Implementation of a sensorless stator flux oriented asynchronous motor drive with high performances at low-speed operation

A sensorless, stator flux oriented asynchronous motor drive has been realized, by using a low-cost, single chip microcontroller. A motor state observer has been implemented, which showed excellent performances, particularly at low speed operation. Two different experimental realizations have been developed, with rated powers equal to about 1.5 kW and 30 kW respectively, and good results have been obtained in both cases. The theoretical approach, the main design choices and the most significant experimental results are presented.