Fault Tree Analysis Based on Logic Grey Gate in Power System

Because there exists the ambiguity in complex systems, and there is the limitation in traditional fault tree, a novel fault tree analysis theory is introduced. In the theory, the probability grey number, which can express the event´s subjective ambiguity and objective ambiguity, is introduced to express the degree and probability that the components go wrong, dynamic envelope is applied to score the relation among components, and a new logic gate, Grey-gate, is advanced for expressing the effect of system reliability when the components go wrong. Finally, the theory of fault diagnosis is applied to analyze the fault effect of the system with software and hardware.