This paper presents an electro-thermal hydrodynamic model that explains the development of different streamer modes in transformer oil. The focus is on the difference between the slow 2 and fast 3 mode streamers discussed in the literature. Through the use of numerical methods the model demonstrates that streamer modes arise in transformer oil due to the electric field dependent molecular ioniz...

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...

Cellulosic paper and oil insulation in a transformer degrade at higher operating temperatures. Degradation is accelerated in the presence of oxygen and moisture. Power transformers being expensive items need to be carefully monitored throughout its operation. Well established time-based maintenance and conservative replacement planning is not feasible in a current market driven electricity indu...

Analyzing the concentration of low molecular acids dissolved in oil is vital in the oil-paper insulation aging diagnostic procedure of power transformers. The existing methods cannot distinguish between different acid types and their strengths. In this study, an improved solution Raman detection platform is fabricated. The direct measurement of dissolved acetic acid, a kind of low molecular aci...

This paper emphasizes on the use of fuzzy approach in dealing with the incipient fault conditions of power transformer. DGA (Dissolved Gas in Oil Analysis) cannot provide better fault diagnosis results when multiple faults are involved. The boundary values specified by the ratio methods are of limited concern .Considering the limitations of convergence of the conventional neural networks in the...

Hierarchical flower-like ZnO nanorods, net-like ZnO nanofibers and ZnO nanobulks have been successfully synthesized via a surfactant assisted hydrothemal method. The synthesized products were characterized by X-ray powder diffraction and field emission scanning electron microscopy, respectively. A possible growth mechanism of the various hierarchical ZnO nanostructures is discussed in detail. G...

The immersed-oil power transformer is so vital equipment in power system that maintenanceengineers take more monitor from transformer’s insulating oil to diagnose what is condition of operation. Then the dissolved gas analysis (DGA) is known for an effective technique on detecting incipient faults in oil-immersed power transformers. In this paper, a practical method is presented which consists ...

This research was carried out to assess the dechlorination and decomposition of Polychlorinated biphenyls (PCBs) in the real waste transformer oil using polyethylene glycol 1000/NaOH through a modified household microwave oven. To do so, the influence of polyethylene glycol (PEG) (1.5-7.5 g) and NaOH (0.3-1.5 g) under microwave (MW) power of 500 W on the dechlorination efficiency of PCBs, exist...

The housing of zinc oxide lightning arresters are playing major role for discharging the lightning surges. Previously porcelain and silicon rubber housings were mainly used depending on the atmospheric conditions but in practice a lot of problems are faced with these housing. Hence this paper presenting the ZnO blocks performance characterizes with different dielectrics such as air, transformer...