Abstract—The Brushless Doubly Fed Reluctance Machine

(BDFRM) is a promising cost-effective alternative solution in applications with narrow speed ranges such as large wind turbines and/or pump-type drives. Apart from providing a comprehensive literature review and analysis of vector (field-oriented) control and direct torque (and flux) control (DTC) methods, the development, and results of experimental verification, of an angular velocity observer-based DTC scheme for sensorless speed operation of the BDFRM which, unlike most of the other DTC concepts, can perform well down to zero supply frequency of the inverter-fed winding, have also been presented in the paper. Index Terms—Control, brushless doubly fed reluctance machines, slip power recovery systems, wind turbines. I