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

The present paper deals with the design and im-plementation of a three-phase, two-level voltage source inverter (VSI) equipped with silicon carbide (SiC)-switches and an output filter featuring sinus-oidal output voltages and currents. The objective of this configuration is twofold, on the one side it reduces the stress on the winding of the machine and the produced noise, and on the other hand it is expected that the range of operation of a sen-sorless field oriented control scheme can be ex-tended. The high switching frequency that can be achieved with the SiC-switches allows the design of a rather small LC filter for the output of the in-verter. Thus, the harmonic content of the machine voltages is minimized. In this way, the measured voltages can be used instead of the reconstructed ones for the enhancement of the voltage model as well as the natural field orientation and the perfor-mance of the control scheme.