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Dan Wu

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4 records found

Standards, Control, Power Quality and Transmission

Journal article (2024) - Dan Wu, Gab-Su Seo, Lie Xu, Chi Su, Łukasz Kocewiak, Zian Qin
Offshore wind is expected to be a major player in the global efforts toward decarbonization, leading to exceptional changes in modern power systems. Understanding the impacts and capabilities of the relatively new and uniquely positioned assets in grids with high integration levels of inverter-based resources, however, is lacking, raising concerns about grid reliability, stability, power quality, and resilience, with the absence of updated grid codes to guide the massive deployment of offshore wind. To help fill the gap, this paper presents an overview of the state-of-the-art technologies of offshore wind power grid integration. First, the paper investigates the most current grid requirements for wind power plant integration, based on a harmonized European Network of Transmission System Operators (ENTSO-E) framework and notable international standards, and it illuminates future directions. The paper discusses the wind turbine and wind power plant control strategies, and new control approaches, such as grid-forming control, are presented in detail. The paper reviews recent research on the ancillary services that offshore wind power plants can potentially provide, which, when harmonized, will not only comply with regulations but also improve the value of the asset. The paper explores topics of wind power plant harmonics, reviewing the latest standards in detail and outlining mitigation methods. The paper also presents stability analysis methods for wind power plants, with discussions centered on validity and computational efficiency. Finally, the paper discusses wind power plant transmission solutions, with a focus on high-voltage direct-current topologies and controls. ...
Journal article (2021) - Ana Palčić, Sara Navarro Jaén, Dan Wu, Mengdie Cai, Chong Liu, Evgeny A. Pidko, Andrei Y. Khodakov, Vitaly Ordomsky, Valentin Valtchev
Embryonic X-ray amorphous semi-formed MFI-type zeolite units mixed with the Cu–Zn–Al catalyst have been used for the direct synthesis of dimethyl ether (DME) from syngas. The hybrid catalyst with embryonic zeolite (EZ) with the particle size of 5 nm has demonstrated superior performance in terms of activity, selectivity, and stability compared to the crystalline ZSM-5 zeolite counterpart and the amorphous aluminosilicate material. The FTIR pyridine adsorption uncovered several types of active sites in EZ, including Brønsted acid sites of medium strength. The DFT modeling pointed out the key role of defect sites leading to lower strength of the acid sites in the embryonic MFI zeolite in comparison with the fully crystalline material. The effect of embryonic zeolite on the DME synthesis has been assigned to enhanced transport of methanol from Cu to ultra-small zeolite precursor units with moderate acidity, hence promoting the efficient dehydration to DME with high selectivity and stability. ...
Conference paper (2012) - Dan Wu, Zhiqiang Guo, Deshang Sha, Zian Qin, Xiaozhong Liao