Patent ID: 7821145

Claim:
An aircraft starting and generating system, comprising: a starter/generator that includes a main machine having a rotor and a stator, an exciter having a rotor and a stator, and a permanent magnet generator having a rotor and a stator; and an inverter/converter/controller that is connected to the starter/generator and that generates AC power to drive the starter/generator in a start mode and that converts AC power obtained from the starter/generator to DC power in a generate mode, wherein the inverter/converter/controller includes rotor position measuring means for measuring an angular position of the respective rotors of the starter/generator based on current and voltage signals obtained from the starter/generator, the rotor position measuring means not including a mechanical position sensor, the rotor position measuring means includes high frequency injection estimation means for performing rotor position estimation when the respective rotors are rotating below a predetermined rotational speed, and voltage mode estimation means for performing rotor position estimation when the respective rotors are rotating equal to or above the predetermined rotational speed.