The paper is presenting a model of optimal allocation of redundancy for auxiliaries belonging to turbo generator groups. They are considered as series-parallel systems. Optimization criterion that has been chosen aims the minimization of acquisition and installation costs, exploitation costs and all other costs due to non-operation. In order to solve the model two algorithms were developed: one is heuristic and the other one is metaheuristic, based on Ant Colony Optimization Algorithm. A case study is presented at the end of the article, showing the methodology for a 55 MVA coal-fired turbo generator group.

Keywords: Redundancy allocation, Reliability optimization, Heuristic algorithm, Thermal power plants