Improvement of Frequency Regulation of Power System Having Renewable Energy Resources

Abstract

A major concern of power system operation is to generate and deliver power economically and reliably, while maintaining the system voltage and frequency within permissible limits. Due to the presence of electric clocks for proper parallel operation of power stations and the correlation between operating frequency and loads, it is required to keep the system frequency within ±5% . In recent times, increasing power demands and constraints of operation, the capacity expansion by integrating Renewable Energy Resources (RER) with conventional power grid has been a better alternative. In this regard, increasing levels of wind generation have resulted in an urgent need for the assessment of their impact on frequency control of power systems. To analyze the integrated system, research work in the area of Automatic Generation Control (AGC) of power system with considerable RER penetration becomes an important issue. newlineAmong various forms of Wind Energy Conversion System (WECS), the integration of Double Fed Induction Generator (DFIG) needs to be investigated to improve their frequency regulation capabilities. The issue is addressed in this work by simultaneous optimization of controller gains of DFIG and thermal systems applying Cuckoo Search Algorithm (CSA). Hydro energy based power system is also an important form of renewable energy, that may be interconnected to another thermal area. However, the initial power surge of a hydro turbine is opposite to that desired. Therefore, the short-term extra active power support from a wind farm (WF) is beneficial for a hydro dominated system to limit initial frequency fall. This is looked into, as the CSA optimized controllers of WECS integrated to hydro systems in a two area hydro-thermal system improves the frequency regulation. newlineTo improve upon the management of limited real power resources in AGC of hybrid systems, the coordinated operation of energy storage devices and series FACTs devices may become useful.