Abstract: A control system includes an electric rotating machine; a driving circuit that is connected to a DC power supply, the driving circuit includes a frequency conversion unit configured such that, when the electric rotating machine is to be driven in a power running mode, the frequency conversion unit converts an output of the DC power supply into AC electric power, and when the electric rotating machine is to be driven in a regenerative operation mode, the frequency conversion unit converts an output of the electric rotating machine into DC electric power; and a control unit that controls the driving circuit, wherein the control unit judges whether a connection between the DC power supply and the driving circuit is being maintained, and is configured such that, when the connection is not being maintained, regenerative electric power generated by the electric rotating machine is reduced by controlling the driving circuit.

Abstract: A fan circuit controls a speed of a fan. A control chip outputs a pulse width modulation (PWM) signal that changes with the temperature of an electronic device that the fan is mounted in. An input circuit converts the PWM signal into a continual voltage signal. An amplifier circuit amplifies the voltage signal and outputs a control signal. When the control signal is less than a threshold voltage, the control circuit is turned on and the fan receives current which is less than preset current. When the control signal is greater than the threshold voltage, the control circuit is turned off and the fan receives current which is greater than the preset current.

Abstract: A method of controlling a power converter in an electric drive machine is disclosed. The method may include determining a first switching frequency and determining a second switching frequency. The method may also include comparing the first switching frequency and the second switching frequency. The method may further include selecting a power converter switching frequency from the lesser of the first switching frequency and the second switching frequency to control a power converter.

Abstract: The controller controls a spindle connected to an induction motor via a belt by controlling the rotational velocity of the induction motor. The spindle has an encoder attached thereto for detecting the position of the spindle, but the induction motor does not have a velocity detector attached thereto. The velocity of the induction motor is estimated from the spindle velocity obtained from output of the encoder, and slip of the belt is detected based on the estimated velocity of the induction motor. When occurrence of slip of the belt is detected, the estimated velocity of the induction motor will not be used for the control of the induction motor.

Abstract: A system and method for controlling an AC motor drive includes a control system programmed with an energy algorithm configured to optimize operation of the motor drive. Specifically, the control system input an initial voltage-frequency command to the AC motor drive based on an initial voltage/frequency (V/Hz) curve, receives a real-time output of the AC motor drive generated according to the initial voltage-frequency command, and feedback a plurality of modified voltage-frequency commands to the AC motor drive, each of the plurality of modified voltage-frequency commands comprising a deviation from the initial V/Hz curve. The control system also determines a real-time value of the motor parameter corresponding to each of the plurality of modified voltage-frequency commands, and feeds back a modified voltage-frequency command to the AC motor drive so that the real-time value of the motor parameter is within a motor parameter tolerance range.

Abstract: An apparatus and method for controlling a hybrid motor, The hybrid motor, uses a permanent magnet instead of a field coil for a rotor, winds a coil round a stator in a multi-phase independent parallel manner, fixes a rectifying type encoder to the rotor and connects a sensor to a driving circuit. The apparatus comprises: an encoder attached to a rotor in cooperation with a pole sensor a speed input unit for generating a speed instruction signal a power switching circuit to generate motor driving signals; a drive module receiving the speed instruction signal and the sensor signal and outputting the speed instruction signal synchronized with the sensor signal as a driving motor signal; a power supply for applying a DC voltage to the power switching circuit; A logic power supply for converting the DC voltage into a logic voltage, and applying logic voltage to the drive module. The motor has n phases, n power switching circuits and n drive modules.

Abstract: A motor control method for an MDPS system makes it possible to provide smoother and easier steering operation at a low cost by improving the OHP performance while supplying appropriate controlling electric current to a motor, without changing the motor or a decelerator used in an MDPS system.

Abstract: Methods and apparatus are provided for a controlling an electric motor that is at least partially disposed within a motor housing. The rotational speed and position of the electric motor are sensed, and a temperature of the electric motor is sensed. The sensor signals are converted to optical signals and are propagated in a fiber optic cable. The electric motor is controlled based, at least in part, on the propagated optical signals.

Abstract: The motor drive apparatus to perform vector control having excellent control performance on a motor includes an A/D converter which acquires currents flowing through a u-phase, a v-phase and a w-phase of the motor, a vector control unit which performs vector control on the motor based on d-axis motor current and q-axis motor current acquired by coordinate-converting the digitalized currents, a motor parameter and a desired angular speed of a motor rotor, a PWM generator which generates a PWM signal to drive the motor based on a motor voltage acquired by the vector control unit, and a parameter estimation unit which estimates a motor resistance, a d-axis motor inductance and a q-axis motor inductance in a direct current excitation state based on maximum peak values and minimum peak values of a d-axis motor voltage and a q-axis motor voltage and estimates a motor inductive voltage constant in a forced commutation control state.

Abstract: The machine in accordance with the present disclosure is an AC machine whose pole numbers can be switched (from pole p1 to pole p2), and whose number of series turns per phase N can be switched say from N0=Nrated to N1=N0/2. Furthermore, it employs an inverter so that the frequency can be changed from a low value (e.g., 5 Hz) to a high value (e.g., 200 Hz). Due to the combination of pole number and number of series turns switching/reconfiguration, a high torque at low speed (e.g., 0 rpm) and a high torque at high speed (e.g., 5,000 rpm) can be achieved, making mechanical gears obsolete. In addition, the output power of the motor can be increased at high speed in direct proportion to the speed increase.

Abstract: Methods and devices are presented herein for estimating induction motor inductance parameters based on instantaneous reactive power. The induction motor inductance parameters, e.g., the stator inductance and the total leakage factor, can be estimated from motor nameplate data and instantaneous reactive power without involving speed sensors or electronic injection circuits.

Abstract: A method and a structure operate a three-phase machine, which is fed by a three-phase converter, using a stator flux regulator and either a slip frequency regulator or a torque regulator. A torque-forming fundamental-frequency current component of the stator current is limited by limiting a setpoint value that is supplied to the slip frequency regulator or to the torque regulator to a maximum slip frequency value maximum torque value. The flux-forming fundamental-frequency current component of the stator current is limited by limiting the speed at which a setpoint value supplied to the stator flux regulator changes to a maximum value. The maximum slip frequency value or maximum torque value is calculated on the basis of a prescribed maximum current value for a stator current fundamental-frequency magnitude of the stator current and on the basis of a filtered actual value of the flux-forming fundamental-frequency current component of the stator current.

Abstract: An inverter control apparatus includes: a state estimator that calculates an estimated current vector and an estimated magnetic flux vector from a motor command voltage vector, a detected current vector, and a motor parameter; a correction voltage calculator that calculates a correction voltage vector on the basis of a current error between the detected current vector and the estimated current vector; and a correction voltage unit that adds the correction voltage vector to the motor command voltage vector.

Abstract: A ripple detection unit detects a ripple current width of a motor current controlled according to PWM control. A ripple reference setting unit sets a reference value of the ripple current width. A frequency adjusting unit sets a control signal indicating a carrier frequency of the PWM control according to a ripple current width deviation. A carrier generation unit generates a carrier of the frequency based on the control signal. Thus, it is possible to realize feedback control of the carrier frequency for maintaining the ripple current width at an appropriate level.

Abstract: An open-loop and/or closed-loop control device for operating an asynchronous machine which is fed by a 3-phase power converter. The open-loop and/or closed-loop control structure has a stator flux controller and a pulse pattern generator for generating pulse signals based on mean values. An output of the stator flux controller is connected to an input of the pulse pattern generator, with the result that the pulse pattern generator can generate the pulse signals as a function of a manipulated variable which is generated by the stator flux controller. The stator flux controller is configured so as to generate the manipulated variable as a function of a desired value of the stator flux of the asynchronous machine and as a function of a desired value of the torque of the asynchronous machine. The stator flux controller has a dead-beat control response.

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 power conversion device includes a converter-inverter controller for controlling a converter and an inverter. The power conversion device further includes a DC capacitor connected between the converter and the inverter and a DC capacitor voltage detector for detecting a DC capacitor voltage Efc between the connection ends of the DC capacitor. The converter-inverter controller provides variable control on the DC capacitor voltage Efc to the converter on the basis of the motor frequency of an AC motor, the DC capacitor voltage Efc, and a pulse mode. Within a predetermined range of motor frequencies, the converter-inverter controller fixes the PWM modulation factor of the inverter to a value m0 and provides operation control to the inverter, where the value m0 being to reduce a harmonic of a predetermined order included in the output voltage from the inverter.

Abstract: Two current threshold values are adopted, which are larger than the upper limit of current of an operating region. When a rotating speed is smaller than a speed threshold value, the current threshold value is adopted as a criterion to judge whether an input current to an inverter is abnormal, and when the rotating speed Rot is larger than that, the other current threshold value is adopted as the criterion.

Abstract: A system and method for measuring and controlling stator winding temperature in an AC motor while idling is disclosed. The system includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of a multi-phase AC motor. The circuit further includes a plurality of switching devices to control current flow and terminal voltages in the multi-phase AC motor and a controller connected to the circuit. The controller is configured to activate the plurality of switching devices to create a DC signal in an output of the motor control device corresponding to an input to the multi-phase AC motor, determine or estimate a stator winding resistance of the multi-phase AC motor based on the DC signal, and estimate a stator temperature from the stator winding resistance. Temperature can then be controlled and regulated by DC injection into the stator windings.

Abstract: A method is provided for controlling an induction motor having a rotor. The method includes receiving a torque command; comparing the torque command to a threshold torque value; generating, with a first estimation module, a first estimated rotor resistance when the torque command is less than or equal to the threshold torque value; generating, with a second estimation module, a second estimated rotor resistance when the torque command is greater than the threshold torque value; and generating control signals for the induction motor based on the first estimated rotor resistance or the second estimated rotor resistance.

Abstract: A fan motor speed control circuit includes: a driving circuit configured to drive a fan motor so as to run at a rotation speed corresponding to a drive signal; a comparison circuit configured to output a comparison signal for matching a rotation speed of the fan motor with a target rotation speed, based on a reference signal corresponding to the target rotation speed of the fan motor and a speed signal corresponding to the rotation speed of the fan motor; and a selection circuit configured to output to the driving circuit the drive signal corresponding to one signal out of the reference signal and the comparison signal, the one signal being a signal by which the fan motor is driven at a higher rotation speed.

Abstract: A method of detecting an output phase loss (OPHL) for a motor drive detects an abnormal OPHL operation when at least one phase of a three-phase current is continually zero. Each phase of the three-phase current is acquired, sampled, filtered, and compared. Hence, a corresponding zero-current counter value is continually added, and a corresponding abnormal current value is set as logic 1 when a zero-phase current of the three-phase current is continually zero. Finally, an OPHL certified value is set as logic 1 to confirm that the motor driver is operated in the abnormal OPHL operation. Therefore, a direct-current and an alternating-current OPHL can be detected before and after the motor driver is operated, respectively.

Abstract: Systems and apparatus are provided for a control module for operating an inverter in a vehicle. A control module comprises a first circuit card assembly and a microprocessor mounted on the first circuit card assembly. The microprocessor is configured to determine a phase modulation command for a first motor phase and determine a modulation criterion for the inverter. An integrated circuit is communicatively coupled to the microprocessor. The integrated circuit is configured to generate a first modulation signal based on the phase modulation command and the modulation criterion and generate a second modulation signal based on the phase modulation command and the modulation criterion.

Abstract: When instructed to switch control modes between overmodulation PWM control and sinusoidal wave PWM control, control device corrects the amplitude of a voltage command signal based on a state of power conversion operation performed by an inverter, so as to suppress a change in an influence of dead time over a voltage applied to an alternating-current motor upon switching the control modes. The state of the power conversion operation performed by the inverter includes at least one of a present value of a carrier frequency in a control mode currently employed, an estimated value of the carrier frequency to be obtained when switching the control modes, the length of the dead time, a power factor of alternating-current power exchanged between the inverter and the alternating-current motor, and a driving state of the alternating-current motor.

Abstract: When an electric vehicle outputs a torque instruction, firstly, a request torque is acquired and a judged whether the acquired request torque is positive or negative (S10) Regardless of the sign of the request torque, it is judged whether the eco-switch is ON (S12, S14) If the request torque has a positive sign and the eco-switch is OFF, a map A is selected (S20). If the eco-switch is ON, a map B which limits the maximum torque to a low value for the map A is selected (S22). If the request torque has a negative sign, a map C is selected regardless of the eco-switch ON/OFF state and the maximum torque is not limited (S24).

Abstract: A method and apparatus are provided for operation of a three-phase rotating electrical machine which has at least two stator winding sets and each stator winding set has three phase windings connected in star, and the star circuits of the stator winding sets have a phase shift of 30 degrees electrical with respect to one another, and an associated converting unit is respectively provided for each stator winding set, in which method the respective stator winding set is fed by the associated converter unit, and a respectively associated regulation device is provided for each converter unit, and each converter unit is driven by means of a drive signal from the associated regulation device independently of regulation devices of the respective other converter units.

Abstract: A method for controlling an induction machine having a rotor includes the steps of obtaining a torque command, calculating an estimated squared value of resistance of the rotor using the torque command, determining an offset for the resistance of the rotor, and generating an updated measure of rotor resistance using the estimated squared value and the offset.

Abstract: A controller for an AC rotary machine, by which a stable rotation angular-frequency estimate (AFE) value can be obtained even in an extremely low speed region of the AC rotary machine is disclosed, and consequently stable control can be performed. The controller includes an AFE outputter that outputs an AFE value based on an angular-frequency calculated value including a rotation AFE value. The AFE outputter includes a lower-limit constant-value (LLCV) outputter that outputs a LLCV, a comparator that compares the angular-frequency calculated value to the LLCV, and a switcher that performs a switching operation according to the comparator. The switcher outputs the angular-frequency calculation value as the AFE value when the angular-frequency calculation value is larger than the LLCV, and outputs the LLCV as the AFE value when the angular-frequency calculation value is equal to or less than the LLCV.

Abstract: A P-range side delimiting position of a movable range of a range change mechanism is learned by rotating a motor to a corresponding rotational position, which corresponds to the P-range side delimiting position. A climb correction amount is set for a learning value of the P-range side delimiting position to correct the learning value of the P-range side delimiting position in view of presence of a relatively small angle of rotation of the motor beyond the corresponding rotational position, which corresponds to the P-range side delimiting position. The climb correction amount is set according to motor temperature information, which is one of a temperature of the motor and a temperature that relates to the temperature of the motor.

Abstract: An apparatus for monitoring current for a motor drive including at least high-side and low-side switching transistors includes a driver circuit for driving a gate of the low-side switching transistor. First circuitry measures a drain to source voltage across the low-side switching transistor and generates a voltage output responsive thereto. Second circuitry has a first state of operation that samples the voltage output of the first circuitry when the low-side switching transistor is turned on and has a second state of operation to sample the voltage output of the first circuitry when the low-side switching transistor is turned off. The second circuitry further generates a monitored output current responsive to the sampled voltage output.

Abstract: A motor bypass is controlled by a digital signal processor (DSP) with embedded control software that allows fault detection and annunciation, serial communications between both a variable frequency drive (VFD) and a bypass controller and the bypass controller and a host computer. The use of the DSP and embedded control software further allows for contactor coil control to provide fault tolerant operation as well as fault condition detection and annunciation to the user.

Abstract: According to one disclosed embodiment, a gate driver circuit for sensorless speed detection and driving a switching stage includes high side and low side switches series connected across a DC bus and having a switching node between the series switches, the gate driver having a bootstrap power supply for powering a high side driver driving the high side switch of the switching stage and a low side driver power supply, and further includes a comparator circuit to periodically compare the voltage between the bootstrap and low side driver power supplies with a threshold and to output a first signal, wherein the first signal indicates current sign and frequency.

Abstract: A motor speed control circuit includes: a voltage generating circuit configured to change either a reference voltage corresponding to a target rotation speed of a motor or a speed voltage corresponding to a rotation speed of the motor, according to a temperature, and output the reference voltage and the speed voltage, either one of which is changed; a comparison circuit configured to compare the speed voltage output from the voltage generating circuit with the reference voltage output from the voltage generating circuit; and a driving circuit configured to drive the motor so as to match a level of the speed voltage to a level of the reference voltage, based on a comparison result from the comparison circuit.

Abstract: A motor control device has: a motor current detecting portion for detecting, based on a current flowing between an inverter and a direct-current power supply, a motor current flowing through a three phase motor; a specified voltage value producing portion for producing a specified voltage value based on the motor current; a specified voltage value holding portion for holding an earlier specified voltage value outputted from the specified voltage value producing portion; and a specific period setting portion for setting a specific period based on a voltage difference between two of U-phase, V-phase, and W-phase voltages. Outside the specific period, the motor is controlled based on the specified voltage value outputted from the specified voltage value producing portion, and, within the specific period, the motor is controlled based on the specified voltage value held by the specified voltage value holding portion.

Abstract: An electronically commutated asynchronous motor (12) features a stator (202), a short-circuit rotor (204), a controller (FOR 20) for field-oriented regulation of the motor (12), a sensor magnet (274) in thermally conductive connection with the short-circuit rotor (204), a rotor position sensor (14A; 18; 18?) arranged at a predetermined distance (d) from the sensor magnet (274) to generate an output signal (HALL, U, U1, U2) that is dependent upon the spatial orientation of the sensor magnet (274), and a temperature evaluation apparatus (CALC_T 44) configured to ascertain, during operation, from the sensor output signal (HALL, U, U1, U2), a temperature value (T) that characterizes a temperature (T_SM, T_S) in the motor (12).

Abstract: In a system for controlling rotation of a rotor of a multiphase rotary electric machine in relation to a stator thereof, a superimposing unit superimposes a first frequency signal on the input signal to the multiphase rotary electric machine. The first frequency signal has a first phase and a first period, and the first period is different from a period of rotation of the rotor. An amplitude detector detects an amplitude of a second frequency signal. The second frequency signal is actually propagated in the multiphase rotary electric machine with a second phase based on the superimposed first frequency signal. A rotation angle determiner determines a rotation angle of the rotor so as to eliminate a difference between the detected amplitude of the second frequency signal and a predetermined target amplitude thereof.

Abstract: The invention relates to a method and to an apparatus for the failsafe monitoring of an electromotive drive (10) without additional sensors. The apparatus comprises a drive having a three-phase control of an electric motor, means (20) for detecting the current and voltage profiles of each of the three phases (U, V, W), as they are forwarded to the motor (10) by drive electronics (12), means (26) for determining the load speed (nL) while using the detected current and voltage values, wherein the determination of the load speed (nL) takes place by calculating an observer model with reference to the detected current, to the detected voltage, to the frequency fFU preset by the control and to the characteristic data of the motor (10) and means (28) for generating a failsafe switch signal (30) for the motor (10) when the calculated load speed (nL) does not correspond to a preset desired speed within the framework of preset tolerances.

Abstract: A method for driving a power bridge (1) which is used for controlling a multiphase electric load (3), is connectable to said electric load (3) through several arms and is drivable by switching functions determining control vectors for controlling the load, wherein said control vectors are subdivided into the free wheel control vectors and active control vectors. The inventive method is characterized in that it comprises the use of a switching function production method which produced a reduced number of switching function combinations corresponding to the free wheel control vectors for producing a sequence of the control vectors.

Abstract: A device for controlling an electromechanical actuator includes an electric motor and an actuator operated by the electric motor. It also includes a digital signal processor (DSP) providing data of reference voltages (Ud—ffw, Uq—ffw) on the basis of an decoupled electrical model of the motor. The processor has at least one Park transformation module receiving measurement data for the currents of at least two supply phases of the motor (i_mot—2, i_mot—3) and a datum for the estimated angle of the motor (?estimated) and transforming them into data regarding the component of current with stator current axis (id) and the component of current in quadrature with the stator current (iq).

Abstract: A driving velocity of a motor is detected by processing a position information signal output from a sensor in accordance with a driving position of a motor. The signal processing device includes a position information signal processor (410) that processes the position information signal and calculates driving velocity information of the motor, and an internal position information generator (460) that reflects a latest driving velocity information (?n) calculated by the position information signal processor (410) and generates a latest presumed position of the motor as internal position information. An amplitude correcting unit (465) detects the amplitude of the position information signal from the sensor and corrects the amplitude of the internal position information signal based on the detected amplitude.

Abstract: A cooling system is provided with a motor drive device, a fan motor, and a Hall element. The motor drive device includes a lock protection circuit and a lock controller. When a control signal instructing rotation of the fan motor that is to be driven instructs stoppage of the motor for a predetermined time-period or longer, the lock controller has the lock protection circuit inactive. At an occasion when the control signal has continued to instruct stoppage of the fan motor for a first time-period or longer, a standby controller starts time measurement, and after a further predetermined second time-period has elapsed, makes at least a part of the motor drive device transition to a standby mode.

Abstract: A method for driving a power bridge (1) which is used for controlling a multiphase electric load (3), connectable to said electric load (3) via several arms and drivable by switching functions which determine free wheel controlling vectors and are active for controlling the load. The inventive method consists in selecting a first switching function production method which produces a reduced number of combinations of switching functions corresponding to the free wheel control vectors or a second switching function production method which produces combinations of switching functions corresponding only to the active control vectors, wherein said method are defined according to a given reference voltage vector and in applying said selected for producing a sequence of control vectors from the produced combinations of switching functions.

Abstract: Systems, apparatus, and methods for operating inductors in a Z-source inverter in a continuous current mode are provided. One system includes an AC motor, a Z-source inverter, and a processor. The inverter is configured to provide current and reactive power to the AC motor. The processor is configured to monitor the current and instruct the inverter to provide a greater amount of reactive power to the AC motor if the current is below/equal to a threshold amount. An apparatus includes means for determining if current produced by the inverter is below/equal to a threshold amount, and means for altering voltage commands supplied to the inverter so that an AC motor is induced to draw additional reactive power. One method includes determining if a plurality of inductors are providing a threshold current amount, and inducing a motor to draw more reactive power if the current is below/equal to the threshold amount.

Abstract: A controller of an electric motor for improving operation efficiency in performing electric conducting control of the electric motor of an axial air-gap type is provided.

Abstract: An aperture driving apparatus includes a swing unit and a stationary unit. The swing unit includes an aperture plate that partially blocks a light, a coil that constitute a voice coil motor for obtaining a driving force for driving the aperture driving plate, and a swing arm that supports the aperture plate and the coil and has a bearing portion between the aperture plate and the coil. The stationary unit includes a swing shaft that engages the bearing portion and swingably supports the swing arm about a swing axis, and a magnet and a yoke that constitute the voice coil motor together with the coil. A control unit of the aperture driving apparatus controls the swing angle of the swing arm using a closed-loop control technique. In the direction of the swing axis, the position of a center of gravity of the swing unit is substantially aligned with a position at which the driving force is applied to the coil.

Abstract: A motor controller system comprises solid state switches for connection between a single phase to three phase static converter and motor terminals for controlling application of three phase power to the motor. Sensors sense power from the static converter. A control is connected to the sensors and the solid state switches for controlling operation of the solid state switches to run the motor. The controller includes a three phase detection scheme for preventing operation of the solid state switches in the absence of desired three phase power from the static converter. A motor start scheme disables the three phase detection scheme for a select time after a motor run signal.

Abstract: A system and method for controlling an AC motor drive includes a control system programmed with an energy algorithm configured to optimize operation of the motor drive. Specifically, the control system receives input of an initial voltage-frequency command to the AC motor drive, receives a real-time output of the AC motor drive generated according to the initial voltage-frequency command, and determines a real-time value of a motor parameter based on the real-time output of the AC motor drive. The control system also inputs a plurality of modified voltage-frequency commands to the AC motor drive, determines the real-time value of the motor parameter corresponding to each of the plurality of modified voltage-frequency commands, and identifies an optimal value of the motor parameter based on the real-time values of the motor parameter.

Abstract: Systems and/or methods that facilitate efficiently controlling speed of an induction motor are presented. An optimized control component controls respective switching of an auxiliary switch component associated with an auxiliary winding of the motor, a main switch component associated with a main winding of the motor, and a capacitance adjuster switch component that facilitates adjusting the amount of capacitance associated with the auxiliary winding. The timing of switching on the auxiliary switch component and main switch component can be controlled such that there can be a time difference between the respective switching on of the auxiliary switch component and main switch component to produce additional phase shift to facilitate improving motor efficiency. The capacitance adjuster switch component can be switched on when motor speed is below a predetermined low speed threshold to facilitate increasing the amount of capacitance associated with the auxiliary winding to improve motor efficiency.

Abstract: A disc apparatus which can judge accurately whether or not a spindle motor is at fault due to a short circuit is provided. A disc apparatus (1) includes a spindle motor (3) which rotates a disc (2), a differential operational amplifier (5) which successively detects output voltages of the spindle motor (3), and a failure judgment unit (10) which calculates an average voltage of the plural output voltages and judges whether or not the spindle motor (3) is at fault in accordance with the average voltage and the output voltages. When counting number of occurrences of a specific state which indicates that one of the two output voltages detected successively is larger than the average voltage and other of the two output voltages is smaller than the average voltage, the failure judgment unit (10) judges that the spindle motor (3) is at fault.

Abstract: A control apparatus for an AC rotary machine, including first voltage command calculation means for calculating first voltage commands from current commands, an angular frequency, and constant set values of the AC rotary machine, second voltage command calculation means for calculating second voltage commands on the basis of difference currents between the current commands and current detection values, so that the difference currents may converge into zero, third voltage command calculation means for calculating third voltage commands by adding the first voltage commands and the second voltage commands, voltage application means for applying voltages to the AC rotary machine on the basis of the third voltage commands, and constant measurement means for calculating the constant set values on the basis of the second voltage commands.