Sökning: "transformer insulation"

Visar resultat 1 - 5 av 14 avhandlingar innehållade orden transformer insulation.

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

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

   Sammanfattning : 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. LÄS MER

3. 2. Diagnosis of Moisture in Transformer Insulation - Application of frequency domain spectroscopy

   Författare :Chandima Ekanayake; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; moisture content; diagnostic methods; modelling; polarisation depolarisation currents PDC ; frequency domain spectroscopy FDS ; dielectric response measurements; Oil-impregnated pressboard paper insulation; Karl Fischer titration KFT ; conductivity; ageing;

   Sammanfattning : This thesis presents application of dielectric response measurements for identifying condition of high voltage insulation in power transformers. Results of such measurements, incorporated with different modelling techniques, allow to estimate moisture content in solid part of transformer insulation. LÄS MER

4. 3. A Novel Oil-immersed Medium Frequency Transformer for Offshore HVDC Wind Farms

   Författare :Mohammad Kharezy; Per Olof Hedekvist; Yuriu Serdyuk; Thomas Hammarström; Karsten Backhaus; RISE; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; prototype design methodology; finite element analysis; HVDC insulation design; medium frequency transformer; Wind energy; DC-DC power converters;

   Sammanfattning : In this project, a design of an oil type medium frequency transformer for offshore wind farm applications is proposed. The design is intended for applications when series coupling of the output of the DC/DC converters of the wind turbine on their secondary side is done to achieve a cost-effective high voltage solution for collecting energy from offshore wind parks. LÄS MER

5. 4. High Voltage DC-biased Oil Type Medium Frequency Transformer; A Green Solution for Series DC Wind Park Concept

   Författare :Mohammad Kharezy; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High voltage DC; Insulation design; Offshore wind farm; Leakage inductance; High power isolated DC DC converter; Dual active bridge; Medium-frequency power transformer; Parasitic capacitance; HVDC;

   Sammanfattning : The electric energy generated by remote offshore wind parks is transported to the consumers using high voltage submarine cables. On the generation site, such transmissions are realized today by collecting the energy produced by several wind turbines in a bulky and expensive transformer placed on a dedicated platform. LÄS MER

7. 5. Effect of Dielectric and Magnetic Material Characteristics on Frequency Response of Power Transformers

   Författare :Nilanga Abeywickrama; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; frequency response analysis; dielectric insulation; Complex permeability; core magnetization; finite element method; transformer diagnosis.; high frequency modelling; magnetic viscosity; silicon steel;

   Sammanfattning : Frequency response analysis (FRA) technique has become increasingly popular for the assessment of mechanicalintegrity in power transformers. This method is based on the fact that the shape of the frequency response at higher frequencies is uniquely determined by the geometrical construction of the transformer. LÄS MER