The energy turnaround with the increasing shares of renewable energy sources and the decreasing amount of rotating masses poses new challenges for energy grids. In the course of introducing the new generation of "e-nacelles", the manufacturer ENERCON wants to make an important contribution here: The power electronics are no longer integrated in the tower, but in the nacelle. The new communication technology developed by Fraunhofer makes it possible to increase the efficiency of the power electronics and reduce the costs of the feed-in converter on the basis of very fast real-time control.

Contribution of the Fraunhofer Institute as part of the joint prototype: The communication technology between the central controller and the converter units (UE). The so-called IGBT (insulated gate bipolar transistor) is controlled cyclically, i.e. the UE are controlled by the central control system with real-time information to ensure optimum efficiency and energy feed-in to the energy grid. The real-time measured values flow into the central control system. Shorter information cycles increase the precision of the control in the overall system and reduce disturbance frequencies, with the result that the quality of the power fed into the grid is significantly increased, while at the same time the life of the IGBT modules is exploited to the fullest. This fast control response is achieved by using Gigabit Ethernet in combination with an optimized protocol and implementation. The solution achieves a cycle time of 1.5 microseconds - a solution that is faster and more precise than the communication systems available on the market. The Fraunhofer Institute in Lemgo developed the optimized communication protocol and implemented it on ENERCON's control hardware. Fraunhofer has thus succeeded in transferring research results, which were first published to the public in 2021 at the KommA scientific conference (www.jk-komma.de), to real applications.

The added values of the new communication technology convinced the two project partners to implement it in the prototype ENERCON-E nacelle model type E-138 EP3 with a rotor diameter of 138 meters and a rated power of 4.26 MW: First, it is particularly easy to integrate the electronics into an existing system because the solution supports plug-and-play capabilities, which also makes the solution more cost-effective. Then, the speed provides the opportunity for more precise, delicate control, allowing the WTG to be operated with higher efficiency and lower wear. This advantage is especially effective with larger wind turbines, which are more powerful than smaller ones and occupy only one site instead of several medium or small ones - so efficiency is greater. 

The deployment or rollout of the next generation of wind turbines could play a significant role in optimizing energy generation from wind and thus make an important contribution to the energy transition or climate protection. The project partners now want to determine how high the concrete potential for increasing the efficiency of an individual turbine actually is during operation.

The project manager for the development of this new communication, Fraunhofer Group Leader Dr.-Ing. Holger Flatt, is pleased with the research results working in the field: "What pleases me personally is that a new technology of ours is being used in a pilot plant. It is the central mission for us at Fraunhofer to put research at the service of application - here it is already in practical, operational use and making a contribution to the energy generation of the future."