Development of ALFC and AVR Control Loop as Laboratory Model using DC-DC Buck Chopper

Abstract

The main objective of Automatic Voltage Regulator (AVR) is to maintain the terminal voltage through controlling the excitation. Automatic Load Frequency Control (ALFC) plays significant role in maintaining the frequency through controlling the mechanical power input to match the varying load requirements. In this paper, the laboratory model of AVR along with ALFC is developed. The proposed AVR and ALFC system based on laboratory model gives an added advantage over the mathematical model due to its materialistic approach. AVR senses the terminal voltage of an alternator and compares with the reference voltage and generates error signal which intern adjusts the field current by using DC-DC Buck chopper. ALFC senses the speed ofthe alternator and compares it with the reference speed and generates error signal which intern adjusts the mechanical power input to an alternator by using DC-DC Buck chopper connected to the armature terminal of the DC-motor. The entire setup is simulated in Matlab@ simulink. The proposed laboratory model based AVR and ALFC system is tested for various loading conditions to validate its effectiveness.