This paper presents an improved model of uniform transformer winding for frequency response analysis (FRA), based on traveling wave theory. The accurate representation of the losses and detailed consideration of measurement chains are the main features of the model. The transfer function expression of the transformer winding and equivalent distributed-parameter circuit for FRA have been derived...

The paper discusses an improved modeling of transformer windings based on particle swarm optimization algorithm (PSO) and frequency response analysis (FRA). With the purpose to accurately identify transformer windings parameters a model-based identification approach is introduced using a well-known lumped parameter model. It includes search space estimation using analytical calculations, which ...

While frequency response analysis (FRA) is a well matured technique widely used by current industry practice to detect the mechanical integrity of power transformers, interpretation FRA signatures still challenging, regardless research efforts in this area. This paper presents method for reliable quantitative and qualitative transformer based on decision tree classification model fully connecte...

Condition monitoring of large power transformers is paramount importance in systems. One the most common indicators transformer aging moisture content oil. In this article, a capacitive sensor able to online measuring presented. The output recorded using Frequency Response Analysis (FRA) device. Comparing FRA results degraded oil with reference test, can be determined. A prototype has been desi...

Frequency response analysis (FRA) is a well-known method to assess the mechanical integrity of active parts power transformer. The measurement procedures FRA are standardized as described in IEEE and IEC standards. However, interpretation results far from reaching an accepted definitive methodology there no reliable code available standard. As contribution this necessity, paper presents intelli...

Frequency response analysis (FRA) is a method of monitoring power transformer’s mechanical integrity. However, identifying the type fault and its severity by comparing measured responses still challenging mostly relies on personnel expertise. This paper taking one step forward to standardize FRA interpretation process proposing guidelines based various international standards case studies. In t...

We previously demonstrated that repeated exposure to extremely low frequency magnetic fields (ELF-MF) increases locomotor activity via stimulation of dopaminergic D1 receptor (J. Pharmacol. Sci., 2007;105:367-371). Since it has been demonstrated that activator protein-1 (AP-1) transcription factors, especially 35-kDa fos-related antigen (FRA), play a key role in the neuronal and behavioral adap...

In Rat-1 fibroblasts nonmitogenic doses of lysophosphatidic acid (LPA) stimulate a transient activation of mitogen-activated protein kinase (MAPK), whereas mitogenic doses elicit a sustained response. This sustained phase of MAPK activation regulates cell fate decisions such as proliferation or differentiation, presumably by inducing a program of gene expression which is not observed in respons...