Characterization of three phase flux reversal machine as an automotive generator

The three phase flux reversal machine (FRM) is a doubly-salient stator-permanent magnet (PM) machine with flux linkage reversal in the stator three phase concentrated windings. It can operate in both motoring and generating modes. In this paper, a prototype three phase flux reversal machine operating as a generator is studied both theoretically and experimentally. The equivalent model considering the core losses is obtained through extensive loss tests. A constant output voltage rectifier-chopper unit is then coupled with the loss model and the PSpice simulation is carried out. Hardware of the rectifier-chopper unit is then built and put into operation together with the FRM. Encouraging results are achieved indicating that the three phase FRM, with proper output control, is a viable option for the next generation automotive generator system with the merits of robustness, low cost, wide speed range and fast transient response. Whereas the studied machine in this paper is only a prototype, a new three phase FRM of improved design is being built and its projected performance in terms of the power density and the cogging torque is much better.