Experimental Testing of a Wind Power Plant with IEC 61400-27 Models for Voltage Regulation Service in Italy

System operators specify different grid services which can be potentially provided by generation units based on renewable energy sources as wind power plants. Those services concern different aspects of system operation and they are defined with specific remuneration schemes. The generation plant aiming to get the remuneration for a given service must fulfill the requirements imposed for that service by the system operator. The paper presents modeling and tuning of an existing wind power plant in Italy for the participation of the wind plant in a voltage regulation service published by the Italian system operator Terna. The wind power plant is composed by 22 2-MW wind turbines and it is modeled for dynamic simulation as Type 3 according to the IEC 61400-27-1 Edition 2 Standard. The model is validated against field measurements obtained by the SCADA system of the wind plant for a reactive power reference step. In order to match the experimental data and overcome the problem of some unknown control parameters, a parameter identification and tuning for the plant controllers is first performed. The validated model is then used to provide a proper parameters adjustment for the compliance of the wind power plant to the voltage regulation service indicated by the system operator.