The Boeing Company
Negative-slope voltage-frequency for starting a variable frequency independent speed motor and speed control

Abstract:

A method may include transmitting an excitation signal from a stator of a motor to a rotor of the motor, where the excitation signal is received at a set of rotor windings, and where the excitation signal produces a rotating magnetic flux at the rotor that generates a first alternating current (AC) voltage at a set of stator windings. The method may further include controlling the excitation signal to equalize and synchronize the first AC voltage to a second AC voltage at an AC bus. After the synchronization, the method may also include electrically connecting the set of stator windings to the AC bus. The method may include reducing an amplitude of the excitation signal to enable current flow from the AC bus to the set of stator windings, thereby generating torque that results in rotation of the rotor.