Design of control strategies for frequency stability of PV-thermal interconnected power system

Abstract

Renewable energy in particular solar energy is a viable option to meet the increasing energy demand for the modern world. The Solar resource in South Africa is among the highest in the world. With the progression of modern society, both energy demands and energy prices are increasing, which has welcomed the introduction of renewable energy resources as an alternative. However, solar radiation varies over the complete day sometimes over the season, and sometimes over the complete year. Further, the power demand is highly variable in nature. Hence, the generated power should match the customer demands over the period of twenty-four hours, and further, it should be economical for customers and electrical utilities. Hence, this study will focus on integrating PV plants with thermal plants to meet the rising customer power demand. The integration of PV with thermal power plants will bring some new challenges in the domain of power system operation & control which is the frequency of the power system should be restricted to well-defined values. Hence, suitable control strategies are to be developed for the successful and smooth operation of the power system. In this research work, an attempt is made to investigate an interlinked system comprising of a thermal and a PV generation system. The control strategies based on PID controllers and their gains tuned through effective tuning techniques are presented. In addition, the concept of fuzzy logic is used to address the problem of frequency managing of PV-Thermal via effectively designing fuzzy proportional, fuzzy integral, and fuzzy PI built control strategies to ensure the frequency regulation of the energy system. The obtained results are shown via a graphical approach, and the best control design is explore and suggested for the considered system. In addition, the scope for further improvement and possible direction areas are also explored and listed in this report.