Optimized Maintenance Decision Of Wind Turbine-generator System Based On Proportional Intensity Model

This thesis firstly introduced the background and significance of the implementation of maintenance optimization about wind turbine-generator system. Then it introduced some basic theoretical knowledge which are related to optimization maintenance of power system equipment, described some parts of the theory of reliability, such as the definitions and connotations of reliability ,failure, distribution, introduced several common reliability indexes, including the failure rate, reliability and life expectancy, briefly introduced the concept of the weibull distribution and the basic steps of maximum likelihood estimation method.The paper studied the concept of proportional hazards model and the process of the model established , put forward optimization maintenance decision based on the model for the wind generator , detailed analysised the parameter estimation methods of different types of proportional hazards model, and realized the maximum likelihood parameter estimation of the model in MATLAB, expounded how to calculate the optimum preventive maintenance interval by the minimum cost method or maximum availability method, then calculated the optimal maintenance threshold, mapped out the optimal maintenance threshold curve in maintenance decision diagram, traced points by using state monitoring datas in maintenance decision diagram, gettd the optimal strategy of maintenance. It realized the specific process of formulating optimization maintenance strategies by using the failure datas and condition monitoring datas of the shaft and the main bearings of the wind generator.The thesis introduced the concept of proportional intensity model and the process of the model established, described the optimization maintenance decision steps using the model for the wind generator, analyzed the parameter estimation method of proportional intensity model in detail, realized the parameter estimation by programming for the model. It expounded the minimum cost method and maximum availability method, calculated the optimum preventive maintenance intervals by using minimum cost method, then can calculate the optimal maintenance threshold, painted the optimal maintenance threshold curve in maintenance decision figure, traced points by using state monitoring data in maintenance decision diagram, and then got the optimal strategy of maintenance.The paper achieved the concrete process of optimized maintenance strategy by using the fault data and condition monitoring data of wind generator gearing box and generator.