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New In-house Test Bench: Fraunhofer IWES And Nordex Cooperate on Grid Integration of Wind Turbines

Hamburg, Germany - Increasing power generation from renewable energy sources is associated with significant impacts on the electrical grid. Until now, validations of the system properties of wind turbines have had to be carried out in a time-consuming manner in the field, but this is set to change.

The Fraunhofer Wind Research Institute IWES and the Nordex Group are intensifying their cooperation in the field of grid integration of wind turbines. With a jointly developed in-house test stand, the time required for measurements can now be significantly reduced from over 12 to 3 months.

Wind turbines: System services for the power grid

As wind turbines feed electricity into the grid via power electronic converters, validation of the system characteristics and grid-supporting properties of wind turbines is becoming increasingly important.

For example, wind turbines must not simply disconnect from the grid (fault-ride-through capacity, FRT) during sudden voltage dips and surges that occur in the power grid. Wind turbines must also provide reactive power and compensation functions for frequency deviations.

Until now, manufacturers have used an extensive measurement setup to prove these properties on prototype turbines in a time-consuming process in the field, but now the Fraunhofer Institute for Wind Energy Systems (IWES) in Bremerhaven and the Nordex Group are taking a new approach.

New in-house test stand drastically reduces the time required for testing

As part of a research project, a hardware-in-the-loop test bench has been developed over a period of three years. On this test bench, the electrical drive train of the wind turbine is tested in isolation on a grid simulator.

The great advantage is that all other components of the wind turbine are simulated in real time and the test stand can of course be operated regardless of the weather. A first generator and converter configuration has already been successfully tested and certified "in the laboratory".

Michael Franke, Vice President Global Engineering of the Nordex Group: "Field validations of turbine system properties are necessary but time-consuming. Added to this is the difficulty of finding a suitable site for the test series. Measurement of the electrical grid properties of a turbine in the field takes more than 12 months until certification. The same test on the IWES test bench has now been completed in three months - a saving of nine months. This test bench represents a major step forward for both partners as it makes a faster time to market possible."

Prof. Dr.-Ing. Andreas Reuter, Director of Fraunhofer IWES: "Thanks to its flexibility and functionality, the test bench is also ideally equipped for the expected future requirements for verification."

Source: IWR Online, 05 Dec 2022