An Optimal Number-Dependent Preventive Maintenance Strategy for Offshore Wind Turbine Blades Considering Logistics

Mahmood Shafiee,Michael Patriksson,Ann-Brith Strömberg

doi:10.1155/2013/205847

Mahmood Shafiee, Michael Patriksson + Show 1 more

Open Access

https://doi.org/10.1155/2013/205847

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Abstract

In offshore wind turbines, the blades are among the most critical and expensive components that suffer from different types of damage due to the harsh maritime environment and high load. The blade damages can be categorized into two types: the minor damage, which only causes a loss in wind capture without resulting in any turbine stoppage, and the major (catastrophic) damage, which stops the wind turbine and can only be corrected by replacement. In this paper, we propose an optimal number-dependent preventive maintenance (NDPM) strategy, in which a maintenance team is transported with an ordinary or expedited lead time to the offshore platform at the occurrence of theNth minor damage or the first major damage, whichever comes first. The long-run expected cost of the maintenance strategy is derived, and the necessary conditions for an optimal solution are obtained. Finally, the proposed model is tested on real data collected from an offshore wind farm database. Also, a sensitivity analysis is conducted in order to evaluate the effect of changes in the model parameters on the optimal solution.

Highlights

Wind energy has become an attractive source of renewable energy in the European energy market because it is free, abundant, and perceived as having a low impact on the environment
We propose an optimal number-dependent preventive maintenance (NDPM) strategy, in which a maintenance team is transported with an ordinary or expedited lead time to the offshore platform at the occurrence of the Nth minor damage or the first major damage, whichever comes first
We propose an optimization model to determine the optimal number of minor damages allowed to occur in a blades system before sending a maintenance team to perform preventive maintenance actions

Summary

Introduction

Wind energy has become an attractive source of renewable energy in the European energy market because it is free, abundant, and perceived as having a low impact on the environment. Byon and Ding [6] propose a season-dependent optimal maintenance strategy for a multistate deteriorating wind turbine in order to reduce the operation costs and enhance the marketability of wind power. N is the damage threshold for performing (PM) action which is considered to be a decision variable under the control of the wind farm manager and should be optimized This strategy, namely, numberdependent preventive maintenance (NDPM), was first considered by Makabe and Morimura [15,16,17] and later extended by Morimura [18] and Park [19]. We propose an optimization model to determine the optimal number of minor damages allowed to occur in a blades system before sending a maintenance team to perform preventive maintenance actions.

Problem Definition

Components of the Model

The Model Formulation and Analysis

An Illustrative Case

Findings

Conclusions and Topics for Future Research