Equivalent modeling of wind farm in frequency domain

Abstract

A frequency-domain modeling method for the wind farm under wind fluctuation is proposed. A linear system named “Positive Wind Channel” is adopted to represent the energy conversion process of the wind farm with considering the spatial effects such as wake effect, wind shear, tower shadow and time-lag effect. A “Negative Wind Speed” is defined to represent the action of pitch angle controller which offsets the surplus power of the incoming wind. A linear system named “Negative Wind Channel” is employed to approximately represent the total effect of all the wind turbine generators' pitch angle controllers. The frequency-domain models of these two channels make up the frequency-domain model of the wind farm. With this model, the output power of the wind farm can be calculated directly by the “Original Incoming Wind Speed” while no time-domain simulation is necessary. The result of the case study shows the effectiveness of this method.