A METHOD AND SYSTEM FOR CONNECTING A WIND TURBINE SYSTEM TO AN ELECTRIC GRID

摘要

A system and method for connecting a wind turbine system (1) to an electric grid (100), comprising a rotor (2) an electric generator (20) and a closed loop hydraulic transmission system (10). The electric generator (20) is directly connected to the electric grid (100) via a main breaker (50). A control unit (30) is arranged for adjusting the pitch angle (ß) for the hydraulic motor (12) to operate in its recommended operating range, and simultaneously adjusting the displacement (d) to maintain a generator output frequency (ft) within a predefined allowable grid frequency range ( f) and a difference in phase angle within a predefined allowable phase angle range ( ) for a predefined time ( t), before sending a control signal (33) to the main breaker (50) to connect the wind turbine power production system (1) to the grid (100).