An opportunistic maintenance strategy for offshore wind turbine based on accessibility evaluation

Abstract

The maintenance costs of offshore wind turbines operated under the irregular, non-stationary conditions limit the development of offshore wind power industry. Unlike onshore wind farms, the weather conditions (wind and waves) have greater impacts on the operation and maintenance of offshore wind farm. Accessibility is a key factor related to the operation and maintenance of offshore wind turbine. Considering the impact of weather conditions on the maintenance activities, the Markov method and dynamic time window are applied to represent the weather conditions, and an index used to evaluate the maintenance accessibility is then proposed. As the wind turbine is a multi-component complex system, this article uses the opportunistic maintenance strategy to optimize the preventive maintenance age and opportunistic maintenance age for the main components of the wind turbine. Taking the minimum expectation cost as objective function, this strategy integrates the maintenance work of the key components. Finally, an offshore wind farm is taken for simulation case study of this strategy; the results showed that the maintenance cost of opportunistic maintenance strategy is 10% lower than that of the preventive maintenance strategy, verifying the effectiveness of the opportunistic maintenance.

A review of operations and maintenance modelling with considerations for novel wind turbine concepts

“…Opportunities can be: during low wind speed [103], performing scheduled maintenance during unscheduled trips [104] and group based maintenance [105]. There is increasing interest in multilevel decision-making and strategy by introducing opportunistic thresholds based on age [106][107][108][109][110], locational clustering [111], and condition [112]. Due to the redundant nature of failures for MRS and XRC, these technologies are in a position to benefit from this strategy.…”

Seizing Opportunity: Maintenance Optimization in Offshore Wind Farms Considering Accessibility, Production, and Crew Dispatch

“…Likewise, the daily power output, p L d,i , is defined in (19), wherein f L d,i ∈ [0, 1] is a function of the daily average wind speed at the turbine's location, V L d,i (m/s), and assumes uniform hourly wind speeds for the LTH. The term m L d,i •τ /24, accounts for the production loss, in case a PM is scheduled at the d-th day for the i-th turbine in the LTH.…”

“…The estimated turbine-specific power curves are then used to determine the hourly and daily normalized power values, f t,i and f L d,i , respectively, given turbine-specific wind speed time series V t,i and V L d,i . Those, combined with R, will be used to estimate the power level of a turbine (in MW) using ( 18) and (19).…”

“…Understandably, inaccurate or overlooked access information in maintenance scheduling can lead to aborted/delayed maintenance activities, cascading failures, and prolonged downtimes. In contrast to the first two groups which define opportunistic maintenance as dispatch-or production-based, this set of methods is referred to hereinafter as accessibility-based opportunistic strategies [18,19].…”

STOCHOS: Stochastic Opportunistic Maintenance Scheduling For Offshore Wind Farms

“…A small fraction of those efforts partially account for revenue losses by incentivizing the grouping of maintenance tasks at periods of low power production (Besnard et al, 2009;Yildirim et al, 2017;Song et al, 2018). A separate line of research focuses on forecasting access-based opportunities (Zhang et al, 2021;Yang et al, 2020;Lubing et al, 2019;Taylor and Jeon, 2018), but largely overlooks those based on economic dependencies and/or those related to revenue losses.…”