A low voltage ride through system for a variable speed wind turbine having an exciter machine and a power converter not connected to the grid

摘要

A variable speed wind turbine having a doubly fed induction generator (DFIG) includes an exciter machine (212) mechanically coupled to the DFIG and a power converter (230) placed between a rotor (211) of the DFIG and the exciter machine which guarantees a stable voltage to the power converter. The exciter is used as power supply for auxiliary components of the wind turbine when the generator speed is at or above a predefined value.