Automatic generation control of a wind farm with variable speed wind turbines

TLDR

Wind farms are viewed as negative loads by utility managers, yet modern variable‑speed turbines allow separate control of active and reactive power. This paper proposes an integrated control system that satisfies utility manager requirements for wind farms. The system employs a two‑level architecture: a supervisory controller sets active and reactive power setpoints for the entire farm, while turbine‑level controllers enforce those setpoints, and the design was validated by numerical simulation of a 37‑turbine farm in northern Spain. Automatic generation control with this architecture improves system performance and grid integration of wind energy without incurring significant additional costs.

Abstract

Wind farms are considered to be negative loads from the point of view of a utility manager. Modern variable-speed wind turbines offer the possibility for controlling active and reactive power separately. This paper presents a new integrated control system of a wind farm according to the utility manager's requirements. This control system is based on two control levels: a supervisory system controls active and reactive power of the whole wind farm by sending out set points to all wind turbines, and a machine control system ensures that set points at the wind turbine level are reached. The system has been validated by numerical simulation using data from a wind farm with 37 variable-speed wind turbine situated in the North of Spain. An automatic generation control of these characteristics promises improved performance of the system and a better grid integration of the wind energy without significant extra costs.