Reliability modelling of medium voltage distribution systems of nuclear power plants using generalized stochastic petri nets

The purpose of this study was to obtain a performable tool based on generalized stochastic Petri nets (GSPN), able to join precise results and fast approach. In practice, it is well known that a dependability analysis in the power systems field is often more difficult to perform due to the multiple dependencies on the specific maintenance policies, on the great number of operation conditions, and the possibility to consider overall distributions (nonexponential) of the operation periods of time and the maintenance activities duration. Under these circumstances, the usage of conventional methods of analysis is limited in what the most precise modelling of all the system characteristics are concerned. This study managed by SNN (National Company-''NuclearElectrica'' S.A.) in cooperation with the ''POLITEHNICA'' of Bucharest analyzes and compares different configurations for the medium voltage (10.5 and 6.3 kV) distribution systems (MVDS). It has a practical connotation (SNN application for Cernavoda NNP) and compares four proposed MVDS configurations for the main auxiliary services. After description and implementation through GSPN, each configuration has been evaluated, in order to choose the most appropriate structure.