Wind is Germany’s most important source of renewable energy, accounting for more than a quarter of all electricity generated. However, wind turbines (especially offshore systems) frequently suffer power losses and downtime due to failing power electronics. To tackle this not insignificant problem, the Fraunhofer Institute for Microstructure of Materials and Systems (IMWS) has been leading a project with commercial partners to develop more resilient components.

Power electronics play a pivotal role in a turbine, ensuring the fluctuating energy generated by variable wind currents is fed evenly into the grid. During these switching processes, however, there are energy losses. The components are also subject to extreme environmental stress including temperature changes, humidity, salt, as well as pressure from high voltages and mechanical forces – all of which limits their lifespan.

Within the programme which was started in 2017 with funding from the Federal Ministry for Economic Affairs and Energy new solutions were developed – such as more robust semiconductor microstructures and double-sided sintered systems to withstand higher chip temperatures – that are better suited to challenging offshore conditions. As a result, power losses have been significantly reduced, power densities improved and the lifetime of the power electronics has increased from 20 to 30 years.

"Together with our partners, we have thus made a major contribution to improved reliability, service life and performance of power electronics in wind turbines and, at the same time, to even greater efficiency in the use of renewable energies," concludes Bianca Böttge, who headed up the project at IMWS, in a press release. The project partners included Infineon Technologies AG, Semikron Elektronik GmbH & Co. KG, Freqcon GmbH and nanoAnalytics GmbH.