Frequency converters are essential components in new types of wind turbines that are operated at variable rotor speeds. However, they are often affected by incidents. These in turn entail cost-intensive repairs, corresponding downtimes and yield losses. Particularly at offshore locations repairs are time-consuming and costly. A better understanding of the influencing factors that cause defects is therefore necessary in order to develop effective countermeasures that increase the reliability of frequency converters for operating wind turbines. The ReCoWind project (Reliable Frequency Converters for Wind Turbines) is pursuing exactly this goal: to increase the reliability of the frequency converters in order to reduce operating costs. Partners from research and industry are working together under the leadership of the Fraunhofer Institute for Wind Energy Systems (IWES).
The core components of the converters – power semiconductor modules, driver units and intermediate circuit components – will be investigated in more detail as part of the joint project. A special focus of the investigations is on the influence of moisture and harmful gases, which impact on the reliability of the electronics. By means of comprehensive data analysis, the partners are aiming to better understand the mechanisms. Based on this, recommendations will be derived which, among other things, apply to the design, measurement technology, operational management and maintenance. A more robust design, for example, will enable the converters to benefit from greater reliability and economy. The results will be tested under realistic conditions.
The German Federal Ministry for Economic Affairs and Energy (BMWi) is funding the project with 3 million euros over a period of three years.