Unified reference frame <i>dq</i> model of the brushless doubly fed machine

Control of the brushless doubly fed machine (BDFM) based on traditional multiple reference frames is complex. To simplify the control scheme, a new and simpler derivation of the dq model of the BDFM is proposed, leading to a unified-reference-frame model. This way, a simple dq model can be established, which could be an interesting tool for control-synthesis tasks. In order to determine the unified reference dq model, restrictions related to BDFM operation, as well as the exact rotor-cage configuration, have been considered. The proposed model has been validated by several experimental results. The work could facilitate future research on improved BDFM field-oriented control strategies.