Abstract: In a control device for a three-phase rotating machine with first and second winding sets, a current feedback computing section includes a current sum controller and a current difference controller. The current sum controller multiplies, by a sum gain, an error between a sum of current command values for alternating currents output from first and second inverters and a sum of sensed current values and computes a sum of voltage command values. The current difference controller multiplies, by a difference gain, an error between a difference of the current command values and a difference between the sensed current values, and computes a difference of voltage command values. In a variable-responsiveness mode, a gain ratio between the sum gain and the difference gain is varied according to a reference frequency such that the current sum controller and the current different controller are different in responsiveness.

Abstract: Provided is an actuator control apparatus including: an observer configured to estimate a state of a load based on a state equation including at least one modeled load parameter; a controller which outputs a signal for controlling the load; a compensation unit which compensates for the signal output from the controller; and an estimator configured to estimate a change of a load parameter, to decide a gain of the compensation unit based on the estimated change of the load parameter, and to update the modeled load parameter.

Abstract: An electric motor control device that performs a voltage phase control includes a voltage generator configured to calculate a d-q axis voltage command value, a stabilization filter having first to fourth filters determined based on a transfer characteristic from an applied voltage to an output electric current and configured to remove resonance characteristics in the d-q axis electric current, and a voltage application unit configured to apply an AC voltage to the electric motor based on the final d-q-axis voltage command value. The stabilization filter is configured to generate the final d-axis voltage command value based on a result obtained by using the first and second filters for each of the d-axis and the q-axis voltage command values and generate the final q-axis voltage command value based on a result obtained by using the third and fourth filters for each of the d-axis and the q-axis voltage command values.

Abstract: Disclosed are a method and system for detecting a fault of a parallel coil type permanent magnet motor. This method includes driving a parallel coil type motor on the basis of a pre-defined current reference value, detecting a phase current vector of the motor, and calculating a current compensation value for removing a negative sequence component of the motor on the basis of the phase current vector.

Abstract: An apparatus for measuring a position deviation of a rotor of a permanent magnet synchronous motor includes a control unit, a power transformation unit, a rotor position estimator and a calculation unit. The control unit receives a d-axis DC voltage signal and a q-axis AC voltage signal and receives an initial value of the rotor position and a high-frequency signal to output a three-phase command signal. The power transformation unit receives the three-phase command signal and outputs a three-phase control signal for controlling the motor. The rotor position estimator receives a three-phase current feedback signal corresponding to an operation of the motor and generates an estimation value of the rotor position. The calculation unit performs calculation to the initial value and the estimation value to generate a deviation value of the rotor position. Moreover, a method for measuring the position deviation is also disclosed herein.

Abstract: A controller-implemented method for monitoring a permanent magnet electric machine includes determining a threshold direct-axis (d-axis) current corresponding to inception of irreversible demagnetization of the permanent magnet based upon material properties of a permanent magnet mounted in a rotor of the PM electric machine and a temperature of the permanent magnet. A d-axis current associated with controlling the PM electric machine is determined, and a state of health of the PM electric machine is determined based upon the threshold d-axis current and the monitored d-axis current.

Abstract: A current control device of a synchronous motor comprises a provisional d-phase current command calculation unit; a voltage amplitude calculation unit calculating a magnitude of a voltage command vector in a previous sampling period; a voltage ratio calculation unit determining a voltage ratio between the magnitude of the voltage command vector and a maximum output voltage of an amplifier; a target d-phase current calculation unit obtaining a d-phase current command in the previous sampling period, and calculating a target d-phase current command from the voltage ratio and the d-phase current command; a correction value calculation unit determining a correction value by passing a difference between the provisional d-phase current command and the target d-phase current command through a low-pass filter; and an adder adding the correction value to the d-phase current command in the present sampling period to calculate a new d-phase current command.

Abstract: There is provided an onboard motor controller that starts a failsafe process in short time at a vehicle collision. A control circuit in the motor controller acquires an acceleration detected by an acceleration sensor. When the acceleration is equal to or higher than a prescribed value, the control circuit determines that a collision of the vehicle has occurred, and executes a switching process of a control mode of a motor. The control circuit immediately switches the control mode of a motor from voltage phase control to current vector control when the collision is detected. The control circuit reads current values from current detectors. When an overcurrent is detected, the control circuit executes a failsafe process to turn off the MOSFETs of an inverter. The control circuit stops a supply of electricity to the inverter by turning off a power supply relay, thereby stopping the rotation of the motor.

Abstract: An apparatus for measuring an error in a resolver includes a first calculator that perform an inverse Park transform based on voltages Uq and Ud at an output of PI current regulators, and delivers voltage setpoint signals PWMA, PWMB, PWMC to a power stage via a line on which a DC voltage Ubus-dc is available. The power stage generates a three-phase system of voltages UA, UB, UC for energizing an electric machine. The apparatus also includes a signal processor that provides an angle measurement ?m. Based on currents MesIA, MesIB, MesIC of the three phases, and on a rotor angle ?r, a second calculator of the device delivers values MesId, MesIq used by the first calculator. A PI voltage regulator delivers an angle ?c for correcting the error by regulating a setpoint value for the voltage Ud.

Abstract: A blower system, including a permanent magnet motor and a wind wheel. The permanent magnet motor includes a stator assembly, a rotor assembly, and a motor controller. The rotor assembly includes a salient pole rotor including a rotor core and magnets embedded in the rotor core. The motor controller includes a microprocessor, a frequency inverter, and a sensor unit. The sensor unit inputs a phase current or phase currents, a phase voltage, and a DC bus voltage into the microprocessor. The microprocessor outputs a signal to control the frequency inverter which is connected to a winding of the stator assembly. The ratio between an air gap of the motor and the thickness of the magnets ranges from 0.03 to 0.065, and the ratio between the length of a pole arc and the length of the magnets ranges from 0.8 to 1.0.

Abstract: An electric drive system includes a motor output shaft rotating on a motor axis and a first electric motor. The system includes an epicyclical gear that includes a sun gear, a ring gear, a plurality of planet gears and a carrier. The sun gear, the ring gear and the carrier gear of the epicyclical gear all rotate on the motor axis, and the carrier gear is connected to the motor output shaft via a first flange. The system also includes a second electric motor interposed between the first electric motor and the epicyclical gear. The second motor shaft has a hollow center along the motor axis and the first motor shaft extends through the hollow center of the second motor shaft and is connected to the sun gear. The system also includes a second flange. The second flange connects the second motor shaft to the carrier. The first flange and the second flange are located at opposite sides of the epicyclical gear.

Abstract: An apparatus includes a sensorless field-oriented control (FOC) motor controller. The motor controller includes a pulse width modulation (PWM) controller configured to generate PWM signals and to provide the PWM signals to an inverter. The motor controller also includes an angle sampler configured to receive a commanded voltage angle signal and to provide the commanded voltage angle signal as an output signal in response to a triggering event. The triggering event is based on a voltage or a current associated with an input or an output of the inverter. The motor controller further includes a first combiner configured to combine (i) a feed-forward voltage angle signal and (ii) a second signal based on the output signal. The first combiner is configured to generate the commanded voltage angle signal. In addition, the motor controller includes a second combiner configured to combine a feed-forward voltage amplitude signal and the second signal.

Abstract: The rotating electric machine includes a stator and a rotor. The rotating electric machine includes a rotor iron core including a plurality of magnetic pole portions in a circumferential direction, a plurality of permanent magnets provided on the rotor iron core, and a stator iron core including a plurality of teeth around each of which coil winding is wound. The stator iron core is configured in such a manner that the tooth facing the magnetic pole portion in the radial direction is substantially magnetically saturated by the permanent magnet in a non-energized state of the stator winding.

Abstract: An estimation section estimates a time period required for a norm of a difference vector between a current flowing to a motor/generator and a command current to attain a threshold level r in each switching mode provisionally set by a mode setting section. A mode determination section determines the switching mode of the longest required time period to be a final switching mode. A drive section controls an inverter to operate in the switching mode determined by the mode switching section.

Abstract: A three-phase permanent magnet motor is controlled by generating two-phase control signals. A rotation speed value is generated representing a rotation speed of the permanent magnet motor based on a q-current reference value and a q-current feedback value, the q-current reference value and the q-current feedback value corresponding to a q-phase winding. A d-phase voltage change value is generated based on a d-current reference value and a d-current feedback value, the d-current reference value and the d-current feedback value corresponding to the d-phase winding. A first d-phase voltage value is generated based on the rotation speed value, the d-phase voltage change value, the d-current reference value and the q-current reference value. A first q-phase voltage value is generated based on the rotation speed value, the q-current reference value and the d-current reference value.

Abstract: An object is to provide a permanent magnet motor controller capable of suppressing the rotary bending vibration that occurs in the permanent magnet motor effectively with simple configuration. A permanent magnet motor controller uses the dq coordinate conversion. A dq target current setting part adds the current component (i*da) that cancels the magnetic attractive force acting in the radial direction of the rotational shaft of the rotor of the permanent magnet motor to the d-axis target current value, whereby the eccentricity of the rotational shaft of the rotor is reduced.

Abstract: A method of compensating for a friction torque of a permanent magnet synchronous motor may include: receiving input of a motor current and a rotor speed of the permanent magnet synchronous motor; estimating a motor torque based on the input motor current; acquiring a first friction torque corresponding to the input rotor speed and the estimated motor torque by using a lookup table of friction torques; compensating for a second friction torque of the permanent magnet synchronous motor based on the first friction torque, wherein the compensating is in response to a first torque command input to control driving of the permanent magnet synchronous motor and outputs a second torque command that compensates for the second friction torque; and/or controlling the driving of the permanent magnet synchronous motor based on the second torque command.

Abstract: A motor control circuit calculates an ?-axis current i? and a ?-axis current i? in a fixed coordinate system based on a W-phase (sensor phase) of an AC motor. The control circuit calculates, at each switching time point and each intermediate time point, the ?-axis current i? from a current iw.sns sensed in the W-phase, and the ?-axis current i? from a differentiated value ?i? determined from the variation quantity of the ?-axis current between every two successive switching time points or intermediate time points. Subsequently, the control circuit calculates a current phase x?=tan?1(i?/i?) relative to the W-phase. Subsequently, the control circuit calculates an estimation factor according to the current phase x? and determines an estimated current iu.est in the U-phase of the AC motor by multiplying the sensed current iw.sns by the calculated estimation factor.

Abstract: A control device for AC rotary machine includes a current vector detection section (3), a magnetic flux vector detection section (9), an adaptive observation section (8), a control section (4), a voltage application section (5), a deviation vector calculation section (6) for outputting a current deviation vector and a magnetic flux deviation vector, and a deviation amplification section (7). The adaptive observation section (8) calculates an estimated current vector, an estimated magnetic flux vector, and an estimated position, based on a voltage instruction vector and an amplified deviation vector. Further, the control section (4) superimposes a high-frequency voltage vector, and the magnetic flux vector detection section (9) calculates a detected magnetic flux vector, based on a magnitude of a high-frequency current vector having the same frequency component as the high-frequency voltage vector, included in a detected current vector, and on a magnitude of a rotor magnetic flux.

Abstract: A synchronous machine control apparatus is characterized by including a magnet condition estimation unit (7, 7a) that estimates the temperature or the magnetic flux of a permanent magnet that forms the magnetic field of a synchronous machine (1), and is characterized in that the magnet condition estimation unit (7, 7a) coordinate-converts an armature current into currents on the ?-? axis consisting of the ? axis and the ? axis that is perpendicular to the ? axis, based on the rotor position and the estimated ? axis, and estimates the temperature or the magnetic flux of the permanent magnet, based on the control command for the synchronous machine (1) and the ?-? axis currents.

Abstract: A control device includes a motor driving unit that supplies electric power to a motor according to a magnetic-pole-phase signal output from the motor; and a rotational-position detecting unit that converts the magnetic-pole-phase signal into a rotational-position detection signal and outputs the rotational-position detection signal. The rotational-position detection signal indicates a rotation amount and a rotation direction of an output shaft of the motor and has a higher resolution than the magnetic-pole-phase signal.

Abstract: A method for driving a motor having a plurality of phases is provided. Initially, first, second, and third intervals for a pulse width modulation (PWM) period from first and second voltage commands are generated. The first and second voltage commands correspond to a voltage vector for the motor, and the voltage vector has an associated sector. A conversion formula is then determined for the first, second, third intervals based on the associated sector for the voltage vector. Using the conversion formula and the first, second, and third intervals, fourth, fifth, and sixth intervals are generated, and a set of PWM signals for the PWM period is generated from the fourth, fifth, and sixth intervals. The motor is then driven with the second set of PWM signals, and a current traversing the plurality of phases with a single shunt is measured.

Abstract: Disclosed are a system and a method for controlling a motor of an electric vehicle. In particular, an output voltage from a battery used to provide power to a motor of an electric vehicle, a speed and a torque of the motor are used to generate a magnetic flux based current control map. A current control command is then generated using the magnetic flux based current control map.

Abstract: In a control apparatus of a rotating device, a voltage command value setting section sets terminal command values on the basis of a command value of a control amount of the rotating device. Individual correcting sections calculate feedback operation amounts on the basis of history information of electric currents flowing in respective terminals of the rotating device and corrects the terminal voltage command values with the feedback operation amounts. A prohibiting section prohibits difference corresponding amounts, which correspond to differences of the feedback operation amounts and an average of the feedback operation amounts, from being reflected in correcting the terminal voltage command values with maintaining polarities when a determining section determines that it is a switching time from one of a power-running control and a regeneration control to the other.

Abstract: A commutated electric drive has an electric motor having a sensor assembly which has a permanent magnet on a shaft of the electric motor and an analog Hall sensor situated stationary relative to the stator of the electric motor opposite to the permanent magnet. A controller for controlling the windings of the electric motor has a memory for storing a calibration Hall signal of the magnetic field of the permanent magnet, measured using the Hall sensor, over one revolution of the shaft. The controller has a device for comparing the calibration Hall signal with an instantaneous Hall signal of the instantaneous magnetic field of the permanent magnet, measured using the Hall sensor. Temperature effects and aging effects may be recognized and taken into account when determining the rotor position.

Abstract: An electric power steering system calculates a motor resistance Rm using a resistance map, and calculates an estimated inducted voltage based on a motor current and a motor voltage. If the estimated induced voltage is determined as being equal to or smaller than a determination value that is set in accordance with the current level, the electric power steering system calculates a motor resistance (estimated motor resistance Rma) and updates the resistance map based on the estimated motor resistance Rma.

Abstract: This motor control device generates a voltage command value from a current command value and performs feedback control by means of a detected current flowing through a motor. The motor control device is provided with: a speed control unit that causes the motor to rotate at a set speed, and performs speed control of the motor on the basis of a speed command value that causes the flow of a d-axis current that is a set amount of current; a current measurement unit that measures a current command value that is on the basis of the output of the speed control unit when the motor is rotated at the set speed and the set amount of d-axis current is flowing; and a correction value calculation unit that calculates a correction value for the rotational position of the motor on the basis of the measured current command value.

Abstract: A controlling apparatus for an electric motor according to an embodiment includes a superposed component generator, an inverter, a current detector, and a magnetic pole position estimator. The superposed component generator generates, at a predetermined cycle, a superposed voltage reference of which vector is shifted by 90 degrees with respect to that of a superposed voltage reference previously generated, in a coordinate system that is set to a stator of the electric motor. The inverter outputs a driving voltage that is based on a driving voltage reference superposed with the superposed voltage reference to the electric motor. The current detector detects currents flowing into respective phases of the electric motor, and outputs the detected currents. The magnetic pole position estimator detects the magnetic pole position of the electric motor based on an amount of change in the detected currents at the predetermined cycle.

Abstract: Embodiments of the present disclosure relate to methods, systems and apparatus for generating voltage command signals for controlling operation of an electric machine. The disclosed embodiments can reduce current and torque oscillation, which can in turn improve machine efficiency and performance, as well as utilization of the DC voltage source.

Abstract: A rotary electric machine control system includes a rotary electric machine (second motor generator), a number-of-revolutions sensor that measures the number of revolutions per predetermined time period of the rotary electric machine, and a controller. The controller has a threshold changing unit for changing a control switching phase that is a control switching threshold to be used for switching the control mode of the rotary electric machine, according to a measurement result of the number of revolutions.

Abstract: A motor control device includes an inverter circuit having switching elements on/off controlled according to a predetermined PWM signal pattern to convert an input direct current to three-phase alternating current supplied to drive an electric motor. A phase current of the motor is detected based on a detection of the input direct current and the PWM signal pattern. A PWM signal generation unit which generates a three-phase PWM signal pattern to enable detecting two-phase currents twice in synchronization with four time-points within a carrier wave period of the PWM signal respectively and so that a detection of current follows a magnetic pole position of the motor. A current differential unit supplies, as current differential values, differences between twice detected current values regarding the two phases respectively, and a magnetic pole position estimation unit estimates the magnetic pole position of the motor based on the current differential values.

Abstract: A synchronous machine controller includes a position detecting unit that detects a position of a rotor, a current detecting unit that detects an armature current, a current command generating unit that generates first and second current commands, a voltage command generating unit that generates a voltage command on the basis of the current commands, the position of the rotor, and the armature current, a power converting unit that outputs a voltage to the synchronous machine on the basis of the voltage command, a magnetic flux estimating unit that estimates an armature interlinkage flux on the basis of a rotational velocity calculated from a variation of the position of the rotor, the voltage command, and the armature current, and a magnet state estimating unit that estimates a magnetic flux or a temperature of the permanent magnet from the position of the rotor, the armature current, and the armature interlinkage flux.

Abstract: Representative implementations of devices and techniques provide optimized control of a three-phase AC motor. A field oriented control (FOC) arrangement uses optimization components and techniques to improve power efficiency of the motor, with fast control response over a full range of motor speeds.

Abstract: A system for controlling a motor of a vehicle that improves fuel economy by minimizing a sum of heat generated by the motor and heat generated by a converter, is disclosed. More specifically, a power source supplies DC electricity; a converter selectively receives and converts the DC electricity of the power source into inverter input voltage. A relay module selectively connects the power source to the converter and an inverter module receives the inverter input voltage from the converter, converts the inverter input voltage into 3-phase AC current, and supplies the 3-phase AC current to the motor. Further, a controller controls operations of the converter, the relay module, and the inverter module, to perform to minimize the inverter input voltage that is a sum of heat generated due to the flux-weakening control and heat generated due to suppression of the flux-weakening control.

Abstract: A position sensorless drive systems for a permanent magnet motors are disclosed. An embodiment includes a square wave voltage source connectable to an input of a permanent magnet motor. At least one current sensor is connectable to the motor, wherein the current sensor is configured to sense the current in at least one power line to the motor in response to the square wave input to the motor. The position of the rotor relative to the stator may be determined based on the current resulting from the square wave voltage.

Abstract: In a control apparatus for an AC electric motor, a dq axis current feedback control unit 44 and a qn axis current feedback control unit 46 execute a feedback control of higher harmonic components of actual currents id and iq flowing in an AC electric machine 10 to higher harmonic current instruction values ?idkr and ?iqkr. A d axis current instruction value adjusting unit 24 and a q axis current instruction value adjusting unit 26 add the higher harmonic current instruction values ?idkr and ?iqkr to fundamental current instruction values idr and iqr. Ad axis current feedback control unit 32 and a q axis current feedback control unit 34 execute a feedback control of a difference between the actual currents id and iq and the sum of the higher harmonic current instruction values ?idkr, ?iqkr and the fundamental current instruction values idr and iqr into zero.

Abstract: A method for operating a motor of a motor-driven power steering (MDPS) includes: generating, by an inverter operating unit, a two-phase operation command by projecting a Q-axis command onto a two-phase operation axis, when an error occurs in any one of three phases; converting, by the inverter operating unit, coordinates of the two-phase operation command into an actual operation axis; calculating, by the inverter operating unit, a two-phase operation voltage by performing proportional integral (PI) control on the two-phase operation command converted into the actual operation axis; and operating, by the inverter diving unit, a motor by applying the two-phase operation voltage to an inverter unit.

Abstract: An electric motor control device includes a current vector controller that follows a target command value for controlling an electric current of the motor by separating the current into a d-axis current and q-axis current orthogonal to each other. The motor control device further includes a driver for driving the motor, a phase-angle generator a phase-angle command generator for generating a phase-angle command ?* based on difference ?v* between an absolute value |v*| of a voltage command supplied from the current vector controller to the driver and a given reference value V1mt, a d-axis current command generator for generating d-axis current command id* based on a sine value of the phase-angle command ?*, and a q-axis current limiter for setting a limit value of q-axis current command iq* based on a cosine value of the phase-angle command ?*.

Abstract: An inverter and a control unit that has a command signal processing unit and a PWM frequency control unit and performs pulse width modulation control are provided. If the command signal processing unit has received a first PWM frequency command signal, it outputs a low PWM frequency command signal so that synchronous or asynchronous PWM control is performed at a PWM frequency in a predetermined frequency range. The command signal processing unit outputs a high PWM frequency command signal so that synchronous or asynchronous PWM control is performed at a higher frequency than the above-mentioned frequency if the command signal processing unit has received a second PWM frequency command signal and until a predetermined time period elapses. The command signal processing unit outputs a low PWM frequency command signal if it has received the second PWM frequency command signal and after the predetermined time period elapsed.

Abstract: A motor driving device of the present invention is a motor driving device that incorporates so-called vector control of controlling a current applied to a motor winding in accordance with the position of a rotor. The motor driving device receives the input of a duty command value from a host controller via a command input port, for example. The motor driving device obtains a current command or a speed command as a command value such that the input duty command value is equal to the duty of a drive pulse output from an inverter. Then, the motor driving device performs vector control based on the obtained command value.

Abstract: A rotary electric machine includes: a stator having a stator winding and a stator core; a rotor having a first magnetic pole section and a second magnetic pole section, where the second magnetic pole section rotates respective to the first magnetic pole section; a shaft provided for the rotor; and a rotary mechanism configured to rotate the second magnetic pole section about the shaft. The rotary mechanism includes: a moving member configured to be movable along the shaft; a lead screw mechanism configured to move the moving member along the shaft; and a rotary member configured to rotate respective to the shaft along with the second magnetic pole section, where the rotary member engages the moving member and the second magnetic pole section.

Abstract: A system. The system includes a processor, a first module, a second module and a third module. The first module is communicably connected to the processor and is configured for calculating a q-axis voltage component and a d-axis voltage component. The second module is communicably connected to the processor and is configured for determining a voltage angle relative to the q-axis. The third module is communicably connected to the processor and is configured for (1) comparing the determined voltage angle to a predetermined value, (2) outputting the determined voltage angle if the determined voltage angle is less than the predetermined value, and (3) outputting the predetermined value if the predetermined value is less than the determined voltage angle.

Abstract: The present invention provides a motor control device including a feedback control system that generates a torque command for reducing a difference between an operation command signal for commanding an operation of a motor and a detection signal of a detector attached to the motor to detect a position and speed of the motor and drives the motor. The motor control device includes a correcting unit configured to estimate an amplitude and a phase of a correction amount for suppressing the detection error included in the detection signal and sequentially update estimation values of the amplitude and the phase and a post-correction-detection-signal calculating unit configured to generate a post-correction detection signal, which is a difference between the detection signal and the correction amount, instead of the detection signal.

Abstract: While enforcing a fake position in the data processing system and applying a zero direct-axis current command, positive and negative quadrature-axis current commands are applied sequentially and at approximately same magnitude to urge the rotor toward an enforced position. A processing module measures a positive quadrature-axis current aligned raw position data after application of the positive quadrature-axis current command and measures negative quadrature-axis current aligned raw position data for the rotor after application of the negative quadrature-axis command. An initial position offset calibrator or data processor determines a difference between the raw position data to determine an alignment of a true averaging axis. An initial position offset calibrator or data processor determines a raw averaging axis position data based on an average of the raw position data.

Abstract: A motor control apparatus according to an embodiment includes a power conversion unit and a control unit. The power conversion unit supplies power to a motor having salient pole characteristic. The control unit performs proportional-integral control on the deviation between a current reference and a current flowing into the motor to generate a voltage reference, and controls the power conversion unit on the basis of the voltage reference. The control unit estimates the magnetic-pole position of a rotor of the motor on the basis of a high-frequency current flowing into the motor by controlling the power conversion unit, and corrects the estimated magnetic-pole position on the basis of an integrated value of the proportional-integral control.

Abstract: This motor control device generates a voltage command value from a current command value and performs feedback control by means of a detected current flowing through a motor. The motor control device is provided with: a correction control unit that, when the motor is being rotated at a set speed, sets a d-axis current command value and a q-axis current command value to each be zero; a current control unit that generates the integrated value of the deviation between the current command value and the detected current; and an integrated value measurement unit that measures the generated integrated value. The correction control unit adjusts the correction value for the rotational position of the motor by adjusting in a manner so that the measured integrated value becomes a value within a pre-determined range.

Abstract: A power conversion device includes a switching circuit with multiple series circuits having upper arm switching elements connected in series with lower arm switching elements, receives DC power to generate AC power for a permanent magnet motor; a control circuit that calculates a state of the switching elements based on input information for each control cycle, and generates a control signal for controlling switching elements according; and a driver circuit that generates a drive signal that renders the switching elements conductive or non-conductive on the basis of the control signal from the control circuit. The control circuit predicts a locus of a d-axial magnetic flux and a locus of a q-axial magnetic flux, and calculates the state of the switching elements so that the d-axial magnetic flux falls within a given d-axial magnetic flux fluctuation range, and the q-axial magnetic flux falls within a given q-axial magnetic flux fluctuation range.

Abstract: A control apparatus for an AC rotary machine includes a control circuit, a power converter, a current detector, and a voltage detector. The control circuit includes: an activation current instruction unit which generates a current instruction for activation; and a start phase setting unit which sets an initial rotation phase for activation control, based on the rotation direction of the AC rotary machine just after activation and on the polarity of current detected by the current detector just after activation. Thus, the current amplitude and torque shock just after activation control is started can be reduced, and assured and stable reactivation is allowed without causing the protection operation.

Abstract: A control system for an electric motor comprises processing means arranged to perform a control process which includes monitoring electrical voltages applied to the motor and electrical currents in the motor, and determining from them the rotational position of the motor. The system is further arranged to monitor at least one parameter of the control process thereby to detect a stall condition of the motor.

Abstract: An estimation section calculates estimated currents corresponding to switching modes, which are provisionally set by a mode setting section. A mode determination section determines one of modes, which has a smallest difference between the estimated currents and command currents, to be a final switching mode. A drive section drives an inverter in the switching mode determined by the determination section. The estimation section uses transient-state inductances as coefficients of time differentiation of currents in voltage equations used for estimation of the estimated currents. These are different from steady-state inductances, which are coefficients of multiplication of currents and electric angular velocity.