Characterization-Based Modelling and Control of a Two-Degrees-of-Freedom Axial Flux Machine

This paper investigates the modelling and control of a two-degrees-of-freedom axial flux motor. Initially, a model of the system is derived and validated against a test motor. Using the model, the limitations of neglecting the nonlinearity when controlling the air gap are demonstrated and a new "net axial rotor force" control scheme is developed. The developed control scheme is demonstrated to achieve consistent performance over the full operating range of air gaps and on average results in a 65% decrease in rise time, 55% decrease in settling time and a 25% reduction in overshoot.