Investigation of power quality and structural loads for two‐bladed wind turbines with rigid and teetered rotors using a wind turbine emulator

Abstract

Two-bladed wind turbines (WTs) are recently discussed as a potential alternative to reduce the cost of energy in offshore wind farms which have a higher cost compared to onshore wind farms. However, the dynamic response and performance of these WTs are different from the three-bladed WTs. In this study, new and comprehensive models for rigid and teetered rotor WTs are developed in FAST and emulated with a setup of the previous simulation-based works. Then, the power quality issues are discussed and compared for two-bladed WTs with rigid and teetered rotors as the main contribution of this study. The performance of a WT with different rotors is evaluated and compared in terms of power fluctuations, voltage fluctuations, flicker emission level. In addition, the structural loads of the turbine are studied and compared with both rotor types. This was done in emulation and simulation by varying linear horizontal and logarithmic vertical wind shear as well as utilising a turbulent wind time series without shear. The study presents results obtained by simulation and by emulation, using a scaled-down WT emulator. It presents conclusions as to which type of rotor offers better performance for various operating conditions.