AC brushless drive with low resolution Hall-effect sensors for an axial flux PM machine

An AC brushless drive in which Hall effect sensors are used as rotor position sensors is presented in this paper. Three different methods to obtain high resolution position information from the low resolution sensors are described and compared through simulation and some preliminary experimental testing. The proposed control algorithm's most innovative feature is it's adaptability to the whole speed range, including start-up, when using any of the three estimation algorithms. The entire control algorithm has been implemented and tested in order to drive an axial-flux PM machine for home appliance applications.