Abstract

Reliability is critical to the design, operation and maintenance, and performance evaluation of offshore wind turbines. In the current literature, the vast majority of the reported reliability data studies are for onshore wind turbines, and reliability data of offshore wind turbines are limitedly available. This paper investigates a new set of reliability data from an offshore wind farm in operation in the UK with the aims to evaluate the reliability of modern multi-megawatt offshore wind turbines and to enrich the current offshore wind reliability database. In addition, offshore wind farm operators often record and store wind farm operational data such as regular operational reports, work orders, and SCADA data for their daily operation while the wind turbine reliability practitioners and system modellers are interested in the failure frequency per wind turbine per unit time, i.e. the failure rate, and/or the downtime per failure of wind turbines subassemblies. Thus, this paper presents a procedure for extracting useful data related to wind turbine failure from the operational data, such as work orders and SCADA data. The failure data are, then, categorised and assigned to each wind turbine subassembly following a common turbine breakdown structure, i.e. the wind turbine taxonomy. Further reliability data analysis and comparison with other existing offshore reliability data in the literature and evaluation of the wind turbine reliability over time are performed. This study can help wind farm operators better understand the current reliability of their offshore wind turbine fleet and provide practitioners with a method for efficiently utilise the operational data for wind turbine reliability analysis and performance assessment.