Wind turbines maintenance management based on fta and bdd

Abstract

The condition of a wind turbine will depend on different elements that compound it. The relationships cause-effects of the different faults can be analysed qualitatively by Fault Tree Analysis (FTA). FTA is a graphical representation of logical relationships between events, where each event has a fault probability associated. In this paper is proposed the quantitatively study of the FTA via Binary Decision Diagram (BDD). BDD is a method which determines the output value of the function by examining the inputs. The BDD method does not analyse the FTA directly, but converts the tree to the Boolean equations that will provide the fault probability of the top event. This conversion presents several problems, where the variable ordering scheme chosen for the construction of the BDD has a crucial effect on its resulting size. It is solved in this paper employing the Level, Top-down-Left-Right, AND, Depth First Search and Breadth-First Search methods for ranking the events (or vertices), and a comparative analysis is done.