Contents I. Introduction
DUE to the fast and large utilization of nonrenewable fossil fuels in the past several tens years and the extensive growing concerns on environmental protection for the earth, a number of practical researches and actual installations of renewable energy systems are quickly proceeding. Recent high oil prices also speeds up the quick development of clean renewable power systems and the discovery of alternative fuels for the future. Wind power energy is one of the most attractive renewable energy resources in the whole world today. To effectively capture the available energy from the randomly varying wind speed, large wind turbines (WT) with proper controls such as pitch control are normally used under variable wind speeds. Among various available generators utilized in wind power generation systems (WPGS), induction generators (IG) operated in either autonomous mode or grid-connection mode are the most extensively employed candidates for variable-speed wind energy conversion systems (WECS) due to their simplicity and robustness. In this paper, steady-state operating conditions and dynamic responses of a commercial WPGS with four identical variable-speed grid-connected induction generators in Taiwan is analyzed. The simulated steady-state results in this paper have been compared with the field measured results of the commercial wind power generation system. The long-term measured results using a precise recorder for over one month were actually performed by the authors.
