Stand-alone Doubly-Fed Induction Generators (DFIGs) with autonomous frequency control

摘要

This paper presents an innovative control which enables a wind farm based on DFIGs to continue operating on islanding because: (1) each stand-alone DFIG has autonomous frequency control over its stator voltage; (2) multiple units of such DFIGs synchronize to form a common wind farm grid frequency; (3) the DFIGs share the wind farm load by using the common wind farm frequency to implement frequency droop control. Autonomous frequency control is based on integrating the properties of phase-locked loops (PLL) with decoupled P-Q control to produce self-sustaining stator voltages by feedback.