System-Level Vulnerability Assessment for EME: From Fault Tree Analysis to Bayesian Networks—Part I: Methodology Framework

摘要

The intense electromagnetic environments (EMEs), such as the intentional electromagnetic interference and electromagnetic pulse, pose severe threats to the normal functions of electric and electronic systems. A system is usually composed of numbers of interdependently linked subsystems or equipments. The interactions of the system and the high-power EME involve large quantities of parameters and scenarios, so the complete tests or computations are usually difficult to fulfill, which leads to a hard mission to assess the system-level electromagnetic vulnerability. This paper provides the thought of divide-and-rule to cope with this problem. First, it divides the system into relatively independent and manageable subsystems, and after respective tests and computations, the subsets of data are fused to characterize the whole system. The key point for this assessment methodology is to set up one model or framework to unify all the activities, which is completed here by the causal Bayesian networks (BNs). The system-level effects and the environment threats are characterized with the probability theory. The modeling and parameter determining techniques are presented. Since fault tree analysis (FTA) is also utilized in the electromagnetic risk assessment, the assessment procedures based on relatively BN and FTA are compared. The final results indicate that BN is capable of extending the modeling and analysis power of FTA