A joint Spanish/Belgian project funded by the EU is close to validating a data-based approach to identifying failure modes in pitch systems on offshore wind turbines, using data-based analytical solutions
Technology developed during the project, ‘Digitalisation of critical components in offshore wind turbines’ (DOCC-OFF), could reduce the incidence of failures and enable improvements in the design, operation and maintenance of pitch systems for offshore wind turbines.
As Basque Energy Cluster and DOFF-OFF project co-ordinator Jose Ignacio Hormaeche explained, the hydraulic pitch system in an offshore wind turbine does not often fail, but when they does, it ranks high on the ‘criticality index’ and can result in significant lost revenue.
One of the reasons a better way to assess the condition of pitch systems is needed, is that problems are not easily prevented using conventional visual inspection techniques and may therefore go undetected.
The purpose of pitch control is to maintain optimum blade angle to achieve certain rotor speeds or power output. Adjusting the blades helps to maximise power output and ensure a turbine does not exceed its maximum rotational speed.
In the DOCC-OFF project, the project partners have developed a condition monitoring strategy they believe can reduce the impact of hydraulic pitch system failures. They plan to validate the concept in the lab in the coming months. Having done so, they hope that a wind turbine manufacturer will test the concept in the real world.
“At the heart of DOCC-OFF is a digital platform that captures and manages operational data,” Mr Hormaeche explained. “The digital platform will use a combination of synthetic and real data to enable windfarm operators to detect potential problems before they occur.
“Development of this hybrid approach combining synthetic and operational data will provide a representative data set and help to improve failure diagnosis. It will work in a number of ways, identifying otherwise critical failure modes and those in which criticality can be reduced via condition monitoring.
“Because it will enable potential problems to be diagnosed before a failure occurs costly downtime can be avoided, along with the lost revenue resulting from it, and operation and maintenance costs can be reduced.”
The partners in the project include Hine Renovables in the Basque region of Spain, a well-known supplier of hydraulic systems and components. Hine is interpreting the data collected in an application developed by another Basque company, Xabet, and interpreting it to understand pitch system failure modes. This will enable Hine to improve the design, the operation and maintenance of pitch systems.
A software company, Xabet developed the digital platform that captures and manages the data from the pitch system and exploits it using analytics tools for the failure modes identified.
Among other things, Sirris in the Flanders region in Belgium specialises in testing offshore wind structures. Now that the main failure modes of pitch systems have been identified by the partners using a failure mode effect and criticality analysis, it will use its laboratory facilities and a test bench to validate them and the digital platform developed in the DOCC-OFF project.
“We expect Sirris to be able to begin bench tests in mid-2021,” Mr Hormaeche explained. “Once we have validated our approach, and validated it at systems level, the next step would be to identify a customer that could let us test the platform in the real world, on an offshore wind turbine. The project is due to wrap up in October 2021.”