DFIG wind turbines operating in a fixed reference frame

Abstract

HVDC connected offshore wind farms represent a weak grid that causes stability issues in voltage oriented controlled converters. In addition the conventional line side converter control is not applicable for island grids without an existing AC-voltage source. A Fixed Reference Frame (FixReF) control proved already beneficial in full scale converter wind turbines. In this paper, the usage of FixReF in wind energy plants with doubly fed induction generators is investigated.