Determining Spare Part Inventory for Offshore Wind Farm Substations based on FMEA Analysis

Abstract

Spare part management is essential for offshore wind farm operators. In spite of the number of offshore wind farms has significantly increased and the setup is similar in most of the wind farms, there is still a huge number of specialized and custom parts with a non-negligible supply time. Due to weather and logistic restrictions the active corrective maintenance time can exceed by far the time that it would take in an onshore environment. This paper proposes an algorithm to determine the optimized spare part inventory of production relevant equipment based on failure mode and effects analysis. From the three orthogonal identifiers, named lost capacity, repair complexity and failure probability, the risk priority number is calculated for the non-spare-part-case and for the spare-part-case. A linear optimization reduces the spare part inventory considering the investment costs, the possible lost energy yield and the availability level of the substation. With the developed algorithm, it is possible to determine the maximum achievable availability level. The risk-level of critical components is significantly lowered by the calculated procurement of spare parts.