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. The controller detects an initial sector within which the rotor is located at start-up, apply the drive signal so as to rotate the motor to a parking angle associated with the detected initial sector, and control a commutation sequence to drive the motor beginning at the parking angle.

A position estimation device acquires detection values of a magnetic field strength at three or more locations of a rotor in accordance with a rotor angle in a range where the rotor angle is less than one rotation. A feature amount calculator is provided to calculate feature amounts of a waveform of the magnetic field strength based on the detection values of the magnetic field strength. An estimator is provided to determine, for each pole pair number of the rotor, whether or not a pattern of a magnitude relationship of the feature amounts learned in advance coincides with a pattern of a magnitude relationship of the feature amounts calculated, and to estimate, as a rotation position of the rotor, the pole pair number with which a pattern of the magnitude relationship coincides.

A drive apparatus for a motor having a stator and a rotor, the drive apparatus including a current detection unit configured to detect, when the motor is rotating, each of multi-phase currents flowing through coils of the stator, and a control unit for controlling the motor by sensor-less control configured to convert the detected multi-phase currents into a d-axis current Id and a q-axis current Iq in a d-q coordinate system, calculate a phase error between an actual rotational position of the rotor and an imaginary rotational position thereof by comparing the d-axis current Id with a d-axis current command value Idref and comparing the q-axis current Iq with the d-axis current command value Idref, perform control so that the phase error gets closer to zero, and output voltage command values to a motor drive circuit.

A drive apparatus for a motor having a stator and a rotor, the drive apparatus including a current detection unit configured to detect, when the motor is rotating, each of multi-phase currents flowing through coils of the stator, and a control unit for controlling the motor by sensor-less control configured to convert the detected multi-phase currents into a d-axis current Id and a q-axis current Iq in a d-q coordinate system, calculate a phase error between an actual rotational position of the rotor and an imaginary rotational position thereof by comparing the d-axis current Id with a d-axis current command value Idref and comparing the q-axis current Iq with the d-axis current command value Idref, perform control so that the phase error gets closer to zero, and output voltage command values to a motor drive circuit.

Provided is a mode control method that includes obtaining a PWM signal; obtaining a duty cycle of the PWM signal; obtaining a target rotational speed of an electric pump based on the duty cycle of the PWM signal; in response to determining that the target rotational speed of the electric pump is equal to 0 and the target rotational speed of the electric pump remains equal to 0 for the set duration, entering the sleep mode by the microcontroller; and in response to determining that the target rotational speed of the electric pump is not equal to 0 or the target rotational speed of the electric pump does not remain equal to 0 for the set duration, entering the working mode by the microcontroller. Further provided are a mode control system, an electronic device and a storage medium.

A motor control device that detects a motor current through ΔΣ AD conversion includes a stop signal generator and a stop signal controller. When a difference between a maximum value and a minimum value of three phase voltage command values to be applied to a motor is smaller than or equal to a predetermined threshold, a stop signal that causes the ΔΣ AD conversion to stop is output with a delay by the time corresponding to a delay in current detection while a leakage current caused by on and off of a power conversion element is occurring.

In the position sensorless control method in low-speed region of the fault-tolerant permanent magnet motor system based on the envelope detection and the non-orthogonal phase-locked loop of the present disclosure, the position sensorless control of the motor is implemented by injecting the high-frequency voltage signals into any two non-faulty phase windings of the motor, extracting the high-frequency response currents of the high-frequency injected phases by the digital bandpass filter, calculating the differential mode inductances of the two phase windings through the envelope detecting and signal processing, and extracting the rotor position and rotational speed signals from the estimated two phase inductances through the non-orthogonal phase-locked loop. In addition, the controller of the present disclosure is small in size, high in accuracy, and high in reliability, which can effectively meet the performance requirements of the onboard electric actuators.

A method of generating motor driving signal includes: obtaining acceleration segment signal for driving motor to start vibrating, constant segment signal for achieving low-frequency vibration tactile effect of the motor, and attenuating segment signal for decreasing vibration quantity of the motor in low frequency manner, frequency of constant segment signal and of attenuating segment signal being smaller than frequency of acceleration segment signal; splicing the acceleration segment signal with the constant segment signal, and reserving idle period with no signal output therebetween to obtain first motor driving signal; adjusting parameter of constant segment signal of first motor driving signal according to vibration feeling requirement, and splicing attenuating segment signal after the adjusted first motor driving signal to obtain second motor driving signal; and adjusting parameter of attenuating segment signal of second motor driving signal, and determining second motor driving signal with highest braking efficiency as final motor driving signal.

The device contains a regulator and an actuator connected electrically to the regulator at the input side and that can be connected electrically to the electric motor at the output side. An input point is interconnected electrically between the regulator and actuator at which an electric detection signal can be input A first return unit connected in parallel to the regulator and the actuator returns a first return signal to the regulator representing a version of an output signal of the actuator transformed and processed by the first return unit. A second return unit returns a second return signal to the first return unit and/or the actuator and represents a version of the output signal of the actuator transformed by the first return unit and processed by the second return unit. The second return signal represents an angle between the rotor and the stator in the electric machine.

A variable speed drive comprises an output for delivering a drive voltage to an electric motor, power inverter, a drive controller, and a current sensor. The drive controller includes a PWM generator, a control law module, and a state variable estimator for estimating a state variable of the electric motor. The module computes a target voltage signal based on state variable estimates provided by the estimator and outputs the target voltage signal to the PWM generator. The generator approximates the target voltage signal with a PWM control signal, controls the inverter using the control signal, computes, based on the deviation between the control signal and the target voltage signal, an estimation support signal, and outputs the estimation support signal to the estimator. The estimator estimates a state variable of the motor based on the estimation support signal and the drive current, and outputs the estimate to the module.