A method of operating an electric or hybrid system comprising a synchronous reluctance electric motor coupled to an electric or hybrid powertrain is described herein. The method comprises determining (i) a torque demand required of the electric motor and (ii) a speed of rotation of the rotor of the electric motor, and storing kinetic energy in a rotor of the electric motor from the powertrain in response to at least one of (i) the determined torque demand falling below a selected torque demand threshold and (ii) the speed of the rotor being below a selected rotor speed threshold. The method further comprises operating the electric motor by powering the electric motor with electricity to deliver energy to the powertrain in response to at least one of: (i) the determined torque demand rising above a selected torque demand threshold and (ii) the speed of the rotor falling below a selected rotor speed threshold.

A system and method for identifying and responding to a condition in which an electric motor fails to start. A rotor core includes slots in which magnets are received to produce an electrical reluctance. A motor controller determines a position of the rotor, uses the determined position to convert a torque demand to a demanded D-axis current value, and compares the demanded value to a supplied D-axis current value. If the demanded value differs from the supplied value by at least a pre-established threshold amount, then the motor is restarted. Otherwise, the difference between the torque demand and an actual current is used to drive a voltage applied to the motor. The controller may also implement a sensorless technology, and may restart the motor if the demanded value differs from the supplied value by at least the threshold amount even if the sensorless technology determines that the motor started.

A synchronous electrical motor, which may operate poly-phase electrical power, is configured to operate at a rated flux configuration and a high flux configuration. To enable the high flux configuration, some coils wound about the stator of the electric motor can be designated bypass coils and can be selectively disconnected from the power source supplying the motor with electrical power. The remaining permanent coils continue to receive full line power and generate a rotating magnetic field with an increased magnetic flux. At startup from standstill conditions, the bypass coils are selectively disconnected so that a flux boost occurs and a corresponding increase in output torque of the electric motor.

A synchronous electrical motor, which may operate poly-phase electrical power, is configured to operate at a rated flux configuration and a high flux configuration. To enable the high flux configuration, some coils wound about the stator of the electric motor can be designated bypass coils and can be selectively disconnected from the power source supplying the motor with electrical power. The remaining permanent coils continue to receive full line power and generate a rotating magnetic field with an increased magnetic flux. At startup from standstill conditions, the bypass coils are selectively disconnected so that a flux boost occurs and a corresponding increase in output torque of the electric motor.

Described is a hybrid permanent magnet and wire wound starter generator system. The system includes a polyphase stator that converts a rotating magnetic field to electrical energy. The system also includes a rotor including a plurality of permanent magnets and a wound rotor section. The plurality of permanent magnets and the wound rotor section each generate a portion of the rotating magnetic field. Further, the system includes a controller that controls a polarity of the wound rotor section by transitioning the wound rotor section between a magnetic flux enhancement mode and a magnetic flux weakening mode.

A torsional mode damping controller in which the controller modifies electrical power to an electrical motor to provide active damping control of torsional vibration in rotating masses. The controller receives a measurement of a rotational speed of the rotating masses ω.sub.m and an estimate or a measurement of a torque transmitted between the rotating masses T.sub.sh; based on the received transmitted torque T.sub.sh, generate a compensating torque to suppress vibration T.sub.com; based on the received rotational speed ω.sub.m and the compensating torque T.sub.com, generate an electromagnetic torque modification signal T.sub.modi; and modify the electrical power provided to the electrical motor on the basis of the electromagnetic torque modification signal T.sub.modi. The controller is further configured to generate compensating torque T.sub.com by applying a filter to the received transmitted torque T.sub.sh, based on plural tunable parameters including a tuning gain K, a cut-off frequency ω.sub.n and a resonant damping ratio ζ.

Disclosed is a motor control apparatus including an inverter part configured to convert DC power into AC power and provide the AC power to a motor, and a controller configured to control driving of the motor by using the inverter part, the controller configured to identify a stop position of a rotor in previous driving of the motor, and control the inverter part to apply an input signal of a specific pattern to the motor according to a start of driving the motor, wherein a phase of the input signal of the specific pattern is determined on the basis of the stop position of the rotor. Other example embodiments may be provided.

A motor control device includes: a second setting unit configured to set an armature current command value and a current phase angle command value based on a rotation speed and a motor torque command value; and a current vector setting unit configured to set a d-axis current command value and a q-axis current command value based on the armature current command value and the current phase angle command value. The second setting unit is configured to set the armature current command value and the current phase angle command value such that an armature current vector which is set based on the d-axis current command value and the q-axis current command value is included in an area surrounded by an armature current vector locus in maximum torque/current control and a vertical axis in a d-q coordinate system.

A power tool, such as a drilling power tool, configured to perform an easy hole start operation upon actuation of a trigger. When the trigger is actuated, the motor is driven at a low speed value. The motor speed is increased to a second speed value during a predetermined time threshold and then driven at the second speed value until the trigger is no longer actuated. In some embodiments, the easy hole start operation may be implemented by an easy hole start switch. In some embodiments, if the easy hole start operation persists for a time greater than a predetermined time threshold, then the motor will shut off.

A method is described for controlling an electric motor having a rotor. The method is carried out after a shutdown of the motor has been initiated. The method includes starting a timer in a motor controller, performing regenerative braking to recapture kinetic energy from the rotor as electrical energy, and using the recaptured electrical energy from the regenerative braking to power the motor controller. If the timer in the motor controller exceeds a predetermined timer value, a flag is set in memory in the motor controller to indicate that the motor has stopped.