft. The electronic circuit includes a circuit sequentially controlling the current of each of the phases producing automatic switching of powering sequences of the phases on the basis of the absolute position of the reduction unit output shaft.

Abstract: An electric motor control system includes a housing and a motor disposed within the housing. The electric motor control system also includes an actuator operatively coupled to the motor and configured to operate in response to an operation of the motor. The electric motor control system further includes a controller disposed within the housing and communicatively coupled to the motor. The electric motor control system also includes a first electric conductor communicatively coupling the motor to the controller, wherein the controller is configured to supply power to and communicate a data signal with the motor over the first electric conductor.

Abstract: Methods and system are provided for controlling permanent magnet motor drive systems. The method comprises the steps of adjusting a first current command in response to a first voltage error to produce a first adjusted current, adjusting a second current command in response to a second voltage error to produce a second adjusted current, limiting each of the first and second adjusted current below a maximum current, converting the first adjusted current to a first potential, converting the second current command to a second potential, and supplying the first and second potentials to the permanent magnet motor. The first voltage error is derived from the second current command, and the second voltage error is derived from the first current command.

Abstract: A motor control device that includes a first speed estimator estimating the rotation speed of the rotor of a permanent-magnet synchronous motor and that controls the motor so that a first estimated rotation speed estimated by the first speed estimator follows the specified speed value further includes a second speed estimator that estimates the rotation speed of the rotor by an estimation method different from that used by the first speed estimator. The motor control device detects synchronization failure based on a comparison between a second estimated rotation speed estimated by the second speed estimator and the first estimated rotation speed or the specified speed value.

Abstract: In a method for operating an EC motor, position-measurement signals are recorded by a position-measuring device, and, on the basis of the position-measurement signals, commutation instants are determined, at which the current supply to the EC motor is commutated. At least one correction value for at least one position-measurement error contained in the position-measurement signals is ascertained and stored. To compensate for the at least one position-measurement error, the correction value is considered when determining the commutation instants.

Abstract: A method and apparatus provide a state observer control system 600 for a motor 106 that uses an extended Kalman filter 330 to predict initial rotor position and afterwards accurately predict rotor position and/or speed under variable types of loading conditions. A control system model 300 is generated that allows variable setting of an initial rotor position to generate estimated rotor position and speed as outputs. The control system model 300 includes an EKF (extended Kalman filter) estimator 330, speed controller 322, a current controller 324, and a variable load component 310. During operation, EKF estimator 330 estimates rotor speed 327 and position 333 based on reference voltages 402, 404 and currents 1325 generated by speed and current controllers 322, 324 and input from frame transformers 326, 328.

Abstract: A Motor driving apparatus adjusts activation start timing of high-side activation control signals UU, VU, WU and the low-side activation control signals UL, VL, and WL with a state determination signal SJ in an activation controller 40, in the period from starting to the time when rotor rotating speed reaches a predetermined value, sets the activation start timing earlier than in normal times to perform leading phase activation control, and in normal times when the rotor rotating speed is a predetermined value or more, controls activation start timing in efficient and optimum phase. Hence, the motor driving apparatus can carry out stable PWM sensorless starting without any starting failure such as oscillation, loss of synchronism and reverse rotation and shorten starting time.

Abstract: In a laser printer, methods and apparatus include commutating a brushless dc motor having three windings. A controller receives discrete motor position signals, such as from hall-effect or FG sensors, and extrapolates motor position between the signals. It commutates the motor based on the extrapolated motor position and updates motor position whenever an actual discrete signal is received. Drive signals from the controller to the motor are such that a current flowing in any of the three windings follows a generally sinusoidal waveform. High and low switches are provided per each winding of the three windings and are cumulatively switched according to an extrapolated motor position based multiplier applied to a pulse width modulation duty cycle. In this regard, lookup tables, counters, registers and the like are provided. An engine card of the printer includes an ASIC with a power driver for use with generally off-the-shelf brushless dc motors.

Abstract: A three-in-one AC servo drive includes a main console, a control module, a power module and a plurality of servo motors. A single drive can be connected to a plurality of motors. The power module and control module for the motors can be integrated to a single modular unit. Therefore, the redundant portion such as communication interface, display unit and I/O unit can be eliminated. The capacitor of the bus of the IGBT module can also be reduced, whereby the occupied space and cost can be reduced with less assembling time.

Abstract: A frequency-variable PWM motor drive circuit includes a drive IC member, a Hall IC member, a PWM converter circuit and a compensation unit. The drive IC member electrically connects with the Hall IC member, the drive IC member further includes a pin electrically connected with the compensation unit and the PWM converter circuit. The PWM converter circuit has a PWM input pin to receive a PWM signal, and converts it into a voltage signal. The compensation unit connects between the pin of the drive IC member and the PWM converter circuit. In operation, the compensation unit can improve a waveform of the voltage signal supplied from the PWM converter circuit, and then output it to the pin of the drive IC member. Consequently, the drive IC member can be steadily operated at predetermined motor speeds under various frequencies of the PWM signals.

Abstract: A position-sensorless motor control device has a superposer that superposes, on the drive current with which the motor is driven, a superposed current having a different frequency than the drive current, a superposed component extractor that extracts, from the motor current fed to the motor, the ?-axis and ?-axis components of the superposed current, and a controller that controls the motor so that the direct-current component of the arithmetic product of the extracted ?-axis and ?-axis components of the superposed current converges to zero.

Abstract: A BLDC motor phase commutation method is provided, which can correctly detect phase commutation timing and position detection timing of a BLDC motor in a compressor to stabilize rotation and RPM of the compressor, thereby minimizing noise and vibration. When the BLDC motor rotates through a mechanical angle corresponding to one period, the BLDC motor operates according to a first scheme in which operation of the BLDC motor in the first phase commutation section of a period is performed in the same manner as in the last phase commutation section of a period immediately prior to the period. After the BLDC motor switches to sensorless mode, the BLDC motor operates according to a third scheme in which the first phase commutation section of a period has a time interval equal to the average of time intervals of first phase commutation sections of periods prior to the period.

Abstract: On a training device, in particular for developing human muscles, having a torque-generating unit which comprises an electric motor and a reduction gearing, and whose output interacts with at least one training element offered to the exercising person, an electric motor is designed as a three phase AC motor. Associated with the latter is a frequency converter for adjusting the frequency and amperage of the three phase current supplied to the electric motor. A control unit is provided upstream of the frequency converter. An angle-of-rotation sensor is associated with the motor whose measured signal is supplied to both the frequency converter and the control unit. The frequency converter is fed by the control unit with a setpoint value of the torque to be generated by the motor which setpoint value receives the measured signal from the angle-of-rotation sensor. The frequency converter adjusts the frequency and the amperage of the motor current using the principle of field-oriented control.

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.