CONTROL OF SINGLE PHASE INDUCTION MOTOR USING FORCED-COMMUTATED ELECTRONIC SWITCHES

ABSTRACT

Single phase induction motors require assistant methods for starting, speed-control and reversing direction of rotation. The available methods suffer from many drawbacks. Most of these drawbacks are due to use of mechanical switches in addition to other expensive electrical equipment. This paper suggests a nonconventional versatile method which realizes all the motor requirements. The method uses two forced-commutated electronic switches to feed a single-phase motor which has two symmetrical stator windings. By this circuit, the motor could produce a high starting torque. Also the speed could be controlled and the direction could be reversed. A state space mathematical model has been developed for the motor and its solid state feeding converter. With the aid of the model, the system has been simulated by a developed computer program. Transient starting characteristics have been computed. Also, steady state speed control characteristics have been obtained for different control strategies. The performance of the motor has been compared with other conventional control methods, and with a method which uses naturally commutated electronic switches.