Stabilitas Tegangan Generator Melalui Desain Kompensator Berbasis Tempat Kedudukan Akar pada PLTMG PT. Siantar Tara Sejati

Abstract

Voltage stability is an essential factor in maintaining the reliability and performance of power generation systems. Instability in generator voltage may reduce power quality and disrupt overall system operation. This study aimed to design a Root Locus-based compensator to improve generator voltage stability at the Gas Engine Power Plant (PLTMG) of PT. Siantar Tara Sejati. The study was conducted by developing a mathematical model of the generator excitation system, consisting of an amplifier, exciter, and synchronous generator, followed by simulation using MATLAB software. The compensator was designed by determining the appropriate pole and zero locations through Root Locus analysis, resulting in a lead compensator capable of improving the dynamic response of the system. The simulation results show that before the addition of the compensator, the closed-loop system had a rise time of 0.5545 seconds, peak time of 1.3776 seconds, settling time of 4.2506 seconds, overshoot of 29.163%, and steady-state error of 0.0833. After the lead compensator was applied, the rise time decreased to 0.3979 seconds, the peak time decreased to 0.9146 seconds, the settling time decreased to 1.4558 seconds, the overshoot was reduced to 15.775%, and the steady-state error decreased to 0.0723. These results indicate that the designed lead compensator is able to improve response speed, enhance system damping, and increase generator voltage stability. Therefore, the Root Locus method is effective for designing compensators to improve the performance of generator excitation systems.