An electric motor control system includes a power inverter and control circuitry configured to control the power inverter either according to a target voltage in a voltage-based control mode or according to a target current in a current-based control mode. A controller is operable to switch operation of the control circuitry between the voltage-based control mode and the current-based control mode. The controller may be configured to operate the control circuitry in the current-based control mode at lower motor operating speeds where stator current margin is of greater significance, and to operate the control circuitry in the voltage-based control mode at higher motor operating speeds where stator voltage margin is of greater significance.

An electric motor control system includes a power inverter and control circuitry configured to control the power inverter either according to a target voltage in a voltage-based control mode or according to a target current in a current-based control mode. A controller is operable to switch operation of the control circuitry between the voltage-based control mode and the current-based control mode. The controller may be configured to operate the control circuitry in the current-based control mode at lower motor operating speeds where stator current margin is of greater significance, and to operate the control circuitry in the voltage-based control mode at higher motor operating speeds where stator voltage margin is of greater significance.

A braking torque closed-loop control system and method for a switch reluctance motor. The closed-loop control system comprises a torque regulator, a mode selector, a current regulator, an angle optimization controller and a torque estimator. On the basis of the rotating speed of the motor, the mode selector implements a phase current soft chopper control in a low rotating speed region and an angle position control in a high rotating speed region. The current regulator performs soft chopper hysteretic current regulation. The angle optimization controller optimizes a turn-on angle and a turn-off angle of a power converter master switch to reduce torque pulsation and improve braking energy feedback efficiency. The torque estimator conducts an on-line estimation of an actual braking torque estimated value of the motor based on an actual phase voltage and current of the motor to achieve braking torque signal feedback.

The regenerative braking controlling system includes an armature current sampling module, a calculating module, and an adjusting module. The calculating module includes a power calculating unit, an optimum phase angle calculating unit, an optimum regenerative current calculating unit, and a sub-optimum regenerative current calculating unit. The armature current sampling module samples current of the three phase armature windings. The power calculating unit determines a relationship between a regenerative power and a phase angle of the armature currents. The optimum phase angle calculating unit calculates an optimum phase angle, and obtain a phase regenerative path based on the optimum phase angle. The optimum regenerative current calculating unit calculates an optimum regenerative current limit point. The sub-optimum regenerative current calculating unit calculates a sub-optimum regenerative current limit point. The adjusting module adjusts regenerative current according to the optimum regenerative current limit point and the sub-optimum regenerative current limit point.

The regenerative braking controlling system includes an armature current sampling module, a calculating module, and an adjusting module. The calculating module includes a power calculating unit, an optimum phase angle calculating unit, an optimum regenerative current calculating unit, and a sub-optimum regenerative current calculating unit. The armature current sampling module samples current of the three phase armature windings. The power calculating unit determines a relationship between a regenerative power and a phase angle of the armature currents. The optimum phase angle calculating unit calculates an optimum phase angle, and obtain a phase regenerative path based on the optimum phase angle. The optimum regenerative current calculating unit calculates an optimum regenerative current limit point. The sub-optimum regenerative current calculating unit calculates a sub-optimum regenerative current limit point. The adjusting module adjusts regenerative current according to the optimum regenerative current limit point and the sub-optimum regenerative current limit point.

A motor braking unit for a washing machine that offers high braking efficiency while preventing overcharging a capacitor in a DC link. The motor braking unit determines a current to be supplied to the motor based on a detected speed of the motor. The motor braking unit dynamically monitors the voltage on the capacitor against a reference voltage. If the capacitor voltage is lower than the reference voltage, the current component Iq is increased to increase the braking torque; and if the capacitor voltage is greater than the reference voltage, the current Iq component is decreased to prevent overcharging on the capacitor by the motor.

A motor braking unit for a washing machine that offers high braking efficiency while preventing overcharging a capacitor in a DC link. The motor braking unit determines a current to be supplied to the motor based on a detected speed of the motor. The motor braking unit dynamically monitors the voltage on the capacitor against a reference voltage. If the capacitor voltage is lower than the reference voltage, the current component Iq is increased to increase the braking torque; and if the capacitor voltage is greater than the reference voltage, the current Iq component is decreased to prevent overcharging on the capacitor by the motor.

Actuators are components of machines, which move and/or control a mechanism or system. During operation, actuators can experience regeneration events, with the actuator actually generating excess energy (e.g., regenerative energy) which must be stored or dissipated to avoid damaging the power supply. An actuator motor controller is configured to implement field oriented voltage control and flux weakening voltage control without current sensors. Dissipating regenerative energy includes providing a motor controller to command a motor drive to modify an input voltage, or to dissipate regenerative energy in a dump circuit. This command can cause motor windings to dissipate regenerative energy. Systems having a plurality of actuators distribute regenerative energy from one actuator to another. A central controller provides centralized regeneration dissipation control for the plurality of actuators. A power distribution unit includes a dump resistor to dissipate regenerative energy in addition to or instead of in the actuators.

A power tool is provided including a housing, a brushless motor disposed within the housing, a power switch circuit that supplies power from a power source to the brushless motor, and a controller configured to receive at least one signal associated with a phase current of the motor, detect an angular position of the rotor based on the phase current of the motor, and apply a drive signal to the power switch circuit to control a commutation of the motor based on the detected angular position of the rotor. If the supply of power to the motor is turned OFF to cause the motor to slow down and is turned back ON while the rotor speed exceeds a speed threshold, the controller electronically brakes the motor for a time interval to measure the phase current of the motor and detects the angular position of the rotor based on the measured phase current.

A power tool is provided including a housing, a brushless motor disposed within the housing, a power switch circuit that supplies power from a power source to the brushless motor, and a controller configured to receive at least one signal associated with a phase current of the motor, detect an angular position of the rotor based on the phase current of the motor, and apply a drive signal to the power switch circuit to control a commutation of the motor based on the detected angular position of the rotor. If the supply of power to the motor is turned OFF to cause the motor to slow down and is turned back ON while the rotor speed exceeds a speed threshold, the controller electronically brakes the motor for a time interval to measure the phase current of the motor and detects the angular position of the rotor based on the measured phase current.