Dynamic group-maintenance strategy for wind farms based on imperfect maintenance model

Abstract

This study investigates a dynamic group-maintenance strategy based on the imperfect maintenance model to reduce the set-up cost involved in the operation and maintenance of wind farms in severe geographical environments. Unlike other approaches proposed in existing studies on group maintenance, the proposed approach considers the economic dependences among wind turbines from the perspective of the entire wind farm, wherein the wind farm can be considered as a multi-device parallel system when the wind turbine is viewed as an independent device. Under this approach, a novel imperfect maintenance model is formulated based on intuitive variables to deal with the deviation from the actual situation caused by the difficulty in determining the virtual age in previous imperfect maintenance models. Furthermore, the optimum solutions at different group maintenance intervals can be achieved by considering the trade-off between the total cost savings and total revenue loss owing to the failed wind turbine not being repaired immediately. Finally, numerical experiments and sensitivity analysis are performed to provide insights into the proposed model structure. Results of the case study and comparisons with other strategies have demonstrated that the proposed dynamic group-maintenance strategy for wind farms has an economic advantage over other maintenance strategies.