LVRT performance of brushless doubly fed induction machines ? A comparison

The Brushless Doubly Fed Induction Machine (B-DFIM) shows promise for use in wind turbine drivetrains. This paper discusses the performance of this machine under symmetric low voltage dips and compares this with the performance of two other machines - the Permanent Magnet Synchronous Machine (PMSM) and the Doubly-Fed Induction Generator (DFIG). Attention is paid to the controller for the B-DFIM and protection methods for improved Low Voltage Ride Through (LVRT) performance are discussed. It is shown that the B-DFIM has an improved LVRT performance when compared with the DFIG, moreover, the B-DFIM does not require an external circuit for protection from low voltage events.