A control device includes angular velocity detecting circuitry, feedback circuitry, torque command calculation circuitry, a limiter, a drive controller, and correction circuitry. The angular velocity detecting circuitry detects an angular velocity of a motor. The feedback circuitry obtains a feedback value from the angular velocity. The torque command calculation circuitry obtains a torque command value according to a superordinate torque command value supplied from a superordinate device and the feedback value. The limiter limits the torque command value obtained by the torque command calculation circuitry so as not to exceed a preset torque upper limit value. The drive controller performs a drive control of the motor according to the limited torque command value. The correction circuitry corrects the superordinate torque command value or the torque command value according to the feedback value and the superordinate torque command value.

A control device includes angular velocity detecting circuitry, feedback circuitry, torque command calculation circuitry, a limiter, a drive controller, and correction circuitry. The angular velocity detecting circuitry detects an angular velocity of a motor. The feedback circuitry obtains a feedback value from the angular velocity. The torque command calculation circuitry obtains a torque command value according to a superordinate torque command value supplied from a superordinate device and the feedback value. The limiter limits the torque command value obtained by the torque command calculation circuitry so as not to exceed a preset torque upper limit value. The drive controller performs a drive control of the motor according to the limited torque command value. The correction circuitry corrects the superordinate torque command value or the torque command value according to the feedback value and the superordinate torque command value.

Stable current control is performed even at the time of occurrence of disturbance, while the steadily occurring current pulsation is suppressed. A motor drive device 100 includes a power conversion circuit 103 that drives an alternating-current motor 101, and a controller 102 that controls the power conversion circuit 103. The controller 102 includes a voltage command calculation unit 108, a control state judgement unit 112, and a control gain change unit 113. When the determination signal output from the control state judgement unit 112 is switched from a determination signal representing a steady state to a determination signal representing a transient state, the control gain change unit 113 immediately changes the control gain to a value of normal setting, and when the judgement signal output from the control state judgement unit 112 is switched from a determination signal representing the transient state to a judgement signal representing the steady state, the control gain change unit 113 changes, with a predetermined delay time, the control gain to a value of high-gain setting.

A drive system includes: a drive device including an electric motor; and a torque controller that controls operations of the electric motor to control torque output from the electric motor. The torque controller includes a target-motor-torque determiner that determines target motor torque based on a sum of motor requested torque and a value obtained by multiplying a gain by sprung-portion-vibration-control torque. The target motor torque is a target value of the torque output from the electric motor. The motor requested torque is determined based on vehicle requested torque requested for driving of the vehicle. The torque controller includes a gain determiner that determines the gain to a value that is less when an absolute value of the motor requested torque is small with respect to the sprung-portion-vibration-control torque than when the absolute value is large with respect to the sprung-portion-vibration-control torque.

A drive system includes: a drive device including an electric motor; and a torque controller that controls operations of the electric motor to control torque output from the electric motor. The torque controller includes a target-motor-torque determiner that determines target motor torque based on a sum of motor requested torque and a value obtained by multiplying a gain by sprung-portion-vibration-control torque. The target motor torque is a target value of the torque output from the electric motor. The motor requested torque is determined based on vehicle requested torque requested for driving of the vehicle. The torque controller includes a gain determiner that determines the gain to a value that is less when an absolute value of the motor requested torque is small with respect to the sprung-portion-vibration-control torque than when the absolute value is large with respect to the sprung-portion-vibration-control torque.

In a motor control apparatus, an exciting unit excites a plurality of excitation phases of a motor. A current measurement unit measures exciting currents flowing through coils of respective phases of the motor, and generates measurement data including measurement values of the exciting currents. A determination unit determines whether or not noise is superimposed on a measurement value included in the measurement data by comparing, with respect to each of the plurality of excitation phases, the measurement data regarding a first phase coil that constitutes that excitation phase with the measurement data regarding a second phase coil that constitutes that excitation phase.

Provided are a method and system for controlling an electric motor, and a controller. The method comprises: controlling an electric motor to operate in an open-loop manner; determining whether a rotational speed of the electric motor reaches a preset rotational speed; if so, determining whether the absolute value of an angle difference between an open-loop angle and a calculated position angle of the electric motor is greater than a preset angle; and if the absolute value of the angle difference is less than or equal to the preset angle, controlling the electric motor to operate in a closed-loop manner so as to avoid the situation where the electric motor cannot operate stably due to problems such as electric motor speed vibration caused by too large an angle difference between the open-loop angle and the position angle.

A method is disclosed for evaluating an operational readiness of an electric motor, such as an electric motor of a fan. The method may be used during initial start-up. The method includes: initiating a run-up process of the electric motor, the speed being changed in several speed levels during the run-up process, generating at least one measured value by measuring a physical variable with a sensor of the electric motor in at least one of the speed levels, loading at least one parameter datum from a parameter memory of the electric motor, wherein the at least one parameter datum corresponds to the at least one measured value generated, and evaluating the at least one measured value for at least one of the speed levels using the at least one loaded parameter datum. Further disclosed are an electric motor with a parameter memory and a parameterization interface as well as a fan with this electric motor and an impeller.

A three-phase motor drive system for operation from a three-phase alternating current (AC) power source. The three-phase motor drive system includes a three-phase hybrid active harmonic filter (AHF) having an input operably connected to the three-phase AC power source, the three-phase hybrid active harmonic filter comprising an active harmonic filter operably connected in parallel with the three-phase AC power source and a three-phase AC reactor disposed in series between the input and an output of the hybrid active harmonic filter. The three-phase motor drive system also includes a three-phase variable frequency motor drive configured to provide excitation signals to a three-phase motor; and a three-phase AC motor operably connected to the three-phase variable frequency motor drive, the three-phase AC motor responsive the excitation signals.

Stable current control is performed even at the time of occurrence of disturbance, while the steadily occurring current pulsation is suppressed. A motor drive device 100 includes a power conversion circuit 103 that drives an alternating-current motor 101, and a controller 102 that controls the power conversion circuit 103. The controller 102 includes a voltage command calculation unit 108, a control state judgement unit 112, and a control gain change unit 113. When the determination signal output from the control state judgement unit 112 is switched from a determination signal representing a steady state to a determination signal representing a transient state, the control gain change unit 113 immediately changes the control gain to a value of normal setting, and when the judgement signal output from the control state judgement unit 112 is switched from a determination signal representing the transient state to a judgement signal representing the steady state, the control gain change unit 113 changes, with a predetermined delay time, the control gain to a value of high-gain setting.