Wind Turbine Reliability Modeling
Author: Símon Einarsson
Year: 2016
Supervisor: Samuel Perkin & Páll Jensson
Abstract
Although the technical concepts and reliability of wind turbines have improved over the years, there is still room for further advancements. Wind turbine operators and researchers have reached a consensus with respect to the need for improvements in the field of wind turbine reliability, associated with operation and maintenance (O&M). Maintainability plays an important role in the operation of wind turbines. The high maintainability requires sufficient maintenance strategies and the right stock of inventory. Service and spare parts are estimated to comprise 26% of the operational expenditure (OPEX). OPEX and availability are key factors that affect the levelized cost of energy (LCoE), whereby OPEX represents 11% - 30% of the LCoE [1].
A quantitative reliability block diagram (RBD) model was developed to use reliability data in order to evaluate wind farm availability and OPEX. The model was developed using the Blocksim software tool developed by Reliasoft Inc. The model was based on reliability data from NREL and verified through a comparison of the estimated OPEX with the OPEX of selected OECD countries.
The model's results were in many ways unexpected, as the behavior of the wind farms are challenging to predict without a simulation model. The model showed that reliability data may be used to analyze O&M strategies, to evaluate the availability, forecast service, and maintenance costs. The sensitivity analysis demonstrated how important it is to prevent the failure of expensive parts. Based on these results, it was concluded that the model is a valuable tool to evaluate and analyze wind farm operation and maintenance.
This study also makes exciting future recommendations for the optimization and reliability centered maintenance, which is specifically designed to maximize system reliability and availability at the lowest price possible.