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Full-Text Articles in Engineering
Control Of Modular Multilevel Converters For Grid Integration Of Full-Scale Wind Energy Conversion Systems, Suman Debnath
Control Of Modular Multilevel Converters For Grid Integration Of Full-Scale Wind Energy Conversion Systems, Suman Debnath
Open Access Dissertations
The growing demand for wind power generation has pushed the capacity of wind turbines towards MW power levels. Higher capacity of the wind turbines necessitates operation of the generators and power electronic conversion systems at higher voltage/power levels. The power electronic conversion system of a wind energy conversion system (WECS) needs to meet the stringent requirements in terms of reliability, efficiency, scalability and ease of maintenance, power quality, and dv/dt stress on the generator/transformer. Although the multilevel converters including the neutral point clamped (NPC) converter and the active NPC converter meet most of the requirements, they fall short in reliability …
Overcoming Fundamental Barriers In Photovoltaic And Terahertz Generation, Chao Zhou
Overcoming Fundamental Barriers In Photovoltaic And Terahertz Generation, Chao Zhou
Open Access Theses
Several fundamental barriers limit the performance of opto-electronic conversion processes below 100%. Two specific examples of current technological interest include photovoltaic conversion of sunlight into electricity (i.e., solar cells), and terahertz generation from optical sources. In particular, solar cells are limited not only by the Carnot limit associated with the second law (approximately 86% at room temperature), but also by radiative recombination, non-reciprocity, carrier thermalization, and sub-bandgap losses. In the case of terahertz generation, the typical process of difference frequency generation relies on two input optical waves with only a small difference between them to generate the desired output; however, …