Provided is a laundry treatment machine including a washing tub, a washing tub motor configured to rotate the washing tub, a drain pump configured to operate to drain the washing tub, a motor configured to operate the drain pump, a converter configured to output DC power, an inverter configured to convert the DC power, a dc terminal voltage detector configured to detect a dc terminal voltage output from the converter, and a controller configured to, when the dc terminal voltage continuously drops during a first period based on an operation of the inverter, perform control to turn off the inverter and operate the converter after the first period. Accordingly, it is possible to stably drive based on the dc terminal voltage during the operation of the drain pump.

A control device includes: an angular velocity detection unit that detects an angular velocity of a motor; a vibration component removal unit that removes a vibration component in a predetermined band from the angular velocity detected by the angular velocity detection unit by filtering; and a current command calculation unit that calculates a current command value of a drive current for driving the motor according to a torque command value and the angular velocity from which the vibration component has been removed by the vibration component removal unit.

A system and a method for use of electric motors in fracturing operations are disclosed. The system includes an electric motor, a turbine generator, an encoderless vector control subsystem, and at least one pump. The turbine generator is adapted to generate electric power for the system. The encoderless vector control subsystem is coupled between the turbine generator and the electric motor to control the electric motor using determined parameters that are based in part on vibration induced in a feature associated with the turbine generator. The at least one pump is adapted to receive torque input from the electric motor.

A magnetic bearing controller for controlling a magnetic levitation motor, the magnetic levitation motor including: a rotor; a pair of electromagnets that causes the rotor to levitate by electromagnetic force; an auxiliary bearing that supports a rotating shaft of the rotor when the rotor is stopped; and a rotor position detector that detects the rotor's position in a levitation direction. The magnetic bearing controller includes an operation current generator that generates an operation current value corresponding to a deviation between a position command value and the rotor's position detected by the rotor position detector. The operation current generator is configured to give a predetermined initial value greater than 0 to the operation current value at a start of levitation for causing the rotor in a state where the rotating shaft of the rotor is supported by the auxiliary bearing to levitate and be positioned at a predetermined target position.

Various embodiments include an actuator comprising: a motor; a transmission; an actuating connection; a first motor line and second motor line and a ground line. The motor is driven in a first or second direction by a motor voltage applied to the first or second motor line. There is also a motor control unit comprising a signal evaluation unit and a downstream actuating device for the motor, and a voltage supply unit to provide, from the first and/or second motor voltage, a supply DC voltage for a power supply of the motor control unit. The signal evaluation unit produces, for the duration of the application of the first and/or second motor voltage to the first and second motor line, associated actuating signals. The motor control unit electrically controls the motor in the associated first or second direction of rotation on the basis of actuating signals.

A variety of methods, controllers and electric machine systems are described that facilitate pulsed control of electric machines (e.g., electric motors and generators) to improve the machine's energy conversion efficiency. Under selected operating conditions, the electric machine is intermittently driven (pulsed). The pulsed operation causes the output of the electric machine to alternate between a first output level and a second output level that is lower than the first output level. The output levels are selected such that at least one of the electric machine and a system that includes the electric machine has a higher energy conversion efficiency during the pulsed operation than the electric machine would have when operated at a third output level that would be required to drive the electric machine in a continuous manner to deliver the desired output. In some embodiments, the second output level is zero torque.

An electric motor controlling system used for vibration suppression of an electric vehicle is disclosed. The controlling system includes a PID-controller and a vibration suppression compensator. The PID-controller generates a basic torque command through performing a calculation based on input speed-error signal of the electric vehicle, the vibration suppression compensator generates a compensated torque command through performing a compensation gain procedure on the input speed-error signal. The vibration suppression compensator further receives a motor speed of the electric vehicle, sets its output as the compensated torque command when the motor speed is smaller than a preset active speed level, otherwise sets the output as 0. The controlling system generates an output torque command via adding up the basic torque command and the output of the vibration suppression compensator, and operates electric motor components of the electric vehicle according to the output torque command.

A motor control system includes a motor, an encoder, and a controller including a controller transmitter configured to transmit a torque command to control the motor. The encoder includes a position detector configured to detect a rotational position of the motor, an encoder receiver configured to receive the torque command from the controller transmitter, first disturbance estimating circuitry configured to estimate a first disturbance torque based on the rotational position and the torque command, and an encoder transmitter configured to transmit the rotational position and the first disturbance torque to the controller.

Technical solutions are described for preventing controller windup in a motor control system. An example system includes a first anti-windup module that receives a commanded voltage and a limited voltage command. The limited voltage command is applied to an electric motor, where the first anti-windup module generates a first modified current command by modifying a current command that is applied to the motor control system. The modification is based on a ratio of the commanded voltage and the limited voltage command. The system further includes a second anti-windup module that receives the commanded voltage and the limited voltage command. The second anti-windup module generates a second modified current command by modifying the first modified current command. The modification based on a difference between the commanded voltage and the limited voltage command.

A method for reducing a total operational load of a method of a model predictive control-by conducting simplifications based on specific observations, in order to drive alternating current motors by using the method of the MPC with a two-level voltage source inverter. The method includes the steps of determining at which one of the predefined sectors a resultant of stator currents is present, determining a motor mode, reducing seven estimation vectors to four estimation vectors and calculating a cost function or reducing seven estimation vectors to five estimation vectors and calculating the cost function.