POWER AND ENERGY ESTIMATIONS IN WECS USING ANN MODELS

Abstract

Wind energy is pollution-free and non-depleting Source of energy. It has huge potential to fulfil the energy requirement of human .Wind En Conversion System (WECS) appears as an attractive alternative for electricity generation, especially when integrated to isolated power system. Wind energy is making significant penetration in to electric grids in various places around the world and need for accurate analysis is increasing in importance. The energy generation by wind- energy conversion system is without fuel cost and nature dependent. Wind energy conversion system (WECS) produce $ a variable power output unlike conventional power plant such as Nuclear, Thermal, Hydro etc. The magnitude of• energy generated by wind turbir,~e is related to different factor s such as Wind speed, Wind direction, Air density, Season of a year, Time of a day 1, etc. Since these variables keep changing over time, the output of wind turbine also changes. Also, other technical constraint such as grid unavailability, turbine breakdown, causes limitations to wind S fir&y pjduction. The power output from the wind turbine is also governed by the design features of wind turbine such as, cut-in speed-the minimum wind speed at which the wind turbine start to deliver useful power, rated wind speed-the wind speed at which the rated power of the machine is reached, and cut-out speed-the maximum wind speed up to which the machine is allowed to deliver power and above this wind speed the wind turbine is shut down to prevent any untoward damage. Generally, the cut-in speed for wind turbine is in range of 2.5 to 3.5m/s and cut-out speed range from 20 to 25 m/s. The rated.power output is produced from wind turbines when the wind speed is above rated wind speed of machine (approximately 14m/s).This makes the total power output • from WECS to vary hourly, daily and monthly. C~ To estimate power and energy of WECS actual field data are used. Field data are collected from seven wind farm with a total capacity of 37.225 MW in Muppandal, Tamilnadu (India) for a period of three years from April 2002 to March 2005.