Power transformer rupture and fire resulting from an arcing fault inside the tank usually leads to significant security risks and serious economic loss. In order to reveal the essence of tank deformation or explosion, this paper presents a 3-D numerical computational tool to simulate the structural dynamic behavior due to overpressure inside transformer tank. To illustrate the effectiveness of ...

Interest has risen among utilities in using natural ester (NE) insulating oils in transformers as a substitute for conventional mineral oil. However, present understanding on aging behaviour of NE-paper composite insulation system and knowledge on application of existing condition monitoring tools for NE-based insulation are inadequate. This limits the cost effective and reliable field applicat...

Polarization-depolarization current (PDC) measurements are now being used as a diagnosis tool to predict the ageing condition of transformer oil-paper insulation. Unfortunately, it is somewhat difficult to obtain the ageing condition of transformer cellulose insulation using the PDC technique due to the variation in transformer insulation geometry. In this literature, to quantify the ageing con...

Kerr electro-optic technique has been used to measure the electric field distribution in high voltage stressed dielectric liquids, where the difference between refractive indices for light polarized parallel and perpendicular to the local electric field is a function of the electric field intensity. For transformer oil, the most widely-used insulating liquids in power apparatus and high voltage...

This research work targets on the effective utilization of WTO (waste transformer oil) in a diesel engine and thereby, reducing the environmental problems caused by its disposal into open land. The novelty of the work lies in adoption of catalytic cracking process to chemically treat WTO, wherein waste fly ash has been considered as a catalyst for the first time. Interestingly, both the oil and...

Well known reasons for local failures in power transformers are caused by partial discharges (PD) in the electric insulation. Continuous deterioration over time increases the defect which finally can lead to a breakdown of the entire insulation. The importance of PD measurement is accommodated by standardized electrical measurement according to IEC 60270 [1] which is required for acceptance cer...

Power transformer is a major component of power system and it’s correct functioning is vital to system operations. It is quite expensive and has no substitute for it’s major role. It is therefore, very important to closely monitor the in-service behavior to avoid costly outages and loss of production. Many devices such as Buchholz relay and Differential relay have been evolved to monitor servic...

The acceptability of four transformer top-oil thermal models are examined vis-à-vis training with measured data. Acceptability is defined as having the qualities of adequacy, consistency, and accuracy. Metrics are used to characterize the likely deficiencies of these models. It is shown that: the classical IEEE/ANSI standard model is unacceptable for model identification purposes. The linear to...

background: in this research, the decomposition of aroclor 1254, including 20 kinds of poly chlorinated biphenyls (pcbs), in real waste transformer oil in the presence of peg1000, naoh, zero valent iron and h2o by microwave (mw) irradiation was studied. methods: central composites design (ccd) method was carried out for experimental design. the effects of microwave power levels (200- 1000 w), r...