Design, modeling and analysis of a brushless doubly-fed doubly-salient machine for electric vehicles

This paper presents a new three-phase 12/8-pole brushless doubly-fed doubly-salient (BDFDS) machine for application to electric vehicles. The key is to design, modeling, analyze and control the proposed BDFDS machine. The output power equation is analytically derived, and the initial calculation of machine dimensions and parameters are also discussed. By using finite element analysis, the field distributions of the BDFDS machine at different load and field current are obtained, in which the magnetic saturation and the coupling between armature current flux and field current flux are considered; moreover, the static characteristics of the proposed machine are given. Based on the static characteristics, the system mathematical model has been established. Hence, the evaluation of system performances is conducted by computer simulations in which the simulation model combines the machine with a 3-phase half-bridge converter. A 12/8-pole BDFDS machine is designed and built for exemplification, and a drive system employing this new machine has been developed and investigated experimentally. Experimental results are also given to verify the validity of the theoretical analyses.