Thermal aging of High Voltage Transformer Insulation (2017/1/11 九州工業大学)



■講 師: Professor Suwarno
■ご所属: Institut Teknologi Bandung(インドネシア)

■演 題: Thermal aging of High Voltage Transformer Insulation

■日 時: 平成 28 年 1 月 11日(水) 14:40 〜 16:10
■場 所: 九州工業大学 総合研究1号棟2階 S-2A講義室(院講義室)

■主催:国立大学法人 九州工業大学大学院 工学府電気電子工学専攻

 High voltage transformer is one of the most important equipments in an electric power system. More than 80 % of transformer failures are due to the insulation problem. In general, main insulation of the HV transformers is composed of paper and transformer oil. It is also well known that the lifetime of a high voltage transformer is determined by the life of the paper insulation. Thermal aging plays a very important role in determining the degradation of the insulation. The aging of paper may start from the factory when the so called VPD (vapour phase drying) thermal process is conducted to achieve acceptable level of overall insulation. The study of the effects of VPD on the degree of polymerization was conducted. The results will be presented. During operation, thermal aging comes is due to the heat from the copper, dielectric as well as magnetic losses. Thermal aging of paper- mineral oil and paper-ester composite insulations were studied under 120oC and 150o C. The efects of thermal aging on the tensile strength and degree of plymerization of the paper were investigated. Morphological change of the paper was investigated using SEM (Scanning Electron Microscopy) while chemical change was elaboratd using EDX (Energy-dispersive X-ray spectroscopy). The change of C, O percentage in paper and the appearance of K during aging process was discussed. The effects of thermal aging on the dielectric properties of the transformer oils such as breakdown voltage, tan d, resistivity, water content, etc were investigated. The dissolved gas analysis (DGA) was also conducted. The correlation of the paper and oil aging was elaborated by using the gasses obtained in DGA.

Page Top