Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 16 of 16 for “"copper losses"”.
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An investigation of copper losses in reverberatory slags
Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Metallurgy, 1943.
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Copper status in multiple trauma patients: measurement of copper balance, serum copper and ceruloplasmin
Changes in copper metabolism have been reported in both thermal injury and skeletal trauma; data regarding copper status in multiple trauma patients (MTP) are nonexistent. Hypercatabolism following multiple trauma may increase copper utilization, deplete copper stores and compromise cuproenzyme …
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Der Einfluss von Lagerstätteneigenschaften auf eine nachhaltige Rohstoffnutzung am Beispiel Kupfer
… subsequent processes where analyzed. The metal losses where analyzed in relation to the mining and processing methods employed and in relation to the ore deposit types the ore is extracted from. The global copper production 1998 was 12.05 Mt. The calculated overall copper loss was 4.2 Mt (26% of …
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Eddy currents in windings of switched reluctance machines
… Since common design tools neglect these losses, the performance of new machine designs is often overestimated. To calculate the eddy current losses a complex two-dimensional finite element model is presented. The model can simulate any transient operating point, considering all relevant …
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Design of segmented outer rotor permanent magnet flux switching motor in transverse shape for high torque applications
… high number of rotor segments and high number of copper conductor. These high materials usage lead to high iron and copper losses that affect performance of motor. This thesis deals with a newly designed structure of the segmented outer rotor permanent magnet flux switching motor in transverse …
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Development of a new single-phase field excitation flux switching motor topology with segmental rotor
… high end coil increased size of motor and high copper losses. Therefore, a new topology of singlephase non-overlap windings 12S-6P FEFSM segmented rotor with the advantages of less weight and non-overlap between armature coil and FEC windings is presented. The design, flux linkage, back-EMF, …
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High-frequency, high-pole count design for improving specific power density of electric machines
… reactance, leakage reactance, and iron/copper losses are realized. The concept is applied to two of the most ubiquitous electric machines today: induction machines and permanent magnet machines. Electrical equivalent circuits are utilized to analytically hypothesize the effect of HFHP …
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Variable Ratio Matrix Transformer based LLC Converter for Two-Stage Low-Voltage DC-DC Converter Efficiency Improvement
… improvement. The transformer secondary copper losses are reduced by taking advantage of the adaptive number of element transformers. In addition, the PWM dc-dc stage achieves better efficiency with variable intermediate bus voltage. The operation principle and design considerations are …
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Design and optimisation of three-phase salient rotor wound field flux switching motor
… rotor and overlapping windings inherit high copper losses and less efficiency due to their long end-windings. This thesis deals with a novel structure of WFFSM employing a salient rotor with nonoverlapping field and armature windings on the stator and a presentation of an unexcited rotor. The …
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Performance limits of linear variable reluctance motors in controlled linear motion applications
… tasks have been examined in relation to the copper losses associated with them in order to assess the trade-off. It has been shown that higher force capability is achieved when force-ripple constraints, which have been customarily emphasized in positioning applications, are relaxed. The …
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Investigation of a GaN-Based Power Supply Topology Utilizing Solid State Transformer for Low Power Applications
… in the transformer secondary side yielding less copper losses. A high-frequency nanocrystalline toroid transformer, based on a modified equation to determine its leakage inductance, is designed and fabricated to satisfy the performance specifications of the converter. A meticulously planned gate …
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Studies of the interactions of CCA and ACA preservative treated wood with soil
… Hayne) were used exclusively.<br/><br/>Copper losses from both types of preservative treated wood were negligible, though adjacent soil copper concentrations significantly increased. These copper accumulations were associated with a reduction in dehydrogenase activity around the …
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Reclosing transients in standard and premium efficiency induction machines in the presence of voltage unbalance
… in order to reduce the stator and rotor copper losses. Using material with a higher permeability, as is the case with energy efficient machines, ensures that the machines are able to retain less residual flux at the point of disconnect than standard motors. It is for this reason that the …
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High-Efficiency Low-Voltage High-Current Power Stage Design Considerations for Fuel Cell Power Conditioning Systems
… non-trivial sources of loss include magnetic losses, copper losses, contact and termination losses, skin effect losses, snubber losses, capacitor equivalent series resistance (ESR) losses, and body diode related losses. Many of the losses can be avoided by carefully designing the system. …
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Investigation of High-Temperature Superconducting Trapped Field Magnets in a Superconducting Motor
… superconducting machines while minimising energy losses. A computational method was devised to determine the optimal combination of layer number and magnetisation current amplitude for achieving the maximum magnetisation field in superconducting machines. Additionally, innovative superconducting …
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Independent power flow control of multiple energy sources using a single electric machine
… experimental approach to segregate constant losses (core and mechanical losses) from load dependent losses (copper losses). All the proposed control methods have been validated by simulation and experimentally, except for the double winding machine where experiments were not done.