Nonlinear Internal Model Control of Wind Farm Power Optimization under Wake Effect

Abstract

This paper is dealing with the efficiency of wind power under the wake effect. In our previous work, the efficiency is shown to be first depending on the wind turbine's applied control strategy, besides the influence of the environment topology. It is also widely demonstrated that the wind turbine performance decreases under sudden wind profile variations. Therefore, the first main control objective was to perform an optimal wind power capture, particularly below-rated wind speed, while avoiding substantial loads on the drive train shafts. Herein, the focus is on the wake effect in wind farms. Indeed, a wind farm is often subject to wake effect in addition to wind disturbance, in consequence, the wind turbines may fail in respecting the optimal power production as expected. The second main objective is then to maximize the power extraction under the wake effect. So, as an extension of our previous work, this present one aims to apply nonlinear internal model control to each turbine within a small wind farm and to point out that, it is indeed essential to consider the wake phenomenon to determine the real performance of a wind farm power production. Validation results using a wind farm simulator are provided to illustrate the theoretical developments applied on a single turbine in comparison with our previous work performed without wake effect, as well as using a small windfarm comprising 5 machines.