Abstract:  ABSTRACT： The wake effect of offshore wind farm has strong regularity, which makes each row of turbines to capture different wind speed and thus work in different states, consequently limitation exists for traditional frequency control based on single equivalent method. According to the characteristics of offshore wind resource and the active power control of doubly-fed induction generator wind turbines, this paper proposes a multi-turbine equivalent frequency control method for offshore wind farm considering wake effect, which can qualitatively and quantitatively analyze the change of the frequency control capability and cost of the wind turbine under different wind conditions and in different schemes. Simulation results show that, compared with the frequency control method with single equivalent and single frequency control command, multi-turbine equivalent method for offshore wind farm based on wind speed sector division is more reasonable. Allocating the frequency control power and time reasonably based on the proposed method can provide better dynamic frequency support as well as shorter recovery time and have higher economy for power system.  

Key words:  KEYWORDS： offshore wind farm, frequency control, wake effect, multi-turbine equivalen