Petri net based Monte Carlo simulation for modeling and analyzing the reliability of distribution substation facilities in Belgian power system

Optimizing substations assets inspection, maintenance and replacement is considered as a key part to ensure the quality and continuity of service to customers. In order to model and analyze the reliability of distribution substation, utilities are looking for more realistic modeling approaches which permits also to implement a reliability-centered maintenance policy. The paper proposes a stochastic Petri net model used as a support for Monte Carlo simulation; it takes into account the main substation processes and the criticality of different possible failure consequences. Two failure modes are considered for the primary and backup protective systems: on-demand failure and spurious operation. Imperfect preventive maintenance actions are carried out systematically after periodic inspections, andminimum repair is carried out if necessary in the mean time. The simulation results provide support for the decision-maker when comparing different alternatives aiming to improve the substation reliability. As an illustration, we have investigated the effect of the structure of the protective system of the feeder.