Desing and application of servo voltage regulator controlled by a microcontroller

viDESING AND APPLICATION OF SERVO VOLTAGE REGULATORCONTROLLED BY A MICROCONTROLLER(M.Sc. Thesis)Nurel BOZKURTGAZ UNIVERSITYINSTITUTE OF SCIENCE AND TECHNOLOGYSeptember 2006ABSTRACTThe primary condition for that any electric powered device can functionwithout any failure or malfuction is to feed with a stable and rated voltage.However, the main power lines of our country, especially in rural and industrialareas, show a weak performance behavior and change according to day hours.Voltage changes occur sometimes slowly as it can be sometimes by sudden sagsswell or fluctuations.Various voltage regulators have been used in order to reduce such effects and toprovide end users with stable working conditions. In this study, servo voltageregulators were preferred because they had very low failure rates while workingand were easy to produce in our country conditions. A permanent magnet DCmotor was used, which was controlled by means of an H bridge in the drivingmechanism of the servo regulator. The system consisted of a toroidaltransformer and a buck- boost transformer.A PIC18F452 microcontroller was used to control the voltage regulator. ThePID control technique was used in the regulator. The control variable was theoutput voltage. The input current and voltage and output current values wereread for protection and data acquisition purposes. The read values like currentviiand voltage and the calculated values like power could be read on the LCDscreen.At the end of the study, it was observed that the output voltage could becontrolled in a range of adjusted limits in spite of variations of line voltage andload currents.Science Code : 626.01.01Key Words : Autotransformer, PID, PIC18F452Page Number : 75Adviser : Assist. Prof. Dr. brahim SEFA