Analysis and Simulation of the Effect of Combining Load Frequency Control and Automatic Voltage Regulation in Hydrothermal Power System

Document Type : Research Paper

Authors

1 Department of Electrical Engineering, Na. C., Islamic Azad University, Najafabad, Iran

2 Smart Microgrid Research Center, Na. C., Islamic Azad University, Najafabad, Iran

3 Digital Processing and Machine Vision Research Center, Na. C., Islamic Azad University, Najafabad, Iran

10.22104/hfe.2025.7649.1366

Abstract

In modern power systems, load dynamics are always dynamic and constantly changing. To maintain the balance between generation and consumption demand during load fluctuations, power systems must operate intelligently and flexibly. Given the lack of sufficient conventional energy sources, it is essential to combine conventional energy sources with renewable energy sources to balance production-consumption. The integration of renewable power production units with intermittent character will cause the uncertainty of active power generation and the mismatch among the generated energy and the required load causes oscillations in the voltage and frequency of the network. Using the load frequency controller (LFC) to adjust the frequency and the automatic voltage regulator (AVR) to control voltage -- through the coordinated management of active and reactive power -- is crucial for enhancing power-system stability, especially in the face of sudden changes in energy demand. In this study, the combined LFC-AVR model is considered for a single-area energy grid, which includes a thermal unit and a hydro plant. Synchronous generators with LFC and AVR are important in providing high-quality and uninterrupted electrical power to the network. The primary purpose of investigation and analysis is to show the influence of coupling AVR and LFC loop simultaneously to regulate voltage and frequency. To improve the system response, an integral controller is used in the LFC loop and a proportional-integral (PI) regulator is employed in the AVR loop. The analysis and simulation results show the reduction of frequency and voltage oscillation due to disturbance in the power system.

Keywords

Main Subjects

References

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Hydrogen, Fuel Cell & Energy Storage
Volume 13, Issue 1
January 2026
Pages 39-54

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