A soft-start circuit which can be applied to a motor controller is provided. The soft-start circuit comprises a controller, a counting unit, a digital-to-analog converter, a current detecting unit, and a comparator. The soft-start circuit uses a plurality of current limit values so as to achieve a maximum output power and prevent damage to a motor coil.

A half-bridge bootstrap circuit includes a high-side switch, a low-side switch, and a boot capacitor. A dynamically controlled minimum duty cycle curve is adopted to guarantee the minimum turn-on time of the low-side switch so that the boot capacitor can be sufficiently charged for keeping the high-side switch in the turn-on state. Also, the value of the minimum duty cycle curve can be dynamically set according to different operational phases of a load, thereby increasing the maximum output power of the load.

An apparatus according to the aspect of the embodiments includes a phase determiner configured to determine a rotational phase of a rotor, a speed determiner configured to determine a rotational speed of the rotor, a controller having a first control mode for controlling the motor by supplying constant currents to windings, and a discriminator configured to discriminate whether a rotation of the motor is abnormal based on the rotational speed when the rotational speed corresponding to a command speed is equal to or higher than a predetermined value in a state where the controller is controlling the motor in the first control mode. When a signal output from the discriminator indicates that the rotation of the motor is abnormal, the controller stops the motor. When the signal output from the discriminator indicates that the rotation is not abnormal, the controller continues a drive of the motor.

An apparatus according to the aspect of the embodiments includes a phase determiner configured to determine a rotational phase of a rotor, a speed determiner configured to determine a rotational speed of the rotor, a controller having a first control mode for controlling the motor by supplying constant currents to windings, and a discriminator configured to discriminate whether a rotation of the motor is abnormal based on the rotational speed when the rotational speed corresponding to a command speed is equal to or higher than a predetermined value in a state where the controller is controlling the motor in the first control mode. When a signal output from the discriminator indicates that the rotation of the motor is abnormal, the controller stops the motor. When the signal output from the discriminator indicates that the rotation is not abnormal, the controller continues a drive of the motor.

A propulsion system is described that includes an electrical bus, a generator configured to provide electrical power to the electrical bus, a plurality of propulsory configured to provide thrust by simultaneously being driven by the electrical power at the electrical bus, and a controller. The controller is configured to synchronize a rotational speed of an individual propulsor from the plurality of propulsory with a rotational speed of the generator after the individual propulsor has become unsynchronized with the rotational speed of the generator by controlling at least one of the rotational speed of the generator, nozzle area of the individual propulsor, or a pitch angle of the individual propulsor.

A propulsion system is described that includes an electrical bus, a generator configured to provide electrical power to the electrical bus, a plurality of propulsory configured to provide thrust by simultaneously being driven by the electrical power at the electrical bus, and a controller. The controller is configured to synchronize a rotational speed of an individual propulsor from the plurality of propulsory with a rotational speed of the generator after the individual propulsor has become unsynchronized with the rotational speed of the generator by controlling at least one of the rotational speed of the generator, nozzle area of the individual propulsor, or a pitch angle of the individual propulsor.

A method of controlling a brushless permanent magnet motor includes measuring a mains power supply voltage of the motor. The method includes determining whether the mains power supply voltage lies within a first range representative of a first country's mains power supply or a second range representative of a second country's mains power supply. The method includes advancing commutation of a winding of the motor relative to a zero-crossing of back EMF in the winding where the mains power supply voltage lies within the first range, and retarding commutation of the winding relative to a zero-crossing of back EMF in the winding where the mains power supply voltage lies within the second range.

A method is disclosed for evaluating an operational readiness of an electric motor, such as an electric motor of a fan. The method may be used during initial start-up. The method includes: initiating a run-up process of the electric motor, the speed being changed in several speed levels during the run-up process, generating at least one measured value by measuring a physical variable with a sensor of the electric motor in at least one of the speed levels, loading at least one parameter datum from a parameter memory of the electric motor, wherein the at least one parameter datum corresponds to the at least one measured value generated, and evaluating the at least one measured value for at least one of the speed levels using the at least one loaded parameter datum. Further disclosed are an electric motor with a parameter memory and a parameterization interface as well as a fan with this electric motor and an impeller.

A drive control method is applicable to a drive system including a driver, a bus and a motor, the motor being directly connected to the bus in a first connection mode or connected to the driver in a second connection mode. The drive control method includes the driver feeding an electric signal to the motor through the output port and simultaneously detecting its own actual output feature; and the driver determining whether the output port is connected to the bus according to the actual output feature. Upon the output port being determined not to be connected to the bus, the driver starts the motor normally. Upon the output port being determined to be connected to the bus, the driver disconnects the output port. In addition, a corresponding drive system, a processing system and a storage medium are disclosed.

A drive control method is applicable to a drive system including a driver, a bus and a motor, the motor being directly connected to the bus in a first connection mode or connected to the driver in a second connection mode. The drive control method includes the driver feeding an electric signal to the motor through the output port and simultaneously detecting its own actual output feature; and the driver determining whether the output port is connected to the bus according to the actual output feature. Upon the output port being determined not to be connected to the bus, the driver starts the motor normally. Upon the output port being determined to be connected to the bus, the driver disconnects the output port. In addition, a corresponding drive system, a processing system and a storage medium are disclosed.