Search for dissertations about: "transformer failure"

Showing result 1 - 5 of 9 swedish dissertations containing the words transformer failure.

2. 1. Condition-based Failure Rate Modelling for Individual Components in the Power System

   Author : Jan Henning Jürgensen; Patrik Hilber; Lars Nordström; Thomas Welte; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Asset management; condition monitoring; diagnostic measures; failure rate; failure rate modeling; transformer diagnostics; Electrical Engineering; Elektro- och systemteknik;

   Abstract : The electrical power grid is one of the most important infrastructures in the modernsociety. It supplies industrial and private customers with electricity and supportsother critical infrastructures such as the water supply. Thus, it is significant that the power grid is a reliable system. READ MORE

4. 2. Dynamic Thermal Rating for Improved Utilization of Wind Farm Export Systems : A Methodology for Improving Load Profile Estimation of Wind Farm Export Transformers

   Author : Zhongtian Li; Patrik Hilber; Tor Laneryd; Stefan Ivanell; Nguyen Nga; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dynamic thermal rating; wake effect; turbine availability; transformer lifetime; transformer aging; dynamisk termisk klassificering; väckningseffekt; turbintillgänglighet; transformatorlivslängd; transformatoråldring; Electrical Engineering; Elektro- och systemteknik;

   Abstract : The power system components connected to renewable energy sources, such as transformers, are often oversized and conservatively loaded. The design of transformers normally ignores the intermittent nature of the connected renewable energy sources (e.g. solar, wind). READ MORE

5. 3. Partial Discharge Signatures of Defects in Insulation Systems Consisting of Oil and Oil-impregnated Paper

   Author : Mohamad Ghaffarian Niasar; Hans Edin; Peter Werelius; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; partial discharge; transformer; oil; ageing; temperature; PD classification;

   Abstract : Partial discharge measurement is a common method for monitoring and diagnostics of power transformers, and can detect insulation malfunctions before they lead to failure. Different parameters extracted from the measured PD activity can be correlated to the PD source, and as a result it is possible to identify the PD source by analyzing the PD activity. READ MORE

6. 4. Diagnostics of Oil-Impregnated Paper Insulation Systems by Utilizing Lightning and Switching Transients

   Author : Roya Nikjoo; Hans Edin; Christer Törnkvist; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Capacitance; Dielectric Response; Loss tangent; Moisture content; Oil - impregnated paper; Temperature; Transformer Bushing; Transients;

   Abstract : Development of the power gridtowards a more reliable and smarter system requires frequent on-line monitoring of the power components. Power transformers and their bushings are particularly important components in a power transmission system and their insulation degradation may lead to catastrophic failures. READ MORE

7. 5. Lifetime modeling and management of transformers

   Author : Johanna Rosenlind; Rajeev Thottappillill; Zhong Dong Wang; KTH; []
   Keywords : transformers; lifetime modeling; asset management; thermal modeling; lifetime estimation;

   Abstract : This work have studied and developed lifetime estimation methods for the power transformer and how these could be used for asset management purposes. It is researchperformed in the intersection of the fields of reliability theory, statistical analysis, and stochastic process theory applied to lifetime estimations and management of transformers. READ MORE