43 KB358 KB40 KB200620252006Babuder, MaksGradnik, TimotejKončan-Gradnik, Majaštevilka:4letnik:739 stranistr. 232-240ISSN:0013-5852ISSN:2232-3236COBISSID:28280069URN:URN:NBN:SI:doc-ZHIULZLGslElektrotehniška zveza SlovenijeElektrotehniški vestnikhlajenjeoptimiranjestaranjetemperaturatransformatorjiPomen optimiranja hlajenja za življenjsko dobo in zanesljivost transformatorjev velikih moči| Importance of cooling system optimization with regard to lifetime and reliability of power transformars|The paper presents different risk aspects of transformer insulation breakdown caused by ageing of transformer insulation. Evaluation of recent artificial ageing of paper-in-oil transformer insulation results explains the effect of winding temperature on the achievement of the targeted transformer lifetime. These results and findings of two studies made at the Milan Vidmar Electric Power Research Institute (EIMV) in 2004/2005 assessing the ageing and cooling system state of large power transformers provided the basis for highlighting the occurrence of unexpected early ageing of particular large transformers that had been installed in the Slovenian power grid around 1980. Issues of temperature measurement and cooling system control associated with oil-forced type of transformaer cooling are discused in detail. Oil-forced type cooling has been installed in majority of the 400 kV and 220 kV large power transformers operating in the Slovenian power grid. The paper also discusses the importance of cooling optimization in order to have transformer residual lifetime extended and its life-cycle cost minimezedV referatu so predstavljeni vidiki tveganja za dielektricno porušitev izolacije transformatorjev zaradi njene ostarelosti. Ovrednotenje pomen izsledkov najnovejših raziskav o procesih staranja v transformatorski izolacilji in obrazložen vpliv temperature olja ter navitij na doseganje pricakovane življenjske dobe transformatorjev. Izsledki teh raziskav in ugotovitve dveh študij EIMV s podrocja ocene ostarelosti in stanja hladilnih sistemov energetskih transformatorjev, opravljenih v letu 2004/2005, so nam omogocili pojasniti pojav nepricakovane, zgodnje ostarelosti nekaterih velikih transformatorjev v Sloveniji, vgrajenih okoli leta 1980. V ta namen je podrobno prikazana problematika merjenja temperatur in krmiljenja hladilnih sistemov transformatorjev s prisilnim tipom sistema hlajenja (OFAF). Tak sistem hlajenja je vgrajen pri skoraj vseh 400kV in 220kV transformatorjih velikih moci v slovenskem elektroenergetskem omrežju. Ovrednoten je vpliv optimiranja hlajenja na podaljšanje preostale življenjske dobe in celotne stroške transformacije - LCC (life cycle cost)TEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaElektrotehniška zveza Slovenije