Evaluation of Wind Farm Control Strategies - Coupling with Drivetrain Degradation

Abstract

A mid-fidelity simulation framework for large offshore wind farms has been developed at SINTEF, for the efficient joint modelling of active power control and structural degradation due to fatigue damage. It bridges two fields of research that are traditionally split: grid integration and mitigation of asset degradation, through multi-objective wind farm control. Component-level damage is brought to farm-level simulations. There, damage and power demand from the grid are linked to stochastic loads and power fluctuations arising from turbulence in the wind, on which a particular emphasis has been set. In a joint project with NTNU, this has been applied to the mitigation of the degradation of power train components (gears and bearings) in curtailed (down-regulated) wind conditions. It is shown that when a farm is requested not to operate at its full available power by the grid operator, it is possible to —to some extent— steer degradation to better fit maintenance scheduling or lifetime extension plans to further reduce LCOE. The framework has been developed in parallel projects in synergy with NorthWind and consists of four main features: (1) a wind farm simulator adapted for stochastic simulations of large wind farms in down-regulated operation, (2) a farm-wide turbulence generator, (3) a wind farm controller and (4) a database for drivetrain degradation based on turbine- and component-level simulations. This report first introduces the concept and motivation, then presents each of the above-mentioned features before linking them in a case study.

Evaluation of Wind Farm Control Strategies - Coupling with Drivetrain Degradation