A doubly-fed reluctance motor drive with sensorless direct torque control

The brushless doubly-fed reluctance machine (BDFRM) is a potential low cost alternative to the existing solutions in applications with limited variable speed ranges. The cost effectiveness of the BDFRM drive can be attributed to the possibility of using a partially rated power electronic converter. This paper proposes a new sensorless direct torque (and flux) control (DTC) algorithm for this machine which appears to be superior In many respects to those used for cage Induction and other AC machines. The scheme developed is also applicable to the doubly-excited wound rotor induction machine. The results shown have demonstrated good controller performance over the desired speed range for different loading conditions.