Researchers at the Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE) in Germany are developing a test procedure for grid-connected inverters. The GFM Benchmark project, developed in collaboration between Fraunhofer and four German grid companies—50Hertz Transmission GmbH, Transnet BW GmbH, Amprion GmbH, and Tennet TSO GmbH—aims to evaluate the grid stability of inverters.
The project invites companies to test the performance of their inverter products. Seven companies from various countries participated, with equipment ranging in capacity from a few kilowatts to 5 megawatts and varying levels of technological maturity, from pilot stage to mass production.
In the laboratory, the research team simulated various grid scenarios, including rapid frequency fluctuations, short circuits, phase jumps, and normal operation, to test the inverters' grid-connected performance. Project Manager Roland Singer stated that while some devices performed similarly under strict requirements, significant differences were observed under other conditions. "We provided optimization recommendations for nearly every device," he said.
Fraunhofer ISE stated that manufacturers are highly motivated to develop grid-connected inverters. This project not only fully demonstrates the market's maturity but also provides a practical basis for future German and European testing standards.
The research team has incorporated the test results into the "Networking Characteristics" document developed by the Grid Technology/Grid Operation Forum of the German Association for Electrical, Electronic and Information Technology (VDE FNN). This document defines the requirements and verification process for networking equipment and lays the foundation for the instantaneous backup market, which is expected to launch in early 2026.
Fraunhofer's test results will be published anonymously and presented to the public at the 24th Wind and Solar Grid Integration Symposium in Berlin on October 8.
Researchers at the Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE) in Germany are developing a test procedure for grid-connected inverters. The GFM Benchmark project, developed in collaboration between Fraunhofer and four German grid companies—50Hertz Transmission GmbH, Transnet BW GmbH, Amprion GmbH, and Tennet TSO GmbH—aims to evaluate the grid stability of inverters.
The project invites companies to test the performance of their inverter products. Seven companies from various countries participated, with equipment ranging in capacity from a few kilowatts to 5 megawatts and varying levels of technological maturity, from pilot stage to mass production.
In the laboratory, the research team simulated various grid scenarios, including rapid frequency fluctuations, short circuits, phase jumps, and normal operation, to test the inverters' grid-connected performance. Project Manager Roland Singer stated that while some devices performed similarly under strict requirements, significant differences were observed under other conditions. "We provided optimization recommendations for nearly every device," he said.
Fraunhofer ISE stated that manufacturers are highly motivated to develop grid-connected inverters. This project not only fully demonstrates the market's maturity but also provides a practical basis for future German and European testing standards.
The research team has incorporated the test results into the "Networking Characteristics" document developed by the Grid Technology/Grid Operation Forum of the German Association for Electrical, Electronic and Information Technology (VDE FNN). This document defines the requirements and verification process for networking equipment and lays the foundation for the instantaneous backup market, which is expected to launch in early 2026.
Fraunhofer's test results will be published anonymously and presented to the public at the 24th Wind and Solar Grid Integration Symposium in Berlin on October 8.
