Load measurements are carried out to determine the actual loads acting on a wind turbine. In other cases they are set up to find out about local strains or stresses in the used material. With its long-time experience DEWI supports the technical development of wind turbines with verification of design loads according to IEC 61400-13.
Load measurements are nowadays indispensable for a focused, efficient and sustainable prototype development. Not only in the certification process but also accompanying the technical development from the prototype to the series-produced machine, full-scale load measurements contribute to success and reassure the designers in their decisions. Measured load data are used to validate and tune the simulation tools, allow the wind turbine dynamics and fatigue behaviour to be examined and can help in verification of extreme loads.
In addition to the load measurement according to IEC, DEWI also offers a special on-line load monitoring of wind turbines and their components. As a cost-effective alternative to IEC-type load measurements, it is particularly suitable for determining site-related strains or stresses in the material. Continuous recording of the measured data allows a direct comparison between the actual site-related loads and the data simulated during the development phase.
The system consists of the measuring device, CAN-bus modules and a PC linked together in a network. The data acquisition process of the load measurement system is automatic. It employs a dedicated software application running on the on-site PC. The measurement quantities acquired on the rotating shaft and the rotor itself as well as those measured on the met mast are transmitted to the measuring device using CAN-bus technology. Load and operational quantities are measured using strain gauges and other appropriate analogue / digital sensors.