A hierarchical supervisory wind power plant controller

Abstract

The operation of future wind power plants (WPPs) will rely on maximizing overall profit rather than power production. Factors like current electricity price, grid code compliance, and maintenance costs will affect operational decision. Therefore, it is expected that plant control strategies will trade different control objectives while respecting the industrial practice, where the different levels in the hierarchy may be provided by different equipment vendors. This work proposes a plant controller that aims to track an operator power command at the WPP level and to reject low-frequency loading due to turbulent winds at individual turbines. The plant control respects the hierarchy in which the turbine-level controller takes precedence, interacting only via power set-point commands to each turbine. The control algorithm is based on parallel control loops along with look-up tables and gain scheduling, and its simplicity and effectiveness make it well-suited for industrial applications. Preliminary simulation results with a 32-turbine WPP indicate that there is a significant synergy effect by coordinating operation of the turbines in a plant. Structural loads can be reduced on certain turbines without excessively burdening the others, while an accurate plant-wide power tracking is still provided.