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.

A power conversion apparatus includes a main circuit unit, a control unit, a current sensor, and a half-wave rectifier unit. The control unit includes current frequency calculation units and monitoring units. The current frequency calculation units calculate current frequencies based on at least either the rising timing or falling timing of current detection signals half-wave rectified by the half-wave rectifier unit. The monitoring units monitor the speed of a motor based on the current frequencies calculated by the current frequency calculation units.

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.

In a rotary electric machine, a rotor, and a stator. The stator includes slots provided in a circumferential direction thereof, and stator windings wound in the slots. The stator windings include n groups of three-phase windings, where n is a power of 2. The slots include first slots each accommodating portions of same-group and same-phase windings in the n groups of three-phase windings. The energizing directions of the same-group and same-phase windings are identical to each other. The second slots each accommodate different-group and same-phase windings in the n groups of three-phase windings. The first slots and the second slots are arranged in the stator at predetermined intervals in a circumferential direction of the stator, and the three-phase windings of each group are wound around the stator with regular intervals therebetween.

A power tool includes a motor, a power supply device, a driver circuit, a parameter acquisition module, and a controller. The motor includes a stator and a rotor. The motor is configured to generate a reluctance torque. The driver circuit is electrically connected to the motor to drive the motor. The parameter acquisition module is configured to acquire a current of the motor, a rotational speed of the motor, and a position of the rotor. The controller is configured to: according to at least one of the current of the motor, the rotational speed of the motor, or the position of the rotor, dynamically adjust a current applied to the stator so that an included angle between a stator flux linkage of the motor and a rotor flux linkage of the motor ranges from 90° to 135°.

A power tool is provided including an electric motor, a power terminal receiving electric power form a power supply, an actuator, a power switch circuit disposed between the power terminal and the electric motor, and a controller controlling a switching operation of the power switch circuit. A power contact switch is coupled to the actuator and disposed on a first current path to selectively connect the power switch circuit to the power supply. A solid-state load switch disposed on a second current path from the power terminal to the controller is controllable via output of the power contact switch or a self-activating feedback signal from the controller. A solid-state override switch is provided controllable via a self-deactivating feedback signal from the controller and having an output commonly coupled to the output of the power contact switch to turn off the load switch even when the power contact switch is closed.

A power tool includes a motor, a power supply device, a driver circuit, a parameter acquisition module, and a controller. The motor includes a stator and a rotor. The motor is configured to generate a reluctance torque. The driver circuit is electrically connected to the motor to drive the motor. The parameter acquisition module is configured to acquire a current of the motor, a rotational speed of the motor, and a position of the rotor. The controller is configured to: according to at least one of the current of the motor, the rotational speed of the motor, or the position of the rotor, dynamically adjust a current applied to the stator so that an included angle between a stator flux linkage of the motor and a rotor flux linkage of the motor ranges from 90° to 135°.

A motor controller includes a current controller configured to generate control signals for driving a permanent magnet synchronous motor (PMSM), where the current controller is configured to measure voltage information and current information of the PMSM; a power constant controller configured to receive the voltage information and the current information, and generate a first target speed based on a target power of the PMSM and based on the voltage information and the current information; first signal generator configured to generate a second target speed; a speed constant controller coupled between the power constant controller and the current controller, wherein the speed constant controller is configured to switchably receive the first target speed and the second target speed, and regulate a motor speed of the PMSM based on the received first target speed or the received second target speed.

A motor control system includes a motor; a motor and a motor control circuit coupled to the motor to provide power to the motor. The motor control circuit includes a power feedback loop having a power reference circuit to provide a reference power level and a power control circuit configured to provide a constant power level to the motor so that the motor operates with a substantially constant power output. The constant power level is proportional to the reference power level. Thus, the motor also provides substantially constant torque when the motor is at a constant speed.

A motor control actuator that drives a permanent magnet synchronous motor (PMSM) with sensorless Field Oriented Control includes a sampling circuit that generates a measurement signal by measuring a back electro motive force (BEMF) of the PMSM, while the PMSM rotates; a PLL that receives the measurement signal and extracts an amplitude and an angle of the BEMF from the measurement signal; and a motor controller that generates a first set of two phase alternating current (AC) voltage components based on an estimated rotor angle, generates a second set of two phase AC voltage components based on the amplitude and the angle, and generates control signals for driving the PMSM based on the first set of two phase AC voltage components. The motor controller performs a catch spin sequence for restarting the PMSM while rotating, the catch spin sequence includes a synchronizing period followed by a closed loop control period.