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The efficiency of the analysis employing finite elements for the design and improvement of electromagnetic devices has already been established several decades. In spite of this, this powerful tool for the advance of power transformer projects has been little utilised due to its complexity and its particular features. This article shall present the formulation of the electromagnetic and thermal problem...
Condition monitoring of power transformers is essential to maintain the reliability of electricity grid. Frequency response analysis (FRA) is a useful tool for the detection of incipient mechanical faults within power transformers. There are various methods of evaluating the frequency spectrum for fault classification and quantification. This paper presents a useful method to detect and to identify...
Water is damaging for transformer insulation, and its presence increases the probability of unexpected failures. Field drying is currently being employed by utilities to reduce the transformer water content when it reaches an excessive value. One of the key aspects to achieve an adequate drying level, is the temperature attained by the solid insulation during the process.
The heat dissipation performance of a panel type radiator attached with rectangular winglets on the air-side was numerically investigated. The natural convection heat transfer of the oil and air were concerned. The numerical results showed that the application of the rectangular winglets can obviously increase the heat dissipation of the panel type radiator. In the computational range of the present...
Power transformers represent the largest portion of capital investment in transmission and distribution substations. In addition, power transformer outages have a considerable economic impact on the operation of an electrical network. One of the most important parameters governing a transformerpsilas life expectancy is the hot-spot temperature (HST) value. The classical approach has been to consider...
A multipoint fiber-optic temperature sensor network integrated inside a power transformer for continuous monitoring of hot-spots on windings, cellulose insulations, and oil, is demonstrated and tested. The temperature sensors are based on proprietary encapsulated fiber Bragg grating (FBG) sensors and the optical interrogation unit uses a special designed narrowband high power broadband fiber source...
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