ABSTRACT
Complex systems are prone to catastrophic failure as the complexity causes the system to collapse by itself. Wind energy system, which is fast growing source of electricity, is rapidly evolving into complexity and size, leading to inherently and unavoidably hazardous by their own nature. The wind turbine failures have significant impact on public health and safety risk, productivity and economy. Although design plays a major role in developing safer and reliable system, yet achieving desired operational safety and reliability remains a difficult task for the wind turbine manufacturers. In order to ensure better safety and reliability during operation, effective design and maintenance measures need to be taken. Criticality analysis of the wind turbine components or its subsystems is one way to achieve these objectives. Criticality analysis helps to identify critical failure modes or items, which in turn, assists in formulating optimal design and maintenance procedures so that better operational safety and reliability of the wind turbines can be obtained. The conventional FMECA, which is used for criticality analysis, takes care of the effect of failure on components, but does not consider the causal relations or interdependencies among failures. This paper presents an effective method of criticality analysis of wind turbine energy system using fuzzy based digraph models and matrix method by taking into account the causal relations/interdependencies among failures. This will help to identify the critical failure modes/units of wind turbine energy system. The proposed method is useful in criticality assessment of wind turbines in design as well as in operation stages.
