Performance Improvement of a Two-phase AC Motor by Using Non-Orthogonal Armature Windings

In a traditional two-phase AC motor, armature windings are orthogonal to each other. This paper investigates the situation wherearmature windings are non-orthogonal. Non-orthogonal armature windings means the electrical shift angle between phase windings of thestator is not 90 electrical degrees. Both two-phase induction motor and two-phase permanent magnet motor are investigated. Twodimensional transient finite element analyses are used to analysis AC motors. First, transient finite element analysis are done on AC motorswith orthogonal stator windings. Afterwards, transient finite element analyses are done on AC motors with non-orthogonal stator windings.Simulation results show that with special electrical shift angle in non-orthogonal armature windings, the AC motor could deliver highertorque in comparison with orthogonal armature windings motor, as well as the acceleration time of the motor is decreased. The shift angleshould be a coefficient of pole pitch, so any shift angle is not possible. The paper searches among possible shift angles and tries to find thebest shift angle which improves motor performance.

Keywords:

AC motor , armature windings , finite element analysis , induction motor , non-orthogonal , orthogonal , permanent magnetmotor , transient