Sökning: "DC magnetization"

Visar resultat 1 - 5 av 10 avhandlingar innehållade orden DC magnetization.

  1. 1. Electromagnetic Modelling of Power Transformers with DC Magnetization

    Författare :Seyed Ali Mousavi; Göran Engdahl; S. V. Kulkarni; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Transformer; Hysteresis; DC magnetization; GICs; FEM; reluctance network method;

    Sammanfattning : DC currents that flow through the ground can be injected to the star windings of power transformers from their grounded neutral points and close their path with transmission lines. The geomagnetically induced currents (GICs) and AC/DC convertors of high voltage direct current (HVDC) systems are the sources of such DC currents. LÄS MER

  3. 2. Electromagnetic Modelling of Power Transformers for Study and Mitigation of Effects of GICs

    Författare :Seyedali Mousavi; Göran Engdahl; Ebrahim Rahimpour; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; transformer; hysteresis; DC magnetization; GMD; GICs; FEM; reluctance network method; low frequency transients; core losses; winding losses; eddy current losses; transformator; hysteresis; DC; likströmsmagnetisering; GMD; GIC; FEM; reluktansnätverksmodell; lågfrekventa transienter; kärnförluster; lindningsförluster; virvelströmsförluster; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : Geomagnetic disturbances that result from solar activities can affect technological systems such as power networks. They may cause DC currents in power networks and saturation of the core in power transformers that leads to destruction in the transformer performance. LÄS MER

  4. 3. 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

  5. 4. Electromagnetic transformer modelling including the ferromagnetic core

    Författare :David Ribbenfjärd; Göran Engdahl; David Jiles; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power transformer; hysteresis; dynamic hysteresis; dynamic magnetization; eddy currents; excess losses; leakage flux; winding model; core model; magnetic measurements; magnetic materials; Electric power engineering; Elkraftteknik;

    Sammanfattning : In order to design a power transformer it is important to understand its internal electromagnetic behaviour. That can be obtained by measurements on physical transformers, analytical expressions and computer simulations. 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