Investigation of Horizontal and Vertical Wind Shear Effects Using a Wind Turbine Emulator

This paper presents modeling and analysis of horizontal and vertical wind shear effects using a wind turbine emulator (WTE) with a comprehensive model. These periodic effects generate power fluctuations and mechanical stress on the wind turbine (WT) components during its operation. The frequency of these fluctuations associates with the rotation speed and the number of blades, whereas the amplitude increases in larger turbines. Although the vertical wind shear effect was modeled in literature using WTEs, the simplified aerodynamic and mechanical models were considered for WTs. In this paper, in addition to the vertical wind shear, the horizontal wind shear is modeled in simulation and experiment using a WTE, which may have more severe effects. The utilized WTE employs a comprehensive model for the WT, which considers aerodynamic, mechanical, and electrical aspects. The interaction of different aspects and mechanical dynamics is included in the WTE, which utilizes AeroDyn and FAST software tools to model the aerodynamic and the mechanical aspects of the WT. A coupled induction motor-induction generator set was employed to develop the WTE, which is used to model the wind shear effects for a fixed-speed WT.