Sensorless Operation of a Permanent Magnet Generator for Aircraft

The paper investigates the improvement in sensorless vector control of induction machines through the use of a non-linear feedback integrator embedded in a standard rotor flux model reference adaptive system (MRAS)-based observer. The feedback integrator compensates for drift and DC-offset and is capable of open loop flux estimation down to frequencies below 0.1 Hz. The paper presents experimental results of a sensorless speed controlled induction motor exploiting a MRAS observer. The sensorless system shows good performance down to frequencies of 0.2 Hz