Iranian Research Organization for Science and Technology (IROST) Hydrogen, Fuel Cell & Energy Storage 2980-8537 12 3 2025 11 01 Simulation of the Dynamic Behavior of the Load Frequency Control System in the Power Network by Combining Different Power Plant 203 216 1494 10.22104/hfe.2024.7214.1330 EN Mohammadreza Moradian Department of Electrical Engineering, Na.C., Islamic Azad University, Najafabad, Iran Smart Microgrid Research Centre, Na.C., Islamic Azad University, Najafabad, Iran 0000-0001-8581-000X Ghazanfar Shahgholian Department of Electrical Engineering, Na.C., Islamic Azad University, Najafabad, Iran Smart Microgrid Research Centre, Na.C., Islamic Azad University, Najafabad, Iran 0000-0003-2774-4694 Journal Article 2025 07 14 Maintaining a relatively constant frequency is crucial in power systems. The secondary control loop plays a key role in ensuring that the frequency stays close to nominal values, while also managing the power exchange between interconnected control areas through established transmission lines. This study focuses on examining and simulating the dynamic behavior of interconnected power systems. Various power system configurations are explored, incorporating steam, hydro, and gas power plants. We present MATLAB-based simulations for both two-area and three-area power systems. The results of these time-domain simulations are analyzed by calculating the eigenvalues of the power system matrix across different scenarios. The findings indicate that in response to step changes in demand load, independent areas exhibit varying frequency droop characteristics, with gas power plants showing the least frequency droop and hydro power plants displaying the most significant frequency droop. https://hfe.irost.ir/article_1494_fcdf25d6e191893e705819b177cddea0.pdf