Novel Scheme of Driving Single Phase PM AC Motor in Uni-Direction

This paper describes a new scheme for driving single phase AC motor which uses permanent magnet for its rotor. The single phase AC PM motor has only one set of coil on the yoke of the stator, and its two pole faces are symmetric shape. The rotor is consists of ferrite permanent magnet magnetized only one pair of poles. As well known, motor having these configurations can not produce significant starting torque at certain direction, and therefore, the rotating direction is absolutely random when it is driven with sinusoidal AC voltage. The main objective of this research is to drive the motor in uni-direction, under constant load, by using fixed frequency AC utility line without changing the motor shape and also with the commercially acceptable low cost.