Research On Preventive Maintenance Strategy And System Realization Of Wind Turbine

Wind energy is one of the most abundant renewable energy sources.In recent years,the installed capacity of wind turbines in my country has increased year by year.Electricity produced by wind power has largely decreased the global appetite for fossil energy production and decreased the growth and use of fossil energy.To a certain degree,the degradation of the natural ecosystem has been mitigated.Although the domestic wind power industry is developing,it also faces a range of difficulties,such as the construction,repair and operation of wind turbines.The primary focus of wind farm operation and maintenance is wind turbine maintenance.Timely and effective maintenance is critical to ensuring the service life,safety,and dependability of equipment.Therefore,by studying the failure rules and reliability of wind turbine components,proposing a practical and economical maintenance and replacement strategy is of great significance to the operation and maintenance management of wind turbines.Aiming at the problems existing in wind farm operation and maintenance,this thesis mainly studies the modeling and optimization of maintenance strategy and the realization of maintenance auxiliary decision-making system.The main research contents are as follows:(1)The maintenance and replacement model of a single-component system under the constraint of reliability is studied.On the basis of a systematic consideration of complex maintenance costs and efficiency,an inadequate preventive maintenance approach under reliability constraints is proposed.A non-equal cycle imperfect preventive maintenance(PM)model based on mixed failure rate is developed as well.Furthermore,the estimation formula for the replacement maintenance time of the equipment shall be based on the limitation of reliability,while the optimum replacement threshold shall be increased by the enumeration process.Moreover,with the minimum average maintenance cost as the goal,the optimal number of PM,PM period and replacement cycle are provided.The sensitivity analysis of the model in this thesis is carried out,and the model in this thesis is contrasted with the model without a restriction of reliability and the model without considering the substitution threshold.(2)Multi-component opportunistic maintenance model based on costeffectiveness ratio is studied.Incorporating the cost-effective approach of research into the multi-component preventive maintenance technique,a cost-effective and efficient preventive maintenance model is proposed.The recursive rule of mixed failure rate is established by using the degree of recovery of mixed failure rate to describe the maintenance effect of different maintenance methods,and the evolution of reliability of each part in each maintenance cycle can be predicted according to the changes of the part itself and the rest.When the component reliability reaches the threshold of preventive maintenance or opportune maintenance,a reasonable maintenance method is selected by comparing the cost-effective ratio according to failure rate.Taking wind turbines as an example,the reliability changes and maintenance plans of multiple components are solved,and then compared with models that do not involve cost-benefit ratio and opportunistic maintenance to enhance the stability and economy of the model.(3)Based on the analysis of the operation and maintenance of wind farms and the proposed preventive maintenance and replacement model in this thesis,the "Wind Turbine Assistant Maintenance Decision Support System" was designed and developed.The integration of knowledge base management,spare parts management and the proposed maintenance model into one system will help maintainers to make maintenance plans,increasing the utilization and reliability of machines,thus saving maintenance costs and enhancing the economy of the enterprise.