Vulnerability and Reliability Assessment of Electrical Power System using Petri Nets

The research aims to build a behavioral models of electrical power systems through the use of Petri nets, covering both traditional reliability analysis (quantitative measurement) and behavior analysis (qualitative measurement) for the detection of topology defects. The development models has allowed to study the operating sequence of the electrical system, where the evolution of the system to be monitored is compared with its ideal evolution. The modelling criterion is then validated by the implementation in two case studies. In the first case, the whole approach is applied to the identification of a complex electrical plant supplying a critical structure such as a hospital. Petri nets are capable of modeling and simulating all the functional dependencies between the system elements and also the correct fault repair behavior for the tested power system. This allows the system to be analyzed for properties such as tolerance of failures and isolation of the safety hazards to determine which functions are most critical and moreover need to be enhanced in order to mitigate the accidental risks. In the second case study, a new approach for LOTO procedures using Petri nets is introduced. The suggested methodology supports mechanical development of the operational procedures that can assists the operator especially for not automatic operations. It proposes some simple rules, a graphical representation of electrical status and an algebraic model to allow an autocheck of the interlocking procedure.