The aging of oil-paper insulation in power transformers may cause serious power failures. Thus, effective monitoring of the condition of the transformer insulation is the key to prevent major accidents. The purpose of this study was to explore the feasibility of confocal laser Raman spectroscopy (CLRS) for assessing the aging condition of oil-paper insulation. Oil-paper insulation samples were ...

Oil testing has found widespread use in assessing the quality of the insulation system of a transformer. Techniques such as Dissolved Gas Analysis (DGA) have been proven to be reliable in this task, but are expensive, laborious and time consuming. It is also not available for field use. This paper proposes the combined use of gas and optical sensing technology for the testing of transformer oil...

Transformers are normally designed and built for use at rated frequency and sinusoidal load current. A non-linear load on a transformer leads to harmonic power losses which cause increased operational costs and additional heating in transformer parts. It leads to higher losses, early fatigue of insulation, premature failure and reduction of the useful life of the transformer. To prevent these p...

he presence of moisture in a transformer deteriorates transformer insulation by decreasing both the electrical and mechanical strength. In general, the mechanical life of the insulation is reduced by half for each doubling in water content [l]; the rate of thermal deterioration of the paper is proportional to its water content [2]. Electrical discharges can occur in a high voltage region due to...

Transformers are normally designed and built for use at rated frequency and perfect sinusoidal load current. A non-linear load on a transformer leads to harmonic power losses which cause increased operational costs and additional heating in power system components. It leads to higher losses, early fatigue of insulation, premature failure and reduction of the useful life of the transformer. To p...

Integrated-optic devices for use in high-voltage substations are reviewed. Specifically, two types of integrated-optic Mach-Zehnder and the integrated-optic Pockels cell are described and compared. A system for monitoring the condition offluid-and-paper insulation systems, such as are used in many current transformers and power transformer bushings, is also described. This condition monitoring ...

Power transformers reliability, amongst other things, depends on its insulation system. High voltage leads are a part of the system and should be properly insulated. This includes positioning an barrier between tank certain distance. distance affects safety factors (breakdown probability) for such The paper presents optimization process with which both breakdown probability vs. could minimized....

The main insulation system in high-voltage direct current (HVDC) transformer consists of oil-paper insulation. The formation of space charge in insulation paper is crucial for the dielectric strength. Unfortunately, space charge behavior changes because of the corrosive sulfur substance in oil. This paper presents the space charge behavior in insulation paper induced by copper sulfide generated...

Twelve men who had been exposed to a minor asbestos hazard have been examined clinically, radiologically, and physiologically, and an assessment of the airborne asbestos concentration has also been made. Ten men had worked in a transformer department lagging transformer windings with asbestos paste for between IS and 37 years. Two of these men showed minor radiological and minor physiological c...