Design and Finite Element Analysis of Brushless Doubly Fed Reluctance Machine for Variable Speed Applications

Doubly fed induction machines (DFIM), permanent magnet synchronous machines (PMSM) and traditional induction machines are widely used for variable speed applications like wind power generation, pump storage, etc. In this context, brushless doubly fed reluctance machine (BDFRM) has emerged as an attractive alternative to such variable speed applications. BDFRM does not contain costly permanent magnet material like that required in PMSM and also it does not necessitate the usage of brushes and slip rings for operation as required in DFIM. Alike DFIM, BDFRM also needs a partial rated power electronics converter (generally 30% of the machine rating) for limited range variable speed operation. Being a new candidate in the machine family, there lies ample opportunity to investigate the design of BDFRM. Thus, the present work investigates a comparative performance study between a simple salient pole rotor BDFRM and radial laminated ducted reluctance rotor BDFRM with the help of finite element analysis. The finite element analysis has been carried out with the help of Ansys Maxwell Electromagnetics tool.