Potential collisions of birds with power plants frequently result in temporary shutdown of concerned turbines enforceable by law. Thus, the need of appropriate sensors for bird monitoring in wind farms is growing. As radar in general has the potential to become one of these sensors, a purpose-built demonstrator is presented in this work. It aims for investigating the chances and problems of radar for bird monitoring inside wind farms.
The authors aim at laying the foundations for the use of sheet‐metal compounds with integrated piezoceramic modules in airplanes or wind turbines. The utilization of piezoceramic modules in aerofoils and rotor blades enables material integrated icing detection or de‐icing. An innovative production technology allows for the integration of piezoceramic modules in sheet‐metal parts. The modules are placed inside an aluminum sheet sandwich structure surrounded by an adhesive layer. A beam for bending with a local sandwich build‐up and an integrated piezomodule is manufactured. The measurement of impedance and phase is used for identification of resonance frequencies. Resonance frequencies change when icing occurs because of its additional mass. First tests on the bending beam identified frequency ranges favorable for icing detection and vibration assisted de‐icing. For this purpose, icing is performed inside a cooling chamber at −25 °C. Furthermore, a demonstrative aerofoil structure (DAS), based on a previously used demonstrator for health‐monitoring, is redesigned and built. Several piezomodules are integrated on positions identified as suitable by a finite element (FE) analysis. The structure with integrated piezomodules is also tested inside the cooling chamber. Icing is detected at the bending beam and the DAS. De‐Icing is possible by means of integrated piezomodules in the bending beam. The obtained results provide information to develop strategies for the use of integrated piezomodules in icing detection and de‐icing systems.
Energy transition also takes place in the distribution grid. A large amount of distributed generation produces energy from renewable energy sources, such as wind or sun, which are attached at low-, medium-or high-voltage level. These voltage levels are not monitored and voltage violations, also caused by additional generators, cannot be captured. Furthermore, the volatile nature of regenerative energies can have negative impacts on grid parameters. In this publication, an algorithm for voltage control is presented to face the changes in the energy supply. The voltage will be stabilized and kept within the defined voltage range using the reactive or active power of the distributed generation. The algorithm has been verified with a designed grid model that contains a high proportion of renewable, distributed generation.