National Automatic Generation Control Approaches for Hydro-Thermal power systems

Abstract

This research project deals with automatic generation control of an interconnected hydrothermal system considering reheat type turbine in thermal plant area and low head turbine in hydro plant area using optimal controllers (PID) and artificial intelligence(PLC). The main goal of AGC is to keep the operating frequency under prescribed limits and maintain the interchange power at the intended level[1]. The optimal control is determined by minimizing a performance index under the proposed output feedback conditions. The results indicate that the controllers exhibit better performance. In fact, the control systems designed on these methods satisfy the load frequency control requirements with a reasonable dynamic response. As in simulation run in Programmable Logic Controller (PLC), indicate the implementation of AGC for two areas where one or two generators are supplying the load but as load change the frequency deviate, so this problem solved by PLC Controller where it senses the under frequency automatically command other generators to support the failure. The stability and reliability of power systems are critical for maintaining economic growth and operational efficiency in modern energy sectors[2]. In Rwanda, the hydro-thermal power system faces significant challenges in addressing frequent load changes, which lead to frequency deviations and potential damage to turbines and generator blades. Automatic Generation Control (AGC) has emerged as a pivotal mechanism for maintaining system frequency and ensuring a balance between power generation and demand. Rwanda’s economy has grown at an average rate of 7.2% over the 5 past years, As a result demand for electricity is increasing at a rate of almost of 8% per year[2]. This study explores national approaches to implementing AGC for hydro-thermal power systems, focusing on optimizing power system stability, enhancing response times, and achieving economic operation. Various control strategies, including ii proportional-integral-derivative (PID) controllers, fuzzy logic, and artificial intelligence-based methods, are analysed for their applicability in the Rwandan context[3]. The research identifies key challenges, such as slow response times and integration of renewable energy sources and proposes tailored solutions to enhance AGC performance in hydro-thermal systems. The dynamical response of the load frequency control problem in an interconnected power system under consideration is improved with a practical viewpoint by designing the optimal output feedback controller. Optimal control methods are proposed, and their dynamic responses are compared. A few modern control techniques are adopted to implement a reliable stabilizing controller. A serious attempt has been undertaken aiming at investigating the load frequency control problem in a power system consisting of two power generation unit and multiple variable load units. The robustness and reliability of the various control schemes is examined through simulations[4]. The findings of this study contribute to the development of sustainable and reliable power systems, offering actionable insights for policymakers, engineers, and researchers in improving power system operations in Rwanda and similar regions.