Bi-Level Decentralized Active and Reactive Power Control for Large-Scale Wind Farm Cluster

This paper proposes a bi-level decentralized active and reactive power control (DARPC) for the large-scale wind farm cluster (WFC) composed of several wind farms. The WFC tracks the active power reference from the transmission system operator (TSO) while controlling the bus voltage of the point of connection (POC), and maintaining the wind turbine (WT) terminal voltages stable in each wind farm. In the upper level, a distributed active and reactive power control scheme based on the consensus protocol is designed for the WFC, which can achieve fair active and reactive power sharing among multiple wind farms, and generates active and reactive power references for each wind farm. In the lower level, a centralized control scheme based on Model Predictive Control (MPC) is proposed, which can effectively regulates active and reactive power outputs of all WTs within the wind farm. The proposed centralized control scheme can maintain WTs terminal voltage close to the rated voltage while tracking the power reference from the upper level control. The DARPC can effectively reduce the computation burden of the WFC controller by distributing the computation and monitoring tasks to several wind farm controllers. Moreover, the communication cost is reduced. A WFC with 8 wind farms and totally 128 WTs was used to validate the proposed DARPC scheme.