Research On Reliability Evalluation And Preventive Opportunity Maintenance Strategy For Wind Turbine

In recent years,with the growing attention paid to the field of clean energy,the wind power industry in every countries has obtained opportunities to develop at top speed.At the same time,due to China’s unique geographical advantages and abundant wind power resources,China’s gross installed capacity of wind power has ranked first in the world since2016.However,on account of the relatively late development of the wind power industry in China,the maintenance and management level of wind power equipment is limited,and the utilization of maintenance data is unreasonable,which results in a large discrepancy between the reliability evaluation results of wind power equipment and the actual running of wind turbines,and further leads to unreasonable maintenance strategy formulated for wind power equipment by taking reliability as the indicator,as well as the frequent occurrence of“over-maintenance” and “under-maintenance”.In order to solve the above problems,this paper studied a new method of reliability evaluation of the wind power equipment from the perspective of the failure characteristics of wind power equipment,established a failure rate evolution model that is more in line with the actual running of the wind turbines,and optimized the traditional preventive maintenance model.The research contents of this paper mainly include the following aspects:Firstly,in view of the difficulty of accurately evaluating the reliability of key components like generators and gearboxes because of the harsh working environment of wind turbines,a new evaluation method of reliability based on improved Weibull distribution model was put forward,taking into account the shutdown failure data and non-shutdown failure data of the key components of the wind turbines.This method not only considers the location of each non-shutdown failure,but also takes into account the impact of the interval length of the failure on the parameter estimation results,while the traditional Weibull distribution only accomplishes the former one.Taking the failure data of a certain type of wind turbines as an example,combining the average rank order method and the least square method to obtain the shape parameters and scale parameters,the function curve of reliability and the function curve of failure rate were obtained,and the correlation analysis was carried out.Through instance analysis,the parameter estimation results of the two models were compared to verify the effectiveness of the proposed new method.Secondly,for the sake of establishing a failure rate evolution model that is more in line with the actual running of the wind turbines,the decline factor of service life and the increase factor of failure probability were introduced.On this basis,minor repairs during the maintenance cycle were considered,so as to establish the preventive maintenance model of wind power equipment based on the reliability constraint of a single component.And the enumeration method was used to obtain the optimum maintenance frequency and the optimum preventive maintenance interval for the key components of the wind turbines in a replacement cycle.Thirdly,in order to solve the problems of unreasonable formulation of maintenance plans of wind power plant,excessive downtime of wind turbines,and frequent occurrence of "over-maintenance" and "under-maintenance",based on the reliability data that conforms more to the actual running of wind power plant,the concept of “opportunistic maintenance”was introduced on the basis of the traditional preventive maintenance model.Moreover,the combination of maintenance and replacement was adopted to establish a preventive opportunistic maintenance model that combines multiple components of wind turbines.And the particle swarm optimization algorithm was used to optimize the opportunistic maintenance reliability margin of each component of the wind turbine,taking the total maintenance cost minimization as the optimization goal.Matlab was taken as the platform to solve the model,and the results showed that the newly established maintenance model can effectively reduce the downtime of the wind turbines and save maintenance costs.In the end,a detailed maintenance plan during the operation cycle was drawn up for the wind turbines.