High-Frequency Modeling of Power Transformers for Use in Frequency Response Analysis (FRA)

A comparison of transformer HF models and their application to PQ analysis

“…This type of model is close to the real behavior of the real transformer [1][2][3]. The main drawback of this approach is the neccessity of information about the physical structure of the machine, including dimensions, materials and geometry.…”

Detection of power transformer bushing faults and oil degradation using frequency response analysis

“…To accurately identify the effect of bushing faults on the electrical parameters of bushing equivalent Tmodel, the physical geometrical dimension of a 10 kVA bushing of the three-phase transformer shown in Figure 2 is simulated using 3D finite element software (Ansys) for healthy and faulty conditions. Faulty bushing is emulated through altering its insulation complex permittivity which is influenced by many factors such as ambient temperature and the structure of the insulation system [7]. The electrical parameters for normal and faulty conditions are extracted using FEM based on the following three steps:…”

Two-dimensional boundary shape reconstructions in rectangular and coaxial waveguides

“…The electric power grid consists of components like power generators, power transformers, switchyards, cables and transmission lines. Most of the existing diagnostic methods for these components are off-line methods, such as frequency response analysis [1] and dielectric spectroscopy [2], which involve a non-service stress of the component and financial loss of revenue during the tests. One widely used on-line method-Dissolved Gas in oil Analysis [3], is an integral method, where the measured gas concentrations can be either the result of a recent fault, or a result of running the component over a long time period.…”