Research Project to Increase Converter Reliability Launched

Text / June 05, 2020

Mid-April saw the virtual kick-off of the »power4re« (Reliable converters for a renewable energy supply) research project. Under the leadership of the Fraunhofer Institute for Wind Energy Systems IWES, five Fraunhofer institutes are working together alongside industry representatives to develop solutions aimed at improving the reliability and robustness of inverters in photovoltaic systems and frequency converters in wind turbines. power4re is being funded to the tune of €3.5 million as part of the Fraunhofer-Gesellschaft’s internal research program PREPARE.

© Fraunhofer IWES
IGBT module of a converter used in wind turbines.

Converters play a central role in the energy transition: they are vital technical components for connecting photovoltaic systems and modern wind turbines to the power grid in order to feed in energy from renewable sources at a grid-compliant voltage and frequency. The converters thus have to be extremely reliable. Yet, they are subject to particularly challenging operating and environmental conditions. They have been among the most frequently failing system components for years and often cause considerable costs. Long-lasting converters which are able to withstand environmental influences are in great demand. They represent an indispensable technological component of the energy transition and, as such, have a high economic potential.

The goal of this three-year project is therefore to develop solutions for substantially improving the reliability and robustness of converters for decentralized electrical energy conversion. The project focuses on investigating in greater detail the application-specific weaknesses determined on the basis of comprehensive field data and damage analyses and their failure mechanisms. Such mechanisms are often the result of the combination of climatic and electrical loads. In addition to hardware modifications and protection concepts, the project is also exploring suitable testing procedures in order to assess them under typical application conditions.

Another important aspect is the development of long-term alliances between Fraunhofer institutes. A total of five Fraunhofer institutes are involved in the power4re project: the Fraunhofer Institute for Integrated Systems and Device Technology IISB, the Fraunhofer Institute for Microstructure of Materials and Systems IMWS, the Fraunhofer Institute for Solar Energy Systems ISE, the Fraunhofer Institute for Wind Energy Systems IWES (consortium manager), and the Fraunhofer Institute for Reliability and Microintegration IZM. A team of consultants is also involved in this power4re project, representing the companies ConverterTec (formerly Woodward Kempen), SMA Solar Technology AG, and Mitsubishi Electric R&D Centre Europe.
Dr. Vera Gramich from the Department for Internal Research Programs is supporting and monitoring this project for the Fraunhofer-Gesellschaft.

»With power4re, we are driving forward a socially responsible energy transition together with our project partners. After all, it is important that wind turbines and PV systems become more reliable so as to cut the generation costs of renewable energy even further. Our comprehensive and long-term system understanding of converters is of great benefit here«, explains Prof. Jan Wenske, Deputy Director Fraunhofer IWES & Technical Director.

»We are opening up new methods for field-data based failure analysis and are working on a condition monitoring system which is focused on the relevant failure mechanisms. We expect that this cross-society cooperation will lead to new, important findings, for example from the comparison of PV and wind applications«, adds Dr. Katharina Fischer, Project Manager and Senior Scientist at Fraunhofer IWES.

The solutions pursued for increasing converter reliability are not solely restricted to wind energy and photovoltaic applications, they may also potentially be of use in other areas such as railway transport, avionics, and electromobility, where converters are also exposed to challenging environmental factors.