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...

The phenolic antioxidants 2,6-ditertiary-butyl paracresol (DBPC) (also known as butylated hydroxytoluene (BHT)) and 2,6-ditertiary-butyl phenol (DBP) are the two most common oxidation inhibitors added to the electrical insulating (transformer) oil and mineral oil based lubricants. The typical recommended value of DBPC and DBP in fresh electrical insulating oil is approximately 0.3% by weight. T...

Reliability of electrical energy networks depends on quality and availability of electrical equipment like power transformers. Local failures inside their insulation may lead to catastrophic breakdowns. To prevent destroying events power transformers are e.g. tested on partial discharge (PD) activity. As testing is just snapshot information about transformers condition, permanent online monitor...

This thesis describes how to provide standardized, current based, differential protection for any three-phase power transformer, including phase-shifting transformers with variable phase angle shift and transformers of all construction types and internal on-load tap-changer configurations. The use of standard transformer differential protection for such applications is considered impossible in ...

The performance of the power system depend on the reliability of its components such as Transformer, transmission lines, circuit breakers etc. National and international standards stipulates a lighting impulse voltage of 1.2/50 when impulse voltage testing electrical equipments. The high voltage Impulse test the with stand capability of power transformer. Then the problems associated in practic...

A virtual instrumentation based scheme is developed for the characterization of magnetic materials. The principle used for measurement is derived from the comparison method of testing instrument transformers. A prototype has been developed by suitably modifying an instrument transformer test set. Characterization of magnetic materials at single frequency and multiple frequencies have been carri...

proper operations of transformer have several issues such as; preventing of unscheduled removal’s, increasing of reliability and continues supply of consumer demand. this result would be obtained that load and harmonic orders of sensitivity transformer at intervals appropriate for next hours and days is predicted to by selecting optimal utilization coefficient, reduction life of transformer is ...