The system voltage is one of the most important parameters, which determines the power quality. The stability of the system voltage is critical for the power system. This paper investigates the analysis of the automatic voltage regulator (AVR) system controlled by stabilizer and PID controller. As the work of the AVR is to maintain the synchronous generator terminal voltage. AVR controller simulation model created in power system based on real data from Baluchaung No.2 Hydro Power Plant (Myanmar) to show that the proposed method is effective. The system modeled consists of the amplifier, exciter, sensor and stabilizer or proportional-integral-derivative (PID) controller. Their characteristics and behavior are also briefly discussed. The transfer function controller blocks use linear block model and control techniques in MATLAB/ Simulink environment. By examining the parameters of the stabilizer and PID controller, the generator terminal voltage variations are predicted. Simulation results demonstrate that the proposed controllers provide better performance characteristics with respect to settling time, oscillations and overshoot.