Position-and-velocity sensorless control for starter generator electrical system using generator back-EMF voltage

A starting system control for operating a brushless generator in a starting mode to convert electrical power into motive power wherein the brushless generator includes a motive power shaft and a main generator portion having a set of armature phase windings which are supplied a parameter of AC power during operation in the starting mode comprising:

• means coupled to the main generator portion armature phase windings for deriving a number of interval pulses relating to the revolution of the motive power shaft from the parameter of AC power supplied to the main generator armature phase windings;
• means coupled to the deriving means for measuring time periods between adjacent interval pulses;
• means coupled to the measuring means for converting the measured time periods into indications of the speed and angular position of the motive power shaft;
• and
• means coupled to the converting means for delivering AC power to the set of main generator portion armature phase windings in dependence upon the speed and angular position indications.

An electric power conversion system operable in a starting mode and in a generating mode, comprising:

• an exciter portion including an exciter field winding and a set of exciter armature windings, said set of exciter armature windings being coupled to a rotor so as to rotate with said rotor;
• a main generator portion including a main generator field winding coupled to said rotor so as to rotate with said rotor, said main generator field winding also being coupled to said exciter armature winding, and a set of main generator armature windings;
• an inverter for supplying AC power to said main generator portion when said power conversion system is in said starting mode;
• and
• a rotor position detector coupled to said main generator portion, said rotor position detector determining the angular position of said rotor based upon a parameter of said AC power provided to said main generator portion.