Stochastic Degradation Model and Preventive Maintenance Decision of Wind Turbines

For the description of the degradation process of wind turbines, the traditional ordinary differential equation (ODE) model is commonly used in the industry. However, the ODE model fails to consider the randomness of the system, i.e. the various random disturbances in the operation. Therefore, an ODE model is established based on the process of system state transition, and randomized into a new stochastic differential equation (SDE) model to describe the stochastic degradation rule of wind turbines. Furthermore, based on the SDE model, the preventive maintenance strategies of wind turbines are proposed, which are time-based maintenance (TBM) strategy and condition-based maintenance (CBM) strategy. Finally, the actual case is simulated by MATLAB and the model and the maintenance strategy are verified.