STRATEGIC MAINTENANCE OF HIGH VOLTAGE EQUIPMENT FROM THE POINT OF RELIABILITY AND RISK

Vzdrževanje je kombinacija vseh tehničnih, upravnih in vodstvenih ukrepov v življenjski dobi naprave s ciljem obdržati jo ali vzpostaviti jo v stanje, v katerem lahko opravlja svojo funkcijo. Je torej običajni proces, ki ga potrebuje vsaka naprava za normalno delovanje. Tudi v prenosni tehniki je vzdrževanje ključnega pomena za varno in zanesljivo obratovanje elektroenergetskega sistema. Terminologija vzdrževanja obravnava dva osnovna pristopa, preventivno in korektivno vzdrževanje. Na področju tehničnih sistemov in s tem tudi prenosnih naprav elektroenergetskega sistema trenutno prevladuje metoda preventivnega vzdrževanja. Ta metoda je lahko časovno opredeljena ali pa povezana s stanjem naprav. Doktorska disertacija obravnava strateško vzdrževanje prenosnih naprav s stališča zanesljivosti in tveganja. Metoda preventivnega vzdrževanja je nadgrajena s konceptom vzdrževanja s poudarkom na zanesljivosti. To je koncept strateškega vzdrževanja, ki se lahko vključuje v sistem upravljanja s sredstvi na nivoju podjetja. Predstavljene so trenutne rešitve vzdrževanja prenosnih sistemov v svetu in Sloveniji s poudarkom na sistemu vzdrževanja v javnem podjetju ELES, d. o. o. Koncept vzdrževanja s poudarkom na zanesljivosti bistveno odstopa od časovno opredeljenega preventivnega vzdrževanja. Izbira trenutka vzdrževanja je odvisna od tehničnega stanja naprave, od pomembnosti naprave in finančno ekonomskih kazalnikov. Pri tem pa mora ostati zanesljivost obratovanja posameznih naprav kakor tudi celotnega elektroenergetskega sistema na najvišjem nivoju. Rešitve, ki so podane v disertaciji, so pridobljene z optimizacijo s pomočjo algoritma diferenčne evolucije in obsegajo proces načrtovanja in dejanske izvedbe vzdrževanja. S tem pristopom se obvladujejo tveganja zanesljivega obratovanja elektroenergetskega sistema in obvladovanja stroškov. Izdelan je splošni optimizacijski algoritem strateškega vzdrževanja prenosnih naprav, praktično pa je preizkušen na napravah in postroju razdelilne transformatorske postaje Divača.Maintenance is a combination of all technical, administrative and management actions in a lifetime of equipment, with the aim of maintaining or establishing the condition, in which the function can be performed. It is a natural process needed for each device to function normally. Even in transmission techniques, maintenance is of key significance for safe and reliable operation of the electricity system. Maintenance terminology deals with two basic approaches, preventive and corrective maintenance. In the area of technical systems and thereby also transmission equipment, from point of reliability, the method of preventative maintenance is currently prevalent. This method can be time-based, or condition-based. This doctoral dissertation addresses strategic maintenance of transmission equipment from the point of reliability and risk. The method of preventive maintenance has been upgraded with the concept of maintenance with focus on reliability. The latter is a concept of strategic maintenance, which may include a system of asset management at a company level. Current solutions of maintenance of transmission systems in the world and in Slovenia are presented with an emphasis on maintenance system in public company ELES d.o.o. The concept of maintenance with the emphasis on reliability significantly deviates from the time, specified for preventive maintenance. Choosing the moment of maintenance depends on the technical condition of the equipment, on its importance and financial-economic indicators. At the same time, the operational reliability of individual devices as well as the entire electric power system should remain at the highest level. The solutions given in the thesis were obtained by introducing optimization using algorithm of differential evolution and include the planning process in the actual execution of maintenance. With this approach, risks of a reliable operation power system and management costs are managed. A general optimization algorithm of strategic maintenance of transmission equipment is made, and is tested on transformer substation Divača