Optimization Maintenance Research Of Wind Turbines Pitch System Based On Opportunistic Maintenance Strategy

The operation condition of wind turbines is complex, which leads tothe high failure rate of wind turbines including pitch system and the hugeloss of maintenance cost. The traditional corrective maintenance andpredetermined maintenance often result in less or more maintenanceactivities, which can’t satisfy the economic requirements and also reducesthe reliability and utilization rate of wind turbine. Based on the analysis ofthe fault data of the variable pitch system, this paper established themulti-component opportunistic maintenance strategy targeted in theeconomy and stop times, restricted by reliability condition. Through themodel simulation and application research of actual data, the reliability ofthe opportunistic maintenance strategy has been proved, and the economicsof this strategy has been shown. Specific work is as follows:First of all, through the analysis of operation condition and fault dataof wind turbines, this paper selected the high fault rate pitch system as theresearch target, with the statistical analysis of pitch system. The resultshows that the communication failure, cleaning and changing of electricalslip ring, safety chain breaking and damage of electrical components arethe four most important failures of the variable pitch system.Secondly, established the Weibull life simulation function andanalyzed the reliability of the key faults of the pitch system. Based on therunning time table of the pitch system, used the maximum likelihoodestimation method and graphical method to solve the Weibull modelparameters. Established the reliability models of the critical failures andmade a comparsion of the failure curves.Finally, established an opportunistic maintenance strategy model targeted by economy and restricted by reliability, as well as amulti-objective optimization model targeted both by economy andshut-down times regards the critical failures of variable pitch system underthe knowledge of their Weibull models known. Through the modelsimulation and application research of actual data, it is obvious that theopportunistic maintenance strategy is better in economy and reduces theshutdown times.