Coordinated Control for an Offshore Wind Power Plant to Provide Fault Ride Through Capability

The operation of ac connected wind power plants equipped with full power converter wind turbines under deep voltage sags on the main ac grid is analyzed. It is identified that standard control schemes, based on the strict application of grid codes, can lead to instability problems when this kind of severe disturbances occurs. A coordinated control scheme is proposed to operate the system, ensuring fault ride through capability. An index alerts of instability proximity and allows to activate active power and reactive power regulation to guarantee safe operation during faults. This paper describes the proposed control approach and demonstrates its performance by means of dynamic simulations with DIgSILENT Power Factory.