Industry, Researchers Studying Power Converter Failures

Fraunhofer IWES has launched a research project called ReCoWind (Reliable Power Converters for Wind Turbines) that aims to bring forward effective protection measures for power converters. 

The three-year project, funded by the German Federal Ministry for Economic Affairs and Energy (BMWi), joins a consortium comprising operators and manufacturers of wind turbines, semiconductors, and converters with research and academic partners.

Together, they will analyse field data from various sites and turbine types, derive damage models and perform experimental tests on components.

Power converters are among the most frequently failing components of wind turbines and are thus associated with high costs and long downtimes, according to Fraunhofer IWES, which states that losses of around EUR 200 million per year arise in Germany alone due to repair costs and revenue losses resulting from failed wind turbine power converters. At offshore sites in particular, repairs present a logistical challenge and cannot be carried out in short notice.

A better understanding of the causes of power converters’ failures was vital in the race to develop effective protective measures and thus improve the profitability of turbine operation, the research institute said.

The main focus of the ReCoWind is on the power-semiconductor modules, their driver units as well as the DC-link components representing the core components of the converters. In view of results of previous investigations, particular attention is paid to the influence of moisture.

More information will be gathered by using special measuring techniques, being developed specifically by the project partners, and testing on commercial components under realistic conditions.

One of the objectives of the project is to improve the converter reliability with a more robust design, the development of procedures for accelerated component testing, and improved concepts for operation and maintenance.

Damage models and models for calculation of the remaining service life will be generated through experimental investigations. At the same time, comprehensive failure and operating data will be evaluated.

Field measurements will be carried out at sites such as the Nordsee One offshore wind farm, which consists of fifty-four 6MW turbines.

The findings will be used to derive recommendations with respect to design, instrumentation, operation and maintenance, which will be made available to the industry.