Search for dissertations about: "Electrical conduction"

Showing result 1 - 5 of 133 swedish dissertations containing the words Electrical conduction.

2. 1. Electrical Characterisations of Bearings

   Author : Abhishek Joshi; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ball bearing; Equivalent circuit model; Lubricants; Bearing Capacitance; Spherical bearing; Mechanical bearing; Bearing currents; Electrical conduction; Electrical characterisation;

   Abstract : Mechanical bearings are an integral part of industry, and are used in various places in order to reduce friction between two interacting surfaces and are used to transmit power and loads. Mechanical bearings are one of the most extensively used components within the wind industry, but on the other hand they are also one of the most dominantly failing failed components. READ MORE

4. 2. Modular Battery Systems for Electric Vehicles based on Multilevel Inverter Topologies - Opportunities and Challenges

   Author : Anton Kersten; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dynamic reconfiguration; Energy storage; Energy efficiency; Drive cycle efficiency; Power MOSFET; vehicles; H-bridge; Multilevel systems; Electromagnetic compatibility; Modular battery systems; Battery system performance; Modular multilevel converters; Conduction losses; Electric vehicles; Batteries; Dual battery pack; Cascaded converters; DC-AC power converters; BMS; Common mode noise; Battery modeling; vehicle electrification;

   Abstract : Modular battery systems based on multilevel inverter (MLI) topologies can possibly overcome some shortcomings of two-level inverters when used for vehicle propulsion. The results presented in this thesis aim to point out the advantages and disadvantages, as well as the technical challenges, of modular vehicle battery systems based on MLIs in comparison to a conventional, two-level IGBT inverter drivetrain. READ MORE

5. 3. A Novel Bone Conduction Implant System

   Author : Hamidreza Taghavi; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sound radiation; amplitude modulation; low-power systems.; bone conduction implant; feedback; bone anchored hearing aid; RF power amplifier; gain headroom; implantable transducer; wireless power and data transmission; RF power and data link;

   Abstract : Bone conduction is the process by which an acoustic signal vibrates the skull bones to stimulate the cochlea. Patients with pure conductive hearing loss, mixed hearing loss, and single sided deafness are sometimes poorly rehabilitated by conventional air conduction hearing aids due to for example the functionality losses in the middle ear. READ MORE

6. 4. The Bone Conduction Implant (BCI) - Preclinical Studies, Technical Design and a Clinical Evaluation

   Author : Hamidreza Taghavi; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Bone conduction implant; Amplitude modulation; Bone anchored hearing aid; Radio frequency power amplifier and inductive link; Long-term implantation.; Low-power systems; Implanted transducer;

   Abstract : The Bone Conduction Implant (BCI) system has been developed as an alternative to the percutaneous bone anchored hearing aid (BAHA) with the advantage that the skin is kept intact. The transducer is permanently implanted and attached to the skull via a flat surface contact to the temporal bone. READ MORE

7. 5. From Light to Dark : Electrical Phenomena in Cu(In,Ga)Se2 Solar Cells

   Author : Piotr Szaniawski; Marika Edoff; Uwe Zimmermann; Jörgen Olsson; Thomas Walter; Uppsala universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Solar cells; Photovoltaics; Cu InGa Se2; CIGS; Electrical characterization; Teknisk fysik med inriktning mot elektronik; Engineering Science with specialization in Electronics;

   Abstract : In Cu(In,Ga)Se2 (CIGS) solar cells the CIGS layer serves as the light absorber, growing naturally p-type. Together with an n-type buffer layer they form a p-n heterojunction. Typically, CdS is used as a buffer, although other, less toxic materials are investigated as alternatives. READ MORE