A tandem control system for a machine tool, according to the present invention, comprises: a numerical control unit; a main operation unit; a PLC which executes a control command via communication with the numerical control unit or the main operation unit; a servo drive which includes a notch filter unit and executes the control command from the PLC; a servo motor unit which is driven under the control of the servo drive; and a power conversion unit which is electrically connected to the servo motor unit and the servo drive so as to apply current to the servo motor unit, wherein the servo drive suppresses resonance due to the operation of the servo motor unit by controlling the application state of current transferred to the power conversion unit according to changes of notch &; filter coefficients calculated in real time at the notch filter unit.

A protection apparatus and a brushless motor system reduce costs of the brushless motor system and ensure normal operation of a brushless motor. The protection apparatus includes a demagnetization apparatus and a control apparatus. The demagnetization apparatus is configured to be bridged between a rectifier circuit and an excitation winding, and is configured to consume, when the brushless motor system is faulty, excess electric energy generated on the excitation winding. The control apparatus is configured to separately connect to an excitation power supply circuit and a controller; and is configured to detect electrical parameters of an input terminal and an output terminal of the excitation power supply circuit, and when determining that the electrical parameters exceed a preset threshold, generate an alarm to the controller and adjust the output electrical parameter of the excitation power supply circuit.

A stator defines multiple stator poles with associated electrical windings. A rotor includes multiple rotor poles. The rotor is movable with respect to the stator and defines, together with the stator, a nominal gap between the stator poles and the rotor poles. The rotor poles includes a magnetically permeable pole material. The rotor also includes a series of frequency programmable flux channels (FPFCs). Each FPFC includes a conductive loop surrounding an associated rotor pole. The stator and the rotor are arranged such that the electrical windings in the stator induce an excitement current within at least one of the FPFCs during start-up.

A commutation error compensation method for an electric motor includes: when a rotor, that has not been corrected, in an electric motor rotates in a set direction, collecting a position signal and a three-phase current signal of the rotor, wherein the position signal of the rotor represents the rotation angle of the rotor; filtering processing on the three-phase current signal to obtain a fundamental component of the three-phase current signal, and determining a position error compensation signal of the electric motor on the basis of the fundamental component of the three-phase current signal; determining an ideal phase interval of the rotor according to the position error compensation signal and the position signal of the rotor; and determining an adjustment method for the rotor of the electric motor according to the ideal phase interval of the rotor, and commutating the rotor of the electric motor according to the adjustment method.

A vehicle includes a battery, an inverter, a permanent magnet electric machine, and a controller. The controller commands discharge of a storage element of the inverter through the permanent magnet electric machine via a current having a zero quadrature axis component and a positive direct axis component.

A method for controlling torque applied during a screw driving operation using a screw driving device. The device includes: an electric motor provided with a rotor; an output member capable of being rotated; and a rebounding impact mechanism rigidly connected to the rotor and to the output member. The method includes power supplying the motor inducing driving the impact mechanism by the rotor and periodically rotating the output member by the impact mechanism; driving the impact mechanism generating a plurality of successive impacts at the end of each of which the rotor rotates in a rebound in the opposite direction to the screw driving operation; determining a maximum rotational frequency reached by the rotor during the rebound following each of the impacts; and stopping the screw driving operation when the maximum rotational frequency reaches a predetermined threshold corresponding to a predetermined torque level.

Described is a method of controlling operation of a synchronous motor. The method comprises, during constant power/speed motor operation, determining a value of a stator voltage (v.sub.s.sup.2) for an orthogonal rotating reference frame of the motor. Comparing the value of the determined stator voltage (v.sub.s.sup.2) to a threshold voltage (v.sub.s_max1.sup.2), said threshold voltage (v.sub.s_max1.sup.2) having a value between that of a maximum stator voltage (v.sub.s_max0.sup.2) for a basic speed mode of operation of the motor and that of a maximum stator voltage (v.sub.s_max2.sup.2) of the motor closed loop controller. If the determined value of the stator voltage (v.sub.s.sup.2) is greater than or equal to the value of the threshold voltage (v.sub.s_max1.sup.2), then controlling operation of the motor in a flux weakening mode of operation until a value of a current component (i.sub.d−Δi.sub.d) in a d-axis reaches a maximum negative value (−i.sub.dmax), or until the value of the stator voltage (v.sub.s.sup.2) is less than the value of the threshold voltage (v.sub.s_max1.sup.2).

A motor control system includes a reference current generator that generates a reference current based on a command, a motor voltage providing device that generates a phase voltage based on the reference current, a high frequency voltage, and a feedback current and provides a motor with the phase voltage, and a high frequency voltage generator that generates the high frequency voltage corresponding to a magnitude of voltage generated based on the reference current and the feedback current.

A motor includes a stator having a winding, and a rotor. The rotor rotates by receiving a rotational magnetic field generated by drive current supplied to the winding. The winding includes a first winding and a second winding, the first and second windings both being excited at the same timing by the drive current. The first winding and the second winding are connected in series. The rotor includes a first pole section and a second pole section. The second pole section faces the second winding at the rotation position of the rotor at which the first pole section faces the first winding. The magnetic force exerted on the stator by the second pole section is weaker than that exerted by the first pole section.

A speed control method for a permanent magnet synchronous motor considering current saturation and disturbance suppression aims to effectively ensure that a current of the motor is always within a given range to avoid the problem of control performance reduction caused by the fact that the current gets into a saturation state, ensure the safety of a system, do not need to use unavailable state variables such as motor acceleration and the like, effectively estimate and compensate disturbances including parameters uncertainty and unknown load torque disturbance existing in a permanent magnet synchronous motor system, and rapidly and accurately control a speed of the motor finally. There is no need to configure a plurality of sensors in practical industrial application, so system building costs can be reduced on the one hand, and the stability of the system can be improved on the other hand.