A microcontroller-based sensorless stator flux-oriented asynchronous motor drive for traction applications

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 and 30 kW, respectively, and good results have been obtained in both cases. The theoretical approach, main design choices, and most significant experimental results are presented.