Failure modes, effects and criticality analysis (FMECA) of power electronic devices using fuzzy logic

The objective of this paper is to present an efficient methodology for the Failure Modes Effects and Criticality Analysis (FMECA) of power electronic devices. The methodology uses fuzzy sets to represent the parameters being used in the conventional FMECA and a knowledge base is developed to identify the rules governing the fuzzy inputs and output. A fuzzy failure mode risk index is introduced to prioritise the criticality of the components for the system operation. The fuzzy inference module is Mamdani type and uses the min-max implication-aggregation method while it was developed in Matlab 6.1. The developed methodology was applied to a typical power electronic device such as a switched-mode-power-supply. The required data of the component failure modes were estimated using a reliability prediction procedure and a failure mode database. The crisp values of the conventional FMECA were used as inputs to the fuzzy FMECA and the fuzzy failure mode risk indices were calculated and compared with the respective indices calculated by the conventional FMECA.