Revolutionizing Offshore Wind Turbine Testing with Mobile Platform

Connecting wind turbines to the public power grid is a significant challenge for manufacturers. It involves more than just testing the functionality of new turbines and putting them into operation. They must also comply with specific limit values for electrical properties and handle dynamic events like short circuits and frequency fluctuations. According to Gesa Quistorf, Group Manager at the Fraunhofer Institute for Wind Energy Systems IWES in Bremerhaven, each wind turbine plays a crucial role in maintaining the stability of the complex power grids.

As wind turbines continue to increase in size and output, traditional test systems are struggling to keep up with the certification requirements. To address this issue, Fraunhofer IWES has developed a mobile test bench as part of the Mobil-Grid-CoP research project. This innovative solution can test even the largest wind turbines, up to 28 megavolt-amperes (MVA), allowing manufacturers to obtain certification more efficiently.

The focus of the research project has been on large offshore wind turbines, given the rapid growth of offshore wind farms. The mobile test bench is specifically designed for the typical offshore voltage level of 66 kV, enabling realistic testing of large turbines under full load conditions. Quistorf explains that the test system acts as a grid emulator, simulating the behavior of the power grid to the test object without compromising the public grid.

During testing, the system evaluates various properties such as response to frequency changes, voltage fluctuations, and grid faults like short circuits in real time. The wind turbine must react within milliseconds to events like short circuits by providing reactive current to support the grid voltage. Only when the turbine meets all specifications and performance requirements can it receive its unit certificate and be put into operation.

The Mobil-Grid-CoP project offers numerous benefits to the wind energy sector, allowing manufacturers to conduct thorough and realistic tests on their prototypes. This reduces the risk of rework and speeds up the certification and commissioning process. The mobile test bench also facilitates upgrades and modernization measures on existing turbines. With its flexible setup, the facility can be combined with other test benches for infrastructure expansion, making it a valuable asset in the transition to renewable energy sources.