Design of a brushless doubly-fed induction motor for adjustable speed drive applications

The paper begins with a delineation of historical evolution of the brushless doubly-fed induction motor (BDFIM) concept. A methodology for the steady-state performance analysis and design of the BDFIM is then given, following a descriptive review of the operating principles and dynamic controls of the BDFIM. A 10 hp brushless doubly-fed induction motor has been designed for comparison with a squirrel-cage induction motor, and a cost comparison is made between the brushless doubly-fed induction motor drive and the baseline squirrel-cage induction motor drive, showing some 30% total system cost savings despite of a cost differential incurred on the BDFIM. A brief discussion of the ramification of potential applications of this new motor technology is also included, with the most promising niche markets identified as variable speed industrial pumps (fans), variable speed constant frequency (VSCF) wind/hydro power generators, high speed traction or spindle drives requiring wide field-weakening ranges and brushless operation.