Metrological evaluation of torque measurement up to 5 MN m under rotation in a 10 MW nacelle test bench

The torque input to nacelles is of great importance for the efficiency determination of these nacelles. For a reliable and traceable torque measurement in nacelle test benches, a torque transfer standard is installed in the drive train directly at the rotor hub of the nacelle and certain combinations of torque and rotational speed, so-called characterisation maps, are applied and measured. In doing so, the torque measurement in the 10 MW nacelle test bench DyNaLab at Fraunhofer IWES is characterised metrologically up to 5 MN m in form of a relative indication deviation including the corresponding expanded measurement uncertainty.