An Envelope-Prediction-Based Sensorless Rotor Position Observation Scheme for LCI-Fed EESM at Zero and Low Speed

An envelope-prediction-based sensorless rotor position observation scheme is proposed for a load commutated inverter (LCI)-fed electrically excited synchronous motor (EESM) at zero and low speed. The proposed rotor position observation scheme does not need to utilize the full controlled power device, nor to modify the LCI drive topology. An interval trigger mode for the exciter control is proposed...