Analysis of the Effect of Excitation Current on Generator Output Voltage andReactive Power at PT. Pelindo Terminal Petikemas New Makassar
Abstract
The industrial sector's need for reliable electrical energy demands a power generation system capable of maintaining voltage and reactive power stability. Synchronous generators play a crucial role in maintaining power quality by regulating excitation current, which influences output voltage and reactive power. This study aims to analyze the effect of excitation current on the output voltage and reactive power of a generator at PT. PELINDO New Makassar Container Terminal and to determine the most stable operating conditions. A descriptive quantitative research method was employed, utilizing a simulation approach with Electrical Transient and Analysis Program (ETAP) software and validating the results against real-time data from generator log sheets. Excitation current was varied within a range of 70% to 110% of the nominal value (2.6 A). Simulation results indicate that increasing the excitation current from 1.82 A to 2.86 A caused the output voltage to rise from 280 V to 440 V and the reactive power to increase from 187.5 kVAR to 200.5 kVAR. Regression and correlation analyses revealed a very strong relationship between excitation current and both output voltage (r = 0.999) and reactive power (r = 0.998). Real-time data also showed a very strong correlation between excitation current and output voltage (r = 0.999), whereas the relationship with reactive power was relatively weak (r = 0.186), influenced by the operation of the Automatic Voltage Regulator (AVR), load fluctuations, and the contribution of capacitor banks. The novelty of this research lies in integrating ETAP simulation results with real-time generator data validation—using regression and correlation analyses—to reveal the distinct characteristics of how excitation current affects output voltage and reactive power under actual operating conditions influenced by the AVR, load changes, and capacitor banks. This study concludes that excitation current directly affects the generator's output voltage and contributes to changes in reactive power; therefore, precise regulation of the excitation current is necessary to maintain the operational stability of the electrical system.