A system and method for reliable control of a high rotor pole switched reluctance machine (HRSRM) utilizing a sensorless reliable control system. The method comprising: energizing at least one of the plurality of stator phases; measuring a first current value and time taken by the first current value to reach a first peak value or preset threshold value of current; determining a self-inductance value; measuring a second current value and time taken by an adjacent un-energized stator phase to reach a second peak value of current; determining a mutual inductance value; and estimating a rotor position utilizing the self-inductance and mutual inductance values; and controlling the HRSRM based on the estimated rotor position.

A motor control apparatus includes: an excitation unit configured to excite a plurality of excitation phases of a motor; a measurement unit configured to measure a physical amount that changes according to an inductance of at least one of a plurality of coils that make up the plurality of excitation phases by exciting each of the plurality of excitation phases, and generate measured data that includes measurement values of the physical amount measured for the plurality of excitation phases; and a determination unit configured to determine, based on the measured data, a rotational position of a rotor of the motor and whether or not at least one of the motor and the excitation unit has a failure.

An arrangement for detecting a direction of rotation of a multi-phase electric motor includes a plurality of single-phase converters. Each single-phase converter of the plurality of single-phase converters supplies one phase of the multi-phase electric motor with current. The arrangement also includes two sensor units that are configured to determine actual values of the phase currents of the multi-phase electric motor and to transmit the actual values to the plurality of single-phase converters. The arrangement also includes a monitoring and control unit in each converter of the plurality of single-phase converters. The monitoring and control unit is configured and programmed to determine the direction of rotation and a speed of rotation of the multi-phase electric motor from the actual values.

Example systems and processes use three-phase vector mutual inductance analysis to detect zero-crossing (ZC) locations of back-electromotive force (BEMF) of an electric motor and to detect its commutation points during start-up or low-speed operation. For each sector of rotation of the rotor, two pairs of three-phase vectors are applied, along with current for the corresponding driving phase. The first pair is alternately applied to move the rotor, and the mutual inductances resulting from such application are compared to detect the zero-crossing (ZC) location in the BEMF of the electric motor in that sector. The second pair is then alternately applied within the same sector to continue to move the rotor, and the mutual inductances from such application are compared to detect the commutation point of the electric motor in that sector. The process may be repeated for each successive sector, changing the driving current at each new sector.

A method and a system for acquiring a rotor position of a rotary transformer are provided. The system includes: a rotary transformer decoder, a low pass filter and a microprocessor, which includes a synchronous demodulation module and a calculation module. The rotary transformer decoder outputs an excitation signal and acquires first position information of the motor rotor. The calculation module performs calculation to acquire second position information of the motor rotor. The rotary transformer decoder and software decoding are integrated to acquire two rotor positions, and the two rotor positions are compared. In a case that a preset determining condition is met, one of the rotor positions is used for motor control, and the other is used as redundant data for backup, thereby improving the reliability of the acquired rotor position.

A device for estimating inductances of an electric machine having a salient-pole rotor is presented. The device comprises a processing system that controls stator voltages to constitute a balanced multi-phase alternating voltage when the rotor is stationary. The processing system estimates a position of the rotor based on a negative sequence component of stator currents. To estimate the quadrature-axis inductance, the processing system controls direct-axis current to be direct current and quadrature-axis voltage to be alternating voltage. The quadrature-axis inductance is estimated based on the quadrature-axis alternating voltage and on quadrature-axis alternating current. To estimate the direct-axis inductance, the processing system controls direct-axis voltage to be alternating voltage and the quadrature-axis voltage to be zero. The direct-axis inductance is estimated based on the direct-axis alternating voltage and on direct-axis alternating current.

A motor control apparatus includes: a voltage control unit configured to control a voltage applied to a plurality of coils in a motor to supply an exciting current; a current detection unit configured to detect an exciting current having flown through the plurality of coils; and a detection unit configured to detect a stop position of a rotor of the motor by performing a detection process, in which the exciting current to at least a first coil of the plurality of coils is supplied by the voltage control unit, and the exciting current is detected by the current detection unit. The detection process includes a first period in which a first voltage of a first polarity is applied to the first coil, and a second period in which a second voltage of a second polarity is applied to the first coil.

A system and method for reliable control of a high rotor pole switched reluctance machine (HRSRM) utilizing a sensorless reliable control system. The method comprising: energizing at least one of the plurality of stator phases; measuring a first current value and time taken by the first current value to reach a first peak value or preset threshold value of current; determining a self-inductance value; measuring a second current value and time taken by an adjacent un-energized stator phase to reach a second peak value of current; determining a mutual inductance value; and estimating a rotor position utilizing the self-inductance and mutual inductance values; and controlling the HRSRM based on the estimated rotor position.

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.

An electric working machine includes an inverter and a controller. The controller switches a current conduction pattern via the inverter and performs a PWM control of a conduction current to a brushless motor. The controller includes switching patterns as the current conduction pattern switched for every commutation timing. The switching patterns include different on and off states for different switching elements. The controller sequentially switches a switching pattern synchronously with a period of the PWM control, detects a rotational position of a brushless motor from a magnitude relation between inductances of the brushless motor produced by switching the switching pattern, and sets the commutation timing.