A system to reconfigure a motor from induction mode to synchronous mode at a zero crossing of the field voltage during startup using only stator current signals is described herein. The zero crossing may be detected by asymmetry induced in the stator currents by a current asymmetry inducing module of the motor. The current asymmetry inducing module may include a resistor and diode in series and in parallel with a discharge resistor of the field windings. Asymmetry is induced in the current obtained from the stator, and used to determine a zero crossing of the field voltage. Upon the rotor reaching a startup frequency and the detected zero-crossing of the field voltage, the motor may be reconfigured from induction mode to synchronous mode.

A system to reconfigure a motor from induction mode to synchronous mode at a zero crossing of the field voltage during startup using only stator current signals is described herein. The zero crossing may be detected by asymmetry induced in the stator currents by a current asymmetry inducing module of the motor. The current asymmetry inducing module may include a resistor and diode in series and in parallel with a discharge resistor of the field windings. Asymmetry is induced in the current obtained from the stator, and used to determine a zero crossing of the field voltage. Upon the rotor reaching a startup frequency and the detected zero-crossing of the field voltage, the motor may be reconfigured from induction mode to synchronous mode.

A method and system for operating a hybrid propulsion system, includes controllably providing a first power to a first bus and a first inverter, electrically coupling a first motor with a second inverter by way of a second bus, operably converting, by the second inverter, the first power received by the first inverter to a starting power adapted for starting the first motor, and increasing, by the second inverter, the starting power to match the first power received.

An assistance method for assisting a pilot of a single-engined rotary-wing aircraft during a flight phase in autorotation, the aircraft including a hybrid power plant provided with a main engine, with an electric machine, with a main gearbox, and with an electrical energy storage device. The aircraft also includes a main rotor driven by the hybrid power plant. In the method, during a flight, operation of the main engine is monitored in order to detect a failure, in particular by means of a drop in power on the main rotor, then, when a failure of the main engine is detected, the electric machine is controlled to deliver auxiliary power We to the main rotor, making it possible to assist a pilot of the aircraft in performing the flight phase in autorotation following the failure.

An assistance method for assisting a pilot of a single-engined rotary-wing aircraft during a flight phase in autorotation, the aircraft including a hybrid power plant provided with a main engine, with an electric machine, with a main gearbox, and with an electrical energy storage device. The aircraft also includes a main rotor driven by the hybrid power plant. In the method, during a flight, operation of the main engine is monitored in order to detect a failure, in particular by means of a drop in power on the main rotor, then, when a failure of the main engine is detected, the electric machine is controlled to deliver auxiliary power We to the main rotor, making it possible to assist a pilot of the aircraft in performing the flight phase in autorotation following the failure.

The disclosure relates to an autonomous apparatus, moving and performing preset work in a defined working area, the autonomous apparatus including an energy module supplying energy to the autonomous apparatus, a motor, a sensor circuit, and a control circuit, the motor obtaining the energy from the energy module, to drive the autonomous apparatus to move and/or work in the working area, the sensor circuit detecting working parameters and environmental parameters of the autonomous apparatus, and transmitting detection results to the control circuit, the control circuit controlling the operation of the motor according to a signal transmitted by the sensor circuit, where the motor is a sensorless brushless motor, and before the motor rotates, the control circuit measures a resistance value of the motor, and estimates, one the basis of the resistance value of the motor, a rotor position of the motor, so as to control the operation of the motor.

Provided is a method for determining the rotational position of a rotor in a permanent magnet synchronous machine, wherein the stator includes windings for a first, second and third phase, including the steps: applying a first voltage pulse to the first phase, determining respective first measures for the current induced by the first voltage pulse in the second and third phase, selecting a first selected phase depending on the first measures for the current, wherein the first selected phase is either the second or the third phase, applying a second voltage pulse to the first selected phase, determining respective second measures for the current induced by the second voltage pulse in the phases of the stator that are not the first selected phase, and determining the rotational position of the rotor depending on the second measures of the current.

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 power conversion system includes an inverter and a controller configured to: responsive to startup of the system, measure a motor speed of the IPM motor; responsive to the motor speed being less than a threshold, generate the inverter switching control signals to perform high frequency injection (HFI); during the HFI, determine a measured angle of the IPM motor; during the HFI, generate the inverter switching control signals to provide an injected current to the IPM motor; detect acceleration or deceleration of the IPM motor responsive to the injected current; selectively determine an electrical angle as half the measured angle or as 180 degrees plus half the measured angle based on the detected acceleration or deceleration of the IPM motor; and responsive to determining the electrical angle, generate the inverter switching control signals to drive the IPM motor to a reference frequency in a normal operating mode of the inverter.

A power conversion system includes an inverter and a controller configured to: responsive to startup of the system, measure a motor speed of the IPM motor; responsive to the motor speed being less than a threshold, generate the inverter switching control signals to perform high frequency injection (HFI); during the HFI, determine a measured angle of the IPM motor; during the HFI, generate the inverter switching control signals to provide an injected current to the IPM motor; detect acceleration or deceleration of the IPM motor responsive to the injected current; selectively determine an electrical angle as half the measured angle or as 180 degrees plus half the measured angle based on the detected acceleration or deceleration of the IPM motor; and responsive to determining the electrical angle, generate the inverter switching control signals to drive the IPM motor to a reference frequency in a normal operating mode of the inverter.