HYDRO GENERATING UNITS MAINTENANCE SCHEDULING USING BENDERS DECOMPOSITION

Maintenance of the power generating facilities in due time is essential for reliable and secure operation of the electric power system. In liberalized electricity market the economical aspects, pointed to the greatest possible revenue, have to be satisfied. On the other hand, technical aspects, which keep the power system above the desired level of safety and reliability, i.e. which are opposed to economical aspects, have to be satisfied as well. Therefore, these two opponent standpoints have to be confronted in order to provide optimal solution which will comply with the strict technical limitations, and which will meet investor's economical requirements. This paper addresses the problem of obtaining the optimal maintenance schedule of hydro generating units. For this purpose, the paper discusses the mathematical programming method - Benders decomposition. After a brief description of the mathematical method, the application of the Benders decomposition on three Croatian hydroelectric power plants in a cascade on the Drava River is carried out.Original Abstract: Pravovremeno odrzavanje proizvodnih postrojenja od iznimne je vaznosti za pouzdan i siguran pogon elektroenergetskog sustava. U uvjetima liberaliziranog trzista elektricne energije ekonomski aspekti, orijentirani na najvecu mogucu dobit, moraju biti zadovoljeni. S druge strane, i tehnicki aspekti, kojima je cilj odrzati elektroenergetski sustav iznad zeljenih granica sigumosti i pouzdanosti, odnosno koji su protivni ekonomskim ciljevima, takoder moraju biti zadovoljeni. Stoga se dva suprotna gledista sukobljavaju u svrhu pronalaska optimalnog rjesenja koje ce zadovoljiti sve tehnicke kriterije i investitora u ekonomskom pogledu. U radu se obraduje problem pronalazenja optimalnog rasporeda odrzavanja hidrogeneratora. U tu svrhu se koristi metoda matematickog programiranja - Bendersova dekompozicija. Nakon kratkog opisa matematicke metode, iznesena je primjena Bendersove dekompozicije na tri hrvatske hidroelektrane u nizu na rijeci Dravi.