Speed drive of single-phase induction motor

In this work, the performance of a closed-loop adjustable speed drive for single-phase induction motor using voltage amplitude control. A microcontroller M68HC11E-9 has been used to implement such techniques. The microcontroller senses the speed´s feedback signal and consequently provides the pulse width variation signal that sets the gate voltage of the chopper, which in turn provides the required voltage for the desired speed. A buck type chopper has been used to control the input voltage of a fully controlled single phase isolated gate bipolar transistor (IGBT) bridge inverter. PWM technique has been employed In this inverter to supply the motor with ac voltage. The simulation and laboratory results proved that the drive system can be used for the speed control of a single-phase induction motor with wide speed range.