Brushless dc generator without permanent magnet

This paper presents characteristic analysis of a without permanent magnet Brushless dc (WPMBLDC) generator. Proposed configuration is a 9/6 BLDC generator in which permanent magnet is replaced with assisted field coil in the rotor. Due to dc current in the assistant field winding, the magnetic field flows axially through the rotor shaft and closes through the stator teeth and the motor housing. Finite Element (FE) analysis has been carried out to confirm the accuracy of the predicted flux-linkage characteristics, which play a key role in the design process. A prototype WPMBLDC machine has been also built and tested; additionally the accuracy of FE analysis is verified by comparing the calculated results with the experimental measured values.