Skip to main content

O&M tools integrating accurate structural health in offshore energy

Periodic Reporting for period 1 - WATEREYE (O&M tools integrating accurate structural health in offshore energy)

Reporting period: 2019-11-01 to 2021-04-30

The highest critical cost related to O&M in offshore wind turbines is caused by structural failures that mainly occur due to corrosion. The WATEREYE project aims to reduce O&M cost, by developing a solution to monitor corrosion in the structure level that will allow predictive maintenance, with the objective of preventing major failures or even the breakdown. This objective will be reached through monitoring critical points of WT, analysing the data to generate a diagnosis and a prognosis maintenance strategy. WATEREYE addresses the whole study of corrosion and its consequences in the different parts of a WT structure. The project develops a monitoring system capable of remotely estimating the corrosion level in exact critical locations of WT structure as a supporting tool for predictive maintenance. In addition, WATEREYE will develop technologies for data analytics, modelling, and diagnosis for WT as well as WF O&M advanced control strategies. These technologies will contribute to significant OPEX reductions and to improve the efficiency and profitability of offshore energy resources.
Next, the most significant achievements reached during the first 18 months of the project are arisen.
Work Package 1 represents the starting point of WATEREYE project with the definition of the project framework and general systems requirements to be developed during the project.
For this purpose, a study on corrosion and its relation with the relevant parts of the wind turbine structure has been carried out, allowing the identification the main challenges that corrosion brings to marine structures. These zones have been defined covering not only structural steel but also protective coatings on the surfaces, helping to clarify the requirements of WATEREYE solution. Moreover, during the development of the WP1 the preliminary technical definition of the solutions has been performed: smart sensors; communications; mobile-platform operating conditions; diagnostics and visualization tools; functionalities of the diagnostic, prognostic and decision support tools; WT and WF control algorithms main outputs and use cases for the WF controller.Finally two scenarios (Canary Island and Scotland East Coast) have been selected as testing scenarios. The main purpose of these sites is to be used as example during validation and testing phase.
Work Package 2 is focused on the design of the most physical components of the WATEREYE solution composed by fixed sensor nodes, a mobile node, a drone, a Drone Docking Station and the WATEREYE Computer. The monitoring system will be capable of remote estimation of the corrosion level at certain locations at the Wind Turbine tower structure: specific locations in the atmospheric and the splash zone.For this purpose, different samples have been produced (non-corroded and corroded, coated and non-coated, different thicknesses) with the aim of characterizing appropriately the ultrasound sensor nodes to get higher accuracy even under harsh conditions. On the other hand, high efforts have been done to design a robust drone based platform able to position accurately the sensor head on the wall.
The main goal of WP3 is to develop algorithms and software tools for ensuring integral intelligent processing of the inspection data generated both by the novel smart sensors developed in WP2 and by the data coming from wind turbines to optimise the O&M of single Wind Turbine.
In WP3, it is planned to propose models for corrosion and coating degradation relevant for the environmental conditions and material under study. Currently, electrochemical tests are running, collecting the necessary data for validation of the corrosion models. In addition, a corrosion simulation tool has been implemented to generate corrosion data that resemble field data as close as possible.Furthermore a 3D visualization tool has been developed to facilitate the visualization of measured absolute and relative thickness of different positions and times on the wind turbine to support the analysis and decision making progress for predictive maintenance.
A corrosion prognosis methodology has been designed by incorporating a corrosion model and a corrosion indicator (wall thickness) which will be extracted from the US signal.A WRF has been integrated with a GAD model and a baseline torque controller for simulating weather and turbine operating conditions on a short term. Two data-driven, ML methods have been derived for weather forecast on long term.
WP4 links the information gained from the WATEREYE measurements with the practical operation of WFs, by developing practical control algorithms that adapt the operation of individual wind turbines. Furthermore, this approach takes into account the advantage of having fleet data, and the overall plant, to the condition of the support-structure determined by the WATEREYE monitoring system.An initial implementation of probabilistic modelling for estimation of the rotor-averaged wind speed and an initial set-up of maintenance tool have been developed.
The WATEREYE system is an integral solution which will allow the WF operators to monitor the structural health of their offshore structures in real-time in an unattended manner as well as to perform an accurate prediction of the RUL of their structures with a final goal of optimizing the schedule of the operation and maintenance at WF level.
Next, the most significant WATEREYE outcomes that present a clear progress beyond the state of the art are listed.
•The monitoring solution aims to detect any early stage defect on the tower walls without any human intervention deploying several fixed sensor nodes on the tower wall and one ultrasound node integrated into a mobile platform.
•Nowadays drones use satellite navigation for positioning and control. For indoors applications this is not available. To create a reliable indoor positioning system, a combination of small sensors will be used to form a robust and precise means to navigate inside offshore structures.
•A 3D wall thickness visualization tool has been designed to visualize the corrosion evolution of specific (critical) locations on a WT structure. The 3D visualization tool will visualize the corrosion measurement data obtained from the mobile (drone) platform and fixed sensors for which this functionality is not available yet today on commercial software.
•Development of Fault Tolerant Control (FTC) algorithms of individual WT considering structural health status prediction, as well as weather forecast. The WT FTC algorithms are developed for load reduction and power optimization.
•Within WATEREYE, the probabilistic analysis tool contributes to a better understanding of the uncertainties that are relevant for development of optimal wind farm control algorithms based on state of corrosion and on maintenance constraints.
•In WATEREYE, WF control and O&M scheduling frameworks will be linked. The focus is set on finding the optimum between on the one side maximizing income from electricity production, and on the other side minimizing downtime cost induced by fatigue damage on relevant components, encompassing change in structural properties (for instance due to corrosion).