A method and apparatus are provided for controlling a sensorless alternating current induction motor (ACIM) having a rotor and a stator comprising a plurality of stator windings by applying a plurality of phase shifted voltages to the plurality of stator windings in the ACIM such that two energized stator windings are connected to first and second phase shifted voltages to cause rotation of the rotor relative to the stator while a third unconnected stator winding is floating so that a DC bus current and an inducted voltage can be measured from the ACIM and used to compute an estimated rotor speed.

A method and apparatus are provided for controlling a sensorless alternating current induction motor (ACIM) having a rotor and a stator comprising a plurality of stator windings by applying a plurality of phase shifted voltages to the plurality of stator windings in the ACIM such that two energized stator windings are connected to first and second phase shifted voltages to cause rotation of the rotor relative to the stator while a third unconnected stator winding is floating so that a DC bus current and an inducted voltage can be measured from the ACIM and used to compute an estimated rotor speed.

A power conversion device of an embodiment includes a rectifier that full-wave rectifies alternating current of a plurality of phases supplied from a power supply side, a capacitor that smoothes an output voltage of the rectifier, a voltage detection unit that detects the smoothed voltage, and an open phase detection unit that detects that an open phase has occurred in the alternating current of the plurality of phases based on a component having a frequency that is twice as high as a fundamental frequency of the alternating current of the plurality of phases included in frequency components of the smoothed voltage.

Disclosed herein are a method for controlling a medium-voltage inverter, and a system including the same. The system includes a motor, a medium-voltage inverter driving the motor, a control unit configured to control an output voltage from the medium-voltage inverter, and an output voltage measuring unit configured to measure counter electromotive force data of the motor including a voltage and a frequency of the counter electromotive force, and transmitting it to the control unit. The control unit generates the output voltage based on the measured counter electromotive force data to re-drive the motor when the output voltage measuring unit completes the measurement of the counter electromotive force data.

Systems and methods for controlling an induction motor are provided. In particular, data indicative of an alternating current voltage signal associated with an induction motor can be received. The alternating current voltage signal can be applied to the induction motor through a switching element coupled between a power source and the induction motor. A zero cross voltage signal can then be generated based at least in part on the data indicative of the alternating current voltage signal. A phase delay period for at least one half cycle period of the zero cross signal can then be determined. Operation of the induction motor can then be controlled by providing one or more control signals to the switching element causing the switching element to conduct current for one or more gating periods. Each gating period can be determined based at least in part on the phase delay period.

Systems and methods for controlling an induction motor are provided. In particular, data indicative of an alternating current voltage signal associated with an induction motor can be received. The alternating current voltage signal can be applied to the induction motor through a switching element coupled between a power source and the induction motor. A zero cross voltage signal can then be generated based at least in part on the data indicative of the alternating current voltage signal. A phase delay period for at least one half cycle period of the zero cross signal can then be determined. Operation of the induction motor can then be controlled by providing one or more control signals to the switching element causing the switching element to conduct current for one or more gating periods. Each gating period can be determined based at least in part on the phase delay period.

Disclosed herein are a method for controlling a medium-voltage inverter, and a system including the same. The system includes a motor, a medium-voltage inverter driving the motor, a control unit configured to control an output voltage from the medium-voltage inverter, and an output voltage measuring unit configured to measure counter electromotive force data of the motor including a voltage and a frequency of the counter electromotive force, and transmitting it to the control unit. The control unit generates the output voltage based on the measured counter electromotive force data to re-drive the motor when the output voltage measuring unit completes the measurement of the counter electromotive force data.

According to an embodiment, a method for compensating instantaneous power failure includes determining whether an input voltage of a plurality of power cells is less than or equal to a first threshold voltage, decreasing, when the input voltage is less than or equal to the first threshold voltage, an output frequency of the inverter, determining whether a voltage of a direct current (DC) link is greater than or equal to a second threshold voltage, and increasing, when the voltage of the DC link is greater than or equal to the second threshold voltage, the output frequency of the inverter. Overvoltage trip may be prevented at the power restoration time and overcurrent trip caused by increase in the slip frequency may be prevented. Thereby, reliability of a medium inverter may be enhanced, and a continuous operation time increased compared to the conventional cases may be ensured.

According to an embodiment, a method for compensating instantaneous power failure includes determining whether an input voltage of a plurality of power cells is less than or equal to a first threshold voltage, decreasing, when the input voltage is less than or equal to the first threshold voltage, an output frequency of the inverter, determining whether a voltage of a direct current (DC) link is greater than or equal to a second threshold voltage, and increasing, when the voltage of the DC link is greater than or equal to the second threshold voltage, the output frequency of the inverter. Overvoltage trip may be prevented at the power restoration time and overcurrent trip caused by increase in the slip frequency may be prevented. Thereby, reliability of a medium inverter may be enhanced, and a continuous operation time increased compared to the conventional cases may be ensured.

A power supply apparatus for an aerospace actuator includes motor drive electronics for actuation of a motor for control of the aerospace actuator, and an energy storage device. The motor drive electronics are configured to receive input electrical energy from an aircraft power grid, receive electrical energy from the energy storage device and provide electrical energy from the grid and/or from the energy storage device to the motor. The energy storage device is configured to store at least one of: excess electrical energy supplied to the motor drive electronics from the grid and regenerated electrical energy from the motor drive electronics. The energy storage device is configured to discharge the stored energy as electrical energy to the motor drive electronics when required.