Wind Load Observer for a 5MW Wind Energy Plant

Abstract

For off-shore wind energy plants (OWEP) inspection, maintenance and repair is much more difficult and more expensive compared to on-shore plants. Therefore, SHM has large potential in this field of application. Wind load monitoring system is especially important as an SHM unit for forecasting of the remaining life-time of the structure. The knowledge of these loads enables to make a better design of the structure and an assessment of damage after extreme events. In the case of WEP it is not possible to measure the forces e.g. resulting from wind or wave loads directly. Therefore, these forces are determined indirectly from dynamic measurements. The indirect reconstruction addresses the inverse problem in mathematical sense and all its consequences, such as ill-posedness. These are solved with an observer-based concept that originally comes from the control engineering area. For the purpose of design, test and prototype implementation of the SHM system for the OWEP project was granted by the German Ministry of Economics together with several research groups and companies. In this contribution an estimation of the wind load for the real 5MW onshore wind energy plant (WEP) in Bremerhaven, Germany is presented which was done within a national project. Wind load reconstruction is carried out online and implemented as a unit into the prototype SHM system.