How to extract maximum torque in a single phase repulsion type motor?
Right Answer is:
The angle between brush axis and stator field axis must be equal to 45°.
The torque in the repulsion motor is given as
Te = 0.5k Is2 Ns2 sin 2α
Where Is and Ns are the stator filed-current and an effective number of stator turns.
α is the angle between the brush axis or rotor field axis to the stator field axis.
Since a constant stator field motor extract maximum torque when
sin 2α = 1 ⇒ 2α = 90° ⇒ α = 45°