In this paper an analysis of different designs of traction transformers is given. The paper describes three-limb transformer design for 7.5 MVA and 10 MVA units and two-limb transformer design for 15 MVA and 16 MVA units. Paper also represents noise level measurement results and sound intensity frequency spectrum for 16 MVA unit. Based on results of measurements taken during heat run test on tr...

frequency response analysis (fra) is popular technique which has been used since the last decade as a diagnostic method for transformers. however, accurate interpretation of fra measurements is still challenging. recent studies reveal that apart from winding deformation, fra data can also be influenced by moisture variation in transformer paper insulation. hence, a specific transformer’s model ...

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv EXECUTIVES UMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . xvii . l.INTRODUCTION .. .:. .................................. l-l 1.1 BACKGROUND .................................... l-l 1.2 MARKETTRENDS ..................................... l-2 1.3 STUDYAPPROACH ..........................

s – Detection of minor faults in power transformer active part is essential because minor faults may develop and lead to major faults and finally irretrievable damages occur. Sweep Frequency Response Analysis (SFRA) is an effective low-voltage, off-line diagnostic tool used for finding out any possible winding displacement or mechanical deterioration inside the Transformer, due to large electro...

In many years teaching of Electric Machinery, Electrical Engineering Theory, and Power System Analysis, I found that students have difficulty learning how to calculate transformer parameters. It is even more difficult for them to understand the reason of reducing capacity of short circuit of three windings transformer which has different capacities in each winding. However, the calculation of t...

Recently, dry power transformer (Dryformer) that performs one step transformation from transmission to distribution voltage levels, has been introduced [1]. The Dryformer (dry power transformer) combines the features of power transformer with that of station distribution transformer, by utilising XLPE insulated round conductor cable for winding construction. The parameters of the cable winding ...

Abstract—Sweep frequency response analysis has been turning out a powerful tool for investigation of mechanical as well as electrical integration of transformers. In this paper various aspect of practical application of SFRA has been studied. Open circuit and short circuit measurement were done on different phases of high voltage and low voltage winding. A case study was presented for the trans...

DC bias will cause abnormal vibration of transformers. Aiming at such a problem, transformer vibration affected by DC bias has been studied combined with transformer core and winding vibration mechanism use multi-physical field simulation software COMSOL in this paper. Furthermore the coupling model of electromagnetic-structural force field has been established, and the variation pattern of inn...