Vector controlled induction machines for stand-alone wind energy applications

This paper describes the system and control structures for vector controlled induction generators used for variable speed, wind energy conversion (WEC) systems. The paper focuses on WEC systems feeding an isolated load or weak grid since for such systems the generated voltage and power flow must be regulated by the WEC system itself and the control structures are not trivial. The structures for both cage induction and doubly-fed induction generators are described and their performance and complexity compared. Experimental results for both systems feeding an isolated load are given and show that both systems are capable of good output voltage regulation whilst tracking the optimal speed for energy capture