Wind shear and tower shadow are the sources of power fluctuation of grid connected wind turbines during continuous operation. This paper presents a simulation model of a MW-level doubly fed induction generator (DFIG) based variable speed wind turbine with a partial-scale back-to-back power converter in Simulink. A simple and effective method of wind power fluctuations mitigation by active curre...

We discuss the cosmological degeneracy between the Hubble parameter H(z), the age of the universe and cosmological parameters describing simple variations from the minimal ΛCDM model. We show that independent determinations of the Hubble parameter H(z) such as those recently obtained from ages of passively evolving galaxies, combined with Cosmic Microwave Background data (WMAP 5years), provides...

The n-type transition metal oxides (TMO) consisting of molybdenum oxide (MoO(x)) and vanadium oxide (V(2)O(x)) are used as an efficient hole extraction layer (HEL) in heterojunction ZnO/PbS quantum dot solar cells (QDSC). A 4.4% NREL-certified device based on the MoO(x) HEL is reported with Al as the back contact material, representing a more than 65% efficiency improvement compared with the ca...

A fully resolved (FR) NREL 5 MW turbine model is employed in two unsteady Reynolds-averaged Navier–Stokes (URANS) simulations (one with and one without the tower) of a periodic atmospheric boundary layer (ABL) to study performance an infinitely large wind farm. The results show that power reduction due tower drag about 5% under assumption driving force ABL unchanged. Two additional using actuat...

Abstract. Wind turbines are designed using a set of simulations to determine the fatigue and ultimate loads, which typically focused solely on unwaked wind turbine operation. These structural loads can be significantly influenced by inflow conditions. Turbines experience altered conditions when placed in wake upstream turbines, additionally influence loads. It is important understand impact unc...

Knowledge of the dynamics wind turbine wakes and its dependence on incoming boundary layer is fundamental to optimize control power production farms. This work aims at investigating effect inflow turbulence wake NREL-5MW turbine. Sparsity-Promoting Dynamic Mode Decomposition (SP-DMD) performed snapshots extracted from large-eddy simulations wake, for detecting most dynamically-relevant flow str...

Dynamic mode decomposition (DMD) has been applied to the wake of NREL-5MW wind turbine invested by a uniform inflow, identify most dynamically relevant coherent structures characterizing this flow. The on snapshot dataset obtained Large-Eddy Simulation flow impinging turbine, whose tower and nacelle are modeled immersed boundary method, whereas rotor blades using actuator line method. Sparsity-...

This paper presents the modeling and simulation of offshore wind power platform for oil and gas companies. Wind energy has become the fastest growing renewable energy in the world and major gains in terms of energy generation are achievable when turbines are moved offshore. The objective of this project is to propose new design of an offshore wind power platform. Offshore wind turbine (OWT) is ...

We report the demonstration of CdTe/MgxCd1-xTe double heterostructures (DHs) with a carrier lifetime of 3.6 μs and an interface recommendation velocity of 1.2 cm/s, comparable to or even better than the best values reported for GaAs/Al0.5Ga0.5As (18 cm/s) and GaAs/Ga0.5In0.5P (1.5 cm/s) DHs. Combined with a p-contact layer (8 nm a-SiCy:H + 4 nm a-Si:H), devices consisting of MgxCd1-xTe/CdTe/Mg0...