V/F Control Method for Pulsating Torque Reduction in a Single Phase Induction Motor

In general, single-phase induction motors have main and auxiliary windings on the stator which is an asymmetrical circuit for the starting torque. Due to an asymmetrical stator circuit, the torque pulsation is generated with noise and loss. The paper proposes the open-loop V/f control method for reducing the torque pulsation in a single-phase induction motor. The proposed method uses a three-leg inverter and power sharing controllers without the start capacitor. The line-to-line voltages of a three-leg inverter correspond to two winding voltages, and the active power sharing of two windings is adjusted by the voltage ratio while the reactive power sharing is adjusted by the phase angle difference. With the proposed method, average active and reactive powers on the stator windings are equal and thus the torque pulsation is reduced in a single-phase induction motor. The effectiveness of the proposed method is validated by simulation and experimental results.