A method for determining current-dependent and/or rotational angle position-dependent characteristic variables of an electrical machine by setting a rotational angle position of blocking a rotor, forming a series current desired value using a series current desired value alternating signal which changes periodically and/or forming a parallel current desired value using a parallel current desired value alternating signal which changes periodically, regulating a series current using the series current desired value and/or a parallel current using the parallel current desired value, measuring phase currents of the electrical machine and determining an established series current and/or an established parallel current, producing series setting voltage coefficients and series current coefficients and/or parallel setting voltage coefficients and parallel current coefficients using a discrete Fourier transform algorithm, and calculating characteristic variables on the basis of series setting voltage coefficients and series current coefficients and/or parallel setting voltage coefficients and parallel current coefficients.

A method for determining current-dependent and/or rotational angle position-dependent characteristic variables of an electrical machine by setting a rotational angle position of blocking a rotor, forming a series current desired value using a series current desired value alternating signal which changes periodically and/or forming a parallel current desired value using a parallel current desired value alternating signal which changes periodically, regulating a series current using the series current desired value and/or a parallel current using the parallel current desired value, measuring phase currents of the electrical machine and determining an established series current and/or an established parallel current, producing series setting voltage coefficients and series current coefficients and/or parallel setting voltage coefficients and parallel current coefficients using a discrete Fourier transform algorithm, and calculating characteristic variables on the basis of series setting voltage coefficients and series current coefficients and/or parallel setting voltage coefficients and parallel current coefficients.

A motor drive monitors operation of a motor and adaptively track disturbances experienced by the motor. The motor drive receives a command signal and a cycle position signal. An estimated disturbance observed throughout a cycle of operation is stored in a look up table, and the motor drive uses the stored values as a feedforward value into a control module. The motor drive adaptively monitors operation of the motor and generates a new estimated disturbance value throughout each subsequent cycle of operation. The values of the estimated disturbance are updated within the look up table as a function of the new estimated disturbance values and of the previously stored values. The stored disturbance values adaptively track cyclic disturbances in the controlled machine or process and to reduce the effects of these cyclic disturbances on tracking error in the controlled machine or process.

A shift range control device includes a plurality of control units provided for each of motor windings. When a motor rotation angle sensor is normal, a drive control unit controls an energization of the motor winding of its own system by using a motor rotation angle signal. When the motor rotation angle sensor has an abnormality and it is determined that an output shaft is rotating before a standby time elapses, the drive control unit does not energize the motor winding of its own system. When it is determined that the output shaft is not rotating even after the standby time has elapsed, the drive control unit controls the energization of the motor winding of its own system without using the motor rotation angle signal.

A shift range control device includes a plurality of control units provided for each of motor windings. When a motor rotation angle sensor is normal, a drive control unit controls an energization of the motor winding of its own system by using a motor rotation angle signal. When the motor rotation angle sensor has an abnormality and it is determined that an output shaft is rotating before a standby time elapses, the drive control unit does not energize the motor winding of its own system. When it is determined that the output shaft is not rotating even after the standby time has elapsed, the drive control unit controls the energization of the motor winding of its own system without using the motor rotation angle signal.

A control circuit of a motor control device estimates an initial magnetic pole position of a rotor using an inductive sensing scheme. When estimating the initial magnetic pole position, a drive circuit applies a voltage to a stator winding at each of L electrical angles (L≥5) while changing the L electrical angles. An absolute value of an electrical angle difference of the voltage applied to the stator winding between an i-th time (2≤i≤L) and an i−1st time is 180−360/L degrees or more and 180+360/L degrees or less. An absolute value of an electrical angle difference of the voltage applied to the stator winding between a 1st time for initial position estimation and a last time before starting initial position estimation is 180−360/L degrees or more and 180+360/L degrees or less.

A control circuit of a motor control device estimates an initial magnetic pole position of a rotor using an inductive sensing scheme. When estimating the initial magnetic pole position, a drive circuit applies a voltage to a stator winding at each of L electrical angles (L≥5) while changing the L electrical angles. An absolute value of an electrical angle difference of the voltage applied to the stator winding between an i-th time (2≤i≤L) and an i−1st time is 180−360/L degrees or more and 180+360/L degrees or less. An absolute value of an electrical angle difference of the voltage applied to the stator winding between a 1st time for initial position estimation and a last time before starting initial position estimation is 180−360/L degrees or more and 180+360/L degrees or less.

A laser projection apparatus includes a laser light source, a diffusion wheel including a motor and a diffusion portion, a diffusion wheel driving circuit, a switch circuit and a main control circuit. The main control circuit is configured to sequentially output first and second startup PWM signals in response to a startup instruction. The diffusion wheel driving circuit is configured to drive the motor to drive the diffusion portion to rotate in response to the second startup PWM signal. The main control circuit is configured to obtain a rotation speed of the motor, and output an operating PWM signal and a first switch signal when the rotation speed reaching a target rotation speed is determined. The diffusion wheel driving circuit is configured to drive the motor to drive the diffusion portion to rotate in response to the operating PWM signal. The switch circuit is configured to provide a laser drive signal to the laser light source in response to the first switch signal, to drive the laser light source to emit laser beams.

A power tool is provided including a brushless motor having a stator defining a plurality of phases, a rotor rotatable relative to the stator, and power terminals electrically connected to the phases of the motor. A power unit is provided including power switches. A control unit is interfaced with the power unit to output a drive signal to one or more of the motor switches to drive the phases of the motor over a series of sectors of the rotor rotation. The control unit is configured detect incorrect rotation of the rotor by applying a first series of voltage pulses to a present sector and a second series of voltage pulses to a previous sector, measuring motor currents associated with the first and second series of voltage pulses, and comparing corresponding motor current measurements to detect a transition from the present sector to the previous sector.

An intelligent electronic device (IED) according to the present disclosure can estimate a full load rotor resistance value as a function of motor positive-sequence resistance. The IED may estimate the full load rotor resistance value by measuring zero-crossings of voltage after a motor disconnect. The IED may also acquire motor current and voltage measurements and calculate motor slip using the acquired motor current and voltage measurements and the estimated full load rotor resistance value.