An axial flux flywheel motor/generator for pulsed power application

This paper presents an axial flux stator coreless permanent magnet flywheel motor/generator set for pulsed power application. This structure can adjust the back electromotive force (EMF) by rotating one of the double stators. Detailed topology of the structure is presented and a closed-form analytical design approach is described. A downsized prototype machine and the corresponding driver are designed and constructed based on the presented analytical approach. No-load parameters of the prototype are measured and compared with the predicted one, showing good agreements. Then losses of the prototype are analyzed. Finally, the prototype is driven in both brushless DC (BLDC) mode and space vector pulse width modulation (SVPWM) mode; actual charging and discharging waveforms are presented.