Model Based Open-Loop Wind Farm Control Using Active Power for Power Increase and Load Reduction

Hyungyu Kim,Insu Paek,Kwansu Kim

doi:10.3390/app7101068

Abstract

A new wind farm control algorithm that adjusts the power output of the most upstream wind turbine in a wind farm for power increase and load reduction was developed in this study. The algorithm finds power commands to individual wind turbines to maximize the total power output from the wind farm when the power command from the transmission system operator is larger than the total available power from the wind farm. To validate this wind farm control algorithm, a relatively high fidelity wind farm simulation tool developed in the previous study was modified to include a wind farm controller which consists of a wind speed estimator, a power command calculator and a simplified wind farm model. In addition, the wind turbine controller in the simulation tool was modified to include a demanded power tracking algorithm. For a virtual wind farm with three 5 MW wind turbines aligned with the wind, simulations were performed with various ambient turbulent intensities, turbine spacing, and control frequencies. It was found from the dynamic simulation using turbulent winds that the proposed wind farm control algorithm can increase the power output and decrease the tower load of the most upstream wind turbine compared with the results with the conventional wind farm control.

Highlights

Offshore wind farms using fixed substructures are mostly constructed in seawaters having a depth of less than 40 m, and this often limits the number of wind turbines that can be installed in a wind farm
7, 1068 a wind farm simulation tool, which was constructed in the previous study,4 of was modified to have communications with the wind farm controller
The wind farm model for control was a simplified version of the wind farm model for dynamic simulation, and consisted of a wind turbine model, wake model, wind propagation and superposition model, and a wind farm control model

Summary

Introduction

Offshore wind farms using fixed substructures are mostly constructed in seawaters having a depth of less than 40 m, and this often limits the number of wind turbines that can be installed in a wind farm. The spacing between wind turbines commonly range from 7 RD to 11 RD, where RD represents the rotor diameter of the wind turbine [1,2]. Considering the fact that the rotor diameters of modern wind turbines commonly reach 100 m, the spacing between wind turbines seems large but it is still necessary to reduce the wake effects from upstream wind turbines on downstream ones which result in lower power and higher load [3]. Investigations on active induction wind farm control to reduce the wake strength by regulating the power of the upstream wind turbines less than their available power have been done by researchers. To prove the idea, wind tunnel tests with micro scale wind turbine model arrays with manually adjustable blade pitches with a turbine spacing of 4.5 RD were used.

Methods

Results

Conclusion