A method of controlling a switched reluctance motor is disclosed herein. The motor comprises a stator carrying a plurality of phase windings and a rotor. The method comprises activating the phase windings in a sequence selected to apply torque to the rotor, wherein during a cycle of rotation of the rotor the phase windings switch between an active state in which current in the phase winding applies torque to the rotor and an inactive state; applying a voltage to a selected phase winding whilst the selected phase winding is in the inactive state to provide a flux in the selected phase winding; determining the current in the selected phase winding; determining the rotor angle based on the current and the flux; and controlling said activating based on the rotor angle.

A device according to an embodiment includes an inverter main circuit; a detector configured to detect a current of an output line of the inverter main circuit; a starting time controller comprising a rotational phase angle estimator configured to calculate, based on a current response value detected by the detector, a value corresponding to a rotational phase angle of a motor connected to the inverter main circuit in a stationary reference frame, and a rotational speed estimator configured to calculate a value corresponding to a rotational speed of the motor by using the value corresponding to the rotational phase angle when the inverter main circuit is started; and a regular time controller configured to calculate, with the value corresponding to the rotational speed as an initial value, an estimated rotational phase angle of the motor in a rotating reference frame.

A device according to an embodiment includes an inverter main circuit; a detector configured to detect a current of an output line of the inverter main circuit; a starting time controller comprising a rotational phase angle estimator configured to calculate, based on a current response value detected by the detector, a value corresponding to a rotational phase angle of a motor connected to the inverter main circuit in a stationary reference frame, and a rotational speed estimator configured to calculate a value corresponding to a rotational speed of the motor by using the value corresponding to the rotational phase angle when the inverter main circuit is started; and a regular time controller configured to calculate, with the value corresponding to the rotational speed as an initial value, an estimated rotational phase angle of the motor in a rotating reference frame.

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 three-phase switched reluctance machine has a rotor, a first stator and a second stator. The rotor, first stator and second stator are coaxially and concentrically disposed. The rotor and both the first stator and second stator have corresponding poles. Only one of the stators has coils wound about its poles, while the other stator does not have any coils. A defined relationship between the number of rotor poles, the number of stator poles on the first stator and the number of stator poles on the second stator may improve the torque quality of the switched reluctance machine.

A three-phase switched reluctance machine has a rotor, a first stator and a second stator. The rotor, first stator and second stator are coaxially and concentrically disposed. The rotor and both the first stator and second stator have corresponding poles. Only one of the stators has coils wound about its poles, while the other stator does not have any coils. A defined relationship between the number of rotor poles, the number of stator poles on the first stator and the number of stator poles on the second stator may improve the torque quality of the switched reluctance machine.

A method and apparatus for quasi-sensorless adaptive control of a high rotor pole switched-reluctance motor (HRSRM). The method comprises the steps of: applying a voltage pulse to an inactive phase winding and measuring current response in each inactive winding. Motor index pulses are used for speed calculation and to establish a time base. Slope of the current is continuously monitored which allows the shaft speed to be updated multiple times and to track any change in speed and fix the dwell angle based on the shaft speed. The apparatus for quasi-sensorless control of a high rotor pole switched-reluctance motor (HRSRM) comprises a switched-reluctance motor having a stator and a rotor, a three-phase inverter controlled by a processor connected to the switched-reluctance motor, a load and a converter.

A method and apparatus for quasi-sensorless adaptive control of a high rotor pole switched-reluctance motor (HRSRM). The method comprises the steps of: applying a voltage pulse to an inactive phase winding and measuring current response in each inactive winding. Motor index pulses are used for speed calculation and to establish a time base. Slope of the current is continuously monitored which allows the shaft speed to be updated multiple times and to track any change in speed and fix the dwell angle based on the shaft speed. The apparatus for quasi-sensorless control of a high rotor pole switched-reluctance motor (HRSRM) comprises a switched-reluctance motor having a stator and a rotor, a three-phase inverter controlled by a processor connected to the switched-reluctance motor, a load and a converter.

An SR drive with an acoustic noise reduction system for reducing vibration and acoustic noise in a switched reluctance motor (SRM). The vibration and acoustic noise at specific harmonics of current excitation in SRM are in a proportional relationship with the radial force harmonics acting at SRM stator teeth. The acoustic noise reduction system includes a processor on which is installed an acoustic noise reduction application designed to derive an optimum current waveform for generating an average torque satisfying an optimum torque condition and creating radial force with minimum amplitude at the desired order of harmonics of current excitation. A reduction in the amplitude of the specific radial force harmonics utilizing the optimum current waveform minimizes the vibration and acoustic noise in the SRM. The acoustic noise reduction system applies turn-on and turn-off angles at the optimum current waveform to improve the system efficiency.

Systems, components, and methods for driving a motor are disclosed, comprising: a motor including: a rotor; and a stator including a plurality of stator phase coils and a plurality of electromagnets, the plurality of electromagnets being inter-dispersed with the plurality of stator phase coils; wherein the motor is configured to produce a first plurality of motor signals. A controller, coupled to the motor to receive the first plurality of motor signals, is configured to: produce a first plurality of control signals to a drive inverter and a DC-DC converter to affect at least one phase current delivered to at least one of the plurality of stator phase coils and an at least one excitation current delivered to at least one of the plurality of electromagnets.