Temperature control and monitoring system for power transformer windings using fiber optic sensors
On-line monitoring of function and condition parameters and the efficiency of the cooling system are key elements in determining the working condition of transformers. This paper presents the implemented hardware and software solutions for carrying out the winding temperature on-line monitoring system using fiber optic sensors. The actual winding temperature is a measurand which defines the condition, load capacity and operating life of transformers. By carrying out the temperature control and monitoring system for power transformer windings using fiber optic sensors, ICMET Craiova aligned itself to the requirements of the international standards.
Experimental thermal investigation of an ONAN distribution transformer by fiber optic sensors
Abstract Transformers are considered as one of the main and high cost components of the power systems. This is due to the fact that their failure may have negative influence on sustainability and quality of energy. In addition, some failures may lead to high cost for replacement or repair and an unplanned outage of a power transformer is highly uneconomical. As a result, as a major equipment in power systems, its correct functioning is vital to enable efficient and reliable operation of electric power system. A transformer can fail due to any combination of electrical, mechanical or thermal stresses. The normal operation life of a transformer is partially related to the deterioration of its insulation through thermal ageing, which is determined mainly by its daily cyclic loadings. In this paper, heat analysis of a 1.5 MVA Oil-Natural Air-Natural cooling mode distribution transformer is experimentally investigated by equipped fiber optic sensors. The density of the fiber optic sensors is increased at the active parts in critical spots. Temperature measurements are realized according to the transformer losses variation and load variation tests. The thermal behavior of the distribution transformer is obtained. Contrary to the existing studies, the obtained results show that also the structure and the design of the transformer affects the hot-spot position and temperature.
Reduction of Surface Flashover of the Beam Screen of the LHC Injection Kickers
The LHC injection kicker magnets include beam screens to shield the ferrite yokes against wake fields resulting from the high intensity beam. The screening is provided by conductors lodged in the inner wall of a ceramic support tube. Operation with increasingly higher bunch intensity, and narrow bunches, now requires improved ferrite screening. This will be implemented by additional conductors; however the good high-voltage behaviour of the kicker magnets must not be compromised by the supplementary screening. Extensive studies and optimisations have been carried out, to better satisfy the often conflicting requirements for low beam coupling impedance, fast magnetic field rise-time, high vacuum and good high voltage behaviour. A new configuration is proposed which reduces significantly the electric field associated with the screen conductors and the secondary electron yield of the surface of the ceramic tube. Results of high voltage test results are also presented.