High-frequency modeling of power transformers for use in frequency response analysis (FRA)

• This paper presents an advanced model of the frequencyresponse of a three-phase power transformer for usein conjunction with diagnostic measurements by the method offrequency response analysis (FRA). The model includes high frequency behavior of the laminated core and the insulationthrough taking into account the frequency dependencies of the complex permittivity of insulation materials (paper, pressboard, and oil) and of the anisotropic complex permeability of magnetic core and conductors. A lumped parameter circuit model is used to simulate the frequency response of open-circuit impedance,short-circuit impedance, and impedance between primary and secondary windings, in which the characteristics of circuit elements are calculated by means of the finite-element method. Theeffect of correct representation of each circuit element on the FRA response is analyzed and discussed in comparison to measurement results on a real transformer.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik -- Annan elektroteknik och elektronik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering -- Other Electrical Engineering, Electronic Engineering, Information Engineering (hsv//eng)

Nyckelord

frequency response analysis

Finite-element method

power transformer diagnostics

high-frequency modeling

Publikations- och innehållstyp

art (ämneskategori)

ref (ämneskategori)