Variable Speed Drive for 1 Ph I.M using Frequency Control Method

The purpose of this study is in electronic scope to develop a control scheme for single phase induction motor application. Many industrial processes require variable speed drives for various applications. The project aims to develop an AC drive for a single phase induction motor based on the variable voltage, variable frequency method by varying the duty cycle of pulse width modulation (PWM) signal. Control schemes should be determined based on the control necessary, the cost and the process. The core of the AC drive is the SG3525A which generates the required pulse width modulation (PWM) signals to gate the H-BRIDGE configuration inverter by which an AC supply of variable voltage and frequency required to drive the induction motor at different speed is achieved. The driver HEF4081B gate pulse generator, optocoupler MCT2E and signal amplifier BC547C serves the purpose of isolation between the SG3525A circuit and the H-BRIDGE configuration inverter and supplies the required gate voltage for the conduction of the power MOSFET (IRF840) in the H-BRIDGE configuration inverter.