EU project adds ‘missing brick’ with innovative approach to WEC testing

The European project IMPACT has created an “innovative approach” for testing wave energy converter (WEC) reliability, performance, and destructivity with the dual hardware-in-the-loop (Dual HIL) platform which tests different parts of the WEC simultaneously.

Short for Innovative Methods for Wave Energy Pathways Acceleration through Novel Criteria and Test Rigs, the IMPACT project said that simultaneous testing provides a holistic picture of how different components behave and impact each other, boosting trust in WEC deployment and cutting testing time and cost.

“The IMPACT project resulted in a new testing infrastructure and applicable methodologies that can be used by WEC developers to accelerate their technology development pathways, and find out eventual criticalities associated with a subsystem or even at WEC level,” said Giacomo Alessandri from VGA.

“The rigs have been designed and proven to be as flexible as possible, to address tests of different WEC and subsystem types, therefore adding a missing brick at the EU level. These capabilities will play a fundamental role in the near future, especially for developers requiring de-risking activities prior deployment of sea-going prototypes.”

Despite significant progress in WEC development, there are several obstacles to commercialization, particularly in ensuring device reliability and the performance of the power take-off (PTO). 

Rig testing helps address these challenges before operational sea tests, increasing the chances of success. IMPACT’s Dual HIL testing platform uses HIL testing and enables the developer to factor in dependencies between the subsystems. This provides a thorough understanding of the WEC and allows developers to anticipate potential subsystem interaction failures, said IMPACT. 

The Dual HIL platform includes two independent rigs that can simultaneously test different WEC subsystems – a drivetrain test rig and a structural components test rig.

The drivetrain test rig, initially built for the EU project IMAGINE, was upgraded through IMPACT to test linear and rotary PTOs for various WECs and to emulate different grid conditions and the point of common coupling. These capabilities were demonstrated during the project by characterizing the performance of an off-the-shelf drivetrain, including a rotary geared generator and both generator- and grid-side converters.

The structural components test rig, designed and built in IMPACT, tests the integrity of components under mechanical stress, such as the mooring system, dynamic power cables, joints, and seals. It has already tested the belt of Carnegie Clean Energy’s CETO 6 WEC.

Feedback data is fed into a real-time simulator and used, along with environmental data, to influence subsequent tests. This provides a comprehensive view of how WEC parts interact under various conditions, said IMPACT.

The IMPACT platform will now be part of the Structural Wave Energy Equipment Test (SWEET) Lab at VGA’s facilities in Deruta.

In March 2022, IMPACT’s partners submitted the final report for the work package which supported the design of test rigs for WECs by focusing on aspects of the electrical subsystems.

The work centered on reviewing grid codes to identify performance requirements and possible compliance tests to be implemented by the rig(s) and creating a wave-to-wire model to simulate power transfer from the WECs to the grid.

The IMPACT project was also supported by €3.3 million from the European Union’s Horizon 2020 program.