Optimal power dispatching in offshore wind farms ensuring power reserve for frequency control and load mitigation
The research work aims at assessing the performance of curtailing methods for frequency regulation and load mitigation in wind farms. A probabilistic approach is considered by resorting to a stochastic characterization of the wind speed and direction, as well as different grid fault scenarios.
The ability to significantly participate in the frequency regulation and provide valuable ancillary services to the Transmission System Operator is one of the present wind farm challenges, due to imprecision in wind speed forecasting and insufficient power reserve in certain operating conditions notably.
The goal of this work is to assess the performance of the curtailing methods to achieve frequency regulation and load mitigation at a wind farm level. Besides the classical de-rating methods using only pitch and torque controllers, yaw optimization for power maximization control is viewed as a new means for power reserve that can be used for the secondary frequency regulation.
Since the wind is turbulent in time and space, the performance of these controllers will be studied in a probabilistic setting, based on different possible sources of unbalance. Improving the participation of wind farms in ancillary services will allow wind farm owners to take part in the electricity market, increasing competitiveness with classical power plants for grid balancing. Moreover, given the steady increase of wind farm participation in the production of electricity, ensuring appropriate power reserve from wind farms will allow avoiding load shedding and partial blackouts, which could have disastrous social and economic effects. Indeed, such phenomena could affect company profitability and, if too frequent, lead to job losses.
Finally, the work is expected to allow for a wider penetration of wind energy in the electricity market, hence limiting CO2 emissions, while ensuring the security of supply.