In this paper, we performed an insulation diagnosis technique for oil-immersed power transformers by an acoustic detection method. Electrode system such as needle to plane electrode was fabricated to simulate a defect of power transformers. In addition, the frequency spectrum of acoustic signals with partial discharge (PD) in insulating oil was analyzed. From the FFT result, the frequency spect...

Abstract The conventional renovation practices, which are mainly characterized by time-consuming manual on-site techniques, partly contribute to the low rate. Accordingly, a faster and more efficient approach is necessary. implementation of prefabricated systems could offer possible solution. These increasingly being studied, but little known about their environmental impact. Hence, this study ...

High temperature operating life (HTOL) testing was performed on embedded planar capacitors (with epoxyBaTiO3 composite dielectric) by subjecting these devices to highly accelerated temperature and voltage aging conditions. The objective of HTOL testing was to precipitate avalanche breakdown failures as a result of defects in the composite dielectric. These defects include porosity, voids, and a...

Power system overvoltages due to switching, lightning and other disturbances are the main problem for designers of the power transformers. Once some frequencies of the incoming surges match with some of the natural frequencies of transformer winding, the resonance phenomenon is expected in transformer winding. The resonant overvoltages may destroy the insulation between turns and cause to insul...

Looking at the increasing request concerning sound insulation in building, TechnoFirst@ and Saint Gobain Vitrage propose an active double-glazing window. In this partnership, TechnoFirst@ brings its experience in active control system. The product will be characterized by a global insulation never obtained. It deals with an acoustic treatment of the air volume. Modelisations have been done and ...

The principle of partial discharge detection is that through partial bridged discharge under high voltage electric field, it detects the inner air-filled cavity of high-voltage insulators. And it is a nondestructive detection method based on discharge magnitude to judge the insulation quality. The detecting system that adopts the partial discharge detection is more rigorous than testing system ...

The tunneling ability of the Formosan subterranean termite Coptotermes formosanus Shiraki through a cellulose insulation material containing11.1% boric acid was tested in choice and nochoice bioassays. We examined tunneling behavior and mortality of termites exposed to treated and untreated insulation material in miniature simulated wall voids. In a choice test termites tunneled through untreat...