SiC-VSI with Sinusoidal Voltages for an Enhanced Sensorless Control of the Induction Machine

The present paper presents the enhancement of the sensorless field oriented control by using the measured terminal voltages instead of the calculated ones in the fundamental wave models. The system under consideration consist of a three-phase induction machine, a two-level voltage source inverter (VSI) equipped with silicon carbide SiC-switches and an output filter providing almost sinusoidal output voltages and currents. The objective of this work is twofold, on one side it is expected that the range of operation of the classical sensorless schemes and of the model reference adaptive system (MRAS) can be extended by using the measured voltages instead of the reconstructed ones. In addition, the use of the natural field orientation (NFO) as a reference model in a MRAS control scheme in order to extend the range of operation of the sensorless speed control is examined.