The Boeing Company
System and method for operating an independent speed variable frequency generator as a starter

Abstract:

A system may include a first bus transfer switch configured to open and close connections between a generator control unit, a pilot permanent magnet generator stage of an independent speed variable frequency (ISVF) generator, and an external power source. The system may further include an inverter configured to set a main field winding of the ISVF generator into a motor state. The system may also include a second bus transfer switch configured to open and close a connection between a main armature winding of the ISVF generator, a power distribution bus, and a motor start driver configured to send a current through the main armature winding to generate a magnetic field pattern that causes the rotor to turn, enabling startup of an engine.