Primary Frequency Regulation by De-loaded Wind Turbines Using Variable Droop with Reserved Power Margin

Abstract

In this paper, we propose a new approach in selection of power margin using actual de-loaded power from wind turbine, which is considered to improve the grid connected wind turbine generator’s power output during frequency perturbations. Using kinetic energy reserve margins of wind turbine generator rotors, de-loading power is provided to support inertia response when the grid frequency event occurs. The frequency support from individual WTGs is regulated based on the available reserve margin, which depends on the prevailing wind velocities. By continuously adjusting the droop of the WTG in response to wind velocities, the primary frequency response can be improved significantly in terms of reduced stresses on WTGs while low wind speeds. Impact of the proposed variable droop in WTGs can be summarized such as, it has better power output from the wind farm, primary frequency regulation using rotor kinetic energy. The satisfactory result was obtained by carefully choosing the power margin for variable droop operation of de-loaded wind turbine generators. To validate our method, numerical simulation is performed in MATLAB/Simulink.