47 research outputs found
Impact of aluminum nitride heatspreaders on the thermal impedance of silicon-on-glass BJTs
No full textAC Loss Modeling of Superconducting Field Windings for a 10MW Wind Turbine Generator - an Analytical and Numerical Analysis
No full textThe total installed capacity of wind turbines is growing as society moves towards a more sustainable energy supply. With the integration of more wind turbines in the grid the price and reliability of future wind turbines are very important. One of the promising drive train topologies currently investigated is the direct drive superconducting wind turbine. This configuration allows for higher reliability, less top mass and nearly full independence of the volatile market of rare earth metals. However, the superconducting windings in such a generator operate only at cryogenic temperatures which is a challenge in the design of the machine. Since superconducting windings operate at a very low temperature it is important to estimate the heat generation in the windings. AC loss is the main cause of heat generation in a superconducting field winding. This thesis attempts to analyse the AC loss in two 10MW superconducting generator designs using analytical and numerical modeling. After introducing the problem description, the theory concerning AC loss in superconducting wires is treated. Then, the methods for both modeling techniques are established and partly validated. The results are then shown and discussed after which the conclusions are drawn. Both generators are designed for the same turbine and therefore have the same rotational speed and rated power which makes them comparable. The geometry however is different and as the results will show, these differences in design result in major differences in AC loss. Depending on machine geometry the analytically calculated AC loss is ranging from 22.2W to 283W in the Non Magnetic Teeth (NMT) design and 0.7kW to 2.9kW in the Iron Teeth (IT) design. The numerically calculated hysteresis loss is on average 154W in the NMT machine and 371W in the IT machine.Sustainable Energy TechnologyElectrical Power EngineeringElectrical Engineering, Mathematics and Computer Scienc
Saddle add-on metallization for RF-IC technology
No full textElectrical Engineering, Mathematics and Computer Scienc
Material-Inversion Solid-Phase Epitaxy of p+ Si forElevated Junctions
No full textMicroelectronicsElectrical Engineering, Mathematics and Computer Scienc
Detection of thermal runaway and extraction of thermal resistance in silicon-on-glass NPN BJTs using the VCB-VBE voltage plane
No full text
Detection of thermal runaway and extraction of thermal resistance in silicon-on-glass NPN BJTs using the VCB-VBE voltage plane
No full textEnhancement of AlN Slender Piezoelectric Cantilevers Actuation by PECVD Silicon Nitride Coating
No full textActuation enhancement for AlN piezoelectric cantilevers is achieved by coating slender AlN beams with a thin PECVD silicon nitride (SiN) layer. Very good linearity and high deflection, up to 19 nm/V of actuation deflection for 200 ?m long cantilevers, at quasi-static mode, is obtained for a 500 nm SiN top layer. This value is three times larger than our previously reported value for cantilevers without the SiN layer. The achieved results make these cantilevers, fabricated in a CMOS compatible process, very promising micro/nano actuators.Delft Institute of Microsystems and NanoelectronicsElectrical Engineering, Mathematics and Computer Scienc
