Achieving Sensorless Control for the Brushless Doubly Fed Induction Machine

The brushless doubly fed induction machine (DFIM), without brushes and slip rings, is regarded as an attractive alternative to the conventional DFIM in terms of reliability. This paper presents a sensorless field-oriented control strategy for the brushless-DFIM, which further increases its attractiveness as a drive system. With the use of a straightforward and alternative time-dynamic brushless-DFIM model, a complete brushless-DFIM based drive is modeled and used for the development of the sensorless control strategy. The developed sensorless control strategy is implemented in an experimental setup. Simulation and measurement results demonstrate that the developed sensorless control strategy can control the brushless-DFIM in a stable and responsive manner over its full operating speed range. In this way, a fully functional sensorless control strategy for the brushless-DFIM is demonstrated for the first time in the literature.