Control ot two-phase induction motor by changing the phase difference angle

A phase-difference angle (PDA) controlled pulse width-modulated (PWM) inverter instead of phase voltage modulation and/or frequency changing is proposed to control the speed, and position of a two-phase induction motor. Several characteristics of a two-phase induction motor driven by the PDA inverter are studied to verify the improvement of the motor performances. Also, speed, and position tracking are achieved using the proposed control technique. A simple PDA inverter circuit is proposed for driving symmetrical and unsymmetrical two-phase induction motors. The inverter provides two-phase independently controlled frequency, voltages and PDA to the primary and auxiliary windings of an induction motor. The dynamic model of two-phase induction motor driven by a PDA inverter expressed in stationary reference frame is established. Also, the main principle characteristics of the two-phase induction motor especially at constant (V/f) and variable PDA are studied and compared to evaluate each method. An experimental prototype, which consists of a PC computer based controller, a PDA inverter, and two phase induction motor is used to verify the validity of the proposed control technique. Both computer simulation and experimentation performed to show the effectiveness of changing PDA to achieve higher performance in speed and position control compared to other methods of control.