Implementation of PLC based automatic voltage controller for standalone induction generator feeding lagging power factor load

The present paper discusses control of voltage and development of controller for lagging power factor load which is connected in series with an excitation capacitance across main winding of standalone induction generator. Poor voltage regulation in 0 to 25 percent series loaded Standalone Induction Generators is a matter of concern when the machine is used in practical applications. The robustness and ruggedness of induction machines catches attention of engineers and scientists throughout the globe to use this machine for energy conversion operation in hydro as well as wind power systems. This machine can be successfully used practically if output voltage of machine is maintained automatically at constant value irrespective of load variations. In this paper an implementation of Programmable Logic Controller (PLC) based automatic voltage controller is shown which maintains voltage across the load at desired value even if the rating of the load is changed. The development of Algorithm for Voltage Control across load is also discussed. The software for the controller is developed with the help of LDMicro Ladder Logic Programming Software and hardware of the controller is implemented with the help of Microcontroller based PLC which employs ATMega328P Microcontroller.