A virtual voltage injection-based speed sensor-less driving control method for an induction motor is provided. First, a virtual voltage signal is injected into a motor flux linkage and rotating speed observer so that there is a difference between an input of the motor flux linkage and rotating speed observer and a command input of the motor. Then, based on any type of the motor flux linkage and rotating speed observer, a motor flux linkage rotation angle and a motor rotor speed are estimated, and the induction motor is driven to run normally with a certain control strategy (such as vector control). Then, based on a signal designed according to this method and injected only into the motor flux linkage and rotating speed observer, the induction motor driven by a speed sensor-less control system for the induction motor may be ensured to output 150% of a rated torque when running at a motor low synchronous rotating speed and a motor zero synchronous rotating speed, and the stability thereof may be kept for a long time.

To provide a controller for AC rotary electric machine which can compensate error of the actual on-duty with respect to the command on-duty calculated from command voltage with good accuracy, with a simple circuit configuration. A controller for AC rotary electric machine detects an actual on-duty of the switching device based on the detection value of the midpoint potential which is the potential of the connection node of the series connection in the series circuit; calculates an on-duty error based on the difference between the command on-duty and the actual on-duty; and corrects the voltage command or the command on-duty based on the on-duty error.

A method is provided for determining a parameter of a field-oriented control (FOC) model for an electric power unit, the electric power unit comprising a three-phase electric motor and an inverter drive for driving the electric motor. The method comprises sending a control signal to the inverter drive; applying a predefined electric voltage to at least two of the phases of the electric motor by the inverter drive in response to the control signal; measuring an electric current that flows in the at least two phases of the electric motor in response to the applied electric voltage; and determining the parameter of the control model for the electric power unit using a value of the applied predefined electric voltage and a value of the measured electric current. An apparatus for determining a parameter of a control model for an electric power unit is provided.

An electric motor control device includes an electronic control unit configured to perform switching control of a switching element of an inverter in PWM control mode when a modulation degree is less than a first predetermined value, perform switching control of the switching element in square wave control mode when the modulation degree is greater than or equal to a second predetermined value, and perform switching control of the switching element in intermediate control mode when the modulation degree is greater than or equal to the first predetermined value and less than the second predetermined value. The intermediate control mode uses a switching pattern in which, in a pulse pattern in the square wave control mode, a slit or a short pulse having the same width as the slit is formed according to whether a pulse is present at the time when a phase current crosses zero.

A motor controller includes a power supply controller controlling a power supply to rotate a rotor to a predetermined position by supplying power to an excitation coil of a predetermined phase among excitation coils of three phases of the rotor at startup of the rotor, the power supply controller selecting the excitation coil of the predetermined phase to which power is supplied in accordance with a position of a magnetic pole of the rotor in a state where the rotor is stopped.

A motor control apparatus includes a motor, a motor driver to drive the motor, a motor current detection unit, a motor state estimation unit, a motor control unit, and first and second abnormality detection units. The motor current detection unit detects a current value of the motor. The motor state estimation unit estimates a state of the motor based on a voltage applied to the motor and the detected current value. The motor control unit applies a driving voltage of first driving corresponding to the estimated state of the motor or apply a driving voltage of second driving, which does not use the estimated motor state, to the motor driver. The first abnormality detection unit detects a rotation abnormality of the motor based on the estimated motor state. The second abnormality detection unit detects the rotation abnormality of the motor based on the detected current value of the motor.

A motor controller includes a power constant controller configured to receive a target power of a permanent magnet synchronous motor (PMSM) and generate a first target speed based on the target power; a first signal generator configured to generate a second target speed; a speed constant controller switchably coupled to the power constant controller and the first signal generator, where the speed constant controller is configured to switchably receive the first target speed and the second target speed, and regulate a motor speed of the PMSM based on the received first target speed or the received second target speed; a first switch configured to switchably couple the speed constant controller to the power constant controller to receive the first target speed or the second target speed; and a first switch controller configured to control a switching state of the first switch based on the motor speed of the PMSM.

Implementations of the present application relate to a starting method and apparatus for a permanent magnet synchronous motor, a power system, and an unmanned aerial vehicle (UAV). The method includes: obtaining a current motor rotational speed and motor position information of the permanent magnet synchronous motor; determining whether the current motor rotational speed is less than a preset minimum rotational speed, and if the current motor rotational speed is less than the preset minimum rotational speed, using the preset minimum rotational speed as a feedback rotational speed; otherwise, using the current motor rotational speed as a feedback rotational speed; and performing closed-loop control on the permanent magnet synchronous motor according to the feedback rotational speed and the motor position information. In this way, the starting method is simplified and simpler. Potential failure risks in various states in the prior art are avoided, thereby effectively improving reliability of a starting process.

To provide a controller for AC rotary electric machine which can compensate error of the actual on-duty with respect to the command on-duty calculated from command voltage with good accuracy, with a simple circuit configuration. A controller for AC rotary electric machine detects an actual on-duty of the switching device based on the detection value of the midpoint potential which is the potential of the connection node of the series connection in the series circuit; calculates an on-duty error based on the difference between the command on-duty and the actual on-duty; and corrects the voltage command or the command on-duty based on the on-duty error.

An approach for detecting rotor anomalies is disclosed. Vibration data for a vibration sensor(s) and for a transient speed operation is classified into a plurality of rotor speed ranges. A predetermined percentile vibration amplitude is determined for each rotor speed range for the vibration sensor(s). Using historical vibration measurement data obtained from a predetermined number of previous transient speed operations performed by at least the rotor, it is determine whether a vibration measurement obtained during the transient speed operation is indicative of a rotor anomaly by determining whether a trend exists in the predetermined percentile vibration amplitude for at least one of the rotor speed ranges and the vibration sensor(s) over a preset number of previous transient speed operations. A rotor anomaly is indicated where a trend exists.