A linear motor system includes: a stator including first to tenth coils; a mover including a permanent magnet; a switcher that switches one or more power supply target coils that serve as power supply targets; and a control device that supplies power to the one or more power supply target coils by using a total mass calculated based on a mass of the permanent magnet. The control device includes: an acquirer that acquires a total number of the one or more power supply target coils; a speed control unit that calculates a post-division total mass by dividing the total mass by the total number of the one or more power supply target coils, and generates a torque instruction by using the post-division total mass; and a current control unit that supplies power to the one or more power supply target coils based on the torque instruction.

An inverter system is configured to mitigate oscillation of a rotary system that drives a generator or electric machine. A torque damping module is configured to receive a commanded torque or an observed torque and to generate a commanded compensating torque to dampen any mechanical oscillation or resonance of the rotary system based on the observed rotational speed of the generator. The torque damping module further comprises a digital filter of order greater than one, a gain adjuster and a limiter.

An inverter system for mitigating oscillation of an electric motor that drives a load comprises a torque command generation module for receiving a commanded torque from an operator of a vehicle. A torque damping module is configured to receive the commanded torque and generating a commanded compensating torque to dampen any mechanical oscillation or resonance of the electric motor based on the observed rotational speed of the motor. The torque damping module further comprises a digital filter of order greater than one, a gain adjuster and a limiter.

An inverter system for mitigating oscillation of an electric motor that drives a load comprises a torque command generation module for receiving a commanded torque from an operator of a vehicle. A torque damping module is configured to receive the commanded torque and generating a commanded compensating torque to dampen any mechanical oscillation or resonance of the electric motor based on the observed rotational speed of the motor. The torque damping module further comprises a digital filter of order greater than one, a gain adjuster and a limiter.

A method for controlling operation of a rotary electric machine includes receiving, via a bandwidth-partitioning harmonic compensation regulator (HCR) of a controller, a commanded torque and rotational speed of the electric machine, and calculating, via the HCR in response to enabling conditions, a dq harmonic compensation current and a dq harmonic compensation voltage for one or more predetermined harmonic orders using the commanded torque and the rotational speed. The harmonic compensation current and voltage cancel torque ripple and current ripple in the one or more predetermined harmonic orders. The method may include injecting an acoustic tone at a predetermined harmonic order. The method additionally includes adding the dq harmonic compensation current and voltage to a dq current and voltage command, respectively, to generate adjusted dq current and voltage commands. The electric machine is then controlled using the adjusted dq current and voltage commands.

A method for controlling operation of a rotary electric machine includes receiving, via a bandwidth-partitioning harmonic compensation regulator (HCR) of a controller, a commanded torque and rotational speed of the electric machine, and calculating, via the HCR in response to enabling conditions, a dq harmonic compensation current and a dq harmonic compensation voltage for one or more predetermined harmonic orders using the commanded torque and the rotational speed. The harmonic compensation current and voltage cancel torque ripple and current ripple in the one or more predetermined harmonic orders. The method may include injecting an acoustic tone at a predetermined harmonic order. The method additionally includes adding the dq harmonic compensation current and voltage to a dq current and voltage command, respectively, to generate adjusted dq current and voltage commands. The electric machine is then controlled using the adjusted dq current and voltage commands.

A motor drive control device includes: a feedback control unit calculating an operation amount (Sad) of a motor such that a rotation speed S3 of the motor matches a target rotation speed S1; a drive control signal generation unit generating a drive control signal Sd based on the operation amount Sad; a current fluctuation detection unit detecting a fluctuation of a current flowing through the motor; a correction instruction unit instructing correction of the operation amount Sad when the fluctuation of the current flowing through the motor is detected by the current fluctuation detection unit; and a correction unit correcting the operation amount Sad and providing the corrected operation amount S2 to the drive control signal generation unit when the correction of the operation amount Sad is instructed from the correction instruction unit.

An object of the present invention is to effectively reduce vibration or noise caused by a motor. An inverter circuit 300 generates an alternating current from a direct current supplied from a direct current power supply 10 by using a plurality of IGBTs 311 which are switching elements, supplies the generated alternating current to a motor 100, and drives the motor 100. This alternating current includes a fundamental harmonic current corresponding to a rotational speed of the motor 100, and a harmonic current of a switching operation of the IGBTs 311. A controller 200 controls a second phase such that a first phase and the second phase are not superimposed on each other at a predetermined motor rotational speed, the first phase being a phase of an excitation force cyclically produced in the motor 100 by the fundamental harmonic current, and the second phase being a phase of an excitation force cyclically produced in the motor 100 by the harmonic current.

An object of the present invention is to effectively reduce vibration or noise caused by a motor. An inverter circuit 300 generates an alternating current from a direct current supplied from a direct current power supply 10 by using a plurality of IGBTs 311 which are switching elements, supplies the generated alternating current to a motor 100, and drives the motor 100. This alternating current includes a fundamental harmonic current corresponding to a rotational speed of the motor 100, and a harmonic current of a switching operation of the IGBTs 311. A controller 200 controls a second phase such that a first phase and the second phase are not superimposed on each other at a predetermined motor rotational speed, the first phase being a phase of an excitation force cyclically produced in the motor 100 by the fundamental harmonic current, and the second phase being a phase of an excitation force cyclically produced in the motor 100 by the harmonic current.

A fastening tool includes: a bit holding portion which detachably holds a driver bit and is configured to rotate in a circumferential direction of the driver bit and move in an axial direction of the driver bit; a motor configured to perform at least one of rotation of the bit holding portion and movement of the bit holding portion along the axial direction; and a control unit configured to control a position of the bit holding portion along the axial direction by a rotation amount of the motor. The control unit is configured to stop rotation of the motor based on a load applied to the motor rotated in one direction of moving the bit holding portion in a direction approaching a fastening target.