StABIL – Sustainable PV Power Converters

In the energy system of the future, which will largely be built without the synchronous generators in conventional power plants that form the grid today, grid-forming inverters will not only keep the grid stable during normal operation, but also in the event of major disruptions. There is still a need for research and development, particularly with regard to the necessary adaptation of hardware and software as well as the loads that will occur on the devices in the future.

To this end, KACO new energy GmbH, Infineon Technologies AG and the Fraunhofer Institute for Solar Energy Systems ISE have joined forces in the project "Sustainable PV power converters - design, load analysis and innovations for a long lifetime“ (StABIL)" to analyze the loads that occur on a grid-forming PV inverter to transfer the knowledge gained to an optimized, durable hardware design.

The project partners are initially investigating which load scenarios grid-forming inverters will be exposed in the future and simulating these in laboratory tests. This should allow conclusions to be drawn about optimal and cost-efficient dimensioning, particularly of the power semiconductors. In a field measurement campaign in a PV park, the newly developed grid-forming PV power converters are tested under real operating conditions and loads. The results will be used to derive typical load profiles, so-called "mission profiles", which in turn will be analyzed in the laboratory in combination with the identified future loads. Recommendations for an optimized design for a long service life of the devices and their components are derived from this feedback and presented to the public.

In this context, the contribution of Fraunhofer ISE consists of the analysis of the loads by means of laboratory measurements and field tests in a PV test field as well as the definition of the resulting design specifications for lifetime-optimized inverters. Infineon Technologies AG is optimizing the overload capacity and service life of the semiconductor modules for the loads of grid-forming operation. The main focus of KACO new energy GmbH lies in the research and development of grid-forming control for PV operation and its transfer to the PV inverters into which the optimized semiconductor modules from Infineon Technologies AG are integrated.