Provided is an electric motor control apparatus (1) configured to extract a speed ripple component from a difference between an angular frequency command and an angular frequency feedback, configured to generate a phase of the speed ripple component from the speed ripple component, configured to multiply a value of a periodic function corresponding to the phase and a given amplitude by each other, to thereby generate a torque compensation value, configured to calculate a torque command value from the difference between the angular frequency command and the angular frequency feedback, and configured to control a current to be output to an electric motor based on a compensated torque command obtained by adding the torque compensation value to the torque command value.

The present disclosure provides a method based on a motor stall protection and a motor stall protection apparatus. The method may includes: obtaining a rotational speed of a motor rotor and an output current of a motor stator; performing a pre-stall protection in response to the rotational speed being less than a first rotational speed threshold and the output current being greater than a first current threshold, the performing a pre-stall protection comprises obtaining a power module temperature, a stall decision value and a first current accumulation value; performing the stall protection in response to the first current accumulation value obtained being greater than the stall decision value. The method based on the motor stall protection provided in the present disclosure may determine a timing of performing the stall protection by periodically comparing the first current accumulation value and the stall decision value.

A power tool is provided including a housing, an electric motor disposed within the housing, a power switch circuit disposed between a power supply and the electric motor, a main controller, and a secondary controller. The main controller is arranged to control a switching operation of the power switch circuit to regulate a speed of the motor, and is configured to monitor at least one of a speed or a rotational direction of the electric motor and deactivate the power switch circuit upon detection of fault condition associated the speed or the rotational direction of the electric motor. The secondary controller is configured to monitor at least one of the speed or the rotational direction of the electric motor independently from the main controller and deactivate the power switch circuit upon detection of fault condition associated the speed or the rotational direction of the electric motor.

A motor drive and method to control a motor in a fluid system. The method may comprise determining a pressure; determining a proportional error as a limited difference between the pressure and a pressure setpoint; determining an integral step as a limited proportional error; determining an integral error as a limited sum of the integral step and a preceding unbound integral error; determining an error as the product of the integral error, the proportional error, and a gain factor; and generating a control signal to cause the inverter to output a motor voltage to drive the motor and maintain the pressure about the pressure setpoint.

Provided is a vehicle door opening/closing device. Given that a door is in an initial fully-open position, a storage unit stores: a target speed map for defining a relation between the door position and the target speed of a motor; and information indicative of an arbitrary fully open position set by a user. A map speed computation unit calculates a map speed based on the target speed map, whereas a gradually decreasing speed calculation unit calculates a gradually decreasing target speed for decreasing at a prescribed deceleration rate as the arbitrary fully open position gets closer so that a prescribed terminal speed is reached at the arbitrary fully open position. A speed sequence control unit switches a set target speed to the gradually decreasing target speed from the map speed at a door position where the gradually decreasing target speed becomes slower than the map speed.

Provided are a motor control method, a motor control device and a variable frequency drive. The method includes: performing an amplitude limiting on a command torque to obtain a target torque; calculating a target current based on the target torque; determining whether an amplitude of the target current is greater than a current limiting amplitude; performing an amplitude limiting on current components of the target current, when the amplitude of the target current is greater than the current limiting amplitude; and controlling a motor based on the current components of the target current after being performed the amplitude limiting. Thus, an amplitude limiting on current of a motor is achieved by performing amplitude limiting on torque and current.

A method of controlling a coasting torque using an electric motor for a vehicle having the electric motor includes: determining a speed range to travel on a forward slope based on the current vehicle speed; determining a target speed within the speed range based on the coasting torque and a travel load depending on vehicle speed; and correcting a driving force of the electric motor in response to the determined target speed.

A valve operating apparatus with controls may include a speed control engageable by a hand of an operator of the apparatus to control a speed characteristic for operating the valve. The speed control may have a zero position corresponding to a zero speed of rotation of a shaft for connecting to the valve, with the speed control being movable out of the zero position to a nonzero position corresponding to a nonzero speed of rotation. A degree of movement of the speed control from the zero position may correspond to a speed of rotation of the shaft such that further movement of the control away from the zero position increases the speed of rotation. Movement of the speed control from the zero position may be characterized by the speed control maintaining the position of the speed control when engagement of the control by the hand of the operator is discontinued.

A motor control actuator configured to drive a permanent magnet synchronous motor (PMSM) with sensorless Field Oriented Control (FOC) includes: a sampling circuit configured to measure a counter electro motive force (CEMF) or a back electro motive force (BEMF) of the PMSM, while the PMSM rotates, and generate a measurement signal based on the measured CEMF or the measured BEMF; a motor controller including a current controller configured to generate control signals for driving the PMSM, the current controller configured to receive the measurement signal and perform a catch spin sequence for restarting the PMSM while rotating based on the measurement signal; and a multi-phase inverter configured to supply multiple phase voltages to the PMSM based on the control signals. The motor controller is configured to match an output voltage of the multi-phase inverter to the measured CEMF or the measured BEMF during the catch spin sequence.

According to the present invention, a control method for a clothing treatment device comprises the steps of: transmitting a power-related order to a motor that provides electric power to a drain pump in order to perform a dehydration process; detecting a unit revolution count of the motor while the dehydration process is performed; determining whether the detected unit revolution count exceeds a preset limited revolution count; reducing the unit revolution count of the motor to a predetermined unit revolution count if the detected unit revolution count exceeds the limited revolution count; and repeatedly transmitting the power-related order to the motor.