Solid-state controlled single-phase induction motor

Single-phase induction motors are widely used in domestic appliances, workshops and factories. Many conventional methods are used to control these motors. There is no one method by which single phase induction motors can be started, speed-controlled and reversed. This paper presents a new method for controlling single-phase induction motors with two symmetrical stator windings utilizing two triacs; one in series with the main winding and the other with the auxiliary one. Such a connection will perform all the required jobs namely; starting, speed control and reversing the direction of rotation. the motor is represented in the dqo reference frame. A rigorous state space mathematical model is developed to describe the system. Kron's tensor technique is applied using variable connection matrix to care for the nonlinearities introduced by the triacs. Computer results for transient and steady state conditions are presented. Also, the proposed method has been verified experimentally.